Add m-esr52 at 52.6.0

65 files changed, 14440 insertions, 0 deletions

diff --git a/hal/Hal.cpp b/hal/Hal.cpp
new file mode 100644
index 000000000..44be2f510
--- /dev/null
+++ b/hal/Hal.cpp
@@ -0,0 +1,1003 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et ft=cpp : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Hal.h"
+
+#include "HalImpl.h"
+#include "HalLog.h"
+#include "HalSandbox.h"
+#include "nsIDOMDocument.h"
+#include "nsIDOMWindow.h"
+#include "nsIDocument.h"
+#include "nsIDocShell.h"
+#include "nsITabChild.h"
+#include "nsIWebNavigation.h"
+#include "nsThreadUtils.h"
+#include "nsXULAppAPI.h"
+#include "nsPIDOMWindow.h"
+#include "nsJSUtils.h"
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/Observer.h"
+#include "mozilla/Services.h"
+#include "mozilla/StaticPtr.h"
+#include "mozilla/dom/ContentChild.h"
+#include "mozilla/dom/ContentParent.h"
+#include "mozilla/dom/ScreenOrientation.h"
+#include "WindowIdentifier.h"
+
+#ifdef XP_WIN
+#include <process.h>
+#define getpid _getpid
+#endif
+
+using namespace mozilla::services;
+using namespace mozilla::dom;
+
+#define PROXY_IF_SANDBOXED(_call)                 \
+  do {                                            \
+    if (InSandbox()) {                            \
+      if (!hal_sandbox::HalChildDestroyed()) {    \
+        hal_sandbox::_call;                       \
+      }                                           \
+    } else {                                      \
+      hal_impl::_call;                            \
+    }                                             \
+  } while (0)
+
+#define RETURN_PROXY_IF_SANDBOXED(_call, defValue)\
+  do {                                            \
+    if (InSandbox()) {                            \
+      if (hal_sandbox::HalChildDestroyed()) {     \
+        return defValue;                          \
+      }                                           \
+      return hal_sandbox::_call;                  \
+    } else {                                      \
+      return hal_impl::_call;                     \
+    }                                             \
+  } while (0)
+
+namespace mozilla {
+namespace hal {
+
+mozilla::LogModule *
+GetHalLog()
+{
+  static mozilla::LazyLogModule sHalLog("hal");
+  return sHalLog;
+}
+
+namespace {
+
+void
+AssertMainThread()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+}
+
+bool
+InSandbox()
+{
+  return GeckoProcessType_Content == XRE_GetProcessType();
+}
+
+void
+AssertMainProcess()
+{
+  MOZ_ASSERT(GeckoProcessType_Default == XRE_GetProcessType());
+}
+
+#if !defined(MOZ_WIDGET_GONK)
+
+bool
+WindowIsActive(nsPIDOMWindowInner* aWindow)
+{
+  nsIDocument* document = aWindow->GetDoc();
+  NS_ENSURE_TRUE(document, false);
+
+  return !document->Hidden();
+}
+
+#endif // !defined(MOZ_WIDGET_GONK)
+
+StaticAutoPtr<WindowIdentifier::IDArrayType> gLastIDToVibrate;
+
+void InitLastIDToVibrate()
+{
+  gLastIDToVibrate = new WindowIdentifier::IDArrayType();
+  ClearOnShutdown(&gLastIDToVibrate);
+}
+
+} // namespace
+
+void
+Vibrate(const nsTArray<uint32_t>& pattern, nsPIDOMWindowInner* window)
+{
+  Vibrate(pattern, WindowIdentifier(window));
+}
+
+void
+Vibrate(const nsTArray<uint32_t>& pattern, const WindowIdentifier &id)
+{
+  AssertMainThread();
+
+#if !defined(MOZ_WIDGET_GONK)
+  // Only active windows may start vibrations.  If |id| hasn't gone
+  // through the IPC layer -- that is, if our caller is the outside
+  // world, not hal_proxy -- check whether the window is active.  If
+  // |id| has gone through IPC, don't check the window's visibility;
+  // only the window corresponding to the bottommost process has its
+  // visibility state set correctly.
+  if (!id.HasTraveledThroughIPC() && !WindowIsActive(id.GetWindow())) {
+    HAL_LOG("Vibrate: Window is inactive, dropping vibrate.");
+    return;
+  }
+#endif // !defined(MOZ_WIDGET_GONK)
+
+  if (!InSandbox()) {
+    if (!gLastIDToVibrate) {
+      InitLastIDToVibrate();
+    }
+    *gLastIDToVibrate = id.AsArray();
+  }
+
+  // Don't forward our ID if we are not in the sandbox, because hal_impl
+  // doesn't need it, and we don't want it to be tempted to read it.  The
+  // empty identifier will assert if it's used.
+  PROXY_IF_SANDBOXED(Vibrate(pattern, InSandbox() ? id : WindowIdentifier()));
+}
+
+void
+CancelVibrate(nsPIDOMWindowInner* window)
+{
+  CancelVibrate(WindowIdentifier(window));
+}
+
+void
+CancelVibrate(const WindowIdentifier &id)
+{
+  AssertMainThread();
+
+  // Although only active windows may start vibrations, a window may
+  // cancel its own vibration even if it's no longer active.
+  //
+  // After a window is marked as inactive, it sends a CancelVibrate
+  // request.  We want this request to cancel a playing vibration
+  // started by that window, so we certainly don't want to reject the
+  // cancellation request because the window is now inactive.
+  //
+  // But it could be the case that, after this window became inactive,
+  // some other window came along and started a vibration.  We don't
+  // want this window's cancellation request to cancel that window's
+  // actively-playing vibration!
+  //
+  // To solve this problem, we keep track of the id of the last window
+  // to start a vibration, and only accepts cancellation requests from
+  // the same window.  All other cancellation requests are ignored.
+
+  if (InSandbox() || (gLastIDToVibrate && *gLastIDToVibrate == id.AsArray())) {
+    // Don't forward our ID if we are not in the sandbox, because hal_impl
+    // doesn't need it, and we don't want it to be tempted to read it.  The
+    // empty identifier will assert if it's used.
+    PROXY_IF_SANDBOXED(CancelVibrate(InSandbox() ? id : WindowIdentifier()));
+  }
+}
+
+template <class InfoType>
+class ObserversManager
+{
+public:
+  void AddObserver(Observer<InfoType>* aObserver) {
+    if (!mObservers) {
+      mObservers = new mozilla::ObserverList<InfoType>();
+    }
+
+    mObservers->AddObserver(aObserver);
+
+    if (mObservers->Length() == 1) {
+      EnableNotifications();
+    }
+  }
+
+  void RemoveObserver(Observer<InfoType>* aObserver) {
+    bool removed = mObservers && mObservers->RemoveObserver(aObserver);
+    if (!removed) {
+      return;
+    }
+
+    if (mObservers->Length() == 0) {
+      DisableNotifications();
+
+      OnNotificationsDisabled();
+
+      delete mObservers;
+      mObservers = nullptr;
+    }
+  }
+
+  void BroadcastInformation(const InfoType& aInfo) {
+    // It is possible for mObservers to be nullptr here on some platforms,
+    // because a call to BroadcastInformation gets queued up asynchronously
+    // while RemoveObserver is running (and before the notifications are
+    // disabled). The queued call can then get run after mObservers has
+    // been nulled out. See bug 757025.
+    if (!mObservers) {
+      return;
+    }
+    mObservers->Broadcast(aInfo);
+  }
+
+protected:
+  virtual void EnableNotifications() = 0;
+  virtual void DisableNotifications() = 0;
+  virtual void OnNotificationsDisabled() {}
+
+private:
+  mozilla::ObserverList<InfoType>* mObservers;
+};
+
+template <class InfoType>
+class CachingObserversManager : public ObserversManager<InfoType>
+{
+public:
+  InfoType GetCurrentInformation() {
+    if (mHasValidCache) {
+      return mInfo;
+    }
+
+    GetCurrentInformationInternal(&mInfo);
+    mHasValidCache = true;
+    return mInfo;
+  }
+
+  void CacheInformation(const InfoType& aInfo) {
+    mHasValidCache = true;
+    mInfo = aInfo;
+  }
+
+  void BroadcastCachedInformation() {
+    this->BroadcastInformation(mInfo);
+  }
+
+protected:
+  virtual void GetCurrentInformationInternal(InfoType*) = 0;
+
+  virtual void OnNotificationsDisabled() {
+    mHasValidCache = false;
+  }
+
+private:
+  InfoType                mInfo;
+  bool                    mHasValidCache;
+};
+
+class BatteryObserversManager : public CachingObserversManager<BatteryInformation>
+{
+protected:
+  void EnableNotifications() {
+    PROXY_IF_SANDBOXED(EnableBatteryNotifications());
+  }
+
+  void DisableNotifications() {
+    PROXY_IF_SANDBOXED(DisableBatteryNotifications());
+  }
+
+  void GetCurrentInformationInternal(BatteryInformation* aInfo) {
+    PROXY_IF_SANDBOXED(GetCurrentBatteryInformation(aInfo));
+  }
+};
+
+static BatteryObserversManager&
+BatteryObservers()
+{
+  static BatteryObserversManager sBatteryObservers;
+  AssertMainThread();
+  return sBatteryObservers;
+}
+
+class NetworkObserversManager : public CachingObserversManager<NetworkInformation>
+{
+protected:
+  void EnableNotifications() {
+    PROXY_IF_SANDBOXED(EnableNetworkNotifications());
+  }
+
+  void DisableNotifications() {
+    PROXY_IF_SANDBOXED(DisableNetworkNotifications());
+  }
+
+  void GetCurrentInformationInternal(NetworkInformation* aInfo) {
+    PROXY_IF_SANDBOXED(GetCurrentNetworkInformation(aInfo));
+  }
+};
+
+static NetworkObserversManager&
+NetworkObservers()
+{
+  static NetworkObserversManager sNetworkObservers;
+  AssertMainThread();
+  return sNetworkObservers;
+}
+
+class WakeLockObserversManager : public ObserversManager<WakeLockInformation>
+{
+protected:
+  void EnableNotifications() {
+    PROXY_IF_SANDBOXED(EnableWakeLockNotifications());
+  }
+
+  void DisableNotifications() {
+    PROXY_IF_SANDBOXED(DisableWakeLockNotifications());
+  }
+};
+
+static WakeLockObserversManager&
+WakeLockObservers()
+{
+  static WakeLockObserversManager sWakeLockObservers;
+  AssertMainThread();
+  return sWakeLockObservers;
+}
+
+class ScreenConfigurationObserversManager : public CachingObserversManager<ScreenConfiguration>
+{
+protected:
+  void EnableNotifications() {
+    PROXY_IF_SANDBOXED(EnableScreenConfigurationNotifications());
+  }
+
+  void DisableNotifications() {
+    PROXY_IF_SANDBOXED(DisableScreenConfigurationNotifications());
+  }
+
+  void GetCurrentInformationInternal(ScreenConfiguration* aInfo) {
+    PROXY_IF_SANDBOXED(GetCurrentScreenConfiguration(aInfo));
+  }
+};
+
+static ScreenConfigurationObserversManager&
+ScreenConfigurationObservers()
+{
+  AssertMainThread();
+  static ScreenConfigurationObserversManager sScreenConfigurationObservers;
+  return sScreenConfigurationObservers;
+}
+
+void
+RegisterBatteryObserver(BatteryObserver* aObserver)
+{
+  AssertMainThread();
+  BatteryObservers().AddObserver(aObserver);
+}
+
+void
+UnregisterBatteryObserver(BatteryObserver* aObserver)
+{
+  AssertMainThread();
+  BatteryObservers().RemoveObserver(aObserver);
+}
+
+void
+GetCurrentBatteryInformation(BatteryInformation* aInfo)
+{
+  AssertMainThread();
+  *aInfo = BatteryObservers().GetCurrentInformation();
+}
+
+void
+NotifyBatteryChange(const BatteryInformation& aInfo)
+{
+  AssertMainThread();
+  BatteryObservers().CacheInformation(aInfo);
+  BatteryObservers().BroadcastCachedInformation();
+}
+
+bool GetScreenEnabled()
+{
+  AssertMainThread();
+  RETURN_PROXY_IF_SANDBOXED(GetScreenEnabled(), false);
+}
+
+void SetScreenEnabled(bool aEnabled)
+{
+  AssertMainThread();
+  PROXY_IF_SANDBOXED(SetScreenEnabled(aEnabled));
+}
+
+bool GetKeyLightEnabled()
+{
+  AssertMainThread();
+  RETURN_PROXY_IF_SANDBOXED(GetKeyLightEnabled(), false);
+}
+
+void SetKeyLightEnabled(bool aEnabled)
+{
+  AssertMainThread();
+  PROXY_IF_SANDBOXED(SetKeyLightEnabled(aEnabled));
+}
+
+bool GetCpuSleepAllowed()
+{
+  // Generally for interfaces that are accessible by normal web content
+  // we should cache the result and be notified on state changes, like
+  // what the battery API does. But since this is only used by
+  // privileged interface, the synchronous getter is OK here.
+  AssertMainThread();
+  RETURN_PROXY_IF_SANDBOXED(GetCpuSleepAllowed(), true);
+}
+
+void SetCpuSleepAllowed(bool aAllowed)
+{
+  AssertMainThread();
+  PROXY_IF_SANDBOXED(SetCpuSleepAllowed(aAllowed));
+}
+
+double GetScreenBrightness()
+{
+  AssertMainThread();
+  RETURN_PROXY_IF_SANDBOXED(GetScreenBrightness(), 0);
+}
+
+void SetScreenBrightness(double aBrightness)
+{
+  AssertMainThread();
+  PROXY_IF_SANDBOXED(SetScreenBrightness(clamped(aBrightness, 0.0, 1.0)));
+}
+
+class SystemClockChangeObserversManager : public ObserversManager<int64_t>
+{
+protected:
+  void EnableNotifications() {
+    PROXY_IF_SANDBOXED(EnableSystemClockChangeNotifications());
+  }
+
+  void DisableNotifications() {
+    PROXY_IF_SANDBOXED(DisableSystemClockChangeNotifications());
+  }
+};
+
+static SystemClockChangeObserversManager&
+SystemClockChangeObservers()
+{
+  static SystemClockChangeObserversManager sSystemClockChangeObservers;
+  AssertMainThread();
+  return sSystemClockChangeObservers;
+}
+
+void
+RegisterSystemClockChangeObserver(SystemClockChangeObserver* aObserver)
+{
+  AssertMainThread();
+  SystemClockChangeObservers().AddObserver(aObserver);
+}
+
+void
+UnregisterSystemClockChangeObserver(SystemClockChangeObserver* aObserver)
+{
+  AssertMainThread();
+  SystemClockChangeObservers().RemoveObserver(aObserver);
+}
+
+void
+NotifySystemClockChange(const int64_t& aClockDeltaMS)
+{
+  SystemClockChangeObservers().BroadcastInformation(aClockDeltaMS);
+}
+
+class SystemTimezoneChangeObserversManager : public ObserversManager<SystemTimezoneChangeInformation>
+{
+protected:
+  void EnableNotifications() {
+    PROXY_IF_SANDBOXED(EnableSystemTimezoneChangeNotifications());
+  }
+
+  void DisableNotifications() {
+    PROXY_IF_SANDBOXED(DisableSystemTimezoneChangeNotifications());
+  }
+};
+
+static SystemTimezoneChangeObserversManager&
+SystemTimezoneChangeObservers()
+{
+  static SystemTimezoneChangeObserversManager sSystemTimezoneChangeObservers;
+  return sSystemTimezoneChangeObservers;
+}
+
+void
+RegisterSystemTimezoneChangeObserver(SystemTimezoneChangeObserver* aObserver)
+{
+  AssertMainThread();
+  SystemTimezoneChangeObservers().AddObserver(aObserver);
+}
+
+void
+UnregisterSystemTimezoneChangeObserver(SystemTimezoneChangeObserver* aObserver)
+{
+  AssertMainThread();
+  SystemTimezoneChangeObservers().RemoveObserver(aObserver);
+}
+
+void
+NotifySystemTimezoneChange(const SystemTimezoneChangeInformation& aSystemTimezoneChangeInfo)
+{
+  nsJSUtils::ResetTimeZone();
+  SystemTimezoneChangeObservers().BroadcastInformation(aSystemTimezoneChangeInfo);
+}
+
+void
+AdjustSystemClock(int64_t aDeltaMilliseconds)
+{
+  AssertMainThread();
+  PROXY_IF_SANDBOXED(AdjustSystemClock(aDeltaMilliseconds));
+}
+
+void
+SetTimezone(const nsCString& aTimezoneSpec)
+{
+  AssertMainThread();
+  PROXY_IF_SANDBOXED(SetTimezone(aTimezoneSpec));
+}
+
+int32_t
+GetTimezoneOffset()
+{
+  AssertMainThread();
+  RETURN_PROXY_IF_SANDBOXED(GetTimezoneOffset(), 0);
+}
+
+nsCString
+GetTimezone()
+{
+  AssertMainThread();
+  RETURN_PROXY_IF_SANDBOXED(GetTimezone(), nsCString(""));
+}
+
+void
+EnableSensorNotifications(SensorType aSensor) {
+  AssertMainThread();
+  PROXY_IF_SANDBOXED(EnableSensorNotifications(aSensor));
+}
+
+void
+DisableSensorNotifications(SensorType aSensor) {
+  AssertMainThread();
+  PROXY_IF_SANDBOXED(DisableSensorNotifications(aSensor));
+}
+
+typedef mozilla::ObserverList<SensorData> SensorObserverList;
+static SensorObserverList* gSensorObservers = nullptr;
+
+static SensorObserverList &
+GetSensorObservers(SensorType sensor_type) {
+  MOZ_ASSERT(sensor_type < NUM_SENSOR_TYPE);
+
+  if(!gSensorObservers) {
+    gSensorObservers = new SensorObserverList[NUM_SENSOR_TYPE];
+  }
+  return gSensorObservers[sensor_type];
+}
+
+void
+RegisterSensorObserver(SensorType aSensor, ISensorObserver *aObserver) {
+  SensorObserverList &observers = GetSensorObservers(aSensor);
+
+  AssertMainThread();
+
+  observers.AddObserver(aObserver);
+  if(observers.Length() == 1) {
+    EnableSensorNotifications(aSensor);
+  }
+}
+
+void
+UnregisterSensorObserver(SensorType aSensor, ISensorObserver *aObserver) {
+  AssertMainThread();
+
+  if (!gSensorObservers) {
+    return;
+  }
+
+  SensorObserverList &observers = GetSensorObservers(aSensor);
+  if (!observers.RemoveObserver(aObserver) || observers.Length() > 0) {
+    return;
+  }
+  DisableSensorNotifications(aSensor);
+
+  // Destroy sSensorObservers only if all observer lists are empty.
+  for (int i = 0; i < NUM_SENSOR_TYPE; i++) {
+    if (gSensorObservers[i].Length() > 0) {
+      return;
+    }
+  }
+  delete [] gSensorObservers;
+  gSensorObservers = nullptr;
+}
+
+void
+NotifySensorChange(const SensorData &aSensorData) {
+  SensorObserverList &observers = GetSensorObservers(aSensorData.sensor());
+
+  AssertMainThread();
+
+  observers.Broadcast(aSensorData);
+}
+
+void
+RegisterNetworkObserver(NetworkObserver* aObserver)
+{
+  AssertMainThread();
+  NetworkObservers().AddObserver(aObserver);
+}
+
+void
+UnregisterNetworkObserver(NetworkObserver* aObserver)
+{
+  AssertMainThread();
+  NetworkObservers().RemoveObserver(aObserver);
+}
+
+void
+GetCurrentNetworkInformation(NetworkInformation* aInfo)
+{
+  AssertMainThread();
+  *aInfo = NetworkObservers().GetCurrentInformation();
+}
+
+void
+NotifyNetworkChange(const NetworkInformation& aInfo)
+{
+  NetworkObservers().CacheInformation(aInfo);
+  NetworkObservers().BroadcastCachedInformation();
+}
+
+void Reboot()
+{
+  AssertMainProcess();
+  AssertMainThread();
+  PROXY_IF_SANDBOXED(Reboot());
+}
+
+void PowerOff()
+{
+  AssertMainProcess();
+  AssertMainThread();
+  PROXY_IF_SANDBOXED(PowerOff());
+}
+
+void StartForceQuitWatchdog(ShutdownMode aMode, int32_t aTimeoutSecs)
+{
+  AssertMainProcess();
+  AssertMainThread();
+  PROXY_IF_SANDBOXED(StartForceQuitWatchdog(aMode, aTimeoutSecs));
+}
+
+void
+RegisterWakeLockObserver(WakeLockObserver* aObserver)
+{
+  AssertMainThread();
+  WakeLockObservers().AddObserver(aObserver);
+}
+
+void
+UnregisterWakeLockObserver(WakeLockObserver* aObserver)
+{
+  AssertMainThread();
+  WakeLockObservers().RemoveObserver(aObserver);
+}
+
+void
+ModifyWakeLock(const nsAString& aTopic,
+               WakeLockControl aLockAdjust,
+               WakeLockControl aHiddenAdjust,
+               uint64_t aProcessID /* = CONTENT_PROCESS_ID_UNKNOWN */)
+{
+  AssertMainThread();
+
+  if (aProcessID == CONTENT_PROCESS_ID_UNKNOWN) {
+    aProcessID = InSandbox() ? ContentChild::GetSingleton()->GetID() :
+                               CONTENT_PROCESS_ID_MAIN;
+  }
+
+  PROXY_IF_SANDBOXED(ModifyWakeLock(aTopic, aLockAdjust,
+                                    aHiddenAdjust, aProcessID));
+}
+
+void
+GetWakeLockInfo(const nsAString& aTopic, WakeLockInformation* aWakeLockInfo)
+{
+  AssertMainThread();
+  PROXY_IF_SANDBOXED(GetWakeLockInfo(aTopic, aWakeLockInfo));
+}
+
+void
+NotifyWakeLockChange(const WakeLockInformation& aInfo)
+{
+  AssertMainThread();
+  WakeLockObservers().BroadcastInformation(aInfo);
+}
+
+void
+RegisterScreenConfigurationObserver(ScreenConfigurationObserver* aObserver)
+{
+  AssertMainThread();
+  ScreenConfigurationObservers().AddObserver(aObserver);
+}
+
+void
+UnregisterScreenConfigurationObserver(ScreenConfigurationObserver* aObserver)
+{
+  AssertMainThread();
+  ScreenConfigurationObservers().RemoveObserver(aObserver);
+}
+
+void
+GetCurrentScreenConfiguration(ScreenConfiguration* aScreenConfiguration)
+{
+  AssertMainThread();
+  *aScreenConfiguration = ScreenConfigurationObservers().GetCurrentInformation();
+}
+
+void
+NotifyScreenConfigurationChange(const ScreenConfiguration& aScreenConfiguration)
+{
+  ScreenConfigurationObservers().CacheInformation(aScreenConfiguration);
+  ScreenConfigurationObservers().BroadcastCachedInformation();
+}
+
+bool
+LockScreenOrientation(const dom::ScreenOrientationInternal& aOrientation)
+{
+  AssertMainThread();
+  RETURN_PROXY_IF_SANDBOXED(LockScreenOrientation(aOrientation), false);
+}
+
+void
+UnlockScreenOrientation()
+{
+  AssertMainThread();
+  PROXY_IF_SANDBOXED(UnlockScreenOrientation());
+}
+
+void
+EnableSwitchNotifications(SwitchDevice aDevice) {
+  AssertMainThread();
+  PROXY_IF_SANDBOXED(EnableSwitchNotifications(aDevice));
+}
+
+void
+DisableSwitchNotifications(SwitchDevice aDevice) {
+  AssertMainThread();
+  PROXY_IF_SANDBOXED(DisableSwitchNotifications(aDevice));
+}
+
+SwitchState GetCurrentSwitchState(SwitchDevice aDevice)
+{
+  AssertMainThread();
+  RETURN_PROXY_IF_SANDBOXED(GetCurrentSwitchState(aDevice), SWITCH_STATE_UNKNOWN);
+}
+
+void NotifySwitchStateFromInputDevice(SwitchDevice aDevice, SwitchState aState)
+{
+  AssertMainThread();
+  PROXY_IF_SANDBOXED(NotifySwitchStateFromInputDevice(aDevice, aState));
+}
+
+typedef mozilla::ObserverList<SwitchEvent> SwitchObserverList;
+
+static SwitchObserverList *sSwitchObserverLists = nullptr;
+
+static SwitchObserverList&
+GetSwitchObserverList(SwitchDevice aDevice) {
+  MOZ_ASSERT(0 <= aDevice && aDevice < NUM_SWITCH_DEVICE);
+  if (sSwitchObserverLists == nullptr) {
+    sSwitchObserverLists = new SwitchObserverList[NUM_SWITCH_DEVICE];
+  }
+  return sSwitchObserverLists[aDevice];
+}
+
+static void
+ReleaseObserversIfNeeded() {
+  for (int i = 0; i < NUM_SWITCH_DEVICE; i++) {
+    if (sSwitchObserverLists[i].Length() != 0)
+      return;
+  }
+
+  //The length of every list is 0, no observer in the list.
+  delete [] sSwitchObserverLists;
+  sSwitchObserverLists = nullptr;
+}
+
+void
+RegisterSwitchObserver(SwitchDevice aDevice, SwitchObserver *aObserver)
+{
+  AssertMainThread();
+  SwitchObserverList& observer = GetSwitchObserverList(aDevice);
+  observer.AddObserver(aObserver);
+  if (observer.Length() == 1) {
+    EnableSwitchNotifications(aDevice);
+  }
+}
+
+void
+UnregisterSwitchObserver(SwitchDevice aDevice, SwitchObserver *aObserver)
+{
+  AssertMainThread();
+
+  if (!sSwitchObserverLists) {
+    return;
+  }
+
+  SwitchObserverList& observer = GetSwitchObserverList(aDevice);
+  if (!observer.RemoveObserver(aObserver) || observer.Length() > 0) {
+    return;
+  }
+
+  DisableSwitchNotifications(aDevice);
+  ReleaseObserversIfNeeded();
+}
+
+void
+NotifySwitchChange(const SwitchEvent& aEvent)
+{
+  // When callback this notification, main thread may call unregister function
+  // first. We should check if this pointer is valid.
+  if (!sSwitchObserverLists)
+    return;
+
+  SwitchObserverList& observer = GetSwitchObserverList(aEvent.device());
+  observer.Broadcast(aEvent);
+}
+
+static AlarmObserver* sAlarmObserver;
+
+bool
+RegisterTheOneAlarmObserver(AlarmObserver* aObserver)
+{
+  MOZ_ASSERT(!InSandbox());
+  MOZ_ASSERT(!sAlarmObserver);
+
+  sAlarmObserver = aObserver;
+  RETURN_PROXY_IF_SANDBOXED(EnableAlarm(), false);
+}
+
+void
+UnregisterTheOneAlarmObserver()
+{
+  if (sAlarmObserver) {
+    sAlarmObserver = nullptr;
+    PROXY_IF_SANDBOXED(DisableAlarm());
+  }
+}
+
+void
+NotifyAlarmFired()
+{
+  if (sAlarmObserver) {
+    sAlarmObserver->Notify(void_t());
+  }
+}
+
+bool
+SetAlarm(int32_t aSeconds, int32_t aNanoseconds)
+{
+  // It's pointless to program an alarm nothing is going to observe ...
+  MOZ_ASSERT(sAlarmObserver);
+  RETURN_PROXY_IF_SANDBOXED(SetAlarm(aSeconds, aNanoseconds), false);
+}
+
+void
+SetProcessPriority(int aPid, ProcessPriority aPriority, uint32_t aLRU)
+{
+  // n.b. The sandboxed implementation crashes; SetProcessPriority works only
+  // from the main process.
+  PROXY_IF_SANDBOXED(SetProcessPriority(aPid, aPriority, aLRU));
+}
+
+void
+SetCurrentThreadPriority(hal::ThreadPriority aThreadPriority)
+{
+  PROXY_IF_SANDBOXED(SetCurrentThreadPriority(aThreadPriority));
+}
+
+void
+SetThreadPriority(PlatformThreadId aThreadId,
+                  hal::ThreadPriority aThreadPriority)
+{
+  PROXY_IF_SANDBOXED(SetThreadPriority(aThreadId, aThreadPriority));
+}
+
+// From HalTypes.h.
+const char*
+ProcessPriorityToString(ProcessPriority aPriority)
+{
+  switch (aPriority) {
+  case PROCESS_PRIORITY_MASTER:
+    return "MASTER";
+  case PROCESS_PRIORITY_PREALLOC:
+    return "PREALLOC";
+  case PROCESS_PRIORITY_FOREGROUND_HIGH:
+    return "FOREGROUND_HIGH";
+  case PROCESS_PRIORITY_FOREGROUND:
+    return "FOREGROUND";
+  case PROCESS_PRIORITY_FOREGROUND_KEYBOARD:
+    return "FOREGROUND_KEYBOARD";
+  case PROCESS_PRIORITY_BACKGROUND_PERCEIVABLE:
+    return "BACKGROUND_PERCEIVABLE";
+  case PROCESS_PRIORITY_BACKGROUND:
+    return "BACKGROUND";
+  case PROCESS_PRIORITY_UNKNOWN:
+    return "UNKNOWN";
+  default:
+    MOZ_ASSERT(false);
+    return "???";
+  }
+}
+
+const char *
+ThreadPriorityToString(ThreadPriority aPriority)
+{
+  switch (aPriority) {
+    case THREAD_PRIORITY_COMPOSITOR:
+      return "COMPOSITOR";
+    default:
+      MOZ_ASSERT(false);
+      return "???";
+  }
+}
+
+void FactoryReset(mozilla::dom::FactoryResetReason& aReason)
+{
+  AssertMainThread();
+  PROXY_IF_SANDBOXED(FactoryReset(aReason));
+}
+
+void
+StartDiskSpaceWatcher()
+{
+  AssertMainProcess();
+  AssertMainThread();
+  PROXY_IF_SANDBOXED(StartDiskSpaceWatcher());
+}
+
+void
+StopDiskSpaceWatcher()
+{
+  AssertMainProcess();
+  AssertMainThread();
+  PROXY_IF_SANDBOXED(StopDiskSpaceWatcher());
+}
+
+uint32_t
+GetTotalSystemMemory()
+{
+  return hal_impl::GetTotalSystemMemory();
+}
+
+bool IsHeadphoneEventFromInputDev()
+{
+  AssertMainThread();
+  RETURN_PROXY_IF_SANDBOXED(IsHeadphoneEventFromInputDev(), false);
+}
+
+nsresult StartSystemService(const char* aSvcName, const char* aArgs)
+{
+  AssertMainThread();
+  RETURN_PROXY_IF_SANDBOXED(StartSystemService(aSvcName, aArgs), NS_ERROR_FAILURE);
+}
+
+void StopSystemService(const char* aSvcName)
+{
+  AssertMainThread();
+  PROXY_IF_SANDBOXED(StopSystemService(aSvcName));
+}
+
+bool SystemServiceIsRunning(const char* aSvcName)
+{
+  AssertMainThread();
+  RETURN_PROXY_IF_SANDBOXED(SystemServiceIsRunning(aSvcName), false);
+}
+
+} // namespace hal
+} // namespace mozilla
diff --git a/hal/Hal.h b/hal/Hal.h
new file mode 100644
index 000000000..e45bbcde2
--- /dev/null
+++ b/hal/Hal.h
@@ -0,0 +1,560 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et ft=cpp : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_Hal_h
+#define mozilla_Hal_h
+
+#include "base/basictypes.h"
+#include "base/platform_thread.h"
+#include "nsTArray.h"
+#include "mozilla/dom/battery/Types.h"
+#include "mozilla/dom/MozPowerManagerBinding.h"
+#include "mozilla/dom/network/Types.h"
+#include "mozilla/dom/power/Types.h"
+#include "mozilla/dom/ScreenOrientation.h"
+#include "mozilla/hal_sandbox/PHal.h"
+#include "mozilla/HalScreenConfiguration.h"
+#include "mozilla/HalTypes.h"
+#include "mozilla/Observer.h"
+#include "mozilla/Types.h"
+
+/*
+ * Hal.h contains the public Hal API.
+ *
+ * By default, this file defines its functions in the hal namespace, but if
+ * MOZ_HAL_NAMESPACE is defined, we'll define our functions in that namespace.
+ *
+ * This is used by HalImpl.h and HalSandbox.h, which define copies of all the
+ * functions here in the hal_impl and hal_sandbox namespaces.
+ */
+
+class nsPIDOMWindowInner;
+
+#ifndef MOZ_HAL_NAMESPACE
+# define MOZ_HAL_NAMESPACE hal
+# define MOZ_DEFINED_HAL_NAMESPACE 1
+#endif
+
+namespace mozilla {
+
+namespace hal {
+
+typedef Observer<void_t> AlarmObserver;
+
+class WindowIdentifier;
+
+typedef Observer<int64_t> SystemClockChangeObserver;
+typedef Observer<SystemTimezoneChangeInformation> SystemTimezoneChangeObserver;
+
+} // namespace hal
+
+namespace MOZ_HAL_NAMESPACE {
+
+/**
+ * Turn the default vibrator device on/off per the pattern specified
+ * by |pattern|.  Each element in the pattern is the number of
+ * milliseconds to turn the vibrator on or off.  The first element in
+ * |pattern| is an "on" element, the next is "off", and so on.
+ *
+ * If |pattern| is empty, any in-progress vibration is canceled.
+ *
+ * Only an active window within an active tab may call Vibrate; calls
+ * from inactive windows and windows on inactive tabs do nothing.
+ *
+ * If you're calling hal::Vibrate from the outside world, pass an
+ * nsIDOMWindow* in place of the WindowIdentifier parameter.
+ * The method with WindowIdentifier will be called automatically.
+ */
+void Vibrate(const nsTArray<uint32_t>& pattern,
+             nsPIDOMWindowInner* aWindow);
+void Vibrate(const nsTArray<uint32_t>& pattern,
+             const hal::WindowIdentifier &id);
+
+/**
+ * Cancel a vibration started by the content window identified by
+ * WindowIdentifier.
+ *
+ * If the window was the last window to start a vibration, the
+ * cancellation request will go through even if the window is not
+ * active.
+ *
+ * As with hal::Vibrate(), if you're calling hal::CancelVibrate from the outside
+ * world, pass an nsIDOMWindow*. The method with WindowIdentifier will be called
+ * automatically.
+ */
+void CancelVibrate(nsPIDOMWindowInner* aWindow);
+void CancelVibrate(const hal::WindowIdentifier &id);
+
+/**
+ * Inform the battery backend there is a new battery observer.
+ * @param aBatteryObserver The observer that should be added.
+ */
+void RegisterBatteryObserver(BatteryObserver* aBatteryObserver);
+
+/**
+ * Inform the battery backend a battery observer unregistered.
+ * @param aBatteryObserver The observer that should be removed.
+ */
+void UnregisterBatteryObserver(BatteryObserver* aBatteryObserver);
+
+/**
+ * Returns the current battery information.
+ */
+void GetCurrentBatteryInformation(hal::BatteryInformation* aBatteryInfo);
+
+/**
+ * Notify of a change in the battery state.
+ * @param aBatteryInfo The new battery information.
+ */
+void NotifyBatteryChange(const hal::BatteryInformation& aBatteryInfo);
+
+/**
+ * Determine whether the device's screen is currently enabled.
+ */
+bool GetScreenEnabled();
+
+/**
+ * Enable or disable the device's screen.
+ *
+ * Note that it may take a few seconds for the screen to turn on or off.
+ */
+void SetScreenEnabled(bool aEnabled);
+
+/**
+ * Determine whether the device's keypad/button backlight is currently enabled.
+ */
+bool GetKeyLightEnabled();
+
+/**
+ * Enable or disable the device's keypad/button backlight.
+ */
+void SetKeyLightEnabled(bool aEnabled);
+
+/**
+ * Get the brightness of the device's screen's backlight, on a scale from 0
+ * (very dim) to 1 (full blast).
+ *
+ * If the display is currently disabled, this returns the brightness the
+ * backlight will have when the display is re-enabled.
+ */
+double GetScreenBrightness();
+
+/**
+ * Set the brightness of the device's screen's backlight, on a scale from 0
+ * (very dimm) to 1 (full blast).  Values larger than 1 are treated like 1, and
+ * values smaller than 0 are treated like 0.
+ *
+ * Note that we may reduce the resolution of the given brightness value before
+ * sending it to the screen.  Therefore if you call SetScreenBrightness(x)
+ * followed by GetScreenBrightness(), the value returned by
+ * GetScreenBrightness() may not be exactly x.
+ */
+void SetScreenBrightness(double aBrightness);
+
+/**
+ * Determine whether the device is allowed to sleep.
+ */
+bool GetCpuSleepAllowed();
+
+/**
+ * Set whether the device is allowed to suspend automatically after
+ * the screen is disabled.
+ */
+void SetCpuSleepAllowed(bool aAllowed);
+
+/**
+ * Register an observer for the sensor of given type.
+ *
+ * The observer will receive data whenever the data generated by the
+ * sensor is avaiable.
+ */
+void RegisterSensorObserver(hal::SensorType aSensor,
+                            hal::ISensorObserver *aObserver);
+
+/**
+ * Unregister an observer for the sensor of given type.
+ */
+void UnregisterSensorObserver(hal::SensorType aSensor,
+                              hal::ISensorObserver *aObserver);
+
+/**
+ * Post a value generated by a sensor.
+ *
+ * This API is internal to hal; clients shouldn't call it directly.
+ */
+void NotifySensorChange(const hal::SensorData &aSensorData);
+
+/**
+ * Enable sensor notifications from the backend
+ *
+ * This method is only visible from implementation of sensor manager.
+ * Rest of the system should not try this.
+ */
+void EnableSensorNotifications(hal::SensorType aSensor);
+
+/**
+ * Disable sensor notifications from the backend
+ *
+ * This method is only visible from implementation of sensor manager.
+ * Rest of the system should not try this.
+ */
+void DisableSensorNotifications(hal::SensorType aSensor);
+
+
+/**
+ * Inform the network backend there is a new network observer.
+ * @param aNetworkObserver The observer that should be added.
+ */
+void RegisterNetworkObserver(NetworkObserver* aNetworkObserver);
+
+/**
+ * Inform the network backend a network observer unregistered.
+ * @param aNetworkObserver The observer that should be removed.
+ */
+void UnregisterNetworkObserver(NetworkObserver* aNetworkObserver);
+
+/**
+ * Returns the current network information.
+ */
+void GetCurrentNetworkInformation(hal::NetworkInformation* aNetworkInfo);
+
+/**
+ * Notify of a change in the network state.
+ * @param aNetworkInfo The new network information.
+ */
+void NotifyNetworkChange(const hal::NetworkInformation& aNetworkInfo);
+
+/**
+ * Adjusting system clock.
+ * @param aDeltaMilliseconds The difference compared with current system clock.
+ */
+void AdjustSystemClock(int64_t aDeltaMilliseconds);
+
+/**
+ * Set timezone
+ * @param aTimezoneSpec The definition can be found in
+ * http://en.wikipedia.org/wiki/List_of_tz_database_time_zones
+ */
+void SetTimezone(const nsCString& aTimezoneSpec);
+
+/**
+ * Get timezone
+ * http://en.wikipedia.org/wiki/List_of_tz_database_time_zones
+ */
+nsCString GetTimezone();
+
+/**
+ * Get timezone offset
+ * returns the timezone offset relative to UTC in minutes (DST effect included)
+ */
+int32_t GetTimezoneOffset();
+
+/**
+ * Register observer for system clock changed notification.
+ * @param aObserver The observer that should be added.
+ */
+void RegisterSystemClockChangeObserver(
+  hal::SystemClockChangeObserver* aObserver);
+
+/**
+ * Unregister the observer for system clock changed.
+ * @param aObserver The observer that should be removed.
+ */
+void UnregisterSystemClockChangeObserver(
+  hal::SystemClockChangeObserver* aObserver);
+
+/**
+ * Notify of a change in the system clock.
+ * @param aClockDeltaMS
+ */
+void NotifySystemClockChange(const int64_t& aClockDeltaMS);
+
+/**
+ * Register observer for system timezone changed notification.
+ * @param aObserver The observer that should be added.
+ */
+void RegisterSystemTimezoneChangeObserver(
+  hal::SystemTimezoneChangeObserver* aObserver);
+
+/**
+ * Unregister the observer for system timezone changed.
+ * @param aObserver The observer that should be removed.
+ */
+void UnregisterSystemTimezoneChangeObserver(
+  hal::SystemTimezoneChangeObserver* aObserver);
+
+/**
+ * Notify of a change in the system timezone.
+ * @param aSystemTimezoneChangeInfo
+ */
+void NotifySystemTimezoneChange(
+  const hal::SystemTimezoneChangeInformation& aSystemTimezoneChangeInfo);
+
+/**
+ * Reboot the device.
+ *
+ * This API is currently only allowed to be used from the main process.
+ */
+void Reboot();
+
+/**
+ * Power off the device.
+ *
+ * This API is currently only allowed to be used from the main process.
+ */
+void PowerOff();
+
+/**
+ * Enable wake lock notifications from the backend.
+ *
+ * This method is only used by WakeLockObserversManager.
+ */
+void EnableWakeLockNotifications();
+
+/**
+ * Disable wake lock notifications from the backend.
+ *
+ * This method is only used by WakeLockObserversManager.
+ */
+void DisableWakeLockNotifications();
+
+/**
+ * Inform the wake lock backend there is a new wake lock observer.
+ * @param aWakeLockObserver The observer that should be added.
+ */
+void RegisterWakeLockObserver(WakeLockObserver* aObserver);
+
+/**
+ * Inform the wake lock backend a wake lock observer unregistered.
+ * @param aWakeLockObserver The observer that should be removed.
+ */
+void UnregisterWakeLockObserver(WakeLockObserver* aObserver);
+
+/**
+ * Adjust a wake lock's counts on behalf of a given process.
+ *
+ * In most cases, you shouldn't need to pass the aProcessID argument; the
+ * default of CONTENT_PROCESS_ID_UNKNOWN is probably what you want.
+ *
+ * @param aTopic        lock topic
+ * @param aLockAdjust   to increase or decrease active locks
+ * @param aHiddenAdjust to increase or decrease hidden locks
+ * @param aProcessID    indicates which process we're modifying the wake lock
+ *                      on behalf of.  It is interpreted as
+ *
+ *                      CONTENT_PROCESS_ID_UNKNOWN: The current process
+ *                      CONTENT_PROCESS_ID_MAIN: The root process
+ *                      X: The process with ContentChild::GetID() == X
+ */
+void ModifyWakeLock(const nsAString &aTopic,
+                    hal::WakeLockControl aLockAdjust,
+                    hal::WakeLockControl aHiddenAdjust,
+                    uint64_t aProcessID = hal::CONTENT_PROCESS_ID_UNKNOWN);
+
+/**
+ * Query the wake lock numbers of aTopic.
+ * @param aTopic        lock topic
+ * @param aWakeLockInfo wake lock numbers
+ */
+void GetWakeLockInfo(const nsAString &aTopic, hal::WakeLockInformation *aWakeLockInfo);
+
+/**
+ * Notify of a change in the wake lock state.
+ * @param aWakeLockInfo The new wake lock information.
+ */
+void NotifyWakeLockChange(const hal::WakeLockInformation& aWakeLockInfo);
+
+/**
+ * Inform the backend there is a new screen configuration observer.
+ * @param aScreenConfigurationObserver The observer that should be added.
+ */
+void RegisterScreenConfigurationObserver(hal::ScreenConfigurationObserver* aScreenConfigurationObserver);
+
+/**
+ * Inform the backend a screen configuration observer unregistered.
+ * @param aScreenConfigurationObserver The observer that should be removed.
+ */
+void UnregisterScreenConfigurationObserver(hal::ScreenConfigurationObserver* aScreenConfigurationObserver);
+
+/**
+ * Returns the current screen configuration.
+ */
+void GetCurrentScreenConfiguration(hal::ScreenConfiguration* aScreenConfiguration);
+
+/**
+ * Notify of a change in the screen configuration.
+ * @param aScreenConfiguration The new screen orientation.
+ */
+void NotifyScreenConfigurationChange(const hal::ScreenConfiguration& aScreenConfiguration);
+
+/**
+ * Lock the screen orientation to the specific orientation.
+ * @return Whether the lock has been accepted.
+ */
+MOZ_MUST_USE bool LockScreenOrientation(const dom::ScreenOrientationInternal& aOrientation);
+
+/**
+ * Unlock the screen orientation.
+ */
+void UnlockScreenOrientation();
+
+/**
+ * Register an observer for the switch of given SwitchDevice.
+ *
+ * The observer will receive data whenever the data generated by the
+ * given switch.
+ */
+void RegisterSwitchObserver(hal::SwitchDevice aDevice, hal::SwitchObserver *aSwitchObserver);
+
+/**
+ * Unregister an observer for the switch of given SwitchDevice.
+ */
+void UnregisterSwitchObserver(hal::SwitchDevice aDevice, hal::SwitchObserver *aSwitchObserver);
+
+/**
+ * Notify the state of the switch.
+ *
+ * This API is internal to hal; clients shouldn't call it directly.
+ */
+void NotifySwitchChange(const hal::SwitchEvent& aEvent);
+
+/**
+ * Get current switch information.
+ */
+hal::SwitchState GetCurrentSwitchState(hal::SwitchDevice aDevice);
+
+/**
+ * Notify switch status change from input device.
+ */
+void NotifySwitchStateFromInputDevice(hal::SwitchDevice aDevice,
+                                      hal::SwitchState aState);
+
+/**
+ * Register an observer that is notified when a programmed alarm
+ * expires.
+ *
+ * Currently, there can only be 0 or 1 alarm observers.
+ */
+MOZ_MUST_USE bool RegisterTheOneAlarmObserver(hal::AlarmObserver* aObserver);
+
+/**
+ * Unregister the alarm observer.  Doing so will implicitly cancel any
+ * programmed alarm.
+ */
+void UnregisterTheOneAlarmObserver();
+
+/**
+ * Notify that the programmed alarm has expired.
+ *
+ * This API is internal to hal; clients shouldn't call it directly.
+ */
+void NotifyAlarmFired();
+
+/**
+ * Program the real-time clock to expire at the time |aSeconds|,
+ * |aNanoseconds|.  These specify a point in real time relative to the
+ * UNIX epoch.  The alarm will fire at this time point even if the
+ * real-time clock is changed; that is, this alarm respects changes to
+ * the real-time clock.  Return true iff the alarm was programmed.
+ *
+ * The alarm can be reprogrammed at any time.
+ *
+ * This API is currently only allowed to be used from non-sandboxed
+ * contexts.
+ */
+MOZ_MUST_USE bool SetAlarm(int32_t aSeconds, int32_t aNanoseconds);
+
+/**
+ * Set the priority of the given process.
+ *
+ * Exactly what this does will vary between platforms.  On *nix we might give
+ * background processes higher nice values.  On other platforms, we might
+ * ignore this call entirely.
+ */
+void SetProcessPriority(int aPid,
+                        hal::ProcessPriority aPriority,
+                        uint32_t aLRU = 0);
+
+
+/**
+ * Set the current thread's priority to appropriate platform-specific value for
+ * given functionality. Instead of providing arbitrary priority numbers you
+ * must specify a type of function like THREAD_PRIORITY_COMPOSITOR.
+ */
+void SetCurrentThreadPriority(hal::ThreadPriority aThreadPriority);
+
+/**
+ * Set a thread priority to appropriate platform-specific value for
+ * given functionality. Instead of providing arbitrary priority numbers you
+ * must specify a type of function like THREAD_PRIORITY_COMPOSITOR.
+ */
+void SetThreadPriority(PlatformThreadId aThreadId,
+                       hal::ThreadPriority aThreadPriority);
+
+/**
+ * Start a watchdog to compulsively shutdown the system if it hangs.
+ * @param aMode Specify how to shutdown the system.
+ * @param aTimeoutSecs Specify the delayed seconds to shutdown the system.
+ *
+ * This API is currently only allowed to be used from the main process.
+ */
+void StartForceQuitWatchdog(hal::ShutdownMode aMode, int32_t aTimeoutSecs);
+
+/**
+ * Perform Factory Reset to wipe out all user data.
+ */
+void FactoryReset(mozilla::dom::FactoryResetReason& aReason);
+
+/**
+ * Start monitoring disk space for low space situations.
+ *
+ * This API is currently only allowed to be used from the main process.
+ */
+void StartDiskSpaceWatcher();
+
+/**
+ * Stop monitoring disk space for low space situations.
+ *
+ * This API is currently only allowed to be used from the main process.
+ */
+void StopDiskSpaceWatcher();
+
+/**
+ * Get total system memory of device being run on in bytes.
+ *
+ * Returns 0 if we are unable to determine this information from /proc/meminfo.
+ */
+uint32_t GetTotalSystemMemory();
+
+/**
+ * Determine whether the headphone switch event is from input device
+ */
+bool IsHeadphoneEventFromInputDev();
+
+/**
+ * Start the system service with the specified name and arguments.
+ */
+nsresult StartSystemService(const char* aSvcName, const char* aArgs);
+
+/**
+ * Stop the system service with the specified name.
+ */
+void StopSystemService(const char* aSvcName);
+
+/**
+ * Determine whether the system service with the specified name is running.
+ */
+bool SystemServiceIsRunning(const char* aSvcName);
+
+} // namespace MOZ_HAL_NAMESPACE
+} // namespace mozilla
+
+#ifdef MOZ_DEFINED_HAL_NAMESPACE
+# undef MOZ_DEFINED_HAL_NAMESPACE
+# undef MOZ_HAL_NAMESPACE
+#endif
+
+#endif  // mozilla_Hal_h
diff --git a/hal/HalImpl.h b/hal/HalImpl.h
new file mode 100644
index 000000000..9143cc5de
--- /dev/null
+++ b/hal/HalImpl.h
@@ -0,0 +1,21 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et ft=cpp : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_HalImpl_h
+#define mozilla_HalImpl_h
+
+#ifdef MOZ_UNIFIED_BUILD
+#error Cannot use HalImpl.h in unified builds.
+#endif
+
+#define MOZ_HAL_NAMESPACE hal_impl
+#undef mozilla_Hal_h
+#undef mozilla_HalInternal_h
+#include "Hal.h"
+#include "HalInternal.h"
+#undef MOZ_HAL_NAMESPACE
+
+#endif // mozilla_HalImpl_h
diff --git a/hal/HalInternal.h b/hal/HalInternal.h
new file mode 100644
index 000000000..d93023dd0
--- /dev/null
+++ b/hal/HalInternal.h
@@ -0,0 +1,105 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et ft=cpp : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_HalInternal_h
+#define mozilla_HalInternal_h 1
+
+/*
+ * This file is included by HalImpl.h and HalSandbox.h with a mechanism similar
+ * to Hal.h. That means those headers set MOZ_HAL_NAMESPACE to specify in which
+ * namespace the internal functions should appear.
+ *
+ * The difference between Hal.h and HalInternal.h is that methods declared in
+ * HalInternal.h don't appear in the hal namespace. That also means this file
+ * should not be included except by HalImpl.h and HalSandbox.h.
+ */
+
+#ifndef MOZ_HAL_NAMESPACE
+# error "You shouldn't directly include HalInternal.h!"
+#endif
+
+namespace mozilla {
+namespace MOZ_HAL_NAMESPACE {
+
+/**
+ * Enables battery notifications from the backend.
+ */
+void EnableBatteryNotifications();
+
+/**
+ * Disables battery notifications from the backend.
+ */
+void DisableBatteryNotifications();
+
+/**
+ * Enables network notifications from the backend.
+ */
+void EnableNetworkNotifications();
+
+/**
+ * Disables network notifications from the backend.
+ */
+void DisableNetworkNotifications();
+
+/**
+ * Enables screen orientation notifications from the backend.
+ */
+void EnableScreenConfigurationNotifications();
+
+/**
+ * Disables screen orientation notifications from the backend.
+ */
+void DisableScreenConfigurationNotifications();
+
+/**
+ * Enable switch notifications from the backend
+ */
+void EnableSwitchNotifications(hal::SwitchDevice aDevice);
+
+/**
+ * Disable switch notifications from the backend
+ */
+void DisableSwitchNotifications(hal::SwitchDevice aDevice);
+
+/**
+ * Enable alarm notifications from the backend.
+ */
+MOZ_MUST_USE bool EnableAlarm();
+
+/**
+ * Disable alarm notifications from the backend.
+ */
+void DisableAlarm();
+
+/**
+ * Enable system clock change notifications from the backend.
+ */
+void EnableSystemClockChangeNotifications();
+
+/**
+ * Disable system clock change notifications from the backend.
+ */
+void DisableSystemClockChangeNotifications();
+
+/**
+ * Enable system timezone change notifications from the backend.
+ */
+void EnableSystemTimezoneChangeNotifications();
+
+/**
+ * Disable system timezone change notifications from the backend.
+ */
+void DisableSystemTimezoneChangeNotifications();
+
+/**
+ * Has the child-side HAL IPC object been destroyed?  If so, you shouldn't send
+ * messages to hal_sandbox.
+ */
+bool HalChildDestroyed();
+} // namespace MOZ_HAL_NAMESPACE
+} // namespace mozilla
+
+#endif  // mozilla_HalInternal_h
diff --git a/hal/HalLog.h b/hal/HalLog.h
new file mode 100644
index 000000000..0d72e98d0
--- /dev/null
+++ b/hal/HalLog.h
@@ -0,0 +1,33 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et ft=cpp : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_HalLog_h
+#define mozilla_HalLog_h
+
+#include "mozilla/Logging.h"
+
+/*
+ * HalLog.h contains internal macros and functions used for logging.
+ *
+ * This should be considered a private include and not used in non-HAL code.
+ * To enable logging in non-debug builds define the PR_FORCE_LOG macro here.
+ */
+
+namespace mozilla {
+
+namespace hal {
+
+mozilla::LogModule *GetHalLog();
+#define HAL_LOG(...) \
+  MOZ_LOG(mozilla::hal::GetHalLog(), LogLevel::Debug, (__VA_ARGS__))
+#define HAL_ERR(...) \
+  MOZ_LOG(mozilla::hal::GetHalLog(), LogLevel::Error, (__VA_ARGS__))
+
+} // namespace hal
+
+} // namespace mozilla
+
+#endif // mozilla_HalLog_h
diff --git a/hal/HalSandbox.h b/hal/HalSandbox.h
new file mode 100644
index 000000000..255a1aae9
--- /dev/null
+++ b/hal/HalSandbox.h
@@ -0,0 +1,17 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et ft=cpp : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_hal_HalSandbox_h
+#define mozilla_hal_HalSandbox_h
+
+#define MOZ_HAL_NAMESPACE hal_sandbox
+#undef mozilla_Hal_h
+#undef mozilla_HalInternal_h
+#include "Hal.h"
+#include "HalInternal.h"
+#undef MOZ_HAL_NAMESPACE
+
+#endif // mozilla_hal_HalSandbox_h
diff --git a/hal/HalScreenConfiguration.h b/hal/HalScreenConfiguration.h
new file mode 100644
index 000000000..dce84fd31
--- /dev/null
+++ b/hal/HalScreenConfiguration.h
@@ -0,0 +1,20 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et ft=cpp : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_HalScreenConfiguration_h
+#define mozilla_HalScreenConfiguration_h
+
+#include "mozilla/Observer.h"
+
+namespace mozilla {
+namespace hal {
+class ScreenConfiguration;
+typedef Observer<ScreenConfiguration> ScreenConfigurationObserver;
+} // namespace hal
+} // namespace mozilla
+
+#endif  // mozilla_HalScreenConfiguration_h
+
diff --git a/hal/HalSensor.h b/hal/HalSensor.h
new file mode 100644
index 000000000..551c4271d
--- /dev/null
+++ b/hal/HalSensor.h
@@ -0,0 +1,80 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et ft=cpp : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef __HAL_SENSOR_H_
+#define __HAL_SENSOR_H_
+
+#include "mozilla/Observer.h"
+
+namespace mozilla {
+namespace hal {
+
+/**
+ * Enumeration of sensor types.  They are used to specify type while
+ * register or unregister an observer for a sensor of given type.
+ * If you add or change any here, do the same in GeckoHalDefines.java.
+ */
+enum SensorType {
+  SENSOR_UNKNOWN = -1,
+  SENSOR_ORIENTATION = 0,
+  SENSOR_ACCELERATION = 1,
+  SENSOR_PROXIMITY = 2,
+  SENSOR_LINEAR_ACCELERATION = 3,
+  SENSOR_GYROSCOPE = 4,
+  SENSOR_LIGHT = 5,
+  SENSOR_ROTATION_VECTOR = 6,
+  SENSOR_GAME_ROTATION_VECTOR = 7,
+  NUM_SENSOR_TYPE
+};
+
+class SensorData;
+
+typedef Observer<SensorData> ISensorObserver;
+
+/**
+ * Enumeration of sensor accuracy types.
+ */
+enum SensorAccuracyType {
+  SENSOR_ACCURACY_UNKNOWN = -1,
+  SENSOR_ACCURACY_UNRELIABLE,
+  SENSOR_ACCURACY_LOW,
+  SENSOR_ACCURACY_MED,
+  SENSOR_ACCURACY_HIGH,
+  NUM_SENSOR_ACCURACY_TYPE
+};
+
+class SensorAccuracy;
+
+typedef Observer<SensorAccuracy> ISensorAccuracyObserver;
+
+} // namespace hal
+} // namespace mozilla
+
+#include "ipc/IPCMessageUtils.h"
+
+namespace IPC {
+  /**
+   * Serializer for SensorType
+   */
+  template <>
+  struct ParamTraits<mozilla::hal::SensorType>:
+    public ContiguousEnumSerializer<
+             mozilla::hal::SensorType,
+             mozilla::hal::SENSOR_UNKNOWN,
+             mozilla::hal::NUM_SENSOR_TYPE> {
+  };
+
+  template <>
+  struct ParamTraits<mozilla::hal::SensorAccuracyType>:
+    public ContiguousEnumSerializer<
+             mozilla::hal::SensorAccuracyType,
+             mozilla::hal::SENSOR_ACCURACY_UNKNOWN,
+             mozilla::hal::NUM_SENSOR_ACCURACY_TYPE> {
+
+  };
+} // namespace IPC
+
+#endif /* __HAL_SENSOR_H_ */
diff --git a/hal/HalTypes.h b/hal/HalTypes.h
new file mode 100644
index 000000000..5f0ad3ff7
--- /dev/null
+++ b/hal/HalTypes.h
@@ -0,0 +1,177 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_hal_Types_h
+#define mozilla_hal_Types_h
+
+#include "ipc/IPCMessageUtils.h"
+#include "mozilla/Observer.h"
+
+namespace mozilla {
+namespace hal {
+
+/**
+ * These constants specify special values for content process IDs.  You can get
+ * a content process ID by calling ContentChild::GetID() or
+ * ContentParent::GetChildID().
+ */
+const uint64_t CONTENT_PROCESS_ID_UNKNOWN = uint64_t(-1);
+const uint64_t CONTENT_PROCESS_ID_MAIN = 0;
+
+/**
+ * These are defined by libhardware, specifically, hardware/libhardware/include/hardware/lights.h
+ * in the gonk subsystem.
+ * If these change and are exposed to JS, make sure nsIHal.idl is updated as well.
+ */
+enum ShutdownMode {
+  eHalShutdownMode_Unknown  = -1,
+  eHalShutdownMode_PowerOff = 0,
+  eHalShutdownMode_Reboot   = 1,
+  eHalShutdownMode_Restart  = 2,
+  eHalShutdownMode_Count    = 3
+};
+
+class SwitchEvent;
+
+enum SwitchDevice {
+  SWITCH_DEVICE_UNKNOWN = -1,
+  SWITCH_HEADPHONES,
+  SWITCH_USB,
+  NUM_SWITCH_DEVICE
+};
+
+enum SwitchState {
+  SWITCH_STATE_UNKNOWN = -1,
+  SWITCH_STATE_ON,
+  SWITCH_STATE_OFF,
+  SWITCH_STATE_HEADSET,          // Headphone with microphone
+  SWITCH_STATE_HEADPHONE,        // without microphone
+  NUM_SWITCH_STATE
+};
+
+typedef Observer<SwitchEvent> SwitchObserver;
+
+// Note that we rely on the order of this enum's entries.  Higher priorities
+// should have larger int values.
+enum ProcessPriority {
+  PROCESS_PRIORITY_UNKNOWN = -1,
+  PROCESS_PRIORITY_BACKGROUND,
+  PROCESS_PRIORITY_BACKGROUND_PERCEIVABLE,
+  PROCESS_PRIORITY_FOREGROUND_KEYBOARD,
+  // The special class for the preallocated process, high memory priority but
+  // low CPU priority.
+  PROCESS_PRIORITY_PREALLOC,
+  // Any priority greater than or equal to FOREGROUND is considered
+  // "foreground" for the purposes of priority testing, for example
+  // CurrentProcessIsForeground().
+  PROCESS_PRIORITY_FOREGROUND,
+  PROCESS_PRIORITY_FOREGROUND_HIGH,
+  PROCESS_PRIORITY_MASTER,
+  NUM_PROCESS_PRIORITY
+};
+
+/**
+ * Values that can be passed to hal::SetCurrentThreadPriority().  These should be
+ * functional in nature, such as COMPOSITOR, instead of levels, like LOW/HIGH.
+ * This allows us to tune our priority scheme for the system in one place such
+ * that it makes sense holistically for the overall operating system.  On gonk
+ * or android we may want different priority schemes than on windows, etc.
+ */
+enum ThreadPriority {
+  THREAD_PRIORITY_COMPOSITOR,
+  NUM_THREAD_PRIORITY
+};
+
+/**
+ * Convert a ProcessPriority enum value to a string.  The strings returned by
+ * this function are statically allocated; do not attempt to free one!
+ *
+ * If you pass an unknown process priority, we fatally assert in debug
+ * builds and otherwise return "???".
+ */
+const char*
+ProcessPriorityToString(ProcessPriority aPriority);
+
+/**
+ * Convert a ThreadPriority enum value to a string.  The strings returned by
+ * this function are statically allocated; do not attempt to free one!
+ *
+ * If you pass an unknown process priority, we assert in debug builds
+ * and otherwise return "???".
+ */
+const char *
+ThreadPriorityToString(ThreadPriority aPriority);
+
+/**
+ * Used by ModifyWakeLock
+ */
+enum WakeLockControl {
+  WAKE_LOCK_REMOVE_ONE = -1,
+  WAKE_LOCK_NO_CHANGE  = 0,
+  WAKE_LOCK_ADD_ONE    = 1,
+  NUM_WAKE_LOCK
+};
+
+} // namespace hal
+} // namespace mozilla
+
+namespace IPC {
+
+/**
+ * Serializer for ShutdownMode.
+ */
+template <>
+struct ParamTraits<mozilla::hal::ShutdownMode>
+  : public ContiguousEnumSerializer<
+             mozilla::hal::ShutdownMode,
+             mozilla::hal::eHalShutdownMode_Unknown,
+             mozilla::hal::eHalShutdownMode_Count>
+{};
+
+/**
+ * WakeLockControl serializer.
+ */
+template <>
+struct ParamTraits<mozilla::hal::WakeLockControl>
+  : public ContiguousEnumSerializer<
+             mozilla::hal::WakeLockControl,
+             mozilla::hal::WAKE_LOCK_REMOVE_ONE,
+             mozilla::hal::NUM_WAKE_LOCK>
+{};
+
+/**
+ * Serializer for SwitchState
+ */
+template <>
+struct ParamTraits<mozilla::hal::SwitchState>:
+  public ContiguousEnumSerializer<
+           mozilla::hal::SwitchState,
+           mozilla::hal::SWITCH_STATE_UNKNOWN,
+           mozilla::hal::NUM_SWITCH_STATE> {
+};
+
+/**
+ * Serializer for SwitchDevice
+ */
+template <>
+struct ParamTraits<mozilla::hal::SwitchDevice>:
+  public ContiguousEnumSerializer<
+           mozilla::hal::SwitchDevice,
+           mozilla::hal::SWITCH_DEVICE_UNKNOWN,
+           mozilla::hal::NUM_SWITCH_DEVICE> {
+};
+
+template <>
+struct ParamTraits<mozilla::hal::ProcessPriority>:
+  public ContiguousEnumSerializer<
+           mozilla::hal::ProcessPriority,
+           mozilla::hal::PROCESS_PRIORITY_UNKNOWN,
+           mozilla::hal::NUM_PROCESS_PRIORITY> {
+};
+
+
+} // namespace IPC
+
+#endif // mozilla_hal_Types_h
diff --git a/hal/HalWakeLock.cpp b/hal/HalWakeLock.cpp
new file mode 100644
index 000000000..af4dc454e
--- /dev/null
+++ b/hal/HalWakeLock.cpp
@@ -0,0 +1,282 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Hal.h"
+#include "mozilla/HalWakeLock.h"
+#include "mozilla/Services.h"
+#include "mozilla/StaticPtr.h"
+#include "mozilla/dom/ContentParent.h"
+#include "nsAutoPtr.h"
+#include "nsClassHashtable.h"
+#include "nsDataHashtable.h"
+#include "nsHashKeys.h"
+#include "nsIPropertyBag2.h"
+#include "nsIObserverService.h"
+
+using namespace mozilla;
+using namespace mozilla::hal;
+
+namespace {
+
+struct LockCount {
+  LockCount()
+    : numLocks(0)
+    , numHidden(0)
+  {}
+  uint32_t numLocks;
+  uint32_t numHidden;
+  nsTArray<uint64_t> processes;
+};
+
+typedef nsDataHashtable<nsUint64HashKey, LockCount> ProcessLockTable;
+typedef nsClassHashtable<nsStringHashKey, ProcessLockTable> LockTable;
+
+int sActiveListeners = 0;
+StaticAutoPtr<LockTable> sLockTable;
+bool sInitialized = false;
+bool sIsShuttingDown = false;
+
+WakeLockInformation
+WakeLockInfoFromLockCount(const nsAString& aTopic, const LockCount& aLockCount)
+{
+  // TODO: Once we abandon b2g18, we can switch this to use the
+  // WakeLockInformation constructor, which is better because it doesn't let us
+  // forget to assign a param.  For now we have to do it this way, because
+  // b2g18 doesn't have the nsTArray <--> InfallibleTArray conversion (bug
+  // 819791).
+
+  WakeLockInformation info;
+  info.topic() = aTopic;
+  info.numLocks() = aLockCount.numLocks;
+  info.numHidden() = aLockCount.numHidden;
+  info.lockingProcesses().AppendElements(aLockCount.processes);
+  return info;
+}
+
+static void
+CountWakeLocks(ProcessLockTable* aTable, LockCount* aTotalCount)
+{
+  for (auto iter = aTable->Iter(); !iter.Done(); iter.Next()) {
+    const uint64_t& key = iter.Key();
+    LockCount count = iter.UserData();
+
+    aTotalCount->numLocks += count.numLocks;
+    aTotalCount->numHidden += count.numHidden;
+
+    // This is linear in the number of processes, but that should be small.
+    if (!aTotalCount->processes.Contains(key)) {
+      aTotalCount->processes.AppendElement(key);
+    }
+  }
+}
+
+class ClearHashtableOnShutdown final : public nsIObserver {
+  ~ClearHashtableOnShutdown() {}
+public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIOBSERVER
+};
+
+NS_IMPL_ISUPPORTS(ClearHashtableOnShutdown, nsIObserver)
+
+NS_IMETHODIMP
+ClearHashtableOnShutdown::Observe(nsISupports* aSubject, const char* aTopic, const char16_t* data)
+{
+  MOZ_ASSERT(!strcmp(aTopic, "xpcom-shutdown"));
+
+  sIsShuttingDown = true;
+  sLockTable = nullptr;
+
+  return NS_OK;
+}
+
+class CleanupOnContentShutdown final : public nsIObserver {
+  ~CleanupOnContentShutdown() {}
+public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIOBSERVER
+};
+
+NS_IMPL_ISUPPORTS(CleanupOnContentShutdown, nsIObserver)
+
+NS_IMETHODIMP
+CleanupOnContentShutdown::Observe(nsISupports* aSubject, const char* aTopic, const char16_t* data)
+{
+  MOZ_ASSERT(!strcmp(aTopic, "ipc:content-shutdown"));
+
+  if (sIsShuttingDown) {
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIPropertyBag2> props = do_QueryInterface(aSubject);
+  if (!props) {
+    NS_WARNING("ipc:content-shutdown message without property bag as subject");
+    return NS_OK;
+  }
+
+  uint64_t childID = 0;
+  nsresult rv = props->GetPropertyAsUint64(NS_LITERAL_STRING("childID"),
+                                           &childID);
+  if (NS_SUCCEEDED(rv)) {
+    for (auto iter = sLockTable->Iter(); !iter.Done(); iter.Next()) {
+      nsAutoPtr<ProcessLockTable>& table = iter.Data();
+
+      if (table->Get(childID, nullptr)) {
+        table->Remove(childID);
+
+        LockCount totalCount;
+        CountWakeLocks(table, &totalCount);
+
+        if (sActiveListeners) {
+          NotifyWakeLockChange(WakeLockInfoFromLockCount(iter.Key(),
+                                                         totalCount));
+        }
+
+        if (totalCount.numLocks == 0) {
+          iter.Remove();
+        }
+      }
+    }
+  } else {
+    NS_WARNING("ipc:content-shutdown message without childID property");
+  }
+  return NS_OK;
+}
+
+void
+Init()
+{
+  sLockTable = new LockTable();
+  sInitialized = true;
+
+  nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
+  if (obs) {
+    obs->AddObserver(new ClearHashtableOnShutdown(), "xpcom-shutdown", false);
+    obs->AddObserver(new CleanupOnContentShutdown(), "ipc:content-shutdown", false);
+  }
+}
+
+} // namespace
+
+namespace mozilla {
+
+namespace hal {
+
+WakeLockState
+ComputeWakeLockState(int aNumLocks, int aNumHidden)
+{
+  if (aNumLocks == 0) {
+    return WAKE_LOCK_STATE_UNLOCKED;
+  } else if (aNumLocks == aNumHidden) {
+    return WAKE_LOCK_STATE_HIDDEN;
+  } else {
+    return WAKE_LOCK_STATE_VISIBLE;
+  }
+}
+
+} // namespace hal
+
+namespace hal_impl {
+
+void
+EnableWakeLockNotifications()
+{
+  sActiveListeners++;
+}
+
+void
+DisableWakeLockNotifications()
+{
+  sActiveListeners--;
+}
+
+void
+ModifyWakeLock(const nsAString& aTopic,
+               hal::WakeLockControl aLockAdjust,
+               hal::WakeLockControl aHiddenAdjust,
+               uint64_t aProcessID)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(aProcessID != CONTENT_PROCESS_ID_UNKNOWN);
+
+  if (sIsShuttingDown) {
+    return;
+  }
+  if (!sInitialized) {
+    Init();
+  }
+
+  ProcessLockTable* table = sLockTable->Get(aTopic);
+  LockCount processCount;
+  LockCount totalCount;
+  if (!table) {
+    table = new ProcessLockTable();
+    sLockTable->Put(aTopic, table);
+  } else {
+    table->Get(aProcessID, &processCount);
+    CountWakeLocks(table, &totalCount);
+  }
+
+  MOZ_ASSERT(processCount.numLocks >= processCount.numHidden);
+  MOZ_ASSERT(aLockAdjust >= 0 || processCount.numLocks > 0);
+  MOZ_ASSERT(aHiddenAdjust >= 0 || processCount.numHidden > 0);
+  MOZ_ASSERT(totalCount.numLocks >= totalCount.numHidden);
+  MOZ_ASSERT(aLockAdjust >= 0 || totalCount.numLocks > 0);
+  MOZ_ASSERT(aHiddenAdjust >= 0 || totalCount.numHidden > 0);
+
+  WakeLockState oldState = ComputeWakeLockState(totalCount.numLocks, totalCount.numHidden);
+  bool processWasLocked = processCount.numLocks > 0;
+
+  processCount.numLocks += aLockAdjust;
+  processCount.numHidden += aHiddenAdjust;
+
+  totalCount.numLocks += aLockAdjust;
+  totalCount.numHidden += aHiddenAdjust;
+
+  if (processCount.numLocks) {
+    table->Put(aProcessID, processCount);
+  } else {
+    table->Remove(aProcessID);
+  }
+  if (!totalCount.numLocks) {
+    sLockTable->Remove(aTopic);
+  }
+
+  if (sActiveListeners &&
+      (oldState != ComputeWakeLockState(totalCount.numLocks,
+                                        totalCount.numHidden) ||
+       processWasLocked != (processCount.numLocks > 0))) {
+
+    WakeLockInformation info;
+    hal::GetWakeLockInfo(aTopic, &info);
+    NotifyWakeLockChange(info);
+  }
+}
+
+void
+GetWakeLockInfo(const nsAString& aTopic, WakeLockInformation* aWakeLockInfo)
+{
+  if (sIsShuttingDown) {
+    NS_WARNING("You don't want to get wake lock information during xpcom-shutdown!");
+    *aWakeLockInfo = WakeLockInformation();
+    return;
+  }
+  if (!sInitialized) {
+    Init();
+  }
+
+  ProcessLockTable* table = sLockTable->Get(aTopic);
+  if (!table) {
+    *aWakeLockInfo = WakeLockInfoFromLockCount(aTopic, LockCount());
+    return;
+  }
+  LockCount totalCount;
+  CountWakeLocks(table, &totalCount);
+  *aWakeLockInfo = WakeLockInfoFromLockCount(aTopic, totalCount);
+}
+
+} // namespace hal_impl
+} // namespace mozilla
diff --git a/hal/HalWakeLock.h b/hal/HalWakeLock.h
new file mode 100644
index 000000000..7ee6327d8
--- /dev/null
+++ b/hal/HalWakeLock.h
@@ -0,0 +1,26 @@
+/* -*- Mode: C++; tab-width: 40; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef __HAL_WAKELOCK_H_
+#define __HAL_WAKELOCK_H_
+
+namespace mozilla {
+namespace hal {
+
+enum WakeLockState {
+  WAKE_LOCK_STATE_UNLOCKED,
+  WAKE_LOCK_STATE_HIDDEN,
+  WAKE_LOCK_STATE_VISIBLE
+};
+
+/**
+ * Return the wake lock state according to the numbers.
+ */
+WakeLockState ComputeWakeLockState(int aNumLocks, int aNumHidden);
+
+} // namespace hal
+} // namespace mozilla
+
+#endif /* __HAL_WAKELOCK_H_ */
diff --git a/hal/WindowIdentifier.cpp b/hal/WindowIdentifier.cpp
new file mode 100644
index 000000000..8e1354ba7
--- /dev/null
+++ b/hal/WindowIdentifier.cpp
@@ -0,0 +1,80 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et ft=cpp : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "WindowIdentifier.h"
+
+#include "mozilla/dom/ContentChild.h"
+#include "nsPIDOMWindow.h"
+
+namespace mozilla {
+namespace hal {
+
+WindowIdentifier::WindowIdentifier()
+  : mWindow(nullptr)
+  , mIsEmpty(true)
+{
+}
+
+WindowIdentifier::WindowIdentifier(nsPIDOMWindowInner* window)
+  : mWindow(window)
+  , mIsEmpty(false)
+{
+  mID.AppendElement(GetWindowID());
+}
+
+WindowIdentifier::WindowIdentifier(const InfallibleTArray<uint64_t> &id,
+                                   nsPIDOMWindowInner* window)
+  : mID(id)
+  , mWindow(window)
+  , mIsEmpty(false)
+{
+  mID.AppendElement(GetWindowID());
+}
+
+WindowIdentifier::WindowIdentifier(const WindowIdentifier &other)
+  : mID(other.mID)
+  , mWindow(other.mWindow)
+  , mIsEmpty(other.mIsEmpty)
+{
+}
+
+const InfallibleTArray<uint64_t>&
+WindowIdentifier::AsArray() const
+{
+  MOZ_ASSERT(!mIsEmpty);
+  return mID;
+}
+
+bool
+WindowIdentifier::HasTraveledThroughIPC() const
+{
+  MOZ_ASSERT(!mIsEmpty);
+  return mID.Length() >= 2;
+}
+
+void
+WindowIdentifier::AppendProcessID()
+{
+  MOZ_ASSERT(!mIsEmpty);
+  mID.AppendElement(dom::ContentChild::GetSingleton()->GetID());
+}
+
+uint64_t
+WindowIdentifier::GetWindowID() const
+{
+  MOZ_ASSERT(!mIsEmpty);
+  return mWindow ? mWindow->WindowID() : UINT64_MAX;
+}
+
+nsPIDOMWindowInner*
+WindowIdentifier::GetWindow() const
+{
+  MOZ_ASSERT(!mIsEmpty);
+  return mWindow;
+}
+
+} // namespace hal
+} // namespace mozilla
diff --git a/hal/WindowIdentifier.h b/hal/WindowIdentifier.h
new file mode 100644
index 000000000..928a16896
--- /dev/null
+++ b/hal/WindowIdentifier.h
@@ -0,0 +1,111 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et ft=cpp : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_hal_WindowIdentifier_h
+#define mozilla_hal_WindowIdentifier_h
+
+#include "mozilla/Types.h"
+#include "nsCOMPtr.h"
+#include "nsTArray.h"
+
+class nsPIDOMWindowInner;
+
+namespace mozilla {
+namespace hal {
+
+/**
+ * This class serves two purposes.
+ *
+ * First, this class wraps a pointer to a window.
+ *
+ * Second, WindowIdentifier lets us uniquely identify a window across
+ * processes.  A window exposes an ID which is unique only within its
+ * process.  Thus to identify a window, we need to know the ID of the
+ * process which contains it.  But the scope of a process's ID is its
+ * parent; that is, two processes with different parents might have
+ * the same ID.
+ *
+ * So to identify a window, we need its ID plus the IDs of all the
+ * processes in the path from the window's process to the root
+ * process.  We throw in the IDs of the intermediate windows (a
+ * content window is contained in a window at each level of the
+ * process tree) for good measures.
+ *
+ * You can access this list of IDs by calling AsArray().
+ */
+class WindowIdentifier
+{
+public:
+  /**
+   * Create an empty WindowIdentifier.  Calls to any of this object's
+   * public methods will assert -- an empty WindowIdentifier may be
+   * used only as a placeholder to code which promises not to touch
+   * the object.
+   */
+  WindowIdentifier();
+
+  /**
+   * Copy constructor.
+   */
+  WindowIdentifier(const WindowIdentifier& other);
+
+  /**
+   * Wrap the given window in a WindowIdentifier.  These two
+   * constructors automatically grab the window's ID and append it to
+   * the array of IDs.
+   *
+   * Note that these constructors allow an implicit conversion to a
+   * WindowIdentifier.
+   */
+  explicit WindowIdentifier(nsPIDOMWindowInner* window);
+
+  /**
+   * Create a new WindowIdentifier with the given id array and window.
+   * This automatically grabs the window's ID and appends it to the
+   * array.
+   */
+  WindowIdentifier(const InfallibleTArray<uint64_t>& id,
+                   nsPIDOMWindowInner* window);
+
+  /**
+   * Get the list of window and process IDs we contain.
+   */
+  typedef InfallibleTArray<uint64_t> IDArrayType;
+  const IDArrayType& AsArray() const;
+
+  /**
+   * Append the ID of the ContentChild singleton to our array of
+   * window/process IDs.
+   */
+  void AppendProcessID();
+
+  /**
+   * Does this WindowIdentifier identify both a window and the process
+   * containing that window?  If so, we say it has traveled through
+   * IPC.
+   */
+  bool HasTraveledThroughIPC() const;
+
+  /**
+   * Get the window this object wraps.
+   */
+  nsPIDOMWindowInner* GetWindow() const;
+
+private:
+  /**
+   * Get the ID of the window object we wrap.
+   */
+  uint64_t GetWindowID() const;
+
+  AutoTArray<uint64_t, 3> mID;
+  nsCOMPtr<nsPIDOMWindowInner> mWindow;
+  bool mIsEmpty;
+};
+
+} // namespace hal
+} // namespace mozilla
+
+#endif // mozilla_hal_WindowIdentifier_h
diff --git a/hal/android/AndroidAlarm.cpp b/hal/android/AndroidAlarm.cpp
new file mode 100644
index 000000000..3b2613be8
--- /dev/null
+++ b/hal/android/AndroidAlarm.cpp
@@ -0,0 +1,48 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Hal.h"
+
+#include "GeneratedJNINatives.h"
+#include "GeneratedJNIWrappers.h"
+
+using namespace mozilla::hal;
+
+namespace mozilla {
+
+class AlarmReceiver : public java::AlarmReceiver::Natives<AlarmReceiver>
+{
+private:
+    AlarmReceiver();
+
+public:
+    static void NotifyAlarmFired() {
+        hal::NotifyAlarmFired();
+    }
+};
+
+namespace hal_impl {
+
+bool
+EnableAlarm()
+{
+    AlarmReceiver::Init();
+    return true;
+}
+
+void
+DisableAlarm()
+{
+    java::GeckoAppShell::DisableAlarm();
+}
+
+bool
+SetAlarm(int32_t aSeconds, int32_t aNanoseconds)
+{
+    return java::GeckoAppShell::SetAlarm(aSeconds, aNanoseconds);
+}
+
+} // hal_impl
+} // mozilla
diff --git a/hal/android/AndroidHal.cpp b/hal/android/AndroidHal.cpp
new file mode 100644
index 000000000..495b623ef
--- /dev/null
+++ b/hal/android/AndroidHal.cpp
@@ -0,0 +1,175 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Hal.h"
+#include "HalImpl.h"
+#include "WindowIdentifier.h"
+#include "AndroidBridge.h"
+#include "mozilla/dom/network/Constants.h"
+#include "mozilla/dom/ScreenOrientation.h"
+#include "nsIScreenManager.h"
+#include "nsServiceManagerUtils.h"
+
+using namespace mozilla::dom;
+using namespace mozilla::hal;
+
+namespace java = mozilla::java;
+
+namespace mozilla {
+namespace hal_impl {
+
+void
+Vibrate(const nsTArray<uint32_t> &pattern, const WindowIdentifier &)
+{
+  // Ignore the WindowIdentifier parameter; it's here only because hal::Vibrate,
+  // hal_sandbox::Vibrate, and hal_impl::Vibrate all must have the same
+  // signature.
+
+  // Strangely enough, the Android Java API seems to treat vibrate([0]) as a
+  // nop.  But we want to treat vibrate([0]) like CancelVibrate!  (Note that we
+  // also need to treat vibrate([]) as a call to CancelVibrate.)
+  bool allZero = true;
+  for (uint32_t i = 0; i < pattern.Length(); i++) {
+    if (pattern[i] != 0) {
+      allZero = false;
+      break;
+    }
+  }
+
+  if (allZero) {
+    hal_impl::CancelVibrate(WindowIdentifier());
+    return;
+  }
+
+  AndroidBridge* b = AndroidBridge::Bridge();
+  if (!b) {
+    return;
+  }
+
+  b->Vibrate(pattern);
+}
+
+void
+CancelVibrate(const WindowIdentifier &)
+{
+  // Ignore WindowIdentifier parameter.
+
+  java::GeckoAppShell::CancelVibrate();
+}
+
+void
+EnableBatteryNotifications()
+{
+  java::GeckoAppShell::EnableBatteryNotifications();
+}
+
+void
+DisableBatteryNotifications()
+{
+  java::GeckoAppShell::DisableBatteryNotifications();
+}
+
+void
+GetCurrentBatteryInformation(hal::BatteryInformation* aBatteryInfo)
+{
+  AndroidBridge::Bridge()->GetCurrentBatteryInformation(aBatteryInfo);
+}
+
+void
+EnableNetworkNotifications()
+{
+  java::GeckoAppShell::EnableNetworkNotifications();
+}
+
+void
+DisableNetworkNotifications()
+{
+  java::GeckoAppShell::DisableNetworkNotifications();
+}
+
+void
+GetCurrentNetworkInformation(hal::NetworkInformation* aNetworkInfo)
+{
+  AndroidBridge::Bridge()->GetCurrentNetworkInformation(aNetworkInfo);
+}
+
+void
+EnableScreenConfigurationNotifications()
+{
+  java::GeckoAppShell::EnableScreenOrientationNotifications();
+}
+
+void
+DisableScreenConfigurationNotifications()
+{
+  java::GeckoAppShell::DisableScreenOrientationNotifications();
+}
+
+void
+GetCurrentScreenConfiguration(ScreenConfiguration* aScreenConfiguration)
+{
+  AndroidBridge* bridge = AndroidBridge::Bridge();
+  if (!bridge) {
+    return;
+  }
+
+  nsresult rv;
+  nsCOMPtr<nsIScreenManager> screenMgr =
+    do_GetService("@mozilla.org/gfx/screenmanager;1", &rv);
+  if (NS_FAILED(rv)) {
+    NS_ERROR("Can't find nsIScreenManager!");
+    return;
+  }
+
+  nsIntRect rect;
+  int32_t colorDepth, pixelDepth;
+  int16_t angle;
+  ScreenOrientationInternal orientation;
+  nsCOMPtr<nsIScreen> screen;
+
+  screenMgr->GetPrimaryScreen(getter_AddRefs(screen));
+  screen->GetRect(&rect.x, &rect.y, &rect.width, &rect.height);
+  screen->GetColorDepth(&colorDepth);
+  screen->GetPixelDepth(&pixelDepth);
+  orientation = static_cast<ScreenOrientationInternal>(bridge->GetScreenOrientation());
+  angle = bridge->GetScreenAngle();
+
+  *aScreenConfiguration =
+    hal::ScreenConfiguration(rect, orientation, angle, colorDepth, pixelDepth);
+}
+
+bool
+LockScreenOrientation(const ScreenOrientationInternal& aOrientation)
+{
+  // Force the default orientation to be portrait-primary.
+  ScreenOrientationInternal orientation =
+    aOrientation == eScreenOrientation_Default ? eScreenOrientation_PortraitPrimary
+                                               : aOrientation;
+
+  switch (orientation) {
+    // The Android backend only supports these orientations.
+    case eScreenOrientation_PortraitPrimary:
+    case eScreenOrientation_PortraitSecondary:
+    case eScreenOrientation_PortraitPrimary | eScreenOrientation_PortraitSecondary:
+    case eScreenOrientation_LandscapePrimary:
+    case eScreenOrientation_LandscapeSecondary:
+    case eScreenOrientation_LandscapePrimary | eScreenOrientation_LandscapeSecondary:
+    case eScreenOrientation_Default:
+      java::GeckoAppShell::LockScreenOrientation(orientation);
+      return true;
+    default:
+      return false;
+  }
+}
+
+void
+UnlockScreenOrientation()
+{
+  java::GeckoAppShell::UnlockScreenOrientation();
+}
+
+} // hal_impl
+} // mozilla
+
diff --git a/hal/android/AndroidSensor.cpp b/hal/android/AndroidSensor.cpp
new file mode 100644
index 000000000..cb1060342
--- /dev/null
+++ b/hal/android/AndroidSensor.cpp
@@ -0,0 +1,25 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Hal.h"
+#include "GeneratedJNIWrappers.h"
+
+using namespace mozilla::hal;
+
+namespace mozilla {
+namespace hal_impl {
+
+void
+EnableSensorNotifications(SensorType aSensor) {
+  java::GeckoAppShell::EnableSensor(aSensor);
+}
+
+void
+DisableSensorNotifications(SensorType aSensor) {
+  java::GeckoAppShell::DisableSensor(aSensor);
+}
+
+} // hal_impl
+} // mozilla
diff --git a/hal/cocoa/CocoaBattery.cpp b/hal/cocoa/CocoaBattery.cpp
new file mode 100644
index 000000000..6f1b7b1dc
--- /dev/null
+++ b/hal/cocoa/CocoaBattery.cpp
@@ -0,0 +1,325 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim set: sw=2 ts=2 et lcs=trail\:.,tab\:>~ : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#import <CoreFoundation/CoreFoundation.h>
+#import <IOKit/ps/IOPowerSources.h>
+#import <IOKit/ps/IOPSKeys.h>
+
+#include <mozilla/Hal.h>
+#include <mozilla/dom/battery/Constants.h>
+#include <mozilla/Services.h>
+
+#include <nsIObserverService.h>
+#include <nsIObserver.h>
+
+#include <dlfcn.h>
+
+#define IOKIT_FRAMEWORK_PATH "/System/Library/Frameworks/IOKit.framework/IOKit"
+
+#ifndef kIOPSTimeRemainingUnknown
+  #define kIOPSTimeRemainingUnknown ((CFTimeInterval)-1.0)
+#endif
+#ifndef kIOPSTimeRemainingUnlimited
+  #define kIOPSTimeRemainingUnlimited ((CFTimeInterval)-2.0)
+#endif
+
+using namespace mozilla::dom::battery;
+
+namespace mozilla {
+namespace hal_impl {
+
+typedef CFTimeInterval (*IOPSGetTimeRemainingEstimateFunc)(void);
+
+class MacPowerInformationService
+{
+public:
+  static MacPowerInformationService* GetInstance();
+  static void Shutdown();
+  static bool IsShuttingDown();
+
+  void BeginListening();
+  void StopListening();
+
+  static void HandleChange(void *aContext);
+
+  ~MacPowerInformationService();
+
+private:
+  MacPowerInformationService();
+
+  // The reference to the runloop that is notified of power changes.
+  CFRunLoopSourceRef mRunLoopSource;
+
+  double mLevel;
+  bool mCharging;
+  double mRemainingTime;
+  bool mShouldNotify;
+
+  friend void GetCurrentBatteryInformation(hal::BatteryInformation* aBatteryInfo);
+
+  static MacPowerInformationService* sInstance;
+  static bool sShuttingDown;
+
+  static void* sIOKitFramework;
+  static IOPSGetTimeRemainingEstimateFunc sIOPSGetTimeRemainingEstimate;
+};
+
+void* MacPowerInformationService::sIOKitFramework;
+IOPSGetTimeRemainingEstimateFunc MacPowerInformationService::sIOPSGetTimeRemainingEstimate;
+
+/*
+ * Implementation of mozilla::hal_impl::EnableBatteryNotifications,
+ *                   mozilla::hal_impl::DisableBatteryNotifications,
+ *               and mozilla::hal_impl::GetCurrentBatteryInformation.
+ */
+
+void
+EnableBatteryNotifications()
+{
+  if (!MacPowerInformationService::IsShuttingDown()) {
+    MacPowerInformationService::GetInstance()->BeginListening();
+  }
+}
+
+void
+DisableBatteryNotifications()
+{
+  if (!MacPowerInformationService::IsShuttingDown()) {
+    MacPowerInformationService::GetInstance()->StopListening();
+  }
+}
+
+void
+GetCurrentBatteryInformation(hal::BatteryInformation* aBatteryInfo)
+{
+  MacPowerInformationService* powerService = MacPowerInformationService::GetInstance();
+
+  aBatteryInfo->level() = powerService->mLevel;
+  aBatteryInfo->charging() = powerService->mCharging;
+  aBatteryInfo->remainingTime() = powerService->mRemainingTime;
+}
+
+bool MacPowerInformationService::sShuttingDown = false;
+
+/*
+ * Following is the implementation of MacPowerInformationService.
+ */
+
+MacPowerInformationService* MacPowerInformationService::sInstance = nullptr;
+
+namespace {
+struct SingletonDestroyer final : public nsIObserver
+{
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIOBSERVER
+
+private:
+  ~SingletonDestroyer() {}
+};
+
+NS_IMPL_ISUPPORTS(SingletonDestroyer, nsIObserver)
+
+NS_IMETHODIMP
+SingletonDestroyer::Observe(nsISupports*, const char* aTopic, const char16_t*)
+{
+  MOZ_ASSERT(!strcmp(aTopic, "xpcom-shutdown"));
+  MacPowerInformationService::Shutdown();
+  return NS_OK;
+}
+} // namespace
+
+/* static */ MacPowerInformationService*
+MacPowerInformationService::GetInstance()
+{
+  if (sInstance) {
+    return sInstance;
+  }
+
+  sInstance = new MacPowerInformationService();
+
+  nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
+  if (obs) {
+    obs->AddObserver(new SingletonDestroyer(), "xpcom-shutdown", false);
+  }
+
+  return sInstance;
+}
+
+bool
+MacPowerInformationService::IsShuttingDown()
+{
+  return sShuttingDown;
+}
+
+void
+MacPowerInformationService::Shutdown()
+{
+  sShuttingDown = true;
+  delete sInstance;
+  sInstance = nullptr;
+}
+
+MacPowerInformationService::MacPowerInformationService()
+  : mRunLoopSource(nullptr)
+  , mLevel(kDefaultLevel)
+  , mCharging(kDefaultCharging)
+  , mRemainingTime(kDefaultRemainingTime)
+  , mShouldNotify(false)
+{
+  // IOPSGetTimeRemainingEstimate (and the related constants) are only available
+  // on 10.7, so we test for their presence at runtime.
+  sIOKitFramework = dlopen(IOKIT_FRAMEWORK_PATH, RTLD_LAZY | RTLD_LOCAL);
+  if (sIOKitFramework) {
+    sIOPSGetTimeRemainingEstimate =
+      (IOPSGetTimeRemainingEstimateFunc)dlsym(sIOKitFramework, "IOPSGetTimeRemainingEstimate");
+  } else {
+    sIOPSGetTimeRemainingEstimate = nullptr;
+  }
+}
+
+MacPowerInformationService::~MacPowerInformationService()
+{
+  MOZ_ASSERT(!mRunLoopSource,
+               "The observers have not been correctly removed! "
+               "(StopListening should have been called)");
+
+  if (sIOKitFramework) {
+    dlclose(sIOKitFramework);
+  }
+}
+
+void
+MacPowerInformationService::BeginListening()
+{
+  // Set ourselves up to be notified about changes.
+  MOZ_ASSERT(!mRunLoopSource, "IOPS Notification Loop Source already set up. "
+                              "(StopListening should have been called)");
+
+  mRunLoopSource = ::IOPSNotificationCreateRunLoopSource(HandleChange, this);
+  if (mRunLoopSource) {
+    ::CFRunLoopAddSource(::CFRunLoopGetCurrent(), mRunLoopSource,
+                         kCFRunLoopDefaultMode);
+
+    // Invoke our callback now so we have data if GetCurrentBatteryInformation is
+    // called before a change happens.
+    HandleChange(this);
+    mShouldNotify = true;
+  }
+}
+
+void
+MacPowerInformationService::StopListening()
+{
+  MOZ_ASSERT(mRunLoopSource, "IOPS Notification Loop Source not set up. "
+                             "(StopListening without BeginListening)");
+
+  ::CFRunLoopRemoveSource(::CFRunLoopGetCurrent(), mRunLoopSource,
+                          kCFRunLoopDefaultMode);
+  mRunLoopSource = nullptr;
+}
+
+void
+MacPowerInformationService::HandleChange(void* aContext) {
+  MacPowerInformationService* power =
+    static_cast<MacPowerInformationService*>(aContext);
+
+  CFTypeRef data = ::IOPSCopyPowerSourcesInfo();
+  if (!data) {
+    ::CFRelease(data);
+    return;
+  }
+
+  // Get the list of power sources.
+  CFArrayRef list = ::IOPSCopyPowerSourcesList(data);
+  if (!list) {
+    ::CFRelease(list);
+    return;
+  }
+
+  // Default values. These will be used if there are 0 sources or we can't find
+  // better information.
+  double level = kDefaultLevel;
+  double charging = kDefaultCharging;
+  double remainingTime = kDefaultRemainingTime;
+
+  // Look for the first battery power source to give us the information we need.
+  // Usually there's only 1 available, depending on current power source.
+  for (CFIndex i = 0; i < ::CFArrayGetCount(list); ++i) {
+    CFTypeRef source = ::CFArrayGetValueAtIndex(list, i);
+    CFDictionaryRef currPowerSourceDesc = ::IOPSGetPowerSourceDescription(data, source);
+    if (!currPowerSourceDesc) {
+      continue;
+    }
+
+    // Get a battery level estimate. This key is required.
+    int currentCapacity = 0;
+    const void* cfRef = ::CFDictionaryGetValue(currPowerSourceDesc, CFSTR(kIOPSCurrentCapacityKey));
+    ::CFNumberGetValue((CFNumberRef)cfRef, kCFNumberSInt32Type, &currentCapacity);
+
+    // This key is also required.
+    int maxCapacity = 0;
+    cfRef = ::CFDictionaryGetValue(currPowerSourceDesc, CFSTR(kIOPSMaxCapacityKey));
+    ::CFNumberGetValue((CFNumberRef)cfRef, kCFNumberSInt32Type, &maxCapacity);
+
+    if (maxCapacity > 0) {
+      level = static_cast<double>(currentCapacity)/static_cast<double>(maxCapacity);
+    }
+
+    // Find out if we're charging.
+    // This key is optional, we fallback to kDefaultCharging if the current power
+    // source doesn't have that info.
+    if(::CFDictionaryGetValueIfPresent(currPowerSourceDesc, CFSTR(kIOPSIsChargingKey), &cfRef)) {
+      charging = ::CFBooleanGetValue((CFBooleanRef)cfRef);
+
+      // Get an estimate of how long it's going to take until we're fully charged.
+      // This key is optional.
+      if (charging) {
+        // Default value that will be changed if we happen to find the actual
+        // remaining time.
+        remainingTime = level == 1.0 ? kDefaultRemainingTime : kUnknownRemainingTime;
+
+        if (::CFDictionaryGetValueIfPresent(currPowerSourceDesc,
+                CFSTR(kIOPSTimeToFullChargeKey), &cfRef)) {
+          int timeToCharge;
+          ::CFNumberGetValue((CFNumberRef)cfRef, kCFNumberIntType, &timeToCharge);
+          if (timeToCharge != kIOPSTimeRemainingUnknown) {
+            remainingTime = timeToCharge*60;
+          }
+        }
+      } else if (sIOPSGetTimeRemainingEstimate) { // not charging
+        // See if we can get a time estimate.
+        CFTimeInterval estimate = sIOPSGetTimeRemainingEstimate();
+        if (estimate == kIOPSTimeRemainingUnlimited || estimate == kIOPSTimeRemainingUnknown) {
+          remainingTime = kUnknownRemainingTime;
+        } else {
+          remainingTime = estimate;
+        }
+      }
+    }
+
+    break;
+  }
+
+  bool isNewData = level != power->mLevel || charging != power->mCharging ||
+                   remainingTime != power->mRemainingTime;
+
+  power->mRemainingTime = remainingTime;
+  power->mCharging = charging;
+  power->mLevel = level;
+
+  // Notify the observers if stuff changed.
+  if (power->mShouldNotify && isNewData) {
+    hal::NotifyBatteryChange(hal::BatteryInformation(power->mLevel,
+                                                     power->mCharging,
+                                                     power->mRemainingTime));
+  }
+
+  ::CFRelease(data);
+  ::CFRelease(list);
+}
+
+} // namespace hal_impl
+} // namespace mozilla
diff --git a/hal/cocoa/CocoaSensor.mm b/hal/cocoa/CocoaSensor.mm
new file mode 100644
index 000000000..ad203073c
--- /dev/null
+++ b/hal/cocoa/CocoaSensor.mm
@@ -0,0 +1,149 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+#include "Hal.h"
+#include "nsITimer.h"
+#include "smslib.h"
+#include "nsComponentManagerUtils.h"
+
+#include <mach/mach.h>
+#include <cmath>
+#import <IOKit/IOKitLib.h>
+
+#define MEAN_GRAVITY 9.80665
+#define DEFAULT_SENSOR_POLL 100
+using namespace mozilla::hal;
+namespace mozilla {
+namespace hal_impl {
+static nsITimer* sUpdateTimer = nullptr;
+static bool sActiveSensors[NUM_SENSOR_TYPE];
+static io_connect_t sDataPort = IO_OBJECT_NULL;
+static uint64_t sLastMean = -1;
+static float
+LMUvalueToLux(uint64_t aValue)
+{
+  //Conversion formula from regression. See Bug 793728.
+  // -3*(10^-27)*x^4 + 2.6*(10^-19)*x^3 + -3.4*(10^-12)*x^2 + 3.9*(10^-5)*x - 0.19
+  long double powerC4 = 1/pow((long double)10,27);
+  long double powerC3 = 1/pow((long double)10,19);
+  long double powerC2 = 1/pow((long double)10,12);
+  long double powerC1 = 1/pow((long double)10,5);
+
+  long double term4 = -3.0 * powerC4 * pow(aValue,4);
+  long double term3 =  2.6 * powerC3 * pow(aValue,3);
+  long double term2 = -3.4 * powerC2 * pow(aValue,2);
+  long double term1 =  3.9 * powerC1 * aValue;
+
+  float lux = ceil(static_cast<float>(term4 + term3 + term2 + term1 - 0.19));
+  return lux > 0 ? lux : 0;
+}
+void
+UpdateHandler(nsITimer *aTimer, void *aClosure)
+{
+  for (int i = 0; i < NUM_SENSOR_TYPE; i++) {
+    if (!sActiveSensors[i]) {
+      continue;
+    }
+    SensorType sensor = static_cast<SensorType>(i);
+    InfallibleTArray<float> values;
+    if (sensor == SENSOR_ACCELERATION) {
+      sms_acceleration accel;
+      smsGetData(&accel);
+
+      values.AppendElement(accel.x * MEAN_GRAVITY);
+      values.AppendElement(accel.y * MEAN_GRAVITY);
+      values.AppendElement(accel.z * MEAN_GRAVITY);
+    } else if (sensor == SENSOR_LIGHT && sDataPort != IO_OBJECT_NULL) {
+      kern_return_t kr;
+      uint32_t outputs = 2;
+      uint64_t lightLMU[outputs];
+
+      kr = IOConnectCallMethod(sDataPort, 0, nil, 0, nil, 0, lightLMU, &outputs, nil, 0);
+      if (kr == KERN_SUCCESS) {
+        uint64_t mean = (lightLMU[0] + lightLMU[1]) / 2;
+        if (mean == sLastMean) {
+          continue;
+        }
+        sLastMean = mean;
+        values.AppendElement(LMUvalueToLux(mean));
+      } else if (kr == kIOReturnBusy) {
+        continue;
+      }
+    }
+
+    hal::SensorData sdata(sensor,
+                          PR_Now(),
+                          values,
+                          hal::SENSOR_ACCURACY_UNKNOWN);
+    hal::NotifySensorChange(sdata);
+  }
+}
+void
+EnableSensorNotifications(SensorType aSensor)
+{
+  if (aSensor == SENSOR_ACCELERATION) {
+    int result = smsStartup(nil, nil);
+
+    if (result != SMS_SUCCESS) {
+      return;
+    }
+
+    if (!smsLoadCalibration()) {
+      return;
+    }
+  } else if (aSensor == SENSOR_LIGHT) {
+    io_service_t serviceObject;
+    serviceObject = IOServiceGetMatchingService(kIOMasterPortDefault,
+                                                IOServiceMatching("AppleLMUController"));
+    if (!serviceObject) {
+      return;
+    }
+    kern_return_t kr;
+    kr = IOServiceOpen(serviceObject, mach_task_self(), 0, &sDataPort);
+    IOObjectRelease(serviceObject);
+    if (kr != KERN_SUCCESS) {
+      return;
+    }
+  } else {
+    NS_WARNING("EnableSensorNotifications called on an unknown sensor type");
+    return;
+  }
+  sActiveSensors[aSensor] = true;
+
+  if (!sUpdateTimer) {
+    CallCreateInstance("@mozilla.org/timer;1", &sUpdateTimer);
+    if (sUpdateTimer) {
+        sUpdateTimer->InitWithFuncCallback(UpdateHandler,
+                                           nullptr,
+                                           DEFAULT_SENSOR_POLL,
+                                           nsITimer::TYPE_REPEATING_SLACK);
+    }
+  }
+}
+void
+DisableSensorNotifications(SensorType aSensor)
+{
+  if (!sActiveSensors[aSensor] || (aSensor != SENSOR_ACCELERATION && aSensor != SENSOR_LIGHT)) {
+    return;
+  }
+
+  sActiveSensors[aSensor] = false;
+
+  if (aSensor == SENSOR_ACCELERATION) {
+    smsShutdown();
+  } else if (aSensor == SENSOR_LIGHT) {
+    IOServiceClose(sDataPort);
+  }
+  // If all sensors are disabled, cancel the update timer.
+  if (sUpdateTimer) {
+    for (int i = 0; i < NUM_SENSOR_TYPE; i++) {
+      if (sActiveSensors[i]) {
+        return;
+      }
+    }
+    sUpdateTimer->Cancel();
+    NS_RELEASE(sUpdateTimer);
+  }
+}
+} // namespace hal_impl
+} // namespace mozilla
diff --git a/hal/cocoa/smslib.h b/hal/cocoa/smslib.h
new file mode 100644
index 000000000..2f0b2664e
--- /dev/null
+++ b/hal/cocoa/smslib.h
@@ -0,0 +1,159 @@
+/*
+ * smslib.h
+ *
+ * SMSLib Sudden Motion Sensor Access Library
+ * Copyright (c) 2010 Suitable Systems
+ * All rights reserved.
+ * 
+ * Developed by: Daniel Griscom
+ *               Suitable Systems
+ *               http://www.suitable.com
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal with the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ * 
+ * - Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimers.
+ * 
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimers in the
+ * documentation and/or other materials provided with the distribution.
+ * 
+ * - Neither the names of Suitable Systems nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this Software without specific prior written permission.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR
+ * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS WITH THE SOFTWARE.
+ *
+ * For more information about SMSLib, see
+ *		<http://www.suitable.com/tools/smslib.html>
+ * or contact
+ *		Daniel Griscom
+ *		Suitable Systems
+ *		1 Centre Street, Suite 204
+ *		Wakefield, MA 01880
+ *		(781) 665-0053
+ *
+ */
+
+#import <Foundation/Foundation.h>
+
+#define SMSLIB_VERSION "1.8"
+
+#pragma mark Structure definitions
+
+// Structure for specifying a 3-axis acceleration. 0.0 means "zero gravities",
+// 1.0 means "one gravity".
+typedef struct sms_acceleration {
+	float x;		// Right-left acceleration (positive is rightwards)
+	float y;		// Front-rear acceleration (positive is rearwards)
+	float z;		// Up-down acceleration (positive is upwards)
+} sms_acceleration;
+
+// Structure for specifying a calibration.
+typedef struct sms_calibration {
+	float zeros[3];	// Zero points for three axes (X, Y, Z)
+	float onegs[3];	// One gravity values for three axes
+} sms_calibration;
+
+#pragma mark Return value definitions
+
+// These are the return values for accelStartup(), giving the
+// various stages where the most successful attempt at accessing
+// the accelerometer failed. The higher the value, the further along the
+// software progressed before failing. The options are:
+//	- Didn't match model name
+#define SMS_FAIL_MODEL			(-7)
+//	- Failure getting dictionary matching desired services
+#define SMS_FAIL_DICTIONARY		(-6)
+//	- Failure getting list of services
+#define SMS_FAIL_LIST_SERVICES	(-5)
+//	- Failure if list of services is empty. The process generally fails
+//		here if run on a machine without a Sudden Motion Sensor.
+#define SMS_FAIL_NO_SERVICES	(-4)
+//	- Failure if error opening device.
+#define SMS_FAIL_OPENING		(-3)
+//	- Failure if opened, but didn't get a connection
+#define SMS_FAIL_CONNECTION		(-2)
+//	- Failure if couldn't access connction using given function and size. This
+//		is where the process would probably fail with a change in Apple's API.
+//		Driver problems often also cause failures here.
+#define SMS_FAIL_ACCESS			(-1)
+//	- Success!
+#define SMS_SUCCESS				(0)
+
+#pragma mark Function declarations
+
+// This starts up the accelerometer code, trying each possible sensor
+// specification. Note that for logging purposes it
+// takes an object and a selector; the object's selector is then invoked
+// with a single NSString as argument giving progress messages. Example
+// logging method:
+//		- (void)logMessage: (NSString *)theString
+// which would be used in accelStartup's invocation thusly:
+//		result = accelStartup(self, @selector(logMessage:));
+// If the object is nil, then no logging is done. Sets calibation from built-in
+// value table. Returns ACCEL_SUCCESS for success, and other (negative)
+// values for various failures (returns value indicating result of
+// most successful trial).
+int smsStartup(id logObject, SEL logSelector);
+
+// This starts up the library in debug mode, ignoring the actual hardware.
+// Returned data is in the form of 1Hz sine waves, with the X, Y and Z
+// axes 120 degrees out of phase; "calibrated" data has range +/- (1.0/5);
+// "uncalibrated" data has range +/- (256/5). X and Y axes centered on 0.0,
+// Z axes centered on 1 (calibrated) or 256 (uncalibrated). 
+// Don't use smsGetBufferLength or smsGetBufferData. Always returns SMS_SUCCESS.
+int smsDebugStartup(id logObject, SEL logSelector);
+
+// Returns the current calibration values.
+void smsGetCalibration(sms_calibration *calibrationRecord);
+
+// Sets the calibration, but does NOT store it as a preference. If the argument
+// is nil then the current calibration is set from the built-in value table.
+void smsSetCalibration(sms_calibration *calibrationRecord);
+
+// Stores the current calibration values as a stored preference.
+void smsStoreCalibration(void);
+
+// Loads the stored preference values into the current calibration.
+// Returns YES if successful.
+BOOL smsLoadCalibration(void);
+
+// Deletes any stored calibration, and then takes the current calibration values
+// from the built-in value table.
+void smsDeleteCalibration(void);
+
+// Fills in the accel record with calibrated acceleration data. Takes
+// 1-2ms to return a value. Returns 0 if success, error number if failure.
+int smsGetData(sms_acceleration *accel);
+
+// Fills in the accel record with uncalibrated acceleration data.
+// Returns 0 if success, error number if failure.
+int smsGetUncalibratedData(sms_acceleration *accel);
+
+// Returns the length of a raw block of data for the current type of sensor.
+int smsGetBufferLength(void);
+
+// Takes a pointer to accelGetRawLength() bytes; sets those bytes
+// to return value from sensor. Make darn sure the buffer length is right!
+void smsGetBufferData(char *buffer);
+
+// This returns an NSString describing the current calibration in
+// human-readable form. Also include a description of the machine.
+NSString *smsGetCalibrationDescription(void);
+
+// Shuts down the accelerometer.
+void smsShutdown(void);
+
diff --git a/hal/cocoa/smslib.mm b/hal/cocoa/smslib.mm
new file mode 100644
index 000000000..c11c1e4d6
--- /dev/null
+++ b/hal/cocoa/smslib.mm
@@ -0,0 +1,938 @@
+/*
+ * smslib.m
+ * 
+ * SMSLib Sudden Motion Sensor Access Library
+ * Copyright (c) 2010 Suitable Systems
+ * All rights reserved.
+ * 
+ * Developed by: Daniel Griscom
+ *               Suitable Systems
+ *               http://www.suitable.com
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal with the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ * 
+ * - Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimers.
+ * 
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimers in the
+ * documentation and/or other materials provided with the distribution.
+ * 
+ * - Neither the names of Suitable Systems nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this Software without specific prior written permission.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR
+ * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS WITH THE SOFTWARE.
+ *
+ * For more information about SMSLib, see
+ *		<http://www.suitable.com/tools/smslib.html>
+ * or contact
+ *		Daniel Griscom
+ *		Suitable Systems
+ *		1 Centre Street, Suite 204
+ *		Wakefield, MA 01880
+ *		(781) 665-0053
+ *
+ */
+
+#import <IOKit/IOKitLib.h>
+#import <sys/sysctl.h>
+#import <math.h>
+#import "smslib.h"
+
+#pragma mark Internal structures
+
+// Represents a single axis of a type of sensor.
+typedef struct axisStruct {
+	int enabled;				// Non-zero if axis is valid in this sensor
+	int index;					// Location in struct of first byte
+	int size;					// Number of bytes
+	float zerog;				// Value meaning "zero g"
+	float oneg;					// Change in value meaning "increase of one g"
+								// (can be negative if axis sensor reversed)
+} axisStruct;
+
+// Represents the configuration of a type of sensor.
+typedef struct sensorSpec {
+	const char *model;			// Prefix of model to be tested
+	const char *name;			// Name of device to be read
+	unsigned int function;		// Kernel function index
+	int recordSize;				// Size of record to be sent/received
+	axisStruct axes[3];			// Description of three axes (X, Y, Z)
+} sensorSpec;
+	
+// Configuration of all known types of sensors. The configurations are
+// tried in order until one succeeds in returning data.
+// All default values are set here, but each axis' zerog and oneg values 
+// may be changed to saved (calibrated) values.
+//
+// These values came from SeisMaCalibrate calibration reports. In general I've
+// found the following:
+//	- All Intel-based SMSs have 250 counts per g, centered on 0, but the signs
+//		are different (and in one case two axes are swapped)
+//	- PowerBooks and iBooks all have sensors centered on 0, and reading
+//		50-53 steps per gravity (but with differing polarities!)
+//	- PowerBooks and iBooks of the same model all have the same axis polarities
+//	- PowerBook and iBook access methods are model- and OS version-specific
+//
+// So, the sequence of tests is:
+//	- Try model-specific access methods. Note that the test is for a match to the
+//		beginning of the model name, e.g. the record with model name "MacBook"
+//		matches computer models "MacBookPro1,2" and "MacBook1,1" (and ""
+//		matches any model).
+//	- If no model-specific record's access fails, then try each model-independent
+//		access method in order, stopping when one works.
+static const sensorSpec sensors[] = {
+	// ****** Model-dependent methods ******
+	// The PowerBook5,6 is one of the G4 models that seems to lose
+	// SMS access until the next reboot.
+	{"PowerBook5,6", "IOI2CMotionSensor", 21, 60, {
+			{1, 0, 1, 0,  51.5},
+			{1, 1, 1, 0, -51.5},
+			{1, 2, 1, 0, -51.5}
+		}
+	},
+	// The PowerBook5,7 is one of the G4 models that seems to lose
+	// SMS access until the next reboot.
+	{"PowerBook5,7", "IOI2CMotionSensor", 21, 60, {
+			{1, 0, 1, 0,  51.5},
+			{1, 1, 1, 0,  51.5},
+			{1, 2, 1, 0,  51.5}
+		}
+	},
+	// Access seems to be reliable on the PowerBook5,8
+	{"PowerBook5,8", "PMUMotionSensor", 21, 60, {
+			{1, 0, 1, 0, -51.5},
+			{1, 1, 1, 0,  51.5},
+			{1, 2, 1, 0, -51.5}
+		}
+	},
+	// Access seems to be reliable on the PowerBook5,9
+	{"PowerBook5,9", "PMUMotionSensor", 21, 60, {
+			{1, 0, 1, 0,  51.5},
+			{1, 1, 1, 0, -51.5},
+			{1, 2, 1, 0, -51.5}
+		}
+	},
+	// The PowerBook6,7 is one of the G4 models that seems to lose
+	// SMS access until the next reboot.
+	{"PowerBook6,7", "IOI2CMotionSensor", 21, 60, {
+			{1, 0, 1, 0,  51.5},
+			{1, 1, 1, 0,  51.5},
+			{1, 2, 1, 0,  51.5}
+		}
+	},
+	// The PowerBook6,8 is one of the G4 models that seems to lose
+	// SMS access until the next reboot.
+	{"PowerBook6,8", "IOI2CMotionSensor", 21, 60, {
+			{1, 0, 1, 0,  51.5},
+			{1, 1, 1, 0,  51.5},
+			{1, 2, 1, 0,  51.5}
+		}
+	},
+	// MacBook Pro Core 2 Duo 17". Note the reversed Y and Z axes.
+	{"MacBookPro2,1", "SMCMotionSensor", 5, 40, {
+			{1, 0, 2, 0,  251},
+			{1, 2, 2, 0, -251},
+			{1, 4, 2, 0, -251}
+		}
+	},
+	// MacBook Pro Core 2 Duo 15" AND 17" with LED backlight, introduced June '07.
+	// NOTE! The 17" machines have the signs of their X and Y axes reversed
+	// from this calibration, but there's no clear way to discriminate between
+	// the two machines.
+	{"MacBookPro3,1", "SMCMotionSensor", 5, 40, {
+			{1, 0, 2, 0, -251},
+			{1, 2, 2, 0,  251},
+			{1, 4, 2, 0, -251}
+		}
+	},
+	// ... specs?
+	{"MacBook5,2", "SMCMotionSensor", 5, 40, {
+			{1, 0, 2, 0, -251},
+			{1, 2, 2, 0,  251},
+			{1, 4, 2, 0, -251}
+		}
+	},
+	// ... specs?
+	{"MacBookPro5,1", "SMCMotionSensor", 5, 40, {
+			{1, 0, 2, 0, -251},
+			{1, 2, 2, 0, -251},
+			{1, 4, 2, 0,  251}
+		}
+	},
+	// ... specs?
+	{"MacBookPro5,2", "SMCMotionSensor", 5, 40, {
+			{1, 0, 2, 0, -251},
+			{1, 2, 2, 0, -251},
+			{1, 4, 2, 0,  251}
+		}
+	},
+	// This is speculative, based on a single user's report. Looks like the X and Y axes
+	// are swapped. This is true for no other known Appple laptop.
+	{"MacBookPro5,3", "SMCMotionSensor", 5, 40, {
+			{1, 2, 2, 0, -251},
+			{1, 0, 2, 0, -251},
+			{1, 4, 2, 0, -251}
+		}
+	},
+	// ... specs?
+	{"MacBookPro5,4", "SMCMotionSensor", 5, 40, {
+			{1, 0, 2, 0, -251},
+			{1, 2, 2, 0, -251},
+			{1, 4, 2, 0,  251}
+		}
+	},
+	// ****** Model-independent methods ******
+	// Seen once with PowerBook6,8 under system 10.3.9; I suspect
+	// other G4-based 10.3.* systems might use this
+	{"", "IOI2CMotionSensor", 24, 60, {
+			{1, 0, 1, 0, 51.5},
+			{1, 1, 1, 0, 51.5},
+			{1, 2, 1, 0, 51.5}
+		}
+	},
+	// PowerBook5,6 , PowerBook5,7 , PowerBook6,7 , PowerBook6,8
+	// under OS X 10.4.*
+	{"", "IOI2CMotionSensor", 21, 60, {
+			{1, 0, 1, 0, 51.5},
+			{1, 1, 1, 0, 51.5},
+			{1, 2, 1, 0, 51.5}
+		}
+	},
+	// PowerBook5,8 , PowerBook5,9 under OS X 10.4.*
+	{"", "PMUMotionSensor", 21, 60, {
+			// Each has two out of three gains negative, but it's different
+			// for the different models. So, this will be right in two out
+			// of three axis for either model.
+			{1, 0, 1,  0, -51.5},
+			{1, 1, 1, -6, -51.5},
+			{1, 2, 1,  0, -51.5}
+		}
+	},
+	// All MacBook, MacBookPro models. Hardware (at least on early MacBookPro 15")
+	// is Kionix KXM52-1050 three-axis accelerometer chip. Data is at
+	// http://kionix.com/Product-Index/product-index.htm. Specific MB and MBP models
+	// that use this are: 
+	//		MacBook1,1
+	//		MacBook2,1
+	//		MacBook3,1
+	//		MacBook4,1
+	//		MacBook5,1
+	//		MacBook6,1
+	//		MacBookAir1,1
+	//		MacBookPro1,1
+	//		MacBookPro1,2
+	//		MacBookPro4,1
+	//		MacBookPro5,5
+	{"", "SMCMotionSensor", 5, 40, {
+			{1, 0, 2, 0, 251},
+			{1, 2, 2, 0, 251},
+			{1, 4, 2, 0, 251}
+		}
+	}
+};
+
+#define SENSOR_COUNT (sizeof(sensors)/sizeof(sensorSpec))
+
+#pragma mark Internal prototypes
+
+static int getData(sms_acceleration *accel, int calibrated, id logObject, SEL logSelector);
+static float getAxis(int which, int calibrated);
+static int signExtend(int value, int size);
+static NSString *getModelName(void);
+static NSString *getOSVersion(void);
+static BOOL loadCalibration(void);
+static void storeCalibration(void);
+static void defaultCalibration(void);
+static void deleteCalibration(void);
+static int prefIntRead(NSString *prefName, BOOL *success);
+static void prefIntWrite(NSString *prefName, int prefValue);
+static float prefFloatRead(NSString *prefName, BOOL *success);
+static void prefFloatWrite(NSString *prefName, float prefValue);
+static void prefDelete(NSString *prefName);
+static void prefSynchronize(void);
+// static long getMicroseconds(void);
+float fakeData(NSTimeInterval time);
+
+#pragma mark Static variables
+
+static int debugging = NO;		// True if debugging (synthetic data)
+static io_connect_t connection;	// Connection for reading accel values
+static int running = NO;		// True if we successfully started
+static unsigned int sensorNum = 0;		// The current index into sensors[]
+static const char *serviceName;	// The name of the current service
+static char *iRecord, *oRecord;	// Pointers to read/write records for sensor
+static int recordSize;			// Size of read/write records
+static unsigned int function;	// Which kernel function should be used
+static float zeros[3];			// X, Y and Z zero calibration values
+static float onegs[3];			// X, Y and Z one-g calibration values
+
+#pragma mark Defines
+
+// Pattern for building axis letter from axis number
+#define INT_TO_AXIS(a) (a == 0 ? @"X" : a == 1 ? @"Y" : @"Z")
+// Name of configuration for given axis' zero (axis specified by integer)
+#define ZERO_NAME(a) [NSString stringWithFormat:@"%@-Axis-Zero", INT_TO_AXIS(a)]
+// Name of configuration for given axis' oneg (axis specified by integer)
+#define ONEG_NAME(a) [NSString stringWithFormat:@"%@-Axis-One-g", INT_TO_AXIS(a)]
+// Name of "Is calibrated" preference
+#define CALIBRATED_NAME (@"Calibrated")
+// Application domain for SeisMac library
+#define APP_ID ((CFStringRef)@"com.suitable.SeisMacLib")
+
+// These #defines make the accelStartup code a LOT easier to read.
+#undef LOG
+#define LOG(message) \
+	if (logObject) { \
+		[logObject performSelector:logSelector withObject:message]; \
+	}
+#define LOG_ARG(format, var1) \
+	if (logObject) { \
+		[logObject performSelector:logSelector \
+			withObject:[NSString stringWithFormat:format, var1]]; \
+	}
+#define LOG_2ARG(format, var1, var2) \
+	if (logObject) { \
+		[logObject performSelector:logSelector \
+			withObject:[NSString stringWithFormat:format, var1, var2]]; \
+	}
+#define LOG_3ARG(format, var1, var2, var3) \
+	if (logObject) { \
+		[logObject performSelector:logSelector \
+			withObject:[NSString stringWithFormat:format, var1, var2, var3]]; \
+	}
+
+#pragma mark Function definitions
+
+// This starts up the accelerometer code, trying each possible sensor
+// specification. Note that for logging purposes it
+// takes an object and a selector; the object's selector is then invoked
+// with a single NSString as argument giving progress messages. Example
+// logging method:
+//		- (void)logMessage: (NSString *)theString
+// which would be used in accelStartup's invocation thusly:
+//		result = accelStartup(self, @selector(logMessage:));
+// If the object is nil, then no logging is done. Sets calibation from built-in
+// value table. Returns ACCEL_SUCCESS for success, and other (negative)
+// values for various failures (returns value indicating result of
+// most successful trial).
+int smsStartup(id logObject, SEL logSelector) {
+	io_iterator_t iterator;
+	io_object_t device;
+	kern_return_t result;
+	sms_acceleration accel;
+	int failure_result = SMS_FAIL_MODEL;
+		
+	running = NO;
+	debugging = NO;
+	
+	NSString *modelName = getModelName();
+	
+	LOG_ARG(@"Machine model: %@\n", modelName);
+	LOG_ARG(@"OS X version: %@\n", getOSVersion());
+	LOG_ARG(@"Accelerometer library version: %s\n", SMSLIB_VERSION);
+		
+	for (sensorNum = 0; sensorNum < SENSOR_COUNT; sensorNum++) {
+		
+		// Set up all specs for this type of sensor
+		serviceName = sensors[sensorNum].name;
+		recordSize = sensors[sensorNum].recordSize;
+		function = sensors[sensorNum].function;
+		
+		LOG_3ARG(@"Trying service \"%s\" with selector %d and %d byte record:\n",
+				serviceName, function, recordSize);
+		
+		NSString *targetName = [NSString stringWithCString:sensors[sensorNum].model
+												  encoding:NSMacOSRomanStringEncoding];
+		LOG_ARG(@"    Comparing model name to target \"%@\": ", targetName);
+		if ([targetName length] == 0 || [modelName hasPrefix:targetName]) {
+			LOG(@"success.\n");
+		} else {
+			LOG(@"failure.\n");
+			// Don't need to increment failure_result.
+			continue;
+		}
+		
+		LOG(@"    Fetching dictionary for service: ");
+		CFMutableDictionaryRef dict = IOServiceMatching(serviceName);
+		
+		if (dict) {
+			LOG(@"success.\n");
+		} else {
+			LOG(@"failure.\n");
+			if (failure_result < SMS_FAIL_DICTIONARY) {
+				failure_result = SMS_FAIL_DICTIONARY;
+			}
+			continue;
+		}
+		
+		LOG(@"    Getting list of matching services: ");
+		result = IOServiceGetMatchingServices(kIOMasterPortDefault, 
+										 dict, 
+										 &iterator);
+		
+		if (result == KERN_SUCCESS) {
+			LOG(@"success.\n");
+		} else {
+			LOG_ARG(@"failure, with return value 0x%x.\n", result);
+			if (failure_result < SMS_FAIL_LIST_SERVICES) {
+				failure_result = SMS_FAIL_LIST_SERVICES;
+			}
+			continue;
+		}
+		
+		LOG(@"    Getting first device in list: ");
+		device = IOIteratorNext(iterator);	
+		
+		if (device == 0) {
+			LOG(@"failure.\n");
+			if (failure_result < SMS_FAIL_NO_SERVICES) {
+				failure_result = SMS_FAIL_NO_SERVICES;
+			}
+			continue;
+		} else {
+			LOG(@"success.\n");
+			LOG(@"    Opening device: ");
+		}
+		
+		result = IOServiceOpen(device, mach_task_self(), 0, &connection);
+		
+		if (result != KERN_SUCCESS) {
+			LOG_ARG(@"failure, with return value 0x%x.\n", result);
+			IOObjectRelease(device);
+			if (failure_result < SMS_FAIL_OPENING) {
+				failure_result = SMS_FAIL_OPENING;
+			}
+			continue;
+		} else if (connection == 0) {
+			LOG_ARG(@"'success', but didn't get a connection (return value was: 0x%x).\n", result);
+			IOObjectRelease(device);
+			if (failure_result < SMS_FAIL_CONNECTION) {
+				failure_result = SMS_FAIL_CONNECTION;
+			}
+			continue;
+		} else {
+			IOObjectRelease(device);
+			LOG(@"success.\n");
+		}
+		LOG(@"    Testing device.\n");
+		
+		defaultCalibration();
+		
+		iRecord = (char*) malloc(recordSize);
+		oRecord = (char*) malloc(recordSize);
+		
+		running = YES;
+		result = getData(&accel, true, logObject, logSelector);
+		running = NO;
+		
+		if (result) {
+			LOG_ARG(@"    Failure testing device, with result 0x%x.\n", result);
+			free(iRecord);
+			iRecord = 0;
+			free(oRecord);
+			oRecord = 0;
+			if (failure_result < SMS_FAIL_ACCESS) {
+				failure_result = SMS_FAIL_ACCESS;
+			}
+			continue;
+		} else {
+			LOG(@"    Success testing device!\n");
+			running = YES;
+			return SMS_SUCCESS;
+		}
+	}
+	return failure_result;
+}
+
+// This starts up the library in debug mode, ignoring the actual hardware.
+// Returned data is in the form of 1Hz sine waves, with the X, Y and Z
+// axes 120 degrees out of phase; "calibrated" data has range +/- (1.0/5);
+// "uncalibrated" data has range +/- (256/5). X and Y axes centered on 0.0,
+// Z axes centered on 1 (calibrated) or 256 (uncalibrated). 
+// Don't use smsGetBufferLength or smsGetBufferData. Always returns SMS_SUCCESS.
+int smsDebugStartup(id logObject, SEL logSelector) {
+	LOG(@"Starting up in debug mode\n");
+	debugging = YES;
+	return SMS_SUCCESS;
+}
+
+// Returns the current calibration values.
+void smsGetCalibration(sms_calibration *calibrationRecord) {
+	int x;
+	
+	for (x = 0; x < 3; x++) {
+		calibrationRecord->zeros[x] = (debugging ? 0 : zeros[x]);
+		calibrationRecord->onegs[x] = (debugging ? 256 : onegs[x]);
+	}
+}
+
+// Sets the calibration, but does NOT store it as a preference. If the argument
+// is nil then the current calibration is set from the built-in value table.
+void smsSetCalibration(sms_calibration *calibrationRecord) {
+	int x;
+	
+	if (!debugging) {
+		if (calibrationRecord) {
+			for (x = 0; x < 3; x++) {
+				zeros[x] = calibrationRecord->zeros[x];
+				onegs[x] = calibrationRecord->onegs[x];
+			}
+		} else {
+			defaultCalibration();
+		}
+	}
+}
+
+// Stores the current calibration values as a stored preference.
+void smsStoreCalibration(void) {
+	if (!debugging)
+		storeCalibration();
+}
+
+// Loads the stored preference values into the current calibration.
+// Returns YES if successful.
+BOOL smsLoadCalibration(void) {
+	if (debugging) {
+		return YES;
+	} else if (loadCalibration()) {
+		return YES;
+	} else {
+		defaultCalibration();
+		return NO;
+	}
+}
+
+// Deletes any stored calibration, and then takes the current calibration values
+// from the built-in value table.
+void smsDeleteCalibration(void) {
+	if (!debugging) {
+		deleteCalibration();
+		defaultCalibration();
+	}
+}
+
+// Fills in the accel record with calibrated acceleration data. Takes
+// 1-2ms to return a value. Returns 0 if success, error number if failure.
+int smsGetData(sms_acceleration *accel) {
+	NSTimeInterval time;
+	if (debugging) {
+		usleep(1500);						// Usually takes 1-2 milliseconds
+		time = [NSDate timeIntervalSinceReferenceDate];
+		accel->x = fakeData(time)/5;
+		accel->y = fakeData(time - 1)/5;
+		accel->z = fakeData(time - 2)/5 + 1.0;
+		return true;
+	} else {
+		return getData(accel, true, nil, nil);
+	}
+}
+
+// Fills in the accel record with uncalibrated acceleration data.
+// Returns 0 if success, error number if failure.
+int smsGetUncalibratedData(sms_acceleration *accel) {
+	NSTimeInterval time;
+	if (debugging) {
+		usleep(1500);						// Usually takes 1-2 milliseconds
+		time = [NSDate timeIntervalSinceReferenceDate];
+		accel->x = fakeData(time) * 256 / 5;
+		accel->y = fakeData(time - 1) * 256 / 5;
+		accel->z = fakeData(time - 2) * 256 / 5 + 256;
+		return true;
+	} else {
+		return getData(accel, false, nil, nil);
+	}
+}
+
+// Returns the length of a raw block of data for the current type of sensor.
+int smsGetBufferLength(void) {
+	if (debugging) {
+		return 0;
+	} else if (running) {
+		return sensors[sensorNum].recordSize;
+	} else {
+		return 0;
+	}
+}
+
+// Takes a pointer to accelGetRawLength() bytes; sets those bytes
+// to return value from sensor. Make darn sure the buffer length is right!
+void smsGetBufferData(char *buffer) {
+	IOItemCount iSize = recordSize;
+	IOByteCount oSize = recordSize;
+	kern_return_t result;
+
+	if (debugging || running == NO) {
+		return;
+	}
+
+	memset(iRecord, 1, iSize);
+	memset(buffer, 0, oSize);
+#if __MAC_OS_X_VERSION_MIN_REQUIRED  >= 1050
+	const size_t InStructSize = recordSize;
+	size_t OutStructSize = recordSize;
+	result = IOConnectCallStructMethod(connection,
+						function,				// magic kernel function number
+						(const void *)iRecord,
+						InStructSize,
+						(void *)buffer,
+						&OutStructSize
+					);
+#else // __MAC_OS_X_VERSION_MIN_REQUIRED 1050
+	result = IOConnectMethodStructureIStructureO(connection,
+						function,				// magic kernel function number
+						iSize,
+						&oSize,
+						iRecord,
+						buffer
+					);
+#endif // __MAC_OS_X_VERSION_MIN_REQUIRED 1050
+	
+	if (result != KERN_SUCCESS) {
+		running = NO;
+	}
+}
+
+// This returns an NSString describing the current calibration in
+// human-readable form. Also include a description of the machine.
+NSString *smsGetCalibrationDescription(void) {
+	BOOL success;
+	NSMutableString *s = [[NSMutableString alloc] init];
+	
+	if (debugging) {
+		[s release];
+		return @"Debugging!";
+	}
+	
+	[s appendString:@"---- SeisMac Calibration Record ----\n \n"];
+	[s appendFormat:@"Machine model: %@\n", 
+		getModelName()];
+	[s appendFormat:@"OS X build: %@\n", 
+		getOSVersion()];
+	[s appendFormat:@"SeisMacLib version %s, record %d\n \n", 
+		SMSLIB_VERSION, sensorNum];
+	[s appendFormat:@"Using service \"%s\", function index %d, size %d\n \n",
+		serviceName, function, recordSize];
+	if (prefIntRead(CALIBRATED_NAME, &success) && success) {
+		[s appendString:@"Calibration values (from calibration):\n"];
+	} else {
+		[s appendString:@"Calibration values (from defaults):\n"];
+	}
+	[s appendFormat:@"    X-Axis-Zero  = %.2f\n", zeros[0]];
+	[s appendFormat:@"    X-Axis-One-g = %.2f\n", onegs[0]];
+	[s appendFormat:@"    Y-Axis-Zero  = %.2f\n", zeros[1]];
+	[s appendFormat:@"    Y-Axis-One-g = %.2f\n", onegs[1]];
+	[s appendFormat:@"    Z-Axis-Zero  = %.2f\n", zeros[2]];
+	[s appendFormat:@"    Z-Axis-One-g = %.2f\n \n", onegs[2]];
+	[s appendString:@"---- End Record ----\n"];
+	return s;
+}
+
+// Shuts down the accelerometer.
+void smsShutdown(void) {
+	if (!debugging) {
+		running = NO;
+		if (iRecord) free(iRecord);
+		if (oRecord) free(oRecord);
+		IOServiceClose(connection);
+	}
+}
+
+#pragma mark Internal functions
+
+// Loads the current calibration from the stored preferences.
+// Returns true iff successful.
+BOOL loadCalibration(void) {
+	BOOL thisSuccess, allSuccess;
+	int x;
+	
+	prefSynchronize();
+	
+	if (prefIntRead(CALIBRATED_NAME, &thisSuccess) && thisSuccess) {
+		// Calibrated. Set all values from saved values.
+		allSuccess = YES;
+		for (x = 0; x < 3; x++) {
+			zeros[x] = prefFloatRead(ZERO_NAME(x), &thisSuccess);
+			allSuccess &= thisSuccess;
+			onegs[x] = prefFloatRead(ONEG_NAME(x), &thisSuccess);
+			allSuccess &= thisSuccess;
+		}
+		return allSuccess;
+	}
+	
+	return NO;
+}
+
+// Stores the current calibration into the stored preferences.
+static void storeCalibration(void) {
+	int x;
+	prefIntWrite(CALIBRATED_NAME, 1);
+	for (x = 0; x < 3; x++) {
+		prefFloatWrite(ZERO_NAME(x), zeros[x]);
+		prefFloatWrite(ONEG_NAME(x), onegs[x]);
+	}	
+	prefSynchronize();
+}
+
+
+// Sets the calibration to its default values.
+void defaultCalibration(void) {
+	int x;
+	for (x = 0; x < 3; x++) {
+		zeros[x] = sensors[sensorNum].axes[x].zerog;
+		onegs[x] = sensors[sensorNum].axes[x].oneg;
+	}
+}
+
+// Deletes the stored preferences.
+static void deleteCalibration(void) {
+	int x;
+	
+	prefDelete(CALIBRATED_NAME);
+	for (x = 0; x < 3; x++) {
+		prefDelete(ZERO_NAME(x));
+		prefDelete(ONEG_NAME(x));
+	}
+	prefSynchronize();
+}
+
+// Read a named floating point value from the stored preferences. Sets
+// the success boolean based on, you guessed it, whether it succeeds.
+static float prefFloatRead(NSString *prefName, BOOL *success) {
+	float result = 0.0f;
+	
+	CFPropertyListRef ref = CFPreferencesCopyAppValue((CFStringRef)prefName, 
+													   APP_ID);
+	// If there isn't such a preference, fail
+	if (ref == NULL) {
+		*success = NO;
+		return result;
+	}
+	CFTypeID typeID = CFGetTypeID(ref);
+	// Is it a number?
+	if (typeID == CFNumberGetTypeID()) {
+		// Is it a floating point number?
+		if (CFNumberIsFloatType((CFNumberRef)ref)) {
+			// Yup: grab it.
+			*success = CFNumberGetValue((__CFNumber*)ref, kCFNumberFloat32Type, &result);
+		} else {
+			// Nope: grab as an integer, and convert to a float.
+			long num;
+			if (CFNumberGetValue((CFNumberRef)ref, kCFNumberLongType, &num)) {
+				result = num;
+				*success = YES;
+			} else {
+				*success = NO;
+			}
+		}
+	// Or is it a string (e.g. set by the command line "defaults" command)?
+	} else if (typeID == CFStringGetTypeID()) {
+		result = (float)CFStringGetDoubleValue((CFStringRef)ref);
+		*success = YES;
+	} else {
+		// Can't convert to a number: fail.
+		*success = NO;
+	}
+	CFRelease(ref);
+	return result;
+}
+
+// Writes a named floating point value to the stored preferences.
+static void prefFloatWrite(NSString *prefName, float prefValue) {
+	CFNumberRef cfFloat = CFNumberCreate(kCFAllocatorDefault,
+										 kCFNumberFloatType,
+										 &prefValue);
+	CFPreferencesSetAppValue((CFStringRef)prefName,
+							 cfFloat,
+							 APP_ID);
+	CFRelease(cfFloat);
+}
+
+// Reads a named integer value from the stored preferences.
+static int prefIntRead(NSString *prefName, BOOL *success) {
+	Boolean internalSuccess;
+	CFIndex result = CFPreferencesGetAppIntegerValue((CFStringRef)prefName,
+													 APP_ID, 
+													 &internalSuccess);
+	*success = internalSuccess;
+	
+	return result;
+}
+
+// Writes a named integer value to the stored preferences.
+static void prefIntWrite(NSString *prefName, int prefValue) {
+	CFPreferencesSetAppValue((CFStringRef)prefName,
+							 (CFNumberRef)[NSNumber numberWithInt:prefValue],
+							 APP_ID);
+}
+
+// Deletes the named preference values.
+static void prefDelete(NSString *prefName) {
+		CFPreferencesSetAppValue((CFStringRef)prefName,
+								 NULL,
+								 APP_ID);
+}
+
+// Synchronizes the local preferences with the stored preferences.
+static void prefSynchronize(void) {
+	CFPreferencesAppSynchronize(APP_ID);
+}
+
+// Internal version of accelGetData, with logging
+int getData(sms_acceleration *accel, int calibrated, id logObject, SEL logSelector) {
+	IOItemCount iSize = recordSize;
+	IOByteCount oSize = recordSize;
+	kern_return_t result;
+	
+	if (running == NO) {
+		return -1;
+	}
+	
+	memset(iRecord, 1, iSize);
+	memset(oRecord, 0, oSize);
+	
+	LOG_2ARG(@"    Querying device (%u, %d): ", 
+			 sensors[sensorNum].function, sensors[sensorNum].recordSize);
+	
+#if __MAC_OS_X_VERSION_MIN_REQUIRED  >= 1050
+	const size_t InStructSize = recordSize;
+	size_t OutStructSize = recordSize;
+	result = IOConnectCallStructMethod(connection,
+						function,				// magic kernel function number
+						(const void *)iRecord,
+						InStructSize,
+						(void *)oRecord,
+						&OutStructSize
+					);
+#else // __MAC_OS_X_VERSION_MIN_REQUIRED 1050
+	result = IOConnectMethodStructureIStructureO(connection,
+						function,				// magic kernel function number
+						iSize,
+						&oSize,
+						iRecord,
+						oRecord
+					);
+#endif // __MAC_OS_X_VERSION_MIN_REQUIRED 1050
+
+	if (result != KERN_SUCCESS) {
+		LOG(@"failed.\n");
+		running = NO;
+		return result;
+	} else {
+		LOG(@"succeeded.\n");
+		
+		accel->x = getAxis(0, calibrated);
+		accel->y = getAxis(1, calibrated);
+		accel->z = getAxis(2, calibrated);
+		return 0;
+	}
+}
+
+// Given the returned record, extracts the value of the given axis. If
+// calibrated, then zero G is 0.0, and one G is 1.0.
+float getAxis(int which, int calibrated) {
+	// Get various values (to make code cleaner)
+	int indx = sensors[sensorNum].axes[which].index;
+	int size = sensors[sensorNum].axes[which].size;
+	float zerog = zeros[which];
+	float oneg = onegs[which];
+	// Storage for value to be returned
+	int value = 0;
+	
+	// Although the values in the returned record should have the proper
+	// endianness, we still have to get it into the proper end of value.
+#if (BYTE_ORDER == BIG_ENDIAN)
+	// On PowerPC processors
+	memcpy(((char *)&value) + (sizeof(int) - size), &oRecord[indx], size);
+#endif
+#if (BYTE_ORDER == LITTLE_ENDIAN)
+	// On Intel processors
+	memcpy(&value, &oRecord[indx], size);
+#endif
+	
+	value = signExtend(value, size);
+	
+	if (calibrated) {
+		// Scale and shift for zero.
+		return ((float)(value - zerog)) / oneg;
+	} else {
+		return value;
+	}
+}
+
+// Extends the sign, given the length of the value.
+int signExtend(int value, int size) {
+	// Extend sign
+	switch (size) {
+		case 1:
+			if (value & 0x00000080)
+				value |= 0xffffff00;
+			break;
+		case 2:
+			if (value & 0x00008000)
+				value |= 0xffff0000;
+			break;
+		case 3:
+			if (value & 0x00800000)
+				value |= 0xff000000;
+			break;
+	}
+	return value;
+}
+
+// Returns the model name of the computer (e.g. "MacBookPro1,1")
+NSString *getModelName(void) {
+	char model[32];
+	size_t len = sizeof(model);
+	int name[2] = {CTL_HW, HW_MODEL};
+	NSString *result;
+	
+	if (sysctl(name, 2, &model, &len, NULL, 0) == 0) {
+		result = [NSString stringWithFormat:@"%s", model];
+	} else {
+		result = @"";
+	}
+	
+	return result;
+}
+
+// Returns the current OS X version and build (e.g. "10.4.7 (build 8J2135a)")
+NSString *getOSVersion(void) {
+	NSDictionary *dict = [NSDictionary dictionaryWithContentsOfFile:
+		@"/System/Library/CoreServices/SystemVersion.plist"];
+	NSString *versionString = [dict objectForKey:@"ProductVersion"];
+	NSString *buildString = [dict objectForKey:@"ProductBuildVersion"];
+	NSString *wholeString = [NSString stringWithFormat:@"%@ (build %@)", 
+		versionString, buildString];
+	return wholeString;
+}
+
+// Returns time within the current second in microseconds.
+// long getMicroseconds() {
+//	struct timeval t;
+//	gettimeofday(&t, 0);
+//	return t.tv_usec;
+//}
+
+// Returns fake data given the time. Range is +/-1.
+float fakeData(NSTimeInterval time) {
+	long secs = lround(floor(time));
+	int secsMod3 = secs % 3;
+	double angle = time * 10 * M_PI * 2;
+	double mag = exp(-(time - (secs - secsMod3)) * 2);
+	return sin(angle) * mag;
+}
+	
diff --git a/hal/fallback/FallbackAlarm.cpp b/hal/fallback/FallbackAlarm.cpp
new file mode 100644
index 000000000..9ec5c48e1
--- /dev/null
+++ b/hal/fallback/FallbackAlarm.cpp
@@ -0,0 +1,79 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Hal.h"
+
+#include <algorithm>
+
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/StaticPtr.h"
+#include "nsComponentManagerUtils.h"
+#include "nsITimer.h"
+#include "nsThreadUtils.h"
+
+namespace mozilla {
+namespace hal_impl {
+
+static void
+TimerCallbackFunc(nsITimer *aTimer, void *aClosure)
+{
+  hal::NotifyAlarmFired();
+}
+
+static StaticRefPtr<nsITimer> sTimer;
+
+bool
+EnableAlarm()
+{
+  static bool initialized = false;
+  if (!initialized) {
+    initialized = true;
+    ClearOnShutdown(&sTimer);
+  }
+
+  nsCOMPtr<nsITimer> timer = do_CreateInstance("@mozilla.org/timer;1");
+  sTimer = timer;
+  MOZ_ASSERT(sTimer);
+  return true;
+}
+
+void
+DisableAlarm()
+{
+  /*
+   * DisableAlarm() may be called after sTimer has been set to null by
+   * ClearOnShutdown().
+   */
+  if (sTimer) {
+    sTimer->Cancel();
+  }
+}
+
+bool
+SetAlarm(int32_t aSeconds, int32_t aNanoseconds)
+{
+  if (!sTimer) {
+    MOZ_ASSERT(false, "We should have enabled the alarm");
+    return false;
+  }
+
+  // Do the math to convert aSeconds and aNanoseconds into milliseconds since
+  // the epoch.
+  int64_t milliseconds = static_cast<int64_t>(aSeconds) * 1000 +
+                         static_cast<int64_t>(aNanoseconds) / 1000000;
+
+  // nsITimer expects relative milliseconds.
+  int64_t relMilliseconds = milliseconds - PR_Now() / 1000;
+
+  // If the alarm time is in the past relative to PR_Now(),
+  // we choose to immediately fire the alarm. Passing 0 means nsITimer will
+  // queue a timeout event immediately.
+  sTimer->InitWithFuncCallback(TimerCallbackFunc, nullptr,
+                               clamped<int64_t>(relMilliseconds, 0, INT32_MAX),
+                               nsITimer::TYPE_ONE_SHOT);
+  return true;
+}
+
+} // namespace hal_impl
+} // namespace mozilla
diff --git a/hal/fallback/FallbackBattery.cpp b/hal/fallback/FallbackBattery.cpp
new file mode 100644
index 000000000..3e5e71574
--- /dev/null
+++ b/hal/fallback/FallbackBattery.cpp
@@ -0,0 +1,30 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et ft=cpp : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Hal.h"
+#include "mozilla/dom/battery/Constants.h"
+
+namespace mozilla {
+namespace hal_impl {
+
+void
+EnableBatteryNotifications()
+{}
+
+void
+DisableBatteryNotifications()
+{}
+
+void
+GetCurrentBatteryInformation(hal::BatteryInformation* aBatteryInfo)
+{
+  aBatteryInfo->level() = dom::battery::kDefaultLevel;
+  aBatteryInfo->charging() = dom::battery::kDefaultCharging;
+  aBatteryInfo->remainingTime() = dom::battery::kDefaultRemainingTime;
+}
+
+} // hal_impl
+} // namespace mozilla
diff --git a/hal/fallback/FallbackDiskSpaceWatcher.cpp b/hal/fallback/FallbackDiskSpaceWatcher.cpp
new file mode 100644
index 000000000..99d144397
--- /dev/null
+++ b/hal/fallback/FallbackDiskSpaceWatcher.cpp
@@ -0,0 +1,19 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+namespace mozilla {
+namespace hal_impl {
+
+void
+StartDiskSpaceWatcher()
+{
+}
+
+void
+StopDiskSpaceWatcher()
+{
+}
+
+} // namespace hal_impl
+} // namespace mozilla
diff --git a/hal/fallback/FallbackFactoryReset.cpp b/hal/fallback/FallbackFactoryReset.cpp
new file mode 100644
index 000000000..76a727702
--- /dev/null
+++ b/hal/fallback/FallbackFactoryReset.cpp
@@ -0,0 +1,18 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: sw=2 ts=8 et :
+ */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Hal.h"
+
+namespace mozilla {
+namespace hal_impl {
+
+void
+FactoryReset(mozilla::dom::FactoryResetReason&)
+{}
+
+} // namespace hal_impl
+} // namespace mozilla
diff --git a/hal/fallback/FallbackMemory.cpp b/hal/fallback/FallbackMemory.cpp
new file mode 100644
index 000000000..2750eebd8
--- /dev/null
+++ b/hal/fallback/FallbackMemory.cpp
@@ -0,0 +1,20 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: sw=2 ts=8 et :
+ */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Hal.h"
+
+namespace mozilla {
+namespace hal_impl {
+
+uint32_t
+GetTotalSystemMemory()
+{
+	return 0;
+}
+
+} // namespace hal_impl
+} // namespace mozilla
diff --git a/hal/fallback/FallbackNetwork.cpp b/hal/fallback/FallbackNetwork.cpp
new file mode 100644
index 000000000..d8995bc6d
--- /dev/null
+++ b/hal/fallback/FallbackNetwork.cpp
@@ -0,0 +1,31 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: sw=2 ts=8 et :
+ */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Hal.h"
+#include "mozilla/dom/network/Constants.h"
+
+namespace mozilla {
+namespace hal_impl {
+
+void
+EnableNetworkNotifications()
+{}
+
+void
+DisableNetworkNotifications()
+{}
+
+void
+GetCurrentNetworkInformation(hal::NetworkInformation* aNetworkInfo)
+{
+  aNetworkInfo->type() = dom::network::kDefaultType;
+  aNetworkInfo->isWifi() = dom::network::kDefaultIsWifi;
+  aNetworkInfo->dhcpGateway() = dom::network::kDefaultDHCPGateway;
+}
+
+} // namespace hal_impl
+} // namespace mozilla
diff --git a/hal/fallback/FallbackPower.cpp b/hal/fallback/FallbackPower.cpp
new file mode 100644
index 000000000..0a53e89ad
--- /dev/null
+++ b/hal/fallback/FallbackPower.cpp
@@ -0,0 +1,25 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et ft=cpp : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Hal.h"
+
+namespace mozilla {
+namespace hal_impl {
+
+void
+Reboot()
+{}
+
+void
+PowerOff()
+{}
+
+void
+StartForceQuitWatchdog(hal::ShutdownMode aMode, int32_t aTimeoutSecs)
+{}
+
+} // namespace hal_impl
+} // namespace mozilla
diff --git a/hal/fallback/FallbackProcessPriority.cpp b/hal/fallback/FallbackProcessPriority.cpp
new file mode 100644
index 000000000..b03b1542e
--- /dev/null
+++ b/hal/fallback/FallbackProcessPriority.cpp
@@ -0,0 +1,21 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Hal.h"
+#include "HalLog.h"
+
+using namespace mozilla::hal;
+
+namespace mozilla {
+namespace hal_impl {
+
+void
+SetProcessPriority(int aPid, ProcessPriority aPriority, uint32_t aLRU)
+{
+  HAL_LOG("FallbackProcessPriority - SetProcessPriority(%d, %s, %u)\n",
+          aPid, ProcessPriorityToString(aPriority), aLRU);
+}
+
+} // namespace hal_impl
+} // namespace mozilla
diff --git a/hal/fallback/FallbackScreenConfiguration.cpp b/hal/fallback/FallbackScreenConfiguration.cpp
new file mode 100644
index 000000000..cbee955fb
--- /dev/null
+++ b/hal/fallback/FallbackScreenConfiguration.cpp
@@ -0,0 +1,63 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Hal.h"
+#include "mozilla/dom/ScreenOrientation.h"
+#include "nsIScreenManager.h"
+#include "nsServiceManagerUtils.h"
+
+namespace mozilla {
+namespace hal_impl {
+
+void
+EnableScreenConfigurationNotifications()
+{
+}
+
+void
+DisableScreenConfigurationNotifications()
+{
+}
+
+void
+GetCurrentScreenConfiguration(hal::ScreenConfiguration* aScreenConfiguration)
+{
+  nsresult rv;
+  nsCOMPtr<nsIScreenManager> screenMgr =
+    do_GetService("@mozilla.org/gfx/screenmanager;1", &rv);
+  if (NS_FAILED(rv)) {
+    NS_ERROR("Can't find nsIScreenManager!");
+    return;
+  }
+
+  nsIntRect rect;
+  int32_t colorDepth, pixelDepth;
+  dom::ScreenOrientationInternal orientation;
+  nsCOMPtr<nsIScreen> screen;
+
+  screenMgr->GetPrimaryScreen(getter_AddRefs(screen));
+  screen->GetRect(&rect.x, &rect.y, &rect.width, &rect.height);
+  screen->GetColorDepth(&colorDepth);
+  screen->GetPixelDepth(&pixelDepth);
+  orientation = rect.width >= rect.height
+                ? dom::eScreenOrientation_LandscapePrimary
+                : dom::eScreenOrientation_PortraitPrimary;
+
+  *aScreenConfiguration =
+      hal::ScreenConfiguration(rect, orientation, 0, colorDepth, pixelDepth);
+}
+
+bool
+LockScreenOrientation(const dom::ScreenOrientationInternal& aOrientation)
+{
+  return false;
+}
+
+void
+UnlockScreenOrientation()
+{
+}
+
+} // namespace hal_impl
+} // namespace mozilla
diff --git a/hal/fallback/FallbackScreenPower.cpp b/hal/fallback/FallbackScreenPower.cpp
new file mode 100644
index 000000000..2a7ad276f
--- /dev/null
+++ b/hal/fallback/FallbackScreenPower.cpp
@@ -0,0 +1,41 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et ft=cpp : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+namespace mozilla {
+namespace hal_impl {
+
+bool
+GetScreenEnabled()
+{
+  return true;
+}
+
+void
+SetScreenEnabled(bool aEnabled)
+{}
+
+bool
+GetKeyLightEnabled()
+{
+  return true;
+}
+
+void
+SetKeyLightEnabled(bool aEnabled)
+{}
+
+double
+GetScreenBrightness()
+{
+  return 1;
+}
+
+void
+SetScreenBrightness(double aBrightness)
+{}
+
+} // namespace hal_impl
+} // namespace mozilla
diff --git a/hal/fallback/FallbackSensor.cpp b/hal/fallback/FallbackSensor.cpp
new file mode 100644
index 000000000..22b1a0436
--- /dev/null
+++ b/hal/fallback/FallbackSensor.cpp
@@ -0,0 +1,23 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* vim: set sw=4 ts=8 et ft=cpp : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/Hal.h"
+
+using namespace mozilla::hal;
+
+namespace mozilla {
+namespace hal_impl {
+
+void
+EnableSensorNotifications(SensorType aSensor) {
+}
+
+void
+DisableSensorNotifications(SensorType aSensor) {
+}
+
+}
+}
diff --git a/hal/fallback/FallbackSwitch.cpp b/hal/fallback/FallbackSwitch.cpp
new file mode 100644
index 000000000..e9b7eab0a
--- /dev/null
+++ b/hal/fallback/FallbackSwitch.cpp
@@ -0,0 +1,39 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/Hal.h"
+
+using namespace mozilla::hal;
+
+namespace mozilla {
+namespace hal_impl {
+
+void
+EnableSwitchNotifications(SwitchDevice aDevice)
+{
+}
+
+void
+DisableSwitchNotifications(SwitchDevice aDevice)
+{
+}
+
+SwitchState
+GetCurrentSwitchState(SwitchDevice aDevice) {
+  return SWITCH_STATE_UNKNOWN;
+}
+
+void
+NotifySwitchStateFromInputDevice(SwitchDevice aDevice, SwitchState aState)
+{
+}
+
+bool IsHeadphoneEventFromInputDev()
+{
+  return false;
+}
+
+} // namespace hal_impl
+} // namespace mozilla
diff --git a/hal/fallback/FallbackSystemService.cpp b/hal/fallback/FallbackSystemService.cpp
new file mode 100644
index 000000000..93365c47c
--- /dev/null
+++ b/hal/fallback/FallbackSystemService.cpp
@@ -0,0 +1,35 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et ft=cpp : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Hal.h"
+
+namespace mozilla {
+namespace hal_impl {
+
+nsresult
+StartSystemService(const char* aSvcName, const char* aArgs)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+void
+StopSystemService(const char* aSvcName)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+}
+
+bool
+SystemServiceIsRunning(const char* aSvcName)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  return false;
+}
+
+} // namespace hal_impl
+} // namespace mozilla
diff --git a/hal/fallback/FallbackThreadPriority.cpp b/hal/fallback/FallbackThreadPriority.cpp
new file mode 100644
index 000000000..dce5dfa82
--- /dev/null
+++ b/hal/fallback/FallbackThreadPriority.cpp
@@ -0,0 +1,29 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Hal.h"
+#include "HalLog.h"
+
+using namespace mozilla::hal;
+
+namespace mozilla {
+namespace hal_impl {
+
+void
+SetCurrentThreadPriority(ThreadPriority aPriority)
+{
+  HAL_LOG("FallbackThreadPriority - SetCurrentThreadPriority(%d)\n",
+          ThreadPriorityToString(aPriority));
+}
+
+void
+SetThreadPriority(PlatformThreadId aThreadId,
+                  ThreadPriority aPriority)
+{
+  HAL_LOG("FallbackThreadPriority - SetThreadPriority(%d, %d)\n",
+          aThreadId, ThreadPriorityToString(aPriority));
+}
+
+} // namespace hal_impl
+} // namespace mozilla
diff --git a/hal/fallback/FallbackTime.cpp b/hal/fallback/FallbackTime.cpp
new file mode 100644
index 000000000..a2c56e817
--- /dev/null
+++ b/hal/fallback/FallbackTime.cpp
@@ -0,0 +1,54 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: sw=2 ts=8 et :
+ */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Hal.h"
+
+namespace mozilla {
+namespace hal_impl {
+
+void 
+AdjustSystemClock(int64_t aDeltaMilliseconds)
+{}
+
+void
+SetTimezone(const nsCString& aTimezoneSpec)
+{}
+
+nsCString
+GetTimezone()
+{
+  return EmptyCString();
+}
+
+int32_t
+GetTimezoneOffset()
+{
+  return 0;
+}
+
+void
+EnableSystemClockChangeNotifications()
+{
+}
+
+void
+DisableSystemClockChangeNotifications()
+{
+}
+
+void
+EnableSystemTimezoneChangeNotifications()
+{
+}
+
+void
+DisableSystemTimezoneChangeNotifications()
+{
+}
+
+} // namespace hal_impl
+} // namespace mozilla
diff --git a/hal/fallback/FallbackVibration.cpp b/hal/fallback/FallbackVibration.cpp
new file mode 100644
index 000000000..ffabe9efe
--- /dev/null
+++ b/hal/fallback/FallbackVibration.cpp
@@ -0,0 +1,23 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et ft=cpp : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Hal.h"
+
+using mozilla::hal::WindowIdentifier;
+
+namespace mozilla {
+namespace hal_impl {
+
+void
+Vibrate(const nsTArray<uint32_t>& pattern, const hal::WindowIdentifier &)
+{}
+
+void
+CancelVibrate(const hal::WindowIdentifier &)
+{}
+
+} // namespace hal_impl
+} // namespace mozilla
diff --git a/hal/fallback/FallbackWakeLocks.cpp b/hal/fallback/FallbackWakeLocks.cpp
new file mode 100644
index 000000000..1fd97a2e6
--- /dev/null
+++ b/hal/fallback/FallbackWakeLocks.cpp
@@ -0,0 +1,23 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et ft=cpp : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Hal.h"
+
+namespace mozilla {
+namespace hal_impl {
+
+bool
+GetCpuSleepAllowed()
+{
+  return true;
+}
+
+void
+SetCpuSleepAllowed(bool allowed)
+{}
+
+} // namespace hal_impl
+} // namespace mozilla
diff --git a/hal/gonk/GonkDiskSpaceWatcher.cpp b/hal/gonk/GonkDiskSpaceWatcher.cpp
new file mode 100644
index 000000000..cdc48ef89
--- /dev/null
+++ b/hal/gonk/GonkDiskSpaceWatcher.cpp
@@ -0,0 +1,324 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Hal.h"
+#include <sys/syscall.h>
+#include <sys/vfs.h>
+#include <fcntl.h>
+#include <errno.h>
+#include "base/message_loop.h"
+#include "base/task.h"
+#include "DiskSpaceWatcher.h"
+#include "fanotify.h"
+#include "nsIObserverService.h"
+#include "nsIDiskSpaceWatcher.h"
+#include "nsThreadUtils.h"
+#include "nsXULAppAPI.h"
+#include "mozilla/ModuleUtils.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/Services.h"
+
+using namespace mozilla;
+
+namespace mozilla { namespace hal_impl { class GonkDiskSpaceWatcher; } }
+
+using namespace mozilla::hal_impl;
+
+namespace mozilla {
+namespace hal_impl {
+
+// NOTE: this should be unnecessary once we no longer support ICS.
+#ifndef __NR_fanotify_init
+#if defined(__ARM_EABI__)
+#define __NR_fanotify_init 367
+#define __NR_fanotify_mark 368
+#elif defined(__i386__)
+#define __NR_fanotify_init 338
+#define __NR_fanotify_mark 339
+#else
+#error "Unhandled architecture"
+#endif
+#endif
+
+// fanotify_init and fanotify_mark functions are syscalls.
+// The user space bits are not part of bionic so we add them here
+// as well as fanotify.h
+int fanotify_init (unsigned int flags, unsigned int event_f_flags)
+{
+  return syscall(__NR_fanotify_init, flags, event_f_flags);
+}
+
+// Add, remove, or modify an fanotify mark on a filesystem object.
+int fanotify_mark (int fanotify_fd, unsigned int flags,
+                   uint64_t mask, int dfd, const char *pathname)
+{
+
+  // On 32 bits platforms we have to convert the 64 bits mask into
+  // two 32 bits ints.
+  if (sizeof(void *) == 4) {
+    union {
+      uint64_t _64;
+      uint32_t _32[2];
+    } _mask;
+    _mask._64 = mask;
+    return syscall(__NR_fanotify_mark, fanotify_fd, flags,
+		   _mask._32[0], _mask._32[1], dfd, pathname);
+  }
+
+  return syscall(__NR_fanotify_mark, fanotify_fd, flags, mask, dfd, pathname);
+}
+
+class GonkDiskSpaceWatcher final : public MessageLoopForIO::Watcher
+{
+public:
+  GonkDiskSpaceWatcher();
+  ~GonkDiskSpaceWatcher() {};
+
+  virtual void OnFileCanReadWithoutBlocking(int aFd);
+
+  // We should never write to the fanotify fd.
+  virtual void OnFileCanWriteWithoutBlocking(int aFd)
+  {
+    MOZ_CRASH("Must not write to fanotify fd");
+  }
+
+  void DoStart();
+  void DoStop();
+
+private:
+  void NotifyUpdate();
+
+  uint64_t mLowThreshold;
+  uint64_t mHighThreshold;
+  TimeDuration mTimeout;
+  TimeStamp  mLastTimestamp;
+  uint64_t mLastFreeSpace;
+  uint32_t mSizeDelta;
+
+  bool mIsDiskFull;
+  uint64_t mFreeSpace;
+
+  int mFd;
+  MessageLoopForIO::FileDescriptorWatcher mReadWatcher;
+};
+
+static GonkDiskSpaceWatcher* gHalDiskSpaceWatcher = nullptr;
+
+#define WATCHER_PREF_LOW        "disk_space_watcher.low_threshold"
+#define WATCHER_PREF_HIGH       "disk_space_watcher.high_threshold"
+#define WATCHER_PREF_TIMEOUT    "disk_space_watcher.timeout"
+#define WATCHER_PREF_SIZE_DELTA "disk_space_watcher.size_delta"
+
+static const char kWatchedPath[] = "/data";
+
+// Helper class to dispatch calls to xpcom on the main thread.
+class DiskSpaceNotifier : public Runnable
+{
+public:
+  DiskSpaceNotifier(const bool aIsDiskFull, const uint64_t aFreeSpace) :
+    mIsDiskFull(aIsDiskFull),
+    mFreeSpace(aFreeSpace) {}
+
+  NS_IMETHOD Run() override
+  {
+    MOZ_ASSERT(NS_IsMainThread());
+    DiskSpaceWatcher::UpdateState(mIsDiskFull, mFreeSpace);
+    return NS_OK;
+  }
+
+private:
+  bool mIsDiskFull;
+  uint64_t mFreeSpace;
+};
+
+// Helper runnable to delete the watcher on the main thread.
+class DiskSpaceCleaner : public Runnable
+{
+public:
+  NS_IMETHOD Run() override
+  {
+    MOZ_ASSERT(NS_IsMainThread());
+    if (gHalDiskSpaceWatcher) {
+      delete gHalDiskSpaceWatcher;
+      gHalDiskSpaceWatcher = nullptr;
+    }
+    return NS_OK;
+  }
+};
+
+GonkDiskSpaceWatcher::GonkDiskSpaceWatcher() :
+  mLastFreeSpace(UINT64_MAX),
+  mIsDiskFull(false),
+  mFreeSpace(UINT64_MAX),
+  mFd(-1)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(gHalDiskSpaceWatcher == nullptr);
+
+  // Default values: 5MB for low threshold, 10MB for high threshold, and
+  // a timeout of 5 seconds.
+  mLowThreshold = Preferences::GetInt(WATCHER_PREF_LOW, 5) * 1024 * 1024;
+  mHighThreshold = Preferences::GetInt(WATCHER_PREF_HIGH, 10) * 1024 * 1024;
+  mTimeout = TimeDuration::FromSeconds(Preferences::GetInt(WATCHER_PREF_TIMEOUT, 5));
+  mSizeDelta = Preferences::GetInt(WATCHER_PREF_SIZE_DELTA, 1) * 1024 * 1024;
+}
+
+void
+GonkDiskSpaceWatcher::DoStart()
+{
+  NS_ASSERTION(XRE_GetIOMessageLoop() == MessageLoopForIO::current(),
+               "Not on the correct message loop");
+
+  mFd = fanotify_init(FAN_CLASS_NOTIF, FAN_CLOEXEC | O_LARGEFILE);
+  if (mFd == -1) {
+    if (errno == ENOSYS) {
+      // Don't change these printf_stderr since we need these logs even
+      // in opt builds.
+      printf_stderr("Warning: No fanotify support in this device's kernel.\n");
+#if ANDROID_VERSION >= 19
+      MOZ_CRASH("Fanotify support must be enabled in the kernel.");
+#endif
+    } else {
+      printf_stderr("Error calling fanotify_init()");
+    }
+    return;
+  }
+
+  if (fanotify_mark(mFd, FAN_MARK_ADD | FAN_MARK_MOUNT, FAN_CLOSE,
+                    0, kWatchedPath) < 0) {
+    NS_WARNING("Error calling fanotify_mark");
+    close(mFd);
+    mFd = -1;
+    return;
+  }
+
+  if (!MessageLoopForIO::current()->WatchFileDescriptor(
+    mFd, /* persistent = */ true,
+    MessageLoopForIO::WATCH_READ,
+    &mReadWatcher, gHalDiskSpaceWatcher)) {
+      NS_WARNING("Unable to watch fanotify fd.");
+      close(mFd);
+      mFd = -1;
+  }
+}
+
+void
+GonkDiskSpaceWatcher::DoStop()
+{
+  NS_ASSERTION(XRE_GetIOMessageLoop() == MessageLoopForIO::current(),
+               "Not on the correct message loop");
+
+  if (mFd != -1) {
+    mReadWatcher.StopWatchingFileDescriptor();
+    fanotify_mark(mFd, FAN_MARK_FLUSH, 0, 0, kWatchedPath);
+    close(mFd);
+    mFd = -1;
+  }
+
+  // Dispatch the cleanup to the main thread.
+  nsCOMPtr<nsIRunnable> runnable = new DiskSpaceCleaner();
+  NS_DispatchToMainThread(runnable);
+}
+
+// We are called off the main thread, so we proxy first to the main thread
+// before calling the xpcom object.
+void
+GonkDiskSpaceWatcher::NotifyUpdate()
+{
+  mLastTimestamp = TimeStamp::Now();
+  mLastFreeSpace = mFreeSpace;
+
+  nsCOMPtr<nsIRunnable> runnable =
+    new DiskSpaceNotifier(mIsDiskFull, mFreeSpace);
+  NS_DispatchToMainThread(runnable);
+}
+
+void
+GonkDiskSpaceWatcher::OnFileCanReadWithoutBlocking(int aFd)
+{
+  struct fanotify_event_metadata* fem = nullptr;
+  char buf[4096];
+  struct statfs sfs;
+  int32_t len, rc;
+
+  do {
+    len = read(aFd, buf, sizeof(buf));
+  } while(len == -1 && errno == EINTR);
+
+  // Bail out if the file is busy.
+  if (len < 0 && errno == ETXTBSY) {
+    return;
+  }
+
+  // We should get an exact multiple of fanotify_event_metadata
+  if (len <= 0 || (len % FAN_EVENT_METADATA_LEN != 0)) {
+    MOZ_CRASH("About to crash: fanotify_event_metadata read error.");
+  }
+
+  fem = reinterpret_cast<fanotify_event_metadata *>(buf);
+
+  while (FAN_EVENT_OK(fem, len)) {
+    rc = fstatfs(fem->fd, &sfs);
+    if (rc < 0) {
+      NS_WARNING("Unable to stat fan_notify fd");
+    } else {
+      bool firstRun = mFreeSpace == UINT64_MAX;
+      mFreeSpace = sfs.f_bavail * sfs.f_bsize;
+      // We change from full <-> free depending on the free space and the
+      // low and high thresholds.
+      // Once we are in 'full' mode we send updates for all size changes with
+      // a minimum of time between messages or when we cross a size change
+      // threshold.
+      if (firstRun) {
+        mIsDiskFull = mFreeSpace <= mLowThreshold;
+        // Always notify the current state at first run.
+        NotifyUpdate();
+      } else if (!mIsDiskFull && (mFreeSpace <= mLowThreshold)) {
+        mIsDiskFull = true;
+        NotifyUpdate();
+      } else if (mIsDiskFull && (mFreeSpace > mHighThreshold)) {
+        mIsDiskFull = false;
+        NotifyUpdate();
+      } else if (mIsDiskFull) {
+        if (mTimeout < TimeStamp::Now() - mLastTimestamp ||
+            mSizeDelta < llabs(mFreeSpace - mLastFreeSpace)) {
+          NotifyUpdate();
+        }
+      }
+    }
+    close(fem->fd);
+    fem = FAN_EVENT_NEXT(fem, len);
+  }
+}
+
+void
+StartDiskSpaceWatcher()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  // Bail out if called several times.
+  if (gHalDiskSpaceWatcher != nullptr) {
+    return;
+  }
+
+  gHalDiskSpaceWatcher = new GonkDiskSpaceWatcher();
+
+  XRE_GetIOMessageLoop()->PostTask(
+    NewNonOwningRunnableMethod(gHalDiskSpaceWatcher, &GonkDiskSpaceWatcher::DoStart));
+}
+
+void
+StopDiskSpaceWatcher()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  if (!gHalDiskSpaceWatcher) {
+    return;
+  }
+
+  XRE_GetIOMessageLoop()->PostTask(
+    NewNonOwningRunnableMethod(gHalDiskSpaceWatcher, &GonkDiskSpaceWatcher::DoStop));
+}
+
+} // namespace hal_impl
+} // namespace mozilla
diff --git a/hal/gonk/GonkHal.cpp b/hal/gonk/GonkHal.cpp
new file mode 100644
index 000000000..05d9295a2
--- /dev/null
+++ b/hal/gonk/GonkHal.cpp
@@ -0,0 +1,2045 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et ft=cpp : */
+/* Copyright 2012 Mozilla Foundation and Mozilla contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/android_alarm.h>
+#include <math.h>
+#include <regex.h>
+#include <sched.h>
+#include <stdio.h>
+#include <sys/klog.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+#include <sys/resource.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "mozilla/DebugOnly.h"
+
+#include "android/log.h"
+#include "cutils/properties.h"
+#include "hardware/hardware.h"
+#include "hardware/lights.h"
+#include "hardware_legacy/uevent.h"
+#include "hardware_legacy/vibrator.h"
+#include "hardware_legacy/power.h"
+#include "libdisplay/GonkDisplay.h"
+#include "utils/threads.h"
+
+#include "base/message_loop.h"
+#include "base/task.h"
+
+#include "Hal.h"
+#include "HalImpl.h"
+#include "HalLog.h"
+#include "mozilla/ArrayUtils.h"
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/dom/battery/Constants.h"
+#include "mozilla/DebugOnly.h"
+#include "mozilla/FileUtils.h"
+#include "mozilla/Monitor.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/Services.h"
+#include "mozilla/StaticMutex.h"
+#include "mozilla/StaticPtr.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/UniquePtrExtensions.h"
+#include "nsAlgorithm.h"
+#include "nsPrintfCString.h"
+#include "nsIObserver.h"
+#include "nsIObserverService.h"
+#include "nsIRecoveryService.h"
+#include "nsIRunnable.h"
+#include "nsScreenManagerGonk.h"
+#include "nsThreadUtils.h"
+#include "nsThreadUtils.h"
+#include "nsIThread.h"
+#include "nsXULAppAPI.h"
+#include "OrientationObserver.h"
+#include "UeventPoller.h"
+#include "nsIWritablePropertyBag2.h"
+#include <algorithm>
+
+#define NsecPerMsec  1000000LL
+#define NsecPerSec   1000000000
+
+// The header linux/oom.h is not available in bionic libc. We
+// redefine some of its constants here.
+
+#ifndef OOM_DISABLE
+#define OOM_DISABLE  (-17)
+#endif
+
+#ifndef OOM_ADJUST_MIN
+#define OOM_ADJUST_MIN  (-16)
+#endif
+
+#ifndef OOM_ADJUST_MAX
+#define OOM_ADJUST_MAX  15
+#endif
+
+#ifndef OOM_SCORE_ADJ_MIN
+#define OOM_SCORE_ADJ_MIN  (-1000)
+#endif
+
+#ifndef OOM_SCORE_ADJ_MAX
+#define OOM_SCORE_ADJ_MAX  1000
+#endif
+
+#ifndef BATTERY_CHARGING_ARGB
+#define BATTERY_CHARGING_ARGB 0x00FF0000
+#endif
+#ifndef BATTERY_FULL_ARGB
+#define BATTERY_FULL_ARGB 0x0000FF00
+#endif
+
+using namespace mozilla;
+using namespace mozilla::hal;
+using namespace mozilla::dom;
+
+namespace mozilla {
+namespace hal_impl {
+
+/**
+ * These are defined by libhardware, specifically, hardware/libhardware/include/hardware/lights.h
+ * in the gonk subsystem.
+ * If these change and are exposed to JS, make sure nsIHal.idl is updated as well.
+ */
+enum LightType {
+  eHalLightID_Backlight     = 0,
+  eHalLightID_Keyboard      = 1,
+  eHalLightID_Buttons       = 2,
+  eHalLightID_Battery       = 3,
+  eHalLightID_Notifications = 4,
+  eHalLightID_Attention     = 5,
+  eHalLightID_Bluetooth     = 6,
+  eHalLightID_Wifi          = 7,
+  eHalLightID_Count  // This should stay at the end
+};
+enum LightMode {
+  eHalLightMode_User   = 0,  // brightness is managed by user setting
+  eHalLightMode_Sensor = 1,  // brightness is managed by a light sensor
+  eHalLightMode_Count
+};
+enum FlashMode {
+  eHalLightFlash_None     = 0,
+  eHalLightFlash_Timed    = 1,  // timed flashing.  Use flashOnMS and flashOffMS for timing
+  eHalLightFlash_Hardware = 2,  // hardware assisted flashing
+  eHalLightFlash_Count
+};
+
+struct LightConfiguration {
+  LightType light;
+  LightMode mode;
+  FlashMode flash;
+  uint32_t flashOnMS;
+  uint32_t flashOffMS;
+  uint32_t color;
+};
+
+static light_device_t* sLights[eHalLightID_Count]; // will be initialized to nullptr
+
+static light_device_t*
+GetDevice(hw_module_t* module, char const* name)
+{
+  int err;
+  hw_device_t* device;
+  err = module->methods->open(module, name, &device);
+  if (err == 0) {
+    return (light_device_t*)device;
+  } else {
+    return nullptr;
+  }
+}
+
+static void
+InitLights()
+{
+  // assume that if backlight is nullptr, nothing has been set yet
+  // if this is not true, the initialization will occur everytime a light is read or set!
+  if (!sLights[eHalLightID_Backlight]) {
+    int err;
+    hw_module_t* module;
+
+    err = hw_get_module(LIGHTS_HARDWARE_MODULE_ID, (hw_module_t const**)&module);
+    if (err == 0) {
+      sLights[eHalLightID_Backlight]
+             = GetDevice(module, LIGHT_ID_BACKLIGHT);
+      sLights[eHalLightID_Keyboard]
+             = GetDevice(module, LIGHT_ID_KEYBOARD);
+      sLights[eHalLightID_Buttons]
+             = GetDevice(module, LIGHT_ID_BUTTONS);
+      sLights[eHalLightID_Battery]
+             = GetDevice(module, LIGHT_ID_BATTERY);
+      sLights[eHalLightID_Notifications]
+             = GetDevice(module, LIGHT_ID_NOTIFICATIONS);
+      sLights[eHalLightID_Attention]
+             = GetDevice(module, LIGHT_ID_ATTENTION);
+      sLights[eHalLightID_Bluetooth]
+             = GetDevice(module, LIGHT_ID_BLUETOOTH);
+      sLights[eHalLightID_Wifi]
+             = GetDevice(module, LIGHT_ID_WIFI);
+        }
+    }
+}
+
+/**
+ * The state last set for the lights until liblights supports
+ * getting the light state.
+ */
+static light_state_t sStoredLightState[eHalLightID_Count];
+
+/**
+* Set the value of a light to a particular color, with a specific flash pattern.
+* light specifices which light.  See Hal.idl for the list of constants
+* mode specifies user set or based on ambient light sensor
+* flash specifies whether or how to flash the light
+* flashOnMS and flashOffMS specify the pattern for XXX flash mode
+* color specifies the color.  If the light doesn't support color, the given color is
+* transformed into a brightness, or just an on/off if that is all the light is capable of.
+* returns true if successful and false if failed.
+*/
+static bool
+SetLight(LightType light, const LightConfiguration& aConfig)
+{
+  light_state_t state;
+
+  InitLights();
+
+  if (light < 0 || light >= eHalLightID_Count ||
+      sLights[light] == nullptr) {
+    return false;
+  }
+
+  memset(&state, 0, sizeof(light_state_t));
+  state.color = aConfig.color;
+  state.flashMode = aConfig.flash;
+  state.flashOnMS = aConfig.flashOnMS;
+  state.flashOffMS = aConfig.flashOffMS;
+  state.brightnessMode = aConfig.mode;
+
+  sLights[light]->set_light(sLights[light], &state);
+  sStoredLightState[light] = state;
+  return true;
+}
+
+/**
+* GET the value of a light returning a particular color, with a specific flash pattern.
+* returns true if successful and false if failed.
+*/
+static bool
+GetLight(LightType light, LightConfiguration* aConfig)
+{
+  light_state_t state;
+
+  if (light < 0 || light >= eHalLightID_Count ||
+      sLights[light] == nullptr) {
+    return false;
+  }
+
+  memset(&state, 0, sizeof(light_state_t));
+  state = sStoredLightState[light];
+
+  aConfig->light = light;
+  aConfig->color = state.color;
+  aConfig->flash = FlashMode(state.flashMode);
+  aConfig->flashOnMS = state.flashOnMS;
+  aConfig->flashOffMS = state.flashOffMS;
+  aConfig->mode = LightMode(state.brightnessMode);
+
+  return true;
+}
+
+namespace {
+
+/**
+ * This runnable runs for the lifetime of the program, once started.  It's
+ * responsible for "playing" vibration patterns.
+ */
+class VibratorRunnable final
+  : public nsIRunnable
+  , public nsIObserver
+{
+public:
+  VibratorRunnable()
+    : mMonitor("VibratorRunnable")
+    , mIndex(0)
+  {
+    nsCOMPtr<nsIObserverService> os = services::GetObserverService();
+    if (!os) {
+      NS_WARNING("Could not get observer service!");
+      return;
+    }
+
+    os->AddObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID, false);
+  }
+
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIRUNNABLE
+  NS_DECL_NSIOBSERVER
+
+  // Run on the main thread, not the vibrator thread.
+  void Vibrate(const nsTArray<uint32_t> &pattern);
+  void CancelVibrate();
+
+  static bool ShuttingDown() { return sShuttingDown; }
+
+protected:
+  ~VibratorRunnable() {}
+
+private:
+  Monitor mMonitor;
+
+  // The currently-playing pattern.
+  nsTArray<uint32_t> mPattern;
+
+  // The index we're at in the currently-playing pattern.  If mIndex >=
+  // mPattern.Length(), then we're not currently playing anything.
+  uint32_t mIndex;
+
+  // Set to true in our shutdown observer.  When this is true, we kill the
+  // vibrator thread.
+  static bool sShuttingDown;
+};
+
+NS_IMPL_ISUPPORTS(VibratorRunnable, nsIRunnable, nsIObserver);
+
+bool VibratorRunnable::sShuttingDown = false;
+
+static StaticRefPtr<VibratorRunnable> sVibratorRunnable;
+
+NS_IMETHODIMP
+VibratorRunnable::Run()
+{
+  MonitorAutoLock lock(mMonitor);
+
+  // We currently assume that mMonitor.Wait(X) waits for X milliseconds.  But in
+  // reality, the kernel might not switch to this thread for some time after the
+  // wait expires.  So there's potential for some inaccuracy here.
+  //
+  // This doesn't worry me too much.  Note that we don't even start vibrating
+  // immediately when VibratorRunnable::Vibrate is called -- we go through a
+  // condvar onto another thread.  Better just to be chill about small errors in
+  // the timing here.
+
+  while (!sShuttingDown) {
+    if (mIndex < mPattern.Length()) {
+      uint32_t duration = mPattern[mIndex];
+      if (mIndex % 2 == 0) {
+        vibrator_on(duration);
+      }
+      mIndex++;
+      mMonitor.Wait(PR_MillisecondsToInterval(duration));
+    }
+    else {
+      mMonitor.Wait();
+    }
+  }
+  sVibratorRunnable = nullptr;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+VibratorRunnable::Observe(nsISupports *subject, const char *topic,
+                          const char16_t *data)
+{
+  MOZ_ASSERT(strcmp(topic, NS_XPCOM_SHUTDOWN_OBSERVER_ID) == 0);
+  MonitorAutoLock lock(mMonitor);
+  sShuttingDown = true;
+  mMonitor.Notify();
+
+  return NS_OK;
+}
+
+void
+VibratorRunnable::Vibrate(const nsTArray<uint32_t> &pattern)
+{
+  MonitorAutoLock lock(mMonitor);
+  mPattern = pattern;
+  mIndex = 0;
+  mMonitor.Notify();
+}
+
+void
+VibratorRunnable::CancelVibrate()
+{
+  MonitorAutoLock lock(mMonitor);
+  mPattern.Clear();
+  mPattern.AppendElement(0);
+  mIndex = 0;
+  mMonitor.Notify();
+}
+
+void
+EnsureVibratorThreadInitialized()
+{
+  if (sVibratorRunnable) {
+    return;
+  }
+
+  sVibratorRunnable = new VibratorRunnable();
+  nsCOMPtr<nsIThread> thread;
+  NS_NewThread(getter_AddRefs(thread), sVibratorRunnable);
+}
+
+} // namespace
+
+void
+Vibrate(const nsTArray<uint32_t> &pattern, const hal::WindowIdentifier &)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  if (VibratorRunnable::ShuttingDown()) {
+    return;
+  }
+  EnsureVibratorThreadInitialized();
+  sVibratorRunnable->Vibrate(pattern);
+}
+
+void
+CancelVibrate(const hal::WindowIdentifier &)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  if (VibratorRunnable::ShuttingDown()) {
+    return;
+  }
+  EnsureVibratorThreadInitialized();
+  sVibratorRunnable->CancelVibrate();
+}
+
+namespace {
+
+class BatteryUpdater : public Runnable {
+public:
+  NS_IMETHOD Run() override
+  {
+    hal::BatteryInformation info;
+    hal_impl::GetCurrentBatteryInformation(&info);
+
+    // Control the battery indicator (led light) here using BatteryInformation
+    // we just retrieved.
+    uint32_t color = 0; // Format: 0x00rrggbb.
+    if (info.charging() && (info.level() == 1)) {
+      // Charging and battery full.
+      color = BATTERY_FULL_ARGB;
+    } else if (info.charging() && (info.level() < 1)) {
+      // Charging but not full.
+      color = BATTERY_CHARGING_ARGB;
+    } // else turn off battery indicator.
+
+    LightConfiguration aConfig;
+    aConfig.light = eHalLightID_Battery;
+    aConfig.mode = eHalLightMode_User;
+    aConfig.flash = eHalLightFlash_None;
+    aConfig.flashOnMS = aConfig.flashOffMS = 0;
+    aConfig.color = color;
+
+    SetLight(eHalLightID_Battery, aConfig);
+
+    hal::NotifyBatteryChange(info);
+
+    {
+      // bug 975667
+      // Gecko gonk hal is required to emit battery charging/level notification via nsIObserverService.
+      // This is useful for XPCOM components that are not statically linked to Gecko and cannot call
+      // hal::EnableBatteryNotifications
+      nsCOMPtr<nsIObserverService> obsService = mozilla::services::GetObserverService();
+      nsCOMPtr<nsIWritablePropertyBag2> propbag =
+        do_CreateInstance("@mozilla.org/hash-property-bag;1");
+      if (obsService && propbag) {
+        propbag->SetPropertyAsBool(NS_LITERAL_STRING("charging"),
+                                   info.charging());
+        propbag->SetPropertyAsDouble(NS_LITERAL_STRING("level"),
+                                   info.level());
+
+        obsService->NotifyObservers(propbag, "gonkhal-battery-notifier", nullptr);
+      }
+    }
+
+    return NS_OK;
+  }
+};
+
+} // namespace
+
+class BatteryObserver final : public IUeventObserver
+{
+public:
+  NS_INLINE_DECL_REFCOUNTING(BatteryObserver)
+
+  BatteryObserver()
+    :mUpdater(new BatteryUpdater())
+  {
+  }
+
+  virtual void Notify(const NetlinkEvent &aEvent)
+  {
+    // this will run on IO thread
+    NetlinkEvent *event = const_cast<NetlinkEvent*>(&aEvent);
+    const char *subsystem = event->getSubsystem();
+    // e.g. DEVPATH=/devices/platform/sec-battery/power_supply/battery
+    const char *devpath = event->findParam("DEVPATH");
+    if (strcmp(subsystem, "power_supply") == 0 &&
+        strstr(devpath, "battery")) {
+      // aEvent will be valid only in this method.
+      NS_DispatchToMainThread(mUpdater);
+    }
+  }
+
+protected:
+  ~BatteryObserver() {}
+
+private:
+  RefPtr<BatteryUpdater> mUpdater;
+};
+
+// sBatteryObserver is owned by the IO thread. Only the IO thread may
+// create or destroy it.
+static StaticRefPtr<BatteryObserver> sBatteryObserver;
+
+static void
+RegisterBatteryObserverIOThread()
+{
+  MOZ_ASSERT(MessageLoop::current() == XRE_GetIOMessageLoop());
+  MOZ_ASSERT(!sBatteryObserver);
+
+  sBatteryObserver = new BatteryObserver();
+  RegisterUeventListener(sBatteryObserver);
+}
+
+void
+EnableBatteryNotifications()
+{
+  XRE_GetIOMessageLoop()->PostTask(
+      NewRunnableFunction(RegisterBatteryObserverIOThread));
+}
+
+static void
+UnregisterBatteryObserverIOThread()
+{
+  MOZ_ASSERT(MessageLoop::current() == XRE_GetIOMessageLoop());
+  MOZ_ASSERT(sBatteryObserver);
+
+  UnregisterUeventListener(sBatteryObserver);
+  sBatteryObserver = nullptr;
+}
+
+void
+DisableBatteryNotifications()
+{
+  XRE_GetIOMessageLoop()->PostTask(
+      NewRunnableFunction(UnregisterBatteryObserverIOThread));
+}
+
+static bool
+GetCurrentBatteryCharge(int* aCharge)
+{
+  bool success = ReadSysFile("/sys/class/power_supply/battery/capacity",
+                             aCharge);
+  if (!success) {
+    return false;
+  }
+
+  #ifdef DEBUG
+  if ((*aCharge < 0) || (*aCharge > 100)) {
+    HAL_LOG("charge level contains unknown value: %d", *aCharge);
+  }
+  #endif
+
+  return (*aCharge >= 0) && (*aCharge <= 100);
+}
+
+static bool
+GetCurrentBatteryCharging(int* aCharging)
+{
+  static const DebugOnly<int> BATTERY_NOT_CHARGING = 0;
+  static const int BATTERY_CHARGING_USB = 1;
+  static const int BATTERY_CHARGING_AC  = 2;
+
+  // Generic device support
+
+  int chargingSrc;
+  bool success =
+    ReadSysFile("/sys/class/power_supply/battery/charging_source", &chargingSrc);
+
+  if (success) {
+    #ifdef DEBUG
+    if (chargingSrc != BATTERY_NOT_CHARGING &&
+        chargingSrc != BATTERY_CHARGING_USB &&
+        chargingSrc != BATTERY_CHARGING_AC) {
+      HAL_LOG("charging_source contained unknown value: %d", chargingSrc);
+    }
+    #endif
+
+    *aCharging = (chargingSrc == BATTERY_CHARGING_USB ||
+                  chargingSrc == BATTERY_CHARGING_AC);
+    return true;
+  }
+
+  // Otoro device support
+
+  char chargingSrcString[16];
+
+  success = ReadSysFile("/sys/class/power_supply/battery/status",
+                        chargingSrcString, sizeof(chargingSrcString));
+  if (success) {
+    *aCharging = strcmp(chargingSrcString, "Charging") == 0 ||
+                 strcmp(chargingSrcString, "Full") == 0;
+    return true;
+  }
+
+  return false;
+}
+
+void
+GetCurrentBatteryInformation(hal::BatteryInformation* aBatteryInfo)
+{
+  int charge;
+  static bool previousCharging = false;
+  static double previousLevel = 0.0, remainingTime = 0.0;
+  static struct timespec lastLevelChange;
+  struct timespec now;
+  double dtime, dlevel;
+
+  if (GetCurrentBatteryCharge(&charge)) {
+    aBatteryInfo->level() = (double)charge / 100.0;
+  } else {
+    aBatteryInfo->level() = dom::battery::kDefaultLevel;
+  }
+
+  int charging;
+
+  if (GetCurrentBatteryCharging(&charging)) {
+    aBatteryInfo->charging() = charging;
+  } else {
+    aBatteryInfo->charging() = true;
+  }
+
+  if (aBatteryInfo->charging() != previousCharging){
+    aBatteryInfo->remainingTime() = dom::battery::kUnknownRemainingTime;
+    memset(&lastLevelChange, 0, sizeof(struct timespec));
+    remainingTime = 0.0;
+  }
+
+  if (aBatteryInfo->charging()) {
+    if (aBatteryInfo->level() == 1.0) {
+      aBatteryInfo->remainingTime() = dom::battery::kDefaultRemainingTime;
+    } else if (aBatteryInfo->level() != previousLevel){
+      if (lastLevelChange.tv_sec != 0) {
+        clock_gettime(CLOCK_MONOTONIC, &now);
+        dtime = now.tv_sec - lastLevelChange.tv_sec;
+        dlevel = aBatteryInfo->level() - previousLevel;
+
+        if (dlevel <= 0.0) {
+          aBatteryInfo->remainingTime() = dom::battery::kUnknownRemainingTime;
+        } else {
+          remainingTime = (double) round(dtime / dlevel * (1.0 - aBatteryInfo->level()));
+          aBatteryInfo->remainingTime() = remainingTime;
+        }
+
+        lastLevelChange = now;
+      } else { // lastLevelChange.tv_sec == 0
+        clock_gettime(CLOCK_MONOTONIC, &lastLevelChange);
+        aBatteryInfo->remainingTime() = dom::battery::kUnknownRemainingTime;
+      }
+
+    } else {
+      clock_gettime(CLOCK_MONOTONIC, &now);
+      dtime = now.tv_sec - lastLevelChange.tv_sec;
+      if (dtime < remainingTime) {
+        aBatteryInfo->remainingTime() = round(remainingTime - dtime);
+      } else {
+        aBatteryInfo->remainingTime() = dom::battery::kUnknownRemainingTime;
+      }
+
+    }
+
+  } else {
+    if (aBatteryInfo->level() == 0.0) {
+      aBatteryInfo->remainingTime() = dom::battery::kDefaultRemainingTime;
+    } else if (aBatteryInfo->level() != previousLevel){
+      if (lastLevelChange.tv_sec != 0) {
+        clock_gettime(CLOCK_MONOTONIC, &now);
+        dtime = now.tv_sec - lastLevelChange.tv_sec;
+        dlevel = previousLevel - aBatteryInfo->level();
+
+        if (dlevel <= 0.0) {
+          aBatteryInfo->remainingTime() = dom::battery::kUnknownRemainingTime;
+        } else {
+          remainingTime = (double) round(dtime / dlevel * aBatteryInfo->level());
+          aBatteryInfo->remainingTime() = remainingTime;
+        }
+
+        lastLevelChange = now;
+      } else { // lastLevelChange.tv_sec == 0
+        clock_gettime(CLOCK_MONOTONIC, &lastLevelChange);
+        aBatteryInfo->remainingTime() = dom::battery::kUnknownRemainingTime;
+      }
+
+    } else {
+      clock_gettime(CLOCK_MONOTONIC, &now);
+      dtime = now.tv_sec - lastLevelChange.tv_sec;
+      if (dtime < remainingTime) {
+        aBatteryInfo->remainingTime() = round(remainingTime - dtime);
+      } else {
+        aBatteryInfo->remainingTime() = dom::battery::kUnknownRemainingTime;
+      }
+
+    }
+  }
+
+  previousCharging = aBatteryInfo->charging();
+  previousLevel = aBatteryInfo->level();
+}
+
+namespace {
+
+// We can write to screenEnabledFilename to enable/disable the screen, but when
+// we read, we always get "mem"!  So we have to keep track ourselves whether
+// the screen is on or not.
+bool sScreenEnabled = true;
+
+// We can read wakeLockFilename to find out whether the cpu wake lock
+// is already acquired, but reading and parsing it is a lot more work
+// than tracking it ourselves, and it won't be accurate anyway (kernel
+// internal wake locks aren't counted here.)
+bool sCpuSleepAllowed = true;
+
+// Some CPU wake locks may be acquired internally in HAL. We use a counter to
+// keep track of these needs. Note we have to hold |sInternalLockCpuMutex|
+// when reading or writing this variable to ensure thread-safe.
+int32_t sInternalLockCpuCount = 0;
+
+} // namespace
+
+bool
+GetScreenEnabled()
+{
+  return sScreenEnabled;
+}
+
+void
+SetScreenEnabled(bool aEnabled)
+{
+  GetGonkDisplay()->SetEnabled(aEnabled);
+  sScreenEnabled = aEnabled;
+}
+
+bool
+GetKeyLightEnabled()
+{
+  LightConfiguration config;
+  bool ok = GetLight(eHalLightID_Buttons, &config);
+  if (ok) {
+    return (config.color != 0x00000000);
+  }
+  return false;
+}
+
+void
+SetKeyLightEnabled(bool aEnabled)
+{
+  LightConfiguration config;
+  config.mode = eHalLightMode_User;
+  config.flash = eHalLightFlash_None;
+  config.flashOnMS = config.flashOffMS = 0;
+  config.color = 0x00000000;
+
+  if (aEnabled) {
+    // Convert the value in [0, 1] to an int between 0 and 255 and then convert
+    // it to a color. Note that the high byte is FF, corresponding to the alpha
+    // channel.
+    double brightness = GetScreenBrightness();
+    uint32_t val = static_cast<int>(round(brightness * 255.0));
+    uint32_t color = (0xff<<24) + (val<<16) + (val<<8) + val;
+
+    config.color = color;
+  }
+
+  SetLight(eHalLightID_Buttons, config);
+  SetLight(eHalLightID_Keyboard, config);
+}
+
+double
+GetScreenBrightness()
+{
+  LightConfiguration config;
+  LightType light = eHalLightID_Backlight;
+
+  bool ok = GetLight(light, &config);
+  if (ok) {
+    // backlight is brightness only, so using one of the RGB elements as value.
+    int brightness = config.color & 0xFF;
+    return brightness / 255.0;
+  }
+  // If GetLight fails, it's because the light doesn't exist.  So return
+  // a value corresponding to "off".
+  return 0;
+}
+
+void
+SetScreenBrightness(double brightness)
+{
+  // Don't use De Morgan's law to push the ! into this expression; we want to
+  // catch NaN too.
+  if (!(0 <= brightness && brightness <= 1)) {
+    HAL_LOG("SetScreenBrightness: Dropping illegal brightness %f.", brightness);
+    return;
+  }
+
+  // Convert the value in [0, 1] to an int between 0 and 255 and convert to a color
+  // note that the high byte is FF, corresponding to the alpha channel.
+  uint32_t val = static_cast<int>(round(brightness * 255.0));
+  uint32_t color = (0xff<<24) + (val<<16) + (val<<8) + val;
+
+  LightConfiguration config;
+  config.mode = eHalLightMode_User;
+  config.flash = eHalLightFlash_None;
+  config.flashOnMS = config.flashOffMS = 0;
+  config.color = color;
+  SetLight(eHalLightID_Backlight, config);
+  if (GetKeyLightEnabled()) {
+    SetLight(eHalLightID_Buttons, config);
+    SetLight(eHalLightID_Keyboard, config);
+  }
+}
+
+static StaticMutex sInternalLockCpuMutex;
+
+static void
+UpdateCpuSleepState()
+{
+  const char *wakeLockFilename = "/sys/power/wake_lock";
+  const char *wakeUnlockFilename = "/sys/power/wake_unlock";
+
+  sInternalLockCpuMutex.AssertCurrentThreadOwns();
+  bool allowed = sCpuSleepAllowed && !sInternalLockCpuCount;
+  WriteSysFile(allowed ? wakeUnlockFilename : wakeLockFilename, "gecko");
+}
+
+static void
+InternalLockCpu() {
+  StaticMutexAutoLock lock(sInternalLockCpuMutex);
+  ++sInternalLockCpuCount;
+  UpdateCpuSleepState();
+}
+
+static void
+InternalUnlockCpu() {
+  StaticMutexAutoLock lock(sInternalLockCpuMutex);
+  --sInternalLockCpuCount;
+  UpdateCpuSleepState();
+}
+
+bool
+GetCpuSleepAllowed()
+{
+  return sCpuSleepAllowed;
+}
+
+void
+SetCpuSleepAllowed(bool aAllowed)
+{
+  StaticMutexAutoLock lock(sInternalLockCpuMutex);
+  sCpuSleepAllowed = aAllowed;
+  UpdateCpuSleepState();
+}
+
+void
+AdjustSystemClock(int64_t aDeltaMilliseconds)
+{
+  int fd;
+  struct timespec now;
+
+  if (aDeltaMilliseconds == 0) {
+    return;
+  }
+
+  // Preventing context switch before setting system clock
+  sched_yield();
+  clock_gettime(CLOCK_REALTIME, &now);
+  now.tv_sec += (time_t)(aDeltaMilliseconds / 1000LL);
+  now.tv_nsec += (long)((aDeltaMilliseconds % 1000LL) * NsecPerMsec);
+  if (now.tv_nsec >= NsecPerSec) {
+    now.tv_sec += 1;
+    now.tv_nsec -= NsecPerSec;
+  }
+
+  if (now.tv_nsec < 0) {
+    now.tv_nsec += NsecPerSec;
+    now.tv_sec -= 1;
+  }
+
+  do {
+    fd = open("/dev/alarm", O_RDWR);
+  } while (fd == -1 && errno == EINTR);
+  ScopedClose autoClose(fd);
+  if (fd < 0) {
+    HAL_LOG("Failed to open /dev/alarm: %s", strerror(errno));
+    return;
+  }
+
+  if (ioctl(fd, ANDROID_ALARM_SET_RTC, &now) < 0) {
+    HAL_LOG("ANDROID_ALARM_SET_RTC failed: %s", strerror(errno));
+  }
+
+  hal::NotifySystemClockChange(aDeltaMilliseconds);
+}
+
+int32_t
+GetTimezoneOffset()
+{
+  PRExplodedTime prTime;
+  PR_ExplodeTime(PR_Now(), PR_LocalTimeParameters, &prTime);
+
+  // Daylight saving time (DST) will be taken into account.
+  int32_t offset = prTime.tm_params.tp_gmt_offset;
+  offset += prTime.tm_params.tp_dst_offset;
+
+  // Returns the timezone offset relative to UTC in minutes.
+  return -(offset / 60);
+}
+
+static int32_t sKernelTimezoneOffset = 0;
+
+static void
+UpdateKernelTimezone(int32_t timezoneOffset)
+{
+  if (sKernelTimezoneOffset == timezoneOffset) {
+    return;
+  }
+
+  // Tell the kernel about the new time zone as well, so that FAT filesystems
+  // will get local timestamps rather than UTC timestamps.
+  //
+  // We assume that /init.rc has a sysclktz entry so that settimeofday has
+  // already been called once before we call it (there is a side-effect in
+  // the kernel the very first time settimeofday is called where it does some
+  // special processing if you only set the timezone).
+  struct timezone tz;
+  memset(&tz, 0, sizeof(tz));
+  tz.tz_minuteswest = timezoneOffset;
+  settimeofday(nullptr, &tz);
+  sKernelTimezoneOffset = timezoneOffset;
+}
+
+void
+SetTimezone(const nsCString& aTimezoneSpec)
+{
+  if (aTimezoneSpec.Equals(GetTimezone())) {
+    // Even though the timezone hasn't changed, we still need to tell the
+    // kernel what the current timezone is. The timezone is persisted in
+    // a property and doesn't change across reboots, but the kernel still
+    // needs to be updated on every boot.
+    UpdateKernelTimezone(GetTimezoneOffset());
+    return;
+  }
+
+  int32_t oldTimezoneOffsetMinutes = GetTimezoneOffset();
+  property_set("persist.sys.timezone", aTimezoneSpec.get());
+  // This function is automatically called by the other time conversion
+  // functions that depend on the timezone. To be safe, we call it manually.
+  tzset();
+  int32_t newTimezoneOffsetMinutes = GetTimezoneOffset();
+  UpdateKernelTimezone(newTimezoneOffsetMinutes);
+  hal::NotifySystemTimezoneChange(
+    hal::SystemTimezoneChangeInformation(
+      oldTimezoneOffsetMinutes, newTimezoneOffsetMinutes));
+}
+
+nsCString
+GetTimezone()
+{
+  char timezone[32];
+  property_get("persist.sys.timezone", timezone, "");
+  return nsCString(timezone);
+}
+
+void
+EnableSystemClockChangeNotifications()
+{
+}
+
+void
+DisableSystemClockChangeNotifications()
+{
+}
+
+void
+EnableSystemTimezoneChangeNotifications()
+{
+}
+
+void
+DisableSystemTimezoneChangeNotifications()
+{
+}
+
+// Nothing to do here.  Gonk widgetry always listens for screen
+// orientation changes.
+void
+EnableScreenConfigurationNotifications()
+{
+}
+
+void
+DisableScreenConfigurationNotifications()
+{
+}
+
+void
+GetCurrentScreenConfiguration(hal::ScreenConfiguration* aScreenConfiguration)
+{
+  RefPtr<nsScreenGonk> screen = nsScreenManagerGonk::GetPrimaryScreen();
+  *aScreenConfiguration = screen->GetConfiguration();
+}
+
+bool
+LockScreenOrientation(const dom::ScreenOrientationInternal& aOrientation)
+{
+  return OrientationObserver::GetInstance()->LockScreenOrientation(aOrientation);
+}
+
+void
+UnlockScreenOrientation()
+{
+  OrientationObserver::GetInstance()->UnlockScreenOrientation();
+}
+
+// This thread will wait for the alarm firing by a blocking IO.
+static pthread_t sAlarmFireWatcherThread;
+
+// If |sAlarmData| is non-null, it's owned by the alarm-watcher thread.
+struct AlarmData {
+public:
+  AlarmData(int aFd) : mFd(aFd),
+                       mGeneration(sNextGeneration++),
+                       mShuttingDown(false) {}
+  ScopedClose mFd;
+  int mGeneration;
+  bool mShuttingDown;
+
+  static int sNextGeneration;
+
+};
+
+int AlarmData::sNextGeneration = 0;
+
+AlarmData* sAlarmData = nullptr;
+
+class AlarmFiredEvent : public Runnable {
+public:
+  AlarmFiredEvent(int aGeneration) : mGeneration(aGeneration) {}
+
+  NS_IMETHOD Run() override {
+    // Guard against spurious notifications caused by an alarm firing
+    // concurrently with it being disabled.
+    if (sAlarmData && !sAlarmData->mShuttingDown &&
+        mGeneration == sAlarmData->mGeneration) {
+      hal::NotifyAlarmFired();
+    }
+    // The fired alarm event has been delivered to the observer (if needed);
+    // we can now release a CPU wake lock.
+    InternalUnlockCpu();
+    return NS_OK;
+  }
+
+private:
+  int mGeneration;
+};
+
+// Runs on alarm-watcher thread.
+static void
+DestroyAlarmData(void* aData)
+{
+  AlarmData* alarmData = static_cast<AlarmData*>(aData);
+  delete alarmData;
+}
+
+// Runs on alarm-watcher thread.
+void ShutDownAlarm(int aSigno)
+{
+  if (aSigno == SIGUSR1 && sAlarmData) {
+    sAlarmData->mShuttingDown = true;
+  }
+  return;
+}
+
+static void*
+WaitForAlarm(void* aData)
+{
+  pthread_cleanup_push(DestroyAlarmData, aData);
+
+  AlarmData* alarmData = static_cast<AlarmData*>(aData);
+
+  while (!alarmData->mShuttingDown) {
+    int alarmTypeFlags = 0;
+
+    // ALARM_WAIT apparently will block even if an alarm hasn't been
+    // programmed, although this behavior doesn't seem to be
+    // documented.  We rely on that here to avoid spinning the CPU
+    // while awaiting an alarm to be programmed.
+    do {
+      alarmTypeFlags = ioctl(alarmData->mFd, ANDROID_ALARM_WAIT);
+    } while (alarmTypeFlags < 0 && errno == EINTR &&
+             !alarmData->mShuttingDown);
+
+    if (!alarmData->mShuttingDown && alarmTypeFlags >= 0 &&
+        (alarmTypeFlags & ANDROID_ALARM_RTC_WAKEUP_MASK)) {
+      // To make sure the observer can get the alarm firing notification
+      // *on time* (the system won't sleep during the process in any way),
+      // we need to acquire a CPU wake lock before firing the alarm event.
+      InternalLockCpu();
+      RefPtr<AlarmFiredEvent> event =
+        new AlarmFiredEvent(alarmData->mGeneration);
+      NS_DispatchToMainThread(event);
+    }
+  }
+
+  pthread_cleanup_pop(1);
+  return nullptr;
+}
+
+bool
+EnableAlarm()
+{
+  MOZ_ASSERT(!sAlarmData);
+
+  int alarmFd = open("/dev/alarm", O_RDWR);
+  if (alarmFd < 0) {
+    HAL_LOG("Failed to open alarm device: %s.", strerror(errno));
+    return false;
+  }
+
+  UniquePtr<AlarmData> alarmData = MakeUnique<AlarmData>(alarmFd);
+
+  struct sigaction actions;
+  memset(&actions, 0, sizeof(actions));
+  sigemptyset(&actions.sa_mask);
+  actions.sa_flags = 0;
+  actions.sa_handler = ShutDownAlarm;
+  if (sigaction(SIGUSR1, &actions, nullptr)) {
+    HAL_LOG("Failed to set SIGUSR1 signal for alarm-watcher thread.");
+    return false;
+  }
+
+  pthread_attr_t attr;
+  pthread_attr_init(&attr);
+  pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
+
+  int status = pthread_create(&sAlarmFireWatcherThread, &attr, WaitForAlarm,
+                              alarmData.get());
+  if (status) {
+    alarmData.reset();
+    HAL_LOG("Failed to create alarm-watcher thread. Status: %d.", status);
+    return false;
+  }
+
+  pthread_attr_destroy(&attr);
+
+  // The thread owns this now.  We only hold a pointer.
+  sAlarmData = alarmData.release();
+  return true;
+}
+
+void
+DisableAlarm()
+{
+  MOZ_ASSERT(sAlarmData);
+
+  // NB: this must happen-before the thread cancellation.
+  sAlarmData = nullptr;
+
+  // The cancel will interrupt the thread and destroy it, freeing the
+  // data pointed at by sAlarmData.
+  DebugOnly<int> err = pthread_kill(sAlarmFireWatcherThread, SIGUSR1);
+  MOZ_ASSERT(!err);
+}
+
+bool
+SetAlarm(int32_t aSeconds, int32_t aNanoseconds)
+{
+  if (!sAlarmData) {
+    HAL_LOG("We should have enabled the alarm.");
+    return false;
+  }
+
+  struct timespec ts;
+  ts.tv_sec = aSeconds;
+  ts.tv_nsec = aNanoseconds;
+
+  // Currently we only support RTC wakeup alarm type.
+  const int result = ioctl(sAlarmData->mFd,
+                           ANDROID_ALARM_SET(ANDROID_ALARM_RTC_WAKEUP), &ts);
+
+  if (result < 0) {
+    HAL_LOG("Unable to set alarm: %s.", strerror(errno));
+    return false;
+  }
+
+  return true;
+}
+
+static int
+OomAdjOfOomScoreAdj(int aOomScoreAdj)
+{
+  // Convert OOM adjustment from the domain of /proc/<pid>/oom_score_adj
+  // to the domain of /proc/<pid>/oom_adj.
+
+  int adj;
+
+  if (aOomScoreAdj < 0) {
+    adj = (OOM_DISABLE * aOomScoreAdj) / OOM_SCORE_ADJ_MIN;
+  } else {
+    adj = (OOM_ADJUST_MAX * aOomScoreAdj) / OOM_SCORE_ADJ_MAX;
+  }
+
+  return adj;
+}
+
+static void
+RoundOomScoreAdjUpWithLRU(int& aOomScoreAdj, uint32_t aLRU)
+{
+  // We want to add minimum value to round OomScoreAdj up according to
+  // the steps by aLRU.
+  aOomScoreAdj +=
+    ceil(((float)OOM_SCORE_ADJ_MAX / OOM_ADJUST_MAX) * aLRU);
+}
+
+#define OOM_LOG(level, args...) __android_log_print(level, "OomLogger", ##args)
+class OomVictimLogger final
+  : public nsIObserver
+{
+public:
+  OomVictimLogger()
+    : mLastLineChecked(-1.0),
+      mRegexes(nullptr)
+  {
+    // Enable timestamps in kernel's printk
+    WriteSysFile("/sys/module/printk/parameters/time", "Y");
+  }
+
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIOBSERVER
+
+protected:
+  ~OomVictimLogger() {}
+
+private:
+  double mLastLineChecked;
+  UniqueFreePtr<regex_t> mRegexes;
+};
+NS_IMPL_ISUPPORTS(OomVictimLogger, nsIObserver);
+
+NS_IMETHODIMP
+OomVictimLogger::Observe(
+  nsISupports* aSubject,
+  const char* aTopic,
+  const char16_t* aData)
+{
+  nsDependentCString event_type(aTopic);
+  if (!event_type.EqualsLiteral("ipc:content-shutdown")) {
+    return NS_OK;
+  }
+
+  // OOM message finding regexes
+  const char* const regexes_raw[] = {
+    ".*select.*to kill.*",
+    ".*send sigkill to.*",
+    ".*lowmem_shrink.*",
+    ".*[Oo]ut of [Mm]emory.*",
+    ".*[Kk]ill [Pp]rocess.*",
+    ".*[Kk]illed [Pp]rocess.*",
+    ".*oom-killer.*",
+    // The regexes below are for the output of dump_task from oom_kill.c
+    // 1st - title 2nd - body lines (8 ints and a string)
+    // oom_adj and oom_score_adj can be negative
+    "\\[ pid \\]   uid  tgid total_vm      rss cpu oom_adj oom_score_adj name",
+    "\\[.*[0-9][0-9]*\\][ ]*[0-9][0-9]*[ ]*[0-9][0-9]*[ ]*[0-9][0-9]*[ ]*[0-9][0-9]*[ ]*[0-9][0-9]*[ ]*.[0-9][0-9]*[ ]*.[0-9][0-9]*.*"
+  };
+  const size_t regex_count = ArrayLength(regexes_raw);
+
+  // Compile our regex just in time
+  if (!mRegexes) {
+    UniqueFreePtr<regex_t> regexes(
+      static_cast<regex_t*>(malloc(sizeof(regex_t) * regex_count))
+    );
+    mRegexes.swap(regexes);
+    for (size_t i = 0; i < regex_count; i++) {
+      int compilation_err =
+        regcomp(&(mRegexes.get()[i]), regexes_raw[i], REG_NOSUB);
+      if (compilation_err) {
+        OOM_LOG(ANDROID_LOG_ERROR, "Cannot compile regex \"%s\"\n", regexes_raw[i]);
+        return NS_OK;
+      }
+    }
+  }
+
+#ifndef KLOG_SIZE_BUFFER
+  // Upstream bionic in commit
+  // e249b059637b49a285ed9f58a2a18bfd054e5d95
+  // deprecated the old klog defs.
+  // Our current bionic does not hit this
+  // change yet so handle the future change.
+  // (ICS doesn't have KLOG_SIZE_BUFFER but
+  // JB and onwards does.)
+  #define KLOG_SIZE_BUFFER KLOG_WRITE
+#endif
+  // Retreive kernel log
+  int msg_buf_size = klogctl(KLOG_SIZE_BUFFER, NULL, 0);
+  UniqueFreePtr<char> msg_buf(static_cast<char *>(malloc(msg_buf_size + 1)));
+  int read_size = klogctl(KLOG_READ_ALL, msg_buf.get(), msg_buf_size);
+
+  // Turn buffer into cstring
+  read_size = read_size > msg_buf_size ? msg_buf_size : read_size;
+  msg_buf.get()[read_size] = '\0';
+
+  // Foreach line
+  char* line_end;
+  char* line_begin = msg_buf.get();
+  for (; (line_end = strchr(line_begin, '\n')); line_begin = line_end + 1) {
+    // make line into cstring
+    *line_end = '\0';
+
+    // Note: Kernel messages look like:
+    // <5>[63648.286409] sd 35:0:0:0: Attached scsi generic sg1 type 0
+    // 5 is the loging level
+    // [*] is the time timestamp, seconds since boot
+    // last comes the logged message
+
+    // Since the logging level can be a string we must
+    // skip it since scanf lacks wildcard matching
+    char*  timestamp_begin = strchr(line_begin, '[');
+    char   after_float;
+    double lineTimestamp = -1;
+    bool   lineTimestampFound = false;
+    if (timestamp_begin &&
+         // Note: scanf treats a ' ' as [ ]*
+         // Note: scanf treats [ %lf] as [ %lf thus we must check
+         // for the closing bracket outselves.
+         2 == sscanf(timestamp_begin, "[ %lf%c", &lineTimestamp, &after_float) &&
+         after_float == ']') {
+      if (lineTimestamp <= mLastLineChecked) {
+        continue;
+      }
+
+      lineTimestampFound = true;
+      mLastLineChecked = lineTimestamp;
+    }
+
+    // Log interesting lines
+    for (size_t i = 0; i < regex_count; i++) {
+      int matching = !regexec(&(mRegexes.get()[i]), line_begin, 0, NULL, 0);
+      if (matching) {
+        // Log content of kernel message. We try to skip the ], but if for
+        // some reason (most likely due to buffer overflow/wraparound), we
+        // can't find the ] then we just log the entire line.
+        char* endOfTimestamp = strchr(line_begin, ']');
+        if (endOfTimestamp && endOfTimestamp[1] == ' ') {
+          // skip the ] and the space that follows it
+          line_begin = endOfTimestamp + 2;
+        }
+        if (!lineTimestampFound) {
+          OOM_LOG(ANDROID_LOG_WARN, "following kill message may be a duplicate");
+        }
+        OOM_LOG(ANDROID_LOG_ERROR, "[Kill]: %s\n", line_begin);
+        break;
+      }
+    }
+  }
+
+  return NS_OK;
+}
+
+/**
+ * Wraps a particular ProcessPriority, giving us easy access to the prefs that
+ * are relevant to it.
+ *
+ * Creating a PriorityClass also ensures that the control group is created.
+ */
+class PriorityClass
+{
+public:
+  /**
+   * Create a PriorityClass for the given ProcessPriority.  This implicitly
+   * reads the relevant prefs and opens the cgroup.procs file of the relevant
+   * control group caching its file descriptor for later use.
+   */
+  PriorityClass(ProcessPriority aPriority);
+
+  /**
+   * Closes the file descriptor for the cgroup.procs file of the associated
+   * control group.
+   */
+  ~PriorityClass();
+
+  PriorityClass(const PriorityClass& aOther);
+  PriorityClass& operator=(const PriorityClass& aOther);
+
+  ProcessPriority Priority()
+  {
+    return mPriority;
+  }
+
+  int32_t OomScoreAdj()
+  {
+    return clamped<int32_t>(mOomScoreAdj, OOM_SCORE_ADJ_MIN, OOM_SCORE_ADJ_MAX);
+  }
+
+  int32_t KillUnderKB()
+  {
+    return mKillUnderKB;
+  }
+
+  nsCString CGroup()
+  {
+    return mGroup;
+  }
+
+  /**
+   * Adds a process to this priority class, this moves the process' PID into
+   * the associated control group.
+   *
+   * @param aPid The PID of the process to be added.
+   */
+  void AddProcess(int aPid);
+
+private:
+  ProcessPriority mPriority;
+  int32_t mOomScoreAdj;
+  int32_t mKillUnderKB;
+  int mCpuCGroupProcsFd;
+  int mMemCGroupProcsFd;
+  nsCString mGroup;
+
+  /**
+   * Return a string that identifies where we can find the value of aPref
+   * that's specific to mPriority.  For example, we might return
+   * "hal.processPriorityManager.gonk.FOREGROUND_HIGH.oomScoreAdjust".
+   */
+  nsCString PriorityPrefName(const char* aPref)
+  {
+    return nsPrintfCString("hal.processPriorityManager.gonk.%s.%s",
+                           ProcessPriorityToString(mPriority), aPref);
+  }
+
+  /**
+   * Get the full path of the cgroup.procs file associated with the group.
+   */
+  nsCString CpuCGroupProcsFilename()
+  {
+    nsCString cgroupName = mGroup;
+
+    /* If mGroup is empty, our cgroup.procs file is the root procs file,
+     * located at /dev/cpuctl/cgroup.procs.  Otherwise our procs file is
+     * /dev/cpuctl/NAME/cgroup.procs. */
+
+    if (!mGroup.IsEmpty()) {
+      cgroupName.AppendLiteral("/");
+    }
+
+    return NS_LITERAL_CSTRING("/dev/cpuctl/") + cgroupName +
+           NS_LITERAL_CSTRING("cgroup.procs");
+  }
+
+  nsCString MemCGroupProcsFilename()
+  {
+    nsCString cgroupName = mGroup;
+
+    /* If mGroup is empty, our cgroup.procs file is the root procs file,
+     * located at /sys/fs/cgroup/memory/cgroup.procs.  Otherwise our procs
+     * file is /sys/fs/cgroup/memory/NAME/cgroup.procs. */
+
+    if (!mGroup.IsEmpty()) {
+      cgroupName.AppendLiteral("/");
+    }
+
+    return NS_LITERAL_CSTRING("/sys/fs/cgroup/memory/") + cgroupName +
+           NS_LITERAL_CSTRING("cgroup.procs");
+  }
+
+  int OpenCpuCGroupProcs()
+  {
+    return open(CpuCGroupProcsFilename().get(), O_WRONLY);
+  }
+
+  int OpenMemCGroupProcs()
+  {
+    return open(MemCGroupProcsFilename().get(), O_WRONLY);
+  }
+};
+
+/**
+ * Try to create the cgroup for the given PriorityClass, if it doesn't already
+ * exist.  This essentially implements mkdir -p; that is, we create parent
+ * cgroups as necessary.  The group parameters are also set according to
+ * the corresponding preferences.
+ *
+ * @param aGroup The name of the group.
+ * @return true if we successfully created the cgroup, or if it already
+ * exists.  Otherwise, return false.
+ */
+static bool
+EnsureCpuCGroupExists(const nsACString &aGroup)
+{
+  NS_NAMED_LITERAL_CSTRING(kDevCpuCtl, "/dev/cpuctl/");
+  NS_NAMED_LITERAL_CSTRING(kSlash, "/");
+
+  nsAutoCString groupName(aGroup);
+  HAL_LOG("EnsureCpuCGroupExists for group '%s'", groupName.get());
+
+  nsAutoCString prefPrefix("hal.processPriorityManager.gonk.cgroups.");
+
+  /* If cgroup is not empty, append the cgroup name and a dot to obtain the
+   * group specific preferences. */
+  if (!aGroup.IsEmpty()) {
+    prefPrefix += aGroup + NS_LITERAL_CSTRING(".");
+  }
+
+  nsAutoCString cpuSharesPref(prefPrefix + NS_LITERAL_CSTRING("cpu_shares"));
+  int cpuShares = Preferences::GetInt(cpuSharesPref.get());
+
+  nsAutoCString cpuNotifyOnMigratePref(prefPrefix
+    + NS_LITERAL_CSTRING("cpu_notify_on_migrate"));
+  int cpuNotifyOnMigrate = Preferences::GetInt(cpuNotifyOnMigratePref.get());
+
+  // Create mCGroup and its parent directories, as necessary.
+  nsCString cgroupIter = aGroup + kSlash;
+
+  int32_t offset = 0;
+  while ((offset = cgroupIter.FindChar('/', offset)) != -1) {
+    nsAutoCString path = kDevCpuCtl + Substring(cgroupIter, 0, offset);
+    int rv = mkdir(path.get(), 0744);
+
+    if (rv == -1 && errno != EEXIST) {
+      HAL_LOG("Could not create the %s control group.", path.get());
+      return false;
+    }
+
+    offset++;
+  }
+  HAL_LOG("EnsureCpuCGroupExists created group '%s'", groupName.get());
+
+  nsAutoCString pathPrefix(kDevCpuCtl + aGroup + kSlash);
+  nsAutoCString cpuSharesPath(pathPrefix + NS_LITERAL_CSTRING("cpu.shares"));
+  if (cpuShares && !WriteSysFile(cpuSharesPath.get(),
+                                 nsPrintfCString("%d", cpuShares).get())) {
+    HAL_LOG("Could not set the cpu share for group %s", cpuSharesPath.get());
+    return false;
+  }
+
+  nsAutoCString notifyOnMigratePath(pathPrefix
+    + NS_LITERAL_CSTRING("cpu.notify_on_migrate"));
+  if (!WriteSysFile(notifyOnMigratePath.get(),
+                    nsPrintfCString("%d", cpuNotifyOnMigrate).get())) {
+    HAL_LOG("Could not set the cpu migration notification flag for group %s",
+            notifyOnMigratePath.get());
+    return false;
+  }
+
+  return true;
+}
+
+static bool
+EnsureMemCGroupExists(const nsACString &aGroup)
+{
+  NS_NAMED_LITERAL_CSTRING(kMemCtl, "/sys/fs/cgroup/memory/");
+  NS_NAMED_LITERAL_CSTRING(kSlash, "/");
+
+  nsAutoCString groupName(aGroup);
+  HAL_LOG("EnsureMemCGroupExists for group '%s'", groupName.get());
+
+  nsAutoCString prefPrefix("hal.processPriorityManager.gonk.cgroups.");
+
+  /* If cgroup is not empty, append the cgroup name and a dot to obtain the
+   * group specific preferences. */
+  if (!aGroup.IsEmpty()) {
+    prefPrefix += aGroup + NS_LITERAL_CSTRING(".");
+  }
+
+  nsAutoCString memSwappinessPref(prefPrefix + NS_LITERAL_CSTRING("memory_swappiness"));
+  int memSwappiness = Preferences::GetInt(memSwappinessPref.get());
+
+  // Create mCGroup and its parent directories, as necessary.
+  nsCString cgroupIter = aGroup + kSlash;
+
+  int32_t offset = 0;
+  while ((offset = cgroupIter.FindChar('/', offset)) != -1) {
+    nsAutoCString path = kMemCtl + Substring(cgroupIter, 0, offset);
+    int rv = mkdir(path.get(), 0744);
+
+    if (rv == -1 && errno != EEXIST) {
+      HAL_LOG("Could not create the %s control group.", path.get());
+      return false;
+    }
+
+    offset++;
+  }
+  HAL_LOG("EnsureMemCGroupExists created group '%s'", groupName.get());
+
+  nsAutoCString pathPrefix(kMemCtl + aGroup + kSlash);
+  nsAutoCString memSwappinessPath(pathPrefix + NS_LITERAL_CSTRING("memory.swappiness"));
+  if (!WriteSysFile(memSwappinessPath.get(),
+                    nsPrintfCString("%d", memSwappiness).get())) {
+    HAL_LOG("Could not set the memory.swappiness for group %s", memSwappinessPath.get());
+    return false;
+  }
+  HAL_LOG("Set memory.swappiness for group %s to %d", memSwappinessPath.get(), memSwappiness);
+
+  return true;
+}
+
+PriorityClass::PriorityClass(ProcessPriority aPriority)
+  : mPriority(aPriority)
+  , mOomScoreAdj(0)
+  , mKillUnderKB(0)
+  , mCpuCGroupProcsFd(-1)
+  , mMemCGroupProcsFd(-1)
+{
+  DebugOnly<nsresult> rv;
+
+  rv = Preferences::GetInt(PriorityPrefName("OomScoreAdjust").get(),
+                           &mOomScoreAdj);
+  MOZ_ASSERT(NS_SUCCEEDED(rv), "Missing oom_score_adj preference");
+
+  rv = Preferences::GetInt(PriorityPrefName("KillUnderKB").get(),
+                           &mKillUnderKB);
+
+  rv = Preferences::GetCString(PriorityPrefName("cgroup").get(), &mGroup);
+  MOZ_ASSERT(NS_SUCCEEDED(rv), "Missing control group preference");
+
+  if (EnsureCpuCGroupExists(mGroup)) {
+    mCpuCGroupProcsFd = OpenCpuCGroupProcs();
+  }
+  if (EnsureMemCGroupExists(mGroup)) {
+    mMemCGroupProcsFd = OpenMemCGroupProcs();
+  }
+}
+
+PriorityClass::~PriorityClass()
+{
+  if (mCpuCGroupProcsFd != -1) {
+    close(mCpuCGroupProcsFd);
+  }
+  if (mMemCGroupProcsFd != -1) {
+    close(mMemCGroupProcsFd);
+  }
+}
+
+PriorityClass::PriorityClass(const PriorityClass& aOther)
+  : mPriority(aOther.mPriority)
+  , mOomScoreAdj(aOther.mOomScoreAdj)
+  , mKillUnderKB(aOther.mKillUnderKB)
+  , mGroup(aOther.mGroup)
+{
+  mCpuCGroupProcsFd = OpenCpuCGroupProcs();
+  mMemCGroupProcsFd = OpenMemCGroupProcs();
+}
+
+PriorityClass& PriorityClass::operator=(const PriorityClass& aOther)
+{
+  mPriority = aOther.mPriority;
+  mOomScoreAdj = aOther.mOomScoreAdj;
+  mKillUnderKB = aOther.mKillUnderKB;
+  mGroup = aOther.mGroup;
+  mCpuCGroupProcsFd = OpenCpuCGroupProcs();
+  mMemCGroupProcsFd = OpenMemCGroupProcs();
+  return *this;
+}
+
+void PriorityClass::AddProcess(int aPid)
+{
+  if (mCpuCGroupProcsFd >= 0) {
+    nsPrintfCString str("%d", aPid);
+
+    if (write(mCpuCGroupProcsFd, str.get(), strlen(str.get())) < 0) {
+      HAL_ERR("Couldn't add PID %d to the %s cpu control group", aPid, mGroup.get());
+    }
+  }
+  if (mMemCGroupProcsFd >= 0) {
+    nsPrintfCString str("%d", aPid);
+
+    if (write(mMemCGroupProcsFd, str.get(), strlen(str.get())) < 0) {
+      HAL_ERR("Couldn't add PID %d to the %s memory control group", aPid, mGroup.get());
+    }
+  }
+}
+
+/**
+ * Get the PriorityClass associated with the given ProcessPriority.
+ *
+ * If you pass an invalid ProcessPriority value, we return null.
+ *
+ * The pointers returned here are owned by GetPriorityClass (don't free them
+ * yourself).  They are guaranteed to stick around until shutdown.
+ */
+PriorityClass*
+GetPriorityClass(ProcessPriority aPriority)
+{
+  static StaticAutoPtr<nsTArray<PriorityClass>> priorityClasses;
+
+  // Initialize priorityClasses if this is the first time we're running this
+  // method.
+  if (!priorityClasses) {
+    priorityClasses = new nsTArray<PriorityClass>();
+    ClearOnShutdown(&priorityClasses);
+
+    for (int32_t i = 0; i < NUM_PROCESS_PRIORITY; i++) {
+      priorityClasses->AppendElement(PriorityClass(ProcessPriority(i)));
+    }
+  }
+
+  if (aPriority < 0 ||
+      static_cast<uint32_t>(aPriority) >= priorityClasses->Length()) {
+    return nullptr;
+  }
+
+  return &(*priorityClasses)[aPriority];
+}
+
+static void
+EnsureKernelLowMemKillerParamsSet()
+{
+  static bool kernelLowMemKillerParamsSet;
+  if (kernelLowMemKillerParamsSet) {
+    return;
+  }
+  kernelLowMemKillerParamsSet = true;
+
+  HAL_LOG("Setting kernel's low-mem killer parameters.");
+
+  // Set /sys/module/lowmemorykiller/parameters/{adj,minfree,notify_trigger}
+  // according to our prefs.  These files let us tune when the kernel kills
+  // processes when we're low on memory, and when it notifies us that we're
+  // running low on available memory.
+  //
+  // adj and minfree are both comma-separated lists of integers.  If adj="A,B"
+  // and minfree="X,Y", then the kernel will kill processes with oom_adj
+  // A or higher once we have fewer than X pages of memory free, and will kill
+  // processes with oom_adj B or higher once we have fewer than Y pages of
+  // memory free.
+  //
+  // notify_trigger is a single integer.   If we set notify_trigger=Z, then
+  // we'll get notified when there are fewer than Z pages of memory free.  (See
+  // GonkMemoryPressureMonitoring.cpp.)
+
+  // Build the adj and minfree strings.
+  nsAutoCString adjParams;
+  nsAutoCString minfreeParams;
+
+  DebugOnly<int32_t> lowerBoundOfNextOomScoreAdj = OOM_SCORE_ADJ_MIN - 1;
+  DebugOnly<int32_t> lowerBoundOfNextKillUnderKB = 0;
+  int32_t countOfLowmemorykillerParametersSets = 0;
+
+  long page_size = sysconf(_SC_PAGESIZE);
+
+  for (int i = NUM_PROCESS_PRIORITY - 1; i >= 0; i--) {
+    // The system doesn't function correctly if we're missing these prefs, so
+    // crash loudly.
+
+    PriorityClass* pc = GetPriorityClass(static_cast<ProcessPriority>(i));
+
+    int32_t oomScoreAdj = pc->OomScoreAdj();
+    int32_t killUnderKB = pc->KillUnderKB();
+
+    if (killUnderKB == 0) {
+      // ProcessPriority values like PROCESS_PRIORITY_FOREGROUND_KEYBOARD,
+      // which has only OomScoreAdjust but lacks KillUnderMB value, will not
+      // create new LMK parameters.
+      continue;
+    }
+
+    // The LMK in kernel silently malfunctions if we assign the parameters
+    // in non-increasing order, so we add this assertion here. See bug 887192.
+    MOZ_ASSERT(oomScoreAdj > lowerBoundOfNextOomScoreAdj);
+    MOZ_ASSERT(killUnderKB > lowerBoundOfNextKillUnderKB);
+
+    // The LMK in kernel only accept 6 sets of LMK parameters. See bug 914728.
+    MOZ_ASSERT(countOfLowmemorykillerParametersSets < 6);
+
+    // adj is in oom_adj units.
+    adjParams.AppendPrintf("%d,", OomAdjOfOomScoreAdj(oomScoreAdj));
+
+    // minfree is in pages.
+    minfreeParams.AppendPrintf("%ld,", killUnderKB * 1024 / page_size);
+
+    lowerBoundOfNextOomScoreAdj = oomScoreAdj;
+    lowerBoundOfNextKillUnderKB = killUnderKB;
+    countOfLowmemorykillerParametersSets++;
+  }
+
+  // Strip off trailing commas.
+  adjParams.Cut(adjParams.Length() - 1, 1);
+  minfreeParams.Cut(minfreeParams.Length() - 1, 1);
+  if (!adjParams.IsEmpty() && !minfreeParams.IsEmpty()) {
+    WriteSysFile("/sys/module/lowmemorykiller/parameters/adj", adjParams.get());
+    WriteSysFile("/sys/module/lowmemorykiller/parameters/minfree",
+                 minfreeParams.get());
+  }
+
+  // Set the low-memory-notification threshold.
+  int32_t lowMemNotifyThresholdKB;
+  if (NS_SUCCEEDED(Preferences::GetInt(
+        "hal.processPriorityManager.gonk.notifyLowMemUnderKB",
+        &lowMemNotifyThresholdKB))) {
+
+    // notify_trigger is in pages.
+    WriteSysFile("/sys/module/lowmemorykiller/parameters/notify_trigger",
+      nsPrintfCString("%ld", lowMemNotifyThresholdKB * 1024 / page_size).get());
+  }
+
+  // Ensure OOM events appear in logcat
+  RefPtr<OomVictimLogger> oomLogger = new OomVictimLogger();
+  nsCOMPtr<nsIObserverService> os = services::GetObserverService();
+  if (os) {
+    os->AddObserver(oomLogger, "ipc:content-shutdown", false);
+  }
+}
+
+void
+SetProcessPriority(int aPid, ProcessPriority aPriority, uint32_t aLRU)
+{
+  HAL_LOG("SetProcessPriority(pid=%d, priority=%d, LRU=%u)",
+          aPid, aPriority, aLRU);
+
+  // If this is the first time SetProcessPriority was called, set the kernel's
+  // OOM parameters according to our prefs.
+  //
+  // We could/should do this on startup instead of waiting for the first
+  // SetProcessPriorityCall.  But in practice, the master process needs to set
+  // its priority early in the game, so we can reasonably rely on
+  // SetProcessPriority being called early in startup.
+  EnsureKernelLowMemKillerParamsSet();
+
+  PriorityClass* pc = GetPriorityClass(aPriority);
+
+  int oomScoreAdj = pc->OomScoreAdj();
+
+  RoundOomScoreAdjUpWithLRU(oomScoreAdj, aLRU);
+
+  // We try the newer interface first, and fall back to the older interface
+  // on failure.
+  if (!WriteSysFile(nsPrintfCString("/proc/%d/oom_score_adj", aPid).get(),
+                    nsPrintfCString("%d", oomScoreAdj).get()))
+  {
+    WriteSysFile(nsPrintfCString("/proc/%d/oom_adj", aPid).get(),
+                 nsPrintfCString("%d", OomAdjOfOomScoreAdj(oomScoreAdj)).get());
+  }
+
+  HAL_LOG("Assigning pid %d to cgroup %s", aPid, pc->CGroup().get());
+  pc->AddProcess(aPid);
+}
+
+static bool
+IsValidRealTimePriority(int aValue, int aSchedulePolicy)
+{
+  return (aValue >= sched_get_priority_min(aSchedulePolicy)) &&
+         (aValue <= sched_get_priority_max(aSchedulePolicy));
+}
+
+static void
+SetThreadNiceValue(pid_t aTid, ThreadPriority aThreadPriority, int aValue)
+{
+  MOZ_ASSERT(aThreadPriority < NUM_THREAD_PRIORITY);
+  MOZ_ASSERT(aThreadPriority >= 0);
+
+  HAL_LOG("Setting thread %d to priority level %s; nice level %d",
+          aTid, ThreadPriorityToString(aThreadPriority), aValue);
+  int rv = setpriority(PRIO_PROCESS, aTid, aValue);
+
+  if (rv) {
+    HAL_LOG("Failed to set thread %d to priority level %s; error %s", aTid,
+            ThreadPriorityToString(aThreadPriority), strerror(errno));
+  }
+}
+
+static void
+SetRealTimeThreadPriority(pid_t aTid,
+                          ThreadPriority aThreadPriority,
+                          int aValue)
+{
+  int policy = SCHED_FIFO;
+
+  MOZ_ASSERT(aThreadPriority < NUM_THREAD_PRIORITY);
+  MOZ_ASSERT(aThreadPriority >= 0);
+  MOZ_ASSERT(IsValidRealTimePriority(aValue, policy), "Invalid real time priority");
+
+  // Setting real time priorities requires using sched_setscheduler
+  HAL_LOG("Setting thread %d to priority level %s; Real Time priority %d, "
+          "Schedule FIFO", aTid, ThreadPriorityToString(aThreadPriority),
+          aValue);
+  sched_param schedParam;
+  schedParam.sched_priority = aValue;
+  int rv = sched_setscheduler(aTid, policy, &schedParam);
+
+  if (rv) {
+    HAL_LOG("Failed to set thread %d to real time priority level %s; error %s",
+            aTid, ThreadPriorityToString(aThreadPriority), strerror(errno));
+  }
+}
+
+/*
+ * Used to store the nice value adjustments and real time priorities for the
+ * various thread priority levels.
+ */
+struct ThreadPriorityPrefs {
+  bool initialized;
+  struct {
+    int nice;
+    int realTime;
+  } priorities[NUM_THREAD_PRIORITY];
+};
+
+/*
+ * Reads the preferences for the various process priority levels and sets up
+ * watchers so that if they're dynamically changed the change is reflected on
+ * the appropriate variables.
+ */
+void
+EnsureThreadPriorityPrefs(ThreadPriorityPrefs* prefs)
+{
+  if (prefs->initialized) {
+    return;
+  }
+
+  for (int i = THREAD_PRIORITY_COMPOSITOR; i < NUM_THREAD_PRIORITY; i++) {
+    ThreadPriority priority = static_cast<ThreadPriority>(i);
+
+    // Read the nice values
+    const char* threadPriorityStr = ThreadPriorityToString(priority);
+    nsPrintfCString niceStr("hal.gonk.%s.nice", threadPriorityStr);
+    Preferences::AddIntVarCache(&prefs->priorities[i].nice, niceStr.get());
+
+    // Read the real-time priorities
+    nsPrintfCString realTimeStr("hal.gonk.%s.rt_priority", threadPriorityStr);
+    Preferences::AddIntVarCache(&prefs->priorities[i].realTime,
+                                realTimeStr.get());
+  }
+
+  prefs->initialized = true;
+}
+
+static void
+DoSetThreadPriority(pid_t aTid, hal::ThreadPriority aThreadPriority)
+{
+  // See bug 999115, we can only read preferences on the main thread otherwise
+  // we create a race condition in HAL
+  MOZ_ASSERT(NS_IsMainThread(), "Can only set thread priorities on main thread");
+  MOZ_ASSERT(aThreadPriority >= 0);
+
+  static ThreadPriorityPrefs prefs = { 0 };
+  EnsureThreadPriorityPrefs(&prefs);
+
+  switch (aThreadPriority) {
+    case THREAD_PRIORITY_COMPOSITOR:
+      break;
+    default:
+      HAL_ERR("Unrecognized thread priority %d; Doing nothing",
+              aThreadPriority);
+      return;
+  }
+
+  int realTimePriority = prefs.priorities[aThreadPriority].realTime;
+
+  if (IsValidRealTimePriority(realTimePriority, SCHED_FIFO)) {
+    SetRealTimeThreadPriority(aTid, aThreadPriority, realTimePriority);
+    return;
+  }
+
+  SetThreadNiceValue(aTid, aThreadPriority,
+                     prefs.priorities[aThreadPriority].nice);
+}
+
+namespace {
+
+/**
+ * This class sets the priority of threads given the kernel thread's id and a
+ * value taken from hal::ThreadPriority.
+ *
+ * This runnable must always be dispatched to the main thread otherwise it will fail.
+ * We have to run this from the main thread since preferences can only be read on
+ * main thread.
+ */
+class SetThreadPriorityRunnable : public Runnable
+{
+public:
+  SetThreadPriorityRunnable(pid_t aThreadId, hal::ThreadPriority aThreadPriority)
+    : mThreadId(aThreadId)
+    , mThreadPriority(aThreadPriority)
+  { }
+
+  NS_IMETHOD Run() override
+  {
+    NS_ASSERTION(NS_IsMainThread(), "Can only set thread priorities on main thread");
+    hal_impl::DoSetThreadPriority(mThreadId, mThreadPriority);
+    return NS_OK;
+  }
+
+private:
+  pid_t mThreadId;
+  hal::ThreadPriority mThreadPriority;
+};
+
+} // namespace
+
+void
+SetCurrentThreadPriority(ThreadPriority aThreadPriority)
+{
+  pid_t threadId = gettid();
+  hal_impl::SetThreadPriority(threadId, aThreadPriority);
+}
+
+void
+SetThreadPriority(PlatformThreadId aThreadId,
+                         ThreadPriority aThreadPriority)
+{
+  switch (aThreadPriority) {
+    case THREAD_PRIORITY_COMPOSITOR: {
+      nsCOMPtr<nsIRunnable> runnable =
+        new SetThreadPriorityRunnable(aThreadId, aThreadPriority);
+      NS_DispatchToMainThread(runnable);
+      break;
+    }
+    default:
+      HAL_LOG("Unrecognized thread priority %d; Doing nothing",
+              aThreadPriority);
+      return;
+  }
+}
+
+void
+FactoryReset(FactoryResetReason& aReason)
+{
+  nsCOMPtr<nsIRecoveryService> recoveryService =
+    do_GetService("@mozilla.org/recovery-service;1");
+  if (!recoveryService) {
+    NS_WARNING("Could not get recovery service!");
+    return;
+  }
+
+  if (aReason == FactoryResetReason::Wipe) {
+    recoveryService->FactoryReset("wipe");
+  } else if (aReason == FactoryResetReason::Root) {
+    recoveryService->FactoryReset("root");
+  } else {
+    recoveryService->FactoryReset("normal");
+  }
+}
+
+} // hal_impl
+} // mozilla
diff --git a/hal/gonk/GonkSensor.cpp b/hal/gonk/GonkSensor.cpp
new file mode 100644
index 000000000..7bd2d3c9b
--- /dev/null
+++ b/hal/gonk/GonkSensor.cpp
@@ -0,0 +1,861 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* Copyright 2012 Mozilla Foundation and Mozilla contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <pthread.h>
+#include <stdio.h>
+
+#include "mozilla/DebugOnly.h"
+#include "mozilla/Saturate.h"
+
+#include "base/basictypes.h"
+#include "base/thread.h"
+#include "base/task.h"
+
+#include "GonkSensorsInterface.h"
+#include "GonkSensorsPollInterface.h"
+#include "GonkSensorsRegistryInterface.h"
+#include "Hal.h"
+#include "HalLog.h"
+#include "HalSensor.h"
+#include "hardware/sensors.h"
+#include "nsThreadUtils.h"
+
+using namespace mozilla::hal;
+
+namespace mozilla {
+
+//
+// Internal implementation
+//
+
+// The value from SensorDevice.h (Android)
+#define DEFAULT_DEVICE_POLL_RATE 200000000 /*200ms*/
+// ProcessOrientation.cpp needs smaller poll rate to detect delay between
+// different orientation angles
+#define ACCELEROMETER_POLL_RATE 66667000 /*66.667ms*/
+
+// This is present in Android from API level 18 onwards, which is 4.3.  We might
+// be building on something before 4.3, so use a local define for its value
+#define MOZ_SENSOR_TYPE_GAME_ROTATION_VECTOR   15
+
+double radToDeg(double a) {
+  return a * (180.0 / M_PI);
+}
+
+static SensorType
+HardwareSensorToHalSensor(int type)
+{
+  switch(type) {
+    case SENSOR_TYPE_ORIENTATION:
+      return SENSOR_ORIENTATION;
+    case SENSOR_TYPE_ACCELEROMETER:
+      return SENSOR_ACCELERATION;
+    case SENSOR_TYPE_PROXIMITY:
+      return SENSOR_PROXIMITY;
+    case SENSOR_TYPE_LIGHT:
+      return SENSOR_LIGHT;
+    case SENSOR_TYPE_GYROSCOPE:
+      return SENSOR_GYROSCOPE;
+    case SENSOR_TYPE_LINEAR_ACCELERATION:
+      return SENSOR_LINEAR_ACCELERATION;
+    case SENSOR_TYPE_ROTATION_VECTOR:
+      return SENSOR_ROTATION_VECTOR;
+    case MOZ_SENSOR_TYPE_GAME_ROTATION_VECTOR:
+      return SENSOR_GAME_ROTATION_VECTOR;
+    default:
+      return SENSOR_UNKNOWN;
+  }
+}
+
+static SensorAccuracyType
+HardwareStatusToHalAccuracy(int status) {
+  return static_cast<SensorAccuracyType>(status);
+}
+
+static int
+HalSensorToHardwareSensor(SensorType type)
+{
+  switch(type) {
+    case SENSOR_ORIENTATION:
+      return SENSOR_TYPE_ORIENTATION;
+    case SENSOR_ACCELERATION:
+      return SENSOR_TYPE_ACCELEROMETER;
+    case SENSOR_PROXIMITY:
+      return SENSOR_TYPE_PROXIMITY;
+    case SENSOR_LIGHT:
+      return SENSOR_TYPE_LIGHT;
+    case SENSOR_GYROSCOPE:
+      return SENSOR_TYPE_GYROSCOPE;
+    case SENSOR_LINEAR_ACCELERATION:
+      return SENSOR_TYPE_LINEAR_ACCELERATION;
+    case SENSOR_ROTATION_VECTOR:
+      return SENSOR_TYPE_ROTATION_VECTOR;
+    case SENSOR_GAME_ROTATION_VECTOR:
+      return MOZ_SENSOR_TYPE_GAME_ROTATION_VECTOR;
+    default:
+      return -1;
+  }
+}
+
+static int
+SensorseventStatus(const sensors_event_t& data)
+{
+  int type = data.type;
+  switch(type) {
+    case SENSOR_ORIENTATION:
+      return data.orientation.status;
+    case SENSOR_LINEAR_ACCELERATION:
+    case SENSOR_ACCELERATION:
+      return data.acceleration.status;
+    case SENSOR_GYROSCOPE:
+      return data.gyro.status;
+  }
+
+  return SENSOR_STATUS_UNRELIABLE;
+}
+
+class SensorRunnable : public Runnable
+{
+public:
+  SensorRunnable(const sensors_event_t& data, const sensor_t* sensors, ssize_t size)
+  {
+    mSensorData.sensor() = HardwareSensorToHalSensor(data.type);
+    mSensorData.accuracy() = HardwareStatusToHalAccuracy(SensorseventStatus(data));
+    mSensorData.timestamp() = data.timestamp;
+    if (mSensorData.sensor() == SENSOR_GYROSCOPE) {
+      // libhardware returns gyro as rad.  convert.
+      mSensorValues.AppendElement(radToDeg(data.data[0]));
+      mSensorValues.AppendElement(radToDeg(data.data[1]));
+      mSensorValues.AppendElement(radToDeg(data.data[2]));
+    } else if (mSensorData.sensor() == SENSOR_PROXIMITY) {
+      mSensorValues.AppendElement(data.data[0]);
+      mSensorValues.AppendElement(0);
+
+      // Determine the maxRange for this sensor.
+      for (ssize_t i = 0; i < size; i++) {
+        if (sensors[i].type == SENSOR_TYPE_PROXIMITY) {
+          mSensorValues.AppendElement(sensors[i].maxRange);
+        }
+      }
+    } else if (mSensorData.sensor() == SENSOR_LIGHT) {
+      mSensorValues.AppendElement(data.data[0]);
+    } else if (mSensorData.sensor() == SENSOR_ROTATION_VECTOR) {
+      mSensorValues.AppendElement(data.data[0]);
+      mSensorValues.AppendElement(data.data[1]);
+      mSensorValues.AppendElement(data.data[2]);
+      if (data.data[3] == 0.0) {
+        // data.data[3] was optional in Android <= API level 18.  It can be computed from 012,
+        // but it's better to take the actual value if one is provided.  The computation is
+        //   v = 1 - d[0]*d[0] - d[1]*d[1] - d[2]*d[2]
+        //   d[3] = v > 0 ? sqrt(v) : 0;
+        // I'm assuming that it will be 0 if it's not passed in.  (The values form a unit
+        // quaternion, so the angle can be computed from the direction vector.)
+        float sx = data.data[0], sy = data.data[1], sz = data.data[2];
+        float v = 1.0f - sx*sx - sy*sy - sz*sz;
+        mSensorValues.AppendElement(v > 0.0f ? sqrt(v) : 0.0f);
+      } else {
+        mSensorValues.AppendElement(data.data[3]);
+      }
+    } else if (mSensorData.sensor() == SENSOR_GAME_ROTATION_VECTOR) {
+      mSensorValues.AppendElement(data.data[0]);
+      mSensorValues.AppendElement(data.data[1]);
+      mSensorValues.AppendElement(data.data[2]);
+      mSensorValues.AppendElement(data.data[3]);
+    } else {
+      mSensorValues.AppendElement(data.data[0]);
+      mSensorValues.AppendElement(data.data[1]);
+      mSensorValues.AppendElement(data.data[2]);
+    }
+    mSensorData.values() = mSensorValues;
+  }
+
+  ~SensorRunnable() {}
+
+  NS_IMETHOD Run() override
+  {
+    NotifySensorChange(mSensorData);
+    return NS_OK;
+  }
+
+private:
+  SensorData mSensorData;
+  AutoTArray<float, 4> mSensorValues;
+};
+
+namespace hal_impl {
+
+static DebugOnly<int> sSensorRefCount[NUM_SENSOR_TYPE];
+static base::Thread* sPollingThread;
+static sensors_poll_device_t* sSensorDevice;
+static sensors_module_t* sSensorModule;
+
+static void
+PollSensors()
+{
+  const size_t numEventMax = 16;
+  sensors_event_t buffer[numEventMax];
+  const sensor_t* sensors;
+  int size = sSensorModule->get_sensors_list(sSensorModule, &sensors);
+
+  do {
+    // didn't check sSensorDevice because already be done on creating pollingThread.
+    int n = sSensorDevice->poll(sSensorDevice, buffer, numEventMax);
+    if (n < 0) {
+      HAL_ERR("Error polling for sensor data (err=%d)", n);
+      break;
+    }
+
+    for (int i = 0; i < n; ++i) {
+      // FIXME: bug 802004, add proper support for the magnetic field sensor.
+      if (buffer[i].type == SENSOR_TYPE_MAGNETIC_FIELD)
+        continue;
+
+      // Bug 938035, transfer HAL data for orientation sensor to meet w3c spec
+      // ex: HAL report alpha=90 means East but alpha=90 means West in w3c spec
+      if (buffer[i].type == SENSOR_TYPE_ORIENTATION) {
+        buffer[i].orientation.azimuth = 360 - buffer[i].orientation.azimuth;
+        buffer[i].orientation.pitch = -buffer[i].orientation.pitch;
+        buffer[i].orientation.roll = -buffer[i].orientation.roll;
+      }
+
+      if (HardwareSensorToHalSensor(buffer[i].type) == SENSOR_UNKNOWN) {
+        // Emulator is broken and gives us events without types set
+        int index;
+        for (index = 0; index < size; index++) {
+          if (sensors[index].handle == buffer[i].sensor) {
+            break;
+          }
+        }
+        if (index < size &&
+            HardwareSensorToHalSensor(sensors[index].type) != SENSOR_UNKNOWN) {
+          buffer[i].type = sensors[index].type;
+        } else {
+          HAL_LOG("Could not determine sensor type of event");
+          continue;
+        }
+      }
+
+      NS_DispatchToMainThread(new SensorRunnable(buffer[i], sensors, size));
+    }
+  } while (true);
+}
+
+static void
+SwitchSensor(bool aActivate, sensor_t aSensor, pthread_t aThreadId)
+{
+  int index = HardwareSensorToHalSensor(aSensor.type);
+
+  MOZ_ASSERT(sSensorRefCount[index] || aActivate);
+
+  sSensorDevice->activate(sSensorDevice, aSensor.handle, aActivate);
+
+  if (aActivate) {
+    if (aSensor.type == SENSOR_TYPE_ACCELEROMETER) {
+      sSensorDevice->setDelay(sSensorDevice, aSensor.handle,
+                   ACCELEROMETER_POLL_RATE);
+    } else {
+      sSensorDevice->setDelay(sSensorDevice, aSensor.handle,
+                   DEFAULT_DEVICE_POLL_RATE);
+    }
+  }
+
+  if (aActivate) {
+    sSensorRefCount[index]++;
+  } else {
+    sSensorRefCount[index]--;
+  }
+}
+
+static void
+SetSensorState(SensorType aSensor, bool activate)
+{
+  int type = HalSensorToHardwareSensor(aSensor);
+  const sensor_t* sensors = nullptr;
+
+  int size = sSensorModule->get_sensors_list(sSensorModule, &sensors);
+  for (ssize_t i = 0; i < size; i++) {
+    if (sensors[i].type == type) {
+      SwitchSensor(activate, sensors[i], pthread_self());
+      break;
+    }
+  }
+}
+
+static void
+EnableSensorNotificationsInternal(SensorType aSensor)
+{
+  if (!sSensorModule) {
+    hw_get_module(SENSORS_HARDWARE_MODULE_ID,
+                       (hw_module_t const**)&sSensorModule);
+    if (!sSensorModule) {
+      HAL_ERR("Can't get sensor HAL module\n");
+      return;
+    }
+
+    sensors_open(&sSensorModule->common, &sSensorDevice);
+    if (!sSensorDevice) {
+      sSensorModule = nullptr;
+      HAL_ERR("Can't get sensor poll device from module \n");
+      return;
+    }
+
+    sensor_t const* sensors;
+    int count = sSensorModule->get_sensors_list(sSensorModule, &sensors);
+    for (size_t i=0 ; i<size_t(count) ; i++) {
+      sSensorDevice->activate(sSensorDevice, sensors[i].handle, 0);
+    }
+  }
+
+  if (!sPollingThread) {
+    sPollingThread = new base::Thread("GonkSensors");
+    MOZ_ASSERT(sPollingThread);
+    // sPollingThread never terminates because poll may never return
+    sPollingThread->Start();
+    sPollingThread->message_loop()->PostTask(
+      NewRunnableFunction(PollSensors));
+  }
+
+  SetSensorState(aSensor, true);
+}
+
+static void
+DisableSensorNotificationsInternal(SensorType aSensor)
+{
+  if (!sSensorModule) {
+    return;
+  }
+  SetSensorState(aSensor, false);
+}
+
+//
+// Daemon
+//
+
+typedef detail::SaturateOp<uint32_t> SaturateOpUint32;
+
+/**
+ * The poll notification handler receives all events about sensors and
+ * sensor events.
+ */
+class SensorsPollNotificationHandler final
+  : public GonkSensorsPollNotificationHandler
+{
+public:
+  SensorsPollNotificationHandler(GonkSensorsPollInterface* aPollInterface)
+    : mPollInterface(aPollInterface)
+  {
+    MOZ_ASSERT(mPollInterface);
+
+    mPollInterface->SetNotificationHandler(this);
+  }
+
+  void EnableSensorsByType(SensorsType aType)
+  {
+    if (SaturateOpUint32(mClasses[aType].mActivated)++) {
+      return;
+    }
+
+    SensorsDeliveryMode deliveryMode = DefaultSensorsDeliveryMode(aType);
+
+    // Old ref-count for the sensor type was 0, so we
+    // activate all sensors of the type.
+    for (size_t i = 0; i < mSensors.Length(); ++i) {
+      if (mSensors[i].mType == aType &&
+          mSensors[i].mDeliveryMode == deliveryMode) {
+        mPollInterface->EnableSensor(mSensors[i].mId, nullptr);
+        mPollInterface->SetPeriod(mSensors[i].mId, DefaultSensorPeriod(aType),
+                                  nullptr);
+      }
+    }
+  }
+
+  void DisableSensorsByType(SensorsType aType)
+  {
+    if (SaturateOpUint32(mClasses[aType].mActivated)-- != 1) {
+      return;
+    }
+
+    SensorsDeliveryMode deliveryMode = DefaultSensorsDeliveryMode(aType);
+
+    // Old ref-count for the sensor type was 1, so we
+    // deactivate all sensors of the type.
+    for (size_t i = 0; i < mSensors.Length(); ++i) {
+      if (mSensors[i].mType == aType &&
+          mSensors[i].mDeliveryMode == deliveryMode) {
+        mPollInterface->DisableSensor(mSensors[i].mId, nullptr);
+      }
+    }
+  }
+
+  void ClearSensorClasses()
+  {
+    for (size_t i = 0; i < MOZ_ARRAY_LENGTH(mClasses); ++i) {
+      mClasses[i] = SensorsSensorClass();
+    }
+  }
+
+  void ClearSensors()
+  {
+    mSensors.Clear();
+  }
+
+  // Methods for SensorsPollNotificationHandler
+  //
+
+  void ErrorNotification(SensorsError aError) override
+  {
+    // XXX: Bug 1206056: Try to repair some of the errors or restart cleanly.
+  }
+
+  void SensorDetectedNotification(int32_t aId, SensorsType aType,
+                                  float aRange, float aResolution,
+                                  float aPower, int32_t aMinPeriod,
+                                  int32_t aMaxPeriod,
+                                  SensorsTriggerMode aTriggerMode,
+                                  SensorsDeliveryMode aDeliveryMode) override
+  {
+    auto i = FindSensorIndexById(aId);
+    if (i == -1) {
+      // Add a new sensor...
+      i = mSensors.Length();
+      mSensors.AppendElement(SensorsSensor(aId, aType, aRange, aResolution,
+                                           aPower, aMinPeriod, aMaxPeriod,
+                                           aTriggerMode, aDeliveryMode));
+    } else {
+      // ...or update an existing one.
+      mSensors[i] = SensorsSensor(aId, aType, aRange, aResolution, aPower,
+                                  aMinPeriod, aMaxPeriod, aTriggerMode,
+                                  aDeliveryMode);
+    }
+
+    mClasses[aType].UpdateFromSensor(mSensors[i]);
+
+    if (mClasses[aType].mActivated &&
+        mSensors[i].mDeliveryMode == DefaultSensorsDeliveryMode(aType)) {
+      // The new sensor's type is enabled, so enable sensor.
+      mPollInterface->EnableSensor(aId, nullptr);
+      mPollInterface->SetPeriod(mSensors[i].mId, DefaultSensorPeriod(aType),
+                                nullptr);
+    }
+  }
+
+  void SensorLostNotification(int32_t aId) override
+  {
+    auto i = FindSensorIndexById(aId);
+    if (i != -1) {
+      mSensors.RemoveElementAt(i);
+    }
+  }
+
+  void EventNotification(int32_t aId, const SensorsEvent& aEvent) override
+  {
+    auto i = FindSensorIndexById(aId);
+    if (i == -1) {
+      HAL_ERR("Sensor %d not registered", aId);
+      return;
+    }
+
+    SensorData sensorData;
+    auto rv = CreateSensorData(aEvent, mClasses[mSensors[i].mType],
+                               sensorData);
+    if (NS_FAILED(rv)) {
+      return;
+    }
+
+    NotifySensorChange(sensorData);
+  }
+
+private:
+  ssize_t FindSensorIndexById(int32_t aId) const
+  {
+    for (size_t i = 0; i < mSensors.Length(); ++i) {
+      if (mSensors[i].mId == aId) {
+        return i;
+      }
+    }
+    return -1;
+  }
+
+  uint64_t DefaultSensorPeriod(SensorsType aType) const
+  {
+    return aType == SENSORS_TYPE_ACCELEROMETER ? ACCELEROMETER_POLL_RATE
+                                               : DEFAULT_DEVICE_POLL_RATE;
+  }
+
+  SensorsDeliveryMode DefaultSensorsDeliveryMode(SensorsType aType) const
+  {
+    if (aType == SENSORS_TYPE_PROXIMITY ||
+        aType == SENSORS_TYPE_SIGNIFICANT_MOTION) {
+      return SENSORS_DELIVERY_MODE_IMMEDIATE;
+    }
+    return SENSORS_DELIVERY_MODE_BEST_EFFORT;
+  }
+
+  SensorType HardwareSensorToHalSensor(SensorsType aType) const
+  {
+    // FIXME: bug 802004, add proper support for the magnetic-field sensor.
+    switch (aType) {
+      case SENSORS_TYPE_ORIENTATION:
+        return SENSOR_ORIENTATION;
+      case SENSORS_TYPE_ACCELEROMETER:
+        return SENSOR_ACCELERATION;
+      case SENSORS_TYPE_PROXIMITY:
+        return SENSOR_PROXIMITY;
+      case SENSORS_TYPE_LIGHT:
+        return SENSOR_LIGHT;
+      case SENSORS_TYPE_GYROSCOPE:
+        return SENSOR_GYROSCOPE;
+      case SENSORS_TYPE_LINEAR_ACCELERATION:
+        return SENSOR_LINEAR_ACCELERATION;
+      case SENSORS_TYPE_ROTATION_VECTOR:
+        return SENSOR_ROTATION_VECTOR;
+      case SENSORS_TYPE_GAME_ROTATION_VECTOR:
+        return SENSOR_GAME_ROTATION_VECTOR;
+      default:
+        NS_NOTREACHED("Invalid sensors type");
+    }
+    return SENSOR_UNKNOWN;
+  }
+
+  SensorAccuracyType HardwareStatusToHalAccuracy(SensorsStatus aStatus) const
+  {
+    return static_cast<SensorAccuracyType>(aStatus - 1);
+  }
+
+  nsresult CreateSensorData(const SensorsEvent& aEvent,
+                            const SensorsSensorClass& aSensorClass,
+                            SensorData& aSensorData) const
+  {
+    AutoTArray<float, 4> sensorValues;
+
+    auto sensor = HardwareSensorToHalSensor(aEvent.mType);
+
+    if (sensor == SENSOR_UNKNOWN) {
+      return NS_ERROR_ILLEGAL_VALUE;
+    }
+
+    aSensorData.sensor() = sensor;
+    aSensorData.accuracy() = HardwareStatusToHalAccuracy(aEvent.mStatus);
+    aSensorData.timestamp() = aEvent.mTimestamp;
+
+    if (aSensorData.sensor() == SENSOR_ORIENTATION) {
+      // Bug 938035: transfer HAL data for orientation sensor to meet W3C spec
+      // ex: HAL report alpha=90 means East but alpha=90 means West in W3C spec
+      sensorValues.AppendElement(360.0 - radToDeg(aEvent.mData.mFloat[0]));
+      sensorValues.AppendElement(-radToDeg(aEvent.mData.mFloat[1]));
+      sensorValues.AppendElement(-radToDeg(aEvent.mData.mFloat[2]));
+    } else if (aSensorData.sensor() == SENSOR_ACCELERATION) {
+      sensorValues.AppendElement(aEvent.mData.mFloat[0]);
+      sensorValues.AppendElement(aEvent.mData.mFloat[1]);
+      sensorValues.AppendElement(aEvent.mData.mFloat[2]);
+    } else if (aSensorData.sensor() == SENSOR_PROXIMITY) {
+      sensorValues.AppendElement(aEvent.mData.mFloat[0]);
+      sensorValues.AppendElement(aSensorClass.mMinValue);
+      sensorValues.AppendElement(aSensorClass.mMaxValue);
+    } else if (aSensorData.sensor() == SENSOR_LINEAR_ACCELERATION) {
+      sensorValues.AppendElement(aEvent.mData.mFloat[0]);
+      sensorValues.AppendElement(aEvent.mData.mFloat[1]);
+      sensorValues.AppendElement(aEvent.mData.mFloat[2]);
+    } else if (aSensorData.sensor() == SENSOR_GYROSCOPE) {
+      sensorValues.AppendElement(radToDeg(aEvent.mData.mFloat[0]));
+      sensorValues.AppendElement(radToDeg(aEvent.mData.mFloat[1]));
+      sensorValues.AppendElement(radToDeg(aEvent.mData.mFloat[2]));
+    } else if (aSensorData.sensor() == SENSOR_LIGHT) {
+      sensorValues.AppendElement(aEvent.mData.mFloat[0]);
+    } else if (aSensorData.sensor() == SENSOR_ROTATION_VECTOR) {
+      sensorValues.AppendElement(aEvent.mData.mFloat[0]);
+      sensorValues.AppendElement(aEvent.mData.mFloat[1]);
+      sensorValues.AppendElement(aEvent.mData.mFloat[2]);
+      sensorValues.AppendElement(aEvent.mData.mFloat[3]);
+    } else if (aSensorData.sensor() == SENSOR_GAME_ROTATION_VECTOR) {
+      sensorValues.AppendElement(aEvent.mData.mFloat[0]);
+      sensorValues.AppendElement(aEvent.mData.mFloat[1]);
+      sensorValues.AppendElement(aEvent.mData.mFloat[2]);
+      sensorValues.AppendElement(aEvent.mData.mFloat[3]);
+    }
+
+    aSensorData.values() = sensorValues;
+
+    return NS_OK;
+  }
+
+  GonkSensorsPollInterface* mPollInterface;
+  nsTArray<SensorsSensor> mSensors;
+  SensorsSensorClass mClasses[SENSORS_NUM_TYPES];
+};
+
+static StaticAutoPtr<SensorsPollNotificationHandler> sPollNotificationHandler;
+
+/**
+ * This is the notifiaction handler for the Sensors interface. If the backend
+ * crashes, we can restart it from here.
+ */
+class SensorsNotificationHandler final : public GonkSensorsNotificationHandler
+{
+public:
+  SensorsNotificationHandler(GonkSensorsInterface* aInterface)
+    : mInterface(aInterface)
+  {
+    MOZ_ASSERT(mInterface);
+
+    mInterface->SetNotificationHandler(this);
+  }
+
+  void BackendErrorNotification(bool aCrashed) override
+  {
+    // XXX: Bug 1206056: restart sensorsd
+  }
+
+private:
+  GonkSensorsInterface* mInterface;
+};
+
+static StaticAutoPtr<SensorsNotificationHandler> sNotificationHandler;
+
+/**
+ * |SensorsRegisterModuleResultHandler| implements the result-handler
+ * callback for registering the Poll service and activating the first
+ * sensors. If an error occures during the process, the result handler
+ * disconnects and closes the backend.
+ */
+class SensorsRegisterModuleResultHandler final
+  : public GonkSensorsRegistryResultHandler
+{
+public:
+  SensorsRegisterModuleResultHandler(
+    uint32_t* aSensorsTypeActivated,
+    GonkSensorsInterface* aInterface)
+    : mSensorsTypeActivated(aSensorsTypeActivated)
+    , mInterface(aInterface)
+  {
+    MOZ_ASSERT(mSensorsTypeActivated);
+    MOZ_ASSERT(mInterface);
+  }
+  void OnError(SensorsError aError) override
+  {
+    GonkSensorsRegistryResultHandler::OnError(aError); // print error message
+    Disconnect(); // Registering failed, so close the connection completely
+  }
+  void RegisterModule(uint32_t aProtocolVersion) override
+  {
+    MOZ_ASSERT(NS_IsMainThread());
+    MOZ_ASSERT(!sPollNotificationHandler);
+
+    // Init, step 3: set notification handler for poll service and vice versa
+    auto pollInterface = mInterface->GetSensorsPollInterface();
+    if (!pollInterface) {
+      Disconnect();
+      return;
+    }
+    if (NS_FAILED(pollInterface->SetProtocolVersion(aProtocolVersion))) {
+      Disconnect();
+      return;
+    }
+
+    sPollNotificationHandler =
+      new SensorsPollNotificationHandler(pollInterface);
+
+    // Init, step 4: activate sensors
+    for (int i = 0; i < SENSORS_NUM_TYPES; ++i) {
+      while (mSensorsTypeActivated[i]) {
+        sPollNotificationHandler->EnableSensorsByType(
+          static_cast<SensorsType>(i));
+        --mSensorsTypeActivated[i];
+      }
+    }
+  }
+public:
+  void Disconnect()
+  {
+    class DisconnectResultHandler final : public GonkSensorsResultHandler
+    {
+    public:
+      void OnError(SensorsError aError)
+      {
+        GonkSensorsResultHandler::OnError(aError); // print error message
+        sNotificationHandler = nullptr;
+      }
+      void Disconnect() override
+      {
+        sNotificationHandler = nullptr;
+      }
+    };
+    mInterface->Disconnect(new DisconnectResultHandler());
+  }
+private:
+  uint32_t* mSensorsTypeActivated;
+  GonkSensorsInterface* mInterface;
+};
+
+/**
+ * |SensorsConnectResultHandler| implements the result-handler
+ * callback for starting the Sensors backend.
+ */
+class SensorsConnectResultHandler final : public GonkSensorsResultHandler
+{
+public:
+  SensorsConnectResultHandler(
+    uint32_t* aSensorsTypeActivated,
+    GonkSensorsInterface* aInterface)
+    : mSensorsTypeActivated(aSensorsTypeActivated)
+    , mInterface(aInterface)
+  {
+    MOZ_ASSERT(mSensorsTypeActivated);
+    MOZ_ASSERT(mInterface);
+  }
+  void OnError(SensorsError aError) override
+  {
+    GonkSensorsResultHandler::OnError(aError); // print error message
+    sNotificationHandler = nullptr;
+  }
+  void Connect() override
+  {
+    MOZ_ASSERT(NS_IsMainThread());
+
+    // Init, step 2: register poll service
+    auto registryInterface = mInterface->GetSensorsRegistryInterface();
+    if (!registryInterface) {
+      return;
+    }
+    registryInterface->RegisterModule(
+      GonkSensorsPollModule::SERVICE_ID,
+      new SensorsRegisterModuleResultHandler(mSensorsTypeActivated,
+                                             mInterface));
+  }
+private:
+  uint32_t* mSensorsTypeActivated;
+  GonkSensorsInterface* mInterface;
+};
+
+static uint32_t sSensorsTypeActivated[SENSORS_NUM_TYPES];
+
+static const SensorsType sSensorsType[] = {
+  [SENSOR_ORIENTATION] = SENSORS_TYPE_ORIENTATION,
+  [SENSOR_ACCELERATION] = SENSORS_TYPE_ACCELEROMETER,
+  [SENSOR_PROXIMITY] = SENSORS_TYPE_PROXIMITY,
+  [SENSOR_LINEAR_ACCELERATION] = SENSORS_TYPE_LINEAR_ACCELERATION,
+  [SENSOR_GYROSCOPE] = SENSORS_TYPE_GYROSCOPE,
+  [SENSOR_LIGHT] = SENSORS_TYPE_LIGHT,
+  [SENSOR_ROTATION_VECTOR] = SENSORS_TYPE_ROTATION_VECTOR,
+  [SENSOR_GAME_ROTATION_VECTOR] = SENSORS_TYPE_GAME_ROTATION_VECTOR
+};
+
+void
+EnableSensorNotificationsDaemon(SensorType aSensor)
+{
+  if ((aSensor < 0) ||
+      (aSensor > static_cast<ssize_t>(MOZ_ARRAY_LENGTH(sSensorsType)))) {
+    HAL_ERR("Sensor type %d not known", aSensor);
+    return; // Unsupported sensor type
+  }
+
+  auto interface = GonkSensorsInterface::GetInstance();
+  if (!interface) {
+    return;
+  }
+
+  if (sPollNotificationHandler) {
+    // Everythings already up and running; enable sensor type.
+    sPollNotificationHandler->EnableSensorsByType(sSensorsType[aSensor]);
+    return;
+  }
+
+  ++SaturateOpUint32(sSensorsTypeActivated[sSensorsType[aSensor]]);
+
+  if (sNotificationHandler) {
+    // We are in the middle of a pending start up; nothing else to do.
+    return;
+  }
+
+  // Start up
+
+  MOZ_ASSERT(!sPollNotificationHandler);
+  MOZ_ASSERT(!sNotificationHandler);
+
+  sNotificationHandler = new SensorsNotificationHandler(interface);
+
+  // Init, step 1: connect to Sensors backend
+  interface->Connect(
+    sNotificationHandler,
+    new SensorsConnectResultHandler(sSensorsTypeActivated, interface));
+}
+
+void
+DisableSensorNotificationsDaemon(SensorType aSensor)
+{
+  if ((aSensor < 0) ||
+      (aSensor > static_cast<ssize_t>(MOZ_ARRAY_LENGTH(sSensorsType)))) {
+    HAL_ERR("Sensor type %d not known", aSensor);
+    return; // Unsupported sensor type
+  }
+
+  if (sPollNotificationHandler) {
+    // Everthings up and running; disable sensors type
+    sPollNotificationHandler->DisableSensorsByType(sSensorsType[aSensor]);
+    return;
+  }
+
+  // We might be in the middle of a startup; decrement type's ref-counter.
+  --SaturateOpUint32(sSensorsTypeActivated[sSensorsType[aSensor]]);
+
+  // TODO: stop sensorsd if all sensors are disabled
+}
+
+//
+// Public interface
+//
+
+// TODO: Remove in-Gecko sensors code. Until all devices' base
+// images come with sensorsd installed, we have to support the
+// in-Gecko implementation as well. So we test for the existance
+// of the binary. If it's there, we use it. Otherwise we run the
+// old code.
+static bool
+HasDaemon()
+{
+  static bool tested;
+  static bool hasDaemon;
+
+  if (MOZ_UNLIKELY(!tested)) {
+    hasDaemon = !access("/system/bin/sensorsd", X_OK);
+    tested = true;
+  }
+
+  return hasDaemon;
+}
+
+void
+EnableSensorNotifications(SensorType aSensor)
+{
+  if (HasDaemon()) {
+    EnableSensorNotificationsDaemon(aSensor);
+  } else {
+    EnableSensorNotificationsInternal(aSensor);
+  }
+}
+
+void
+DisableSensorNotifications(SensorType aSensor)
+{
+  if (HasDaemon()) {
+    DisableSensorNotificationsDaemon(aSensor);
+  } else {
+    DisableSensorNotificationsInternal(aSensor);
+  }
+}
+
+} // hal_impl
+} // mozilla
diff --git a/hal/gonk/GonkSensorsHelpers.cpp b/hal/gonk/GonkSensorsHelpers.cpp
new file mode 100644
index 000000000..ccc940c7c
--- /dev/null
+++ b/hal/gonk/GonkSensorsHelpers.cpp
@@ -0,0 +1,112 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "GonkSensorsHelpers.h"
+
+namespace mozilla {
+namespace hal {
+
+//
+// Unpacking
+//
+
+nsresult
+UnpackPDU(DaemonSocketPDU& aPDU, SensorsEvent& aOut)
+{
+  nsresult rv = UnpackPDU(aPDU, aOut.mType);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  rv = UnpackPDU(aPDU, aOut.mTimestamp);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  rv = UnpackPDU(aPDU, aOut.mStatus);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  size_t i = 0;
+
+  switch (aOut.mType) {
+    case SENSORS_TYPE_MAGNETIC_FIELD_UNCALIBRATED:
+    case SENSORS_TYPE_GYROSCOPE_UNCALIBRATED:
+      /* 6 data values */
+      rv = UnpackPDU(aPDU, aOut.mData.mFloat[i++]);
+      if (NS_FAILED(rv)) {
+        return rv;
+      }
+      /* fall through */
+    case SENSORS_TYPE_ROTATION_VECTOR:
+    case SENSORS_TYPE_GAME_ROTATION_VECTOR:
+    case SENSORS_TYPE_GEOMAGNETIC_ROTATION_VECTOR:
+      /* 5 data values */
+      rv = UnpackPDU(aPDU, aOut.mData.mFloat[i++]);
+      if (NS_FAILED(rv)) {
+        return rv;
+      }
+      rv = UnpackPDU(aPDU, aOut.mData.mFloat[i++]);
+      if (NS_FAILED(rv)) {
+        return rv;
+      }
+      /* fall through */
+    case SENSORS_TYPE_ACCELEROMETER:
+    case SENSORS_TYPE_GEOMAGNETIC_FIELD:
+    case SENSORS_TYPE_ORIENTATION:
+    case SENSORS_TYPE_GYROSCOPE:
+    case SENSORS_TYPE_GRAVITY:
+    case SENSORS_TYPE_LINEAR_ACCELERATION:
+      /* 3 data values */
+      rv = UnpackPDU(aPDU, aOut.mData.mFloat[i++]);
+      if (NS_FAILED(rv)) {
+        return rv;
+      }
+      rv = UnpackPDU(aPDU, aOut.mData.mFloat[i++]);
+      if (NS_FAILED(rv)) {
+        return rv;
+      }
+      /* fall through */
+    case SENSORS_TYPE_LIGHT:
+    case SENSORS_TYPE_PRESSURE:
+    case SENSORS_TYPE_TEMPERATURE:
+    case SENSORS_TYPE_PROXIMITY:
+    case SENSORS_TYPE_RELATIVE_HUMIDITY:
+    case SENSORS_TYPE_AMBIENT_TEMPERATURE:
+    case SENSORS_TYPE_HEART_RATE:
+    case SENSORS_TYPE_TILT_DETECTOR:
+    case SENSORS_TYPE_WAKE_GESTURE:
+    case SENSORS_TYPE_GLANCE_GESTURE:
+    case SENSORS_TYPE_PICK_UP_GESTURE:
+    case SENSORS_TYPE_WRIST_TILT_GESTURE:
+    case SENSORS_TYPE_SIGNIFICANT_MOTION:
+    case SENSORS_TYPE_STEP_DETECTED:
+      /* 1 data value */
+      rv = UnpackPDU(aPDU, aOut.mData.mFloat[i++]);
+      if (NS_FAILED(rv)) {
+        return rv;
+      }
+      break;
+    case SENSORS_TYPE_STEP_COUNTER:
+      /* 1 data value */
+      rv = UnpackPDU(aPDU, aOut.mData.mUint[0]);
+      if (NS_FAILED(rv)) {
+        return rv;
+      }
+      break;
+    default:
+      if (MOZ_HAL_IPC_UNPACK_WARN_IF(true, SensorsEvent)) {
+        return NS_ERROR_ILLEGAL_VALUE;
+      }
+  }
+  rv = UnpackPDU(aPDU, aOut.mDeliveryMode);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  return NS_OK;
+}
+
+} // namespace hal
+} // namespace mozilla
diff --git a/hal/gonk/GonkSensorsHelpers.h b/hal/gonk/GonkSensorsHelpers.h
new file mode 100644
index 000000000..5218af53a
--- /dev/null
+++ b/hal/gonk/GonkSensorsHelpers.h
@@ -0,0 +1,226 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef hal_gonk_GonkSensorsHelpers_h
+#define hal_gonk_GonkSensorsHelpers_h
+
+#include <mozilla/ipc/DaemonSocketPDU.h>
+#include <mozilla/ipc/DaemonSocketPDUHelpers.h>
+#include "SensorsTypes.h"
+
+namespace mozilla {
+namespace hal {
+
+using mozilla::ipc::DaemonSocketPDU;
+using mozilla::ipc::DaemonSocketPDUHeader;
+using mozilla::ipc::DaemonSocketPDUHelpers::Convert;
+using mozilla::ipc::DaemonSocketPDUHelpers::PackPDU;
+using mozilla::ipc::DaemonSocketPDUHelpers::UnpackPDU;
+
+using namespace mozilla::ipc::DaemonSocketPDUHelpers;
+
+//
+// Conversion
+//
+// The functions below convert the input value to the output value's
+// type and perform extension tests on the validity of the result. On
+// success the output value will be returned in |aOut|. The functions
+// return NS_OK on success, or an XPCOM error code otherwise.
+//
+// See the documentation of the HAL IPC framework for more information
+// on conversion functions.
+//
+
+nsresult
+Convert(int32_t aIn, SensorsStatus& aOut)
+{
+  static const uint8_t sStatus[] = {
+    [0] = SENSORS_STATUS_NO_CONTACT, // '-1'
+    [1] = SENSORS_STATUS_UNRELIABLE, // '0'
+    [2] = SENSORS_STATUS_ACCURACY_LOW, // '1'
+    [3] = SENSORS_STATUS_ACCURACY_MEDIUM, // '2'
+    [4] = SENSORS_STATUS_ACCURACY_HIGH // '3'
+  };
+  static const int8_t sOffset = -1; // '-1' is the lower bound of the status
+
+  if (MOZ_HAL_IPC_CONVERT_WARN_IF(aIn < sOffset, int32_t, SensorsStatus) ||
+      MOZ_HAL_IPC_CONVERT_WARN_IF(
+        aIn >= (static_cast<ssize_t>(MOZ_ARRAY_LENGTH(sStatus)) + sOffset),
+        int32_t, SensorsStatus)) {
+    return NS_ERROR_ILLEGAL_VALUE;
+  }
+  aOut = static_cast<SensorsStatus>(sStatus[aIn - sOffset]);
+  return NS_OK;
+}
+
+nsresult
+Convert(uint8_t aIn, SensorsDeliveryMode& aOut)
+{
+  static const uint8_t sMode[] = {
+    [0x00] = SENSORS_DELIVERY_MODE_BEST_EFFORT,
+    [0x01] = SENSORS_DELIVERY_MODE_IMMEDIATE
+  };
+  if (MOZ_HAL_IPC_CONVERT_WARN_IF(
+        aIn >= MOZ_ARRAY_LENGTH(sMode), uint8_t, SensorsDeliveryMode)) {
+    return NS_ERROR_ILLEGAL_VALUE;
+  }
+  aOut = static_cast<SensorsDeliveryMode>(sMode[aIn]);
+  return NS_OK;
+}
+
+nsresult
+Convert(uint8_t aIn, SensorsError& aOut)
+{
+  static const uint8_t sError[] = {
+    [0x00] = SENSORS_ERROR_NONE,
+    [0x01] = SENSORS_ERROR_FAIL,
+    [0x02] = SENSORS_ERROR_NOT_READY,
+    [0x03] = SENSORS_ERROR_NOMEM,
+    [0x04] = SENSORS_ERROR_BUSY,
+    [0x05] = SENSORS_ERROR_DONE,
+    [0x06] = SENSORS_ERROR_UNSUPPORTED,
+    [0x07] = SENSORS_ERROR_PARM_INVALID
+  };
+  if (MOZ_HAL_IPC_CONVERT_WARN_IF(
+        aIn >= MOZ_ARRAY_LENGTH(sError), uint8_t, SensorsError)) {
+    return NS_ERROR_ILLEGAL_VALUE;
+  }
+  aOut = static_cast<SensorsError>(sError[aIn]);
+  return NS_OK;
+}
+
+nsresult
+Convert(uint8_t aIn, SensorsTriggerMode& aOut)
+{
+  static const uint8_t sMode[] = {
+    [0x00] = SENSORS_TRIGGER_MODE_CONTINUOUS,
+    [0x01] = SENSORS_TRIGGER_MODE_ON_CHANGE,
+    [0x02] = SENSORS_TRIGGER_MODE_ONE_SHOT,
+    [0x03] = SENSORS_TRIGGER_MODE_SPECIAL
+  };
+  if (MOZ_HAL_IPC_CONVERT_WARN_IF(
+        aIn >= MOZ_ARRAY_LENGTH(sMode), uint8_t, SensorsTriggerMode)) {
+    return NS_ERROR_ILLEGAL_VALUE;
+  }
+  aOut = static_cast<SensorsTriggerMode>(sMode[aIn]);
+  return NS_OK;
+}
+
+nsresult
+Convert(uint32_t aIn, SensorsType& aOut)
+{
+  static const uint8_t sType[] = {
+    [0x00] = 0, // invalid, required by gcc
+    [0x01] = SENSORS_TYPE_ACCELEROMETER,
+    [0x02] = SENSORS_TYPE_GEOMAGNETIC_FIELD,
+    [0x03] = SENSORS_TYPE_ORIENTATION,
+    [0x04] = SENSORS_TYPE_GYROSCOPE,
+    [0x05] = SENSORS_TYPE_LIGHT,
+    [0x06] = SENSORS_TYPE_PRESSURE,
+    [0x07] = SENSORS_TYPE_TEMPERATURE,
+    [0x08] = SENSORS_TYPE_PROXIMITY,
+    [0x09] = SENSORS_TYPE_GRAVITY,
+    [0x0a] = SENSORS_TYPE_LINEAR_ACCELERATION,
+    [0x0b] = SENSORS_TYPE_ROTATION_VECTOR,
+    [0x0c] = SENSORS_TYPE_RELATIVE_HUMIDITY,
+    [0x0d] = SENSORS_TYPE_AMBIENT_TEMPERATURE,
+    [0x0e] = SENSORS_TYPE_MAGNETIC_FIELD_UNCALIBRATED,
+    [0x0f] = SENSORS_TYPE_GAME_ROTATION_VECTOR,
+    [0x10] = SENSORS_TYPE_GYROSCOPE_UNCALIBRATED,
+    [0x11] = SENSORS_TYPE_SIGNIFICANT_MOTION,
+    [0x12] = SENSORS_TYPE_STEP_DETECTED,
+    [0x13] = SENSORS_TYPE_STEP_COUNTER,
+    [0x14] = SENSORS_TYPE_GEOMAGNETIC_ROTATION_VECTOR,
+    [0x15] = SENSORS_TYPE_HEART_RATE,
+    [0x16] = SENSORS_TYPE_TILT_DETECTOR,
+    [0x17] = SENSORS_TYPE_WAKE_GESTURE,
+    [0x18] = SENSORS_TYPE_GLANCE_GESTURE,
+    [0x19] = SENSORS_TYPE_PICK_UP_GESTURE,
+    [0x1a] = SENSORS_TYPE_WRIST_TILT_GESTURE
+  };
+  if (MOZ_HAL_IPC_CONVERT_WARN_IF(
+        !aIn, uint32_t, SensorsType) ||
+      MOZ_HAL_IPC_CONVERT_WARN_IF(
+        aIn >= MOZ_ARRAY_LENGTH(sType), uint32_t, SensorsType)) {
+    return NS_ERROR_ILLEGAL_VALUE;
+  }
+  aOut = static_cast<SensorsType>(sType[aIn]);
+  return NS_OK;
+}
+
+nsresult
+Convert(nsresult aIn, SensorsError& aOut)
+{
+  if (NS_SUCCEEDED(aIn)) {
+    aOut = SENSORS_ERROR_NONE;
+  } else if (aIn == NS_ERROR_OUT_OF_MEMORY) {
+    aOut = SENSORS_ERROR_NOMEM;
+  } else if (aIn == NS_ERROR_ILLEGAL_VALUE) {
+    aOut = SENSORS_ERROR_PARM_INVALID;
+  } else {
+    aOut = SENSORS_ERROR_FAIL;
+  }
+  return NS_OK;
+}
+
+//
+// Packing
+//
+// Pack functions store a value in PDU. See the documentation of the
+// HAL IPC framework for more information.
+//
+// There are currently no sensor-specific pack functions necessary. If
+// you add one, put it below.
+//
+
+//
+// Unpacking
+//
+// Unpack function retrieve a value from a PDU. The functions return
+// NS_OK on success, or an XPCOM error code otherwise. On sucess, the
+// returned value is stored in the second argument |aOut|.
+//
+// See the documentation of the HAL IPC framework for more information
+// on unpack functions.
+//
+
+nsresult
+UnpackPDU(DaemonSocketPDU& aPDU, SensorsDeliveryMode& aOut)
+{
+  return UnpackPDU(aPDU, UnpackConversion<uint8_t, SensorsDeliveryMode>(aOut));
+}
+
+nsresult
+UnpackPDU(DaemonSocketPDU& aPDU, SensorsError& aOut)
+{
+  return UnpackPDU(aPDU, UnpackConversion<uint8_t, SensorsError>(aOut));
+}
+
+nsresult
+UnpackPDU(DaemonSocketPDU& aPDU, SensorsEvent& aOut);
+
+nsresult
+UnpackPDU(DaemonSocketPDU& aPDU, SensorsStatus& aOut)
+{
+  return UnpackPDU(aPDU, UnpackConversion<int32_t, SensorsStatus>(aOut));
+}
+
+nsresult
+UnpackPDU(DaemonSocketPDU& aPDU, SensorsTriggerMode& aOut)
+{
+  return UnpackPDU(aPDU, UnpackConversion<uint8_t, SensorsTriggerMode>(aOut));
+}
+
+nsresult
+UnpackPDU(DaemonSocketPDU& aPDU, SensorsType& aOut)
+{
+  return UnpackPDU(aPDU, UnpackConversion<uint32_t, SensorsType>(aOut));
+}
+
+} // namespace hal
+} // namespace mozilla
+
+#endif // hal_gonk_GonkSensorsHelpers_h
diff --git a/hal/gonk/GonkSensorsInterface.cpp b/hal/gonk/GonkSensorsInterface.cpp
new file mode 100644
index 000000000..51e1ff50c
--- /dev/null
+++ b/hal/gonk/GonkSensorsInterface.cpp
@@ -0,0 +1,494 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "GonkSensorsInterface.h"
+#include "GonkSensorsPollInterface.h"
+#include "GonkSensorsRegistryInterface.h"
+#include "HalLog.h"
+#include <mozilla/ipc/DaemonSocket.h>
+#include <mozilla/ipc/DaemonSocketConnector.h>
+#include <mozilla/ipc/ListenSocket.h>
+
+namespace mozilla {
+namespace hal {
+
+using namespace mozilla::ipc;
+
+//
+// GonkSensorsResultHandler
+//
+
+void
+GonkSensorsResultHandler::OnError(SensorsError aError)
+{
+  HAL_ERR("Received error code %d", static_cast<int>(aError));
+}
+
+void
+GonkSensorsResultHandler::Connect()
+{ }
+
+void
+GonkSensorsResultHandler::Disconnect()
+{ }
+
+GonkSensorsResultHandler::~GonkSensorsResultHandler()
+{ }
+
+//
+// GonkSensorsNotificationHandler
+//
+
+void
+GonkSensorsNotificationHandler::BackendErrorNotification(bool aCrashed)
+{
+  if (aCrashed) {
+    HAL_ERR("Sensors backend crashed");
+  } else {
+    HAL_ERR("Error in sensors backend");
+  }
+}
+
+GonkSensorsNotificationHandler::~GonkSensorsNotificationHandler()
+{ }
+
+//
+// GonkSensorsProtocol
+//
+
+class GonkSensorsProtocol final
+  : public DaemonSocketIOConsumer
+  , public GonkSensorsRegistryModule
+  , public GonkSensorsPollModule
+{
+public:
+  GonkSensorsProtocol();
+
+  void SetConnection(DaemonSocket* aConnection);
+
+  already_AddRefed<DaemonSocketResultHandler> FetchResultHandler(
+    const DaemonSocketPDUHeader& aHeader);
+
+  // Methods for |SensorsRegistryModule| and |SensorsPollModule|
+  //
+
+  nsresult Send(DaemonSocketPDU* aPDU,
+                DaemonSocketResultHandler* aRes) override;
+
+  // Methods for |DaemonSocketIOConsumer|
+  //
+
+  void Handle(DaemonSocketPDU& aPDU) override;
+  void StoreResultHandler(const DaemonSocketPDU& aPDU) override;
+
+private:
+  void HandleRegistrySvc(const DaemonSocketPDUHeader& aHeader,
+                         DaemonSocketPDU& aPDU,
+                         DaemonSocketResultHandler* aRes);
+  void HandlePollSvc(const DaemonSocketPDUHeader& aHeader,
+                     DaemonSocketPDU& aPDU,
+                     DaemonSocketResultHandler* aRes);
+
+  DaemonSocket* mConnection;
+  nsTArray<RefPtr<DaemonSocketResultHandler>> mResultHandlerQ;
+};
+
+GonkSensorsProtocol::GonkSensorsProtocol()
+{ }
+
+void
+GonkSensorsProtocol::SetConnection(DaemonSocket* aConnection)
+{
+  mConnection = aConnection;
+}
+
+already_AddRefed<DaemonSocketResultHandler>
+GonkSensorsProtocol::FetchResultHandler(const DaemonSocketPDUHeader& aHeader)
+{
+  MOZ_ASSERT(!NS_IsMainThread());
+
+  if (aHeader.mOpcode & 0x80) {
+    return nullptr; // Ignore notifications
+  }
+
+  RefPtr<DaemonSocketResultHandler> res = mResultHandlerQ.ElementAt(0);
+  mResultHandlerQ.RemoveElementAt(0);
+
+  return res.forget();
+}
+
+void
+GonkSensorsProtocol::HandleRegistrySvc(
+  const DaemonSocketPDUHeader& aHeader, DaemonSocketPDU& aPDU,
+  DaemonSocketResultHandler* aRes)
+{
+  GonkSensorsRegistryModule::HandleSvc(aHeader, aPDU, aRes);
+}
+
+void
+GonkSensorsProtocol::HandlePollSvc(
+  const DaemonSocketPDUHeader& aHeader, DaemonSocketPDU& aPDU,
+  DaemonSocketResultHandler* aRes)
+{
+  GonkSensorsPollModule::HandleSvc(aHeader, aPDU, aRes);
+}
+
+// |SensorsRegistryModule|, |SensorsPollModule|
+
+nsresult
+GonkSensorsProtocol::Send(DaemonSocketPDU* aPDU,
+                          DaemonSocketResultHandler* aRes)
+{
+  MOZ_ASSERT(mConnection);
+  MOZ_ASSERT(aPDU);
+
+  aPDU->SetConsumer(this);
+  aPDU->SetResultHandler(aRes);
+  aPDU->UpdateHeader();
+
+  if (mConnection->GetConnectionStatus() == SOCKET_DISCONNECTED) {
+    HAL_ERR("Sensors socket is disconnected");
+    return NS_ERROR_FAILURE;
+  }
+
+  mConnection->SendSocketData(aPDU); // Forward PDU to data channel
+
+  return NS_OK;
+}
+
+// |DaemonSocketIOConsumer|
+
+void
+GonkSensorsProtocol::Handle(DaemonSocketPDU& aPDU)
+{
+  static void (GonkSensorsProtocol::* const HandleSvc[])(
+    const DaemonSocketPDUHeader&, DaemonSocketPDU&,
+    DaemonSocketResultHandler*) = {
+    [GonkSensorsRegistryModule::SERVICE_ID] =
+      &GonkSensorsProtocol::HandleRegistrySvc,
+    [GonkSensorsPollModule::SERVICE_ID] =
+      &GonkSensorsProtocol::HandlePollSvc
+  };
+
+  DaemonSocketPDUHeader header;
+
+  if (NS_FAILED(UnpackPDU(aPDU, header))) {
+    return;
+  }
+  if (!(header.mService < MOZ_ARRAY_LENGTH(HandleSvc)) ||
+      !HandleSvc[header.mService]) {
+    HAL_ERR("Sensors service %d unknown", header.mService);
+    return;
+  }
+
+  RefPtr<DaemonSocketResultHandler> res = FetchResultHandler(header);
+
+  (this->*(HandleSvc[header.mService]))(header, aPDU, res);
+}
+
+void
+GonkSensorsProtocol::StoreResultHandler(const DaemonSocketPDU& aPDU)
+{
+  MOZ_ASSERT(!NS_IsMainThread());
+
+  mResultHandlerQ.AppendElement(aPDU.GetResultHandler());
+}
+
+//
+// GonkSensorsInterface
+//
+
+GonkSensorsInterface*
+GonkSensorsInterface::GetInstance()
+{
+  static GonkSensorsInterface* sGonkSensorsInterface;
+
+  if (sGonkSensorsInterface) {
+    return sGonkSensorsInterface;
+  }
+
+  sGonkSensorsInterface = new GonkSensorsInterface();
+
+  return sGonkSensorsInterface;
+}
+
+void
+GonkSensorsInterface::SetNotificationHandler(
+  GonkSensorsNotificationHandler* aNotificationHandler)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  mNotificationHandler = aNotificationHandler;
+}
+
+/*
+ * The connect procedure consists of several steps.
+ *
+ *  (1) Start listening for the command channel's socket connection: We
+ *      do this before anything else, so that we don't miss connection
+ *      requests from the Sensors daemon. This step will create a listen
+ *      socket.
+ *
+ *  (2) Start the Sensors daemon: When the daemon starts up it will open
+ *      a socket connection to Gecko and thus create the data channel.
+ *      Gecko already opened the listen socket in step (1). Step (2) ends
+ *      with the creation of the data channel.
+ *
+ *  (3) Signal success to the caller.
+ *
+ * If any step fails, we roll-back the procedure and signal an error to the
+ * caller.
+ */
+void
+GonkSensorsInterface::Connect(GonkSensorsNotificationHandler* aNotificationHandler,
+                          GonkSensorsResultHandler* aRes)
+{
+#define BASE_SOCKET_NAME "sensorsd"
+  static unsigned long POSTFIX_LENGTH = 16;
+
+  // If we could not cleanup properly before and an old
+  // instance of the daemon is still running, we kill it
+  // here.
+  mozilla::hal::StopSystemService("sensorsd");
+
+  mNotificationHandler = aNotificationHandler;
+
+  mResultHandlerQ.AppendElement(aRes);
+
+  if (!mProtocol) {
+    mProtocol = MakeUnique<GonkSensorsProtocol>();
+  }
+
+  if (!mListenSocket) {
+    mListenSocket = new ListenSocket(this, LISTEN_SOCKET);
+  }
+
+  // Init, step 1: Listen for data channel... */
+
+  if (!mDataSocket) {
+    mDataSocket = new DaemonSocket(mProtocol.get(), this, DATA_SOCKET);
+  } else if (mDataSocket->GetConnectionStatus() == SOCKET_CONNECTED) {
+    // Command channel should not be open; let's close it.
+    mDataSocket->Close();
+  }
+
+  // The listen socket's name is generated with a random postfix. This
+  // avoids naming collisions if we still have a listen socket from a
+  // previously failed cleanup. It also makes it hard for malicious
+  // external programs to capture the socket name or connect before
+  // the daemon can do so. If no random postfix can be generated, we
+  // simply use the base name as-is.
+  nsresult rv = DaemonSocketConnector::CreateRandomAddressString(
+    NS_LITERAL_CSTRING(BASE_SOCKET_NAME), POSTFIX_LENGTH, mListenSocketName);
+  if (NS_FAILED(rv)) {
+    mListenSocketName.AssignLiteral(BASE_SOCKET_NAME);
+  }
+
+  rv = mListenSocket->Listen(new DaemonSocketConnector(mListenSocketName),
+                             mDataSocket);
+  if (NS_FAILED(rv)) {
+    OnConnectError(DATA_SOCKET);
+    return;
+  }
+
+  // The protocol implementation needs a data channel for
+  // sending commands to the daemon. We set it here, because
+  // this is the earliest time when it's available.
+  mProtocol->SetConnection(mDataSocket);
+}
+
+/*
+ * Disconnecting is inverse to connecting.
+ *
+ *  (1) Close data socket: We close the data channel and the daemon will
+ *      will notice. Once we see the socket's disconnect, we continue with
+ *      the cleanup.
+ *
+ *  (2) Close listen socket: The listen socket is not active any longer
+ *      and we simply close it.
+ *
+ *  (3) Signal success to the caller.
+ *
+ * We don't have to stop the daemon explicitly. It will cleanup and quit
+ * after it noticed the closing of the data channel
+ *
+ * Rolling back half-completed cleanups is not possible. In the case of
+ * an error, we simply push forward and try to recover during the next
+ * initialization.
+ */
+void
+GonkSensorsInterface::Disconnect(GonkSensorsResultHandler* aRes)
+{
+  mNotificationHandler = nullptr;
+
+  // Cleanup, step 1: Close data channel
+  mDataSocket->Close();
+
+  mResultHandlerQ.AppendElement(aRes);
+}
+
+GonkSensorsRegistryInterface*
+GonkSensorsInterface::GetSensorsRegistryInterface()
+{
+  if (mRegistryInterface) {
+    return mRegistryInterface.get();
+  }
+
+  mRegistryInterface = MakeUnique<GonkSensorsRegistryInterface>(mProtocol.get());
+
+  return mRegistryInterface.get();
+}
+
+GonkSensorsPollInterface*
+GonkSensorsInterface::GetSensorsPollInterface()
+{
+  if (mPollInterface) {
+    return mPollInterface.get();
+  }
+
+  mPollInterface = MakeUnique<GonkSensorsPollInterface>(mProtocol.get());
+
+  return mPollInterface.get();
+}
+
+GonkSensorsInterface::GonkSensorsInterface()
+  : mNotificationHandler(nullptr)
+{ }
+
+GonkSensorsInterface::~GonkSensorsInterface()
+{ }
+
+void
+GonkSensorsInterface::DispatchError(GonkSensorsResultHandler* aRes,
+                                SensorsError aError)
+{
+  DaemonResultRunnable1<GonkSensorsResultHandler, void,
+                        SensorsError, SensorsError>::Dispatch(
+    aRes, &GonkSensorsResultHandler::OnError,
+    ConstantInitOp1<SensorsError>(aError));
+}
+
+void
+GonkSensorsInterface::DispatchError(
+  GonkSensorsResultHandler* aRes, nsresult aRv)
+{
+  SensorsError error;
+
+  if (NS_FAILED(Convert(aRv, error))) {
+    error = SENSORS_ERROR_FAIL;
+  }
+  DispatchError(aRes, error);
+}
+
+// |DaemonSocketConsumer|, |ListenSocketConsumer|
+
+void
+GonkSensorsInterface::OnConnectSuccess(int aIndex)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(!mResultHandlerQ.IsEmpty());
+
+  switch (aIndex) {
+    case LISTEN_SOCKET: {
+        // Init, step 2: Start Sensors daemon
+        nsCString args("-a ");
+        args.Append(mListenSocketName);
+        mozilla::hal::StartSystemService("sensorsd", args.get());
+      }
+      break;
+    case DATA_SOCKET:
+      if (!mResultHandlerQ.IsEmpty()) {
+        // Init, step 3: Signal success
+        RefPtr<GonkSensorsResultHandler> res = mResultHandlerQ.ElementAt(0);
+        mResultHandlerQ.RemoveElementAt(0);
+        if (res) {
+          res->Connect();
+        }
+      }
+      break;
+  }
+}
+
+void
+GonkSensorsInterface::OnConnectError(int aIndex)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(!mResultHandlerQ.IsEmpty());
+
+  switch (aIndex) {
+    case DATA_SOCKET:
+      // Stop daemon and close listen socket
+      mozilla::hal::StopSystemService("sensorsd");
+      mListenSocket->Close();
+      // fall through
+    case LISTEN_SOCKET:
+      if (!mResultHandlerQ.IsEmpty()) {
+        // Signal error to caller
+        RefPtr<GonkSensorsResultHandler> res = mResultHandlerQ.ElementAt(0);
+        mResultHandlerQ.RemoveElementAt(0);
+        if (res) {
+          DispatchError(res, SENSORS_ERROR_FAIL);
+        }
+      }
+      break;
+  }
+}
+
+/*
+ * Disconnects can happend
+ *
+ *  (a) during startup,
+ *  (b) during regular service, or
+ *  (c) during shutdown.
+ *
+ * For cases (a) and (c), |mResultHandlerQ| contains an element. For
+ * case (b) |mResultHandlerQ| will be empty. This distinguishes a crash in
+ * the daemon. The following procedure to recover from crashes consists of
+ * several steps for case (b).
+ *
+ *  (1) Close listen socket.
+ *  (2) Wait for all sockets to be disconnected and inform caller about
+ *      the crash.
+ *  (3) After all resources have been cleaned up, let the caller restart
+ *      the daemon.
+ */
+void
+GonkSensorsInterface::OnDisconnect(int aIndex)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  switch (aIndex) {
+    case DATA_SOCKET:
+      // Cleanup, step 2 (Recovery, step 1): Close listen socket
+      mListenSocket->Close();
+      break;
+    case LISTEN_SOCKET:
+      // Cleanup, step 3: Signal success to caller
+      if (!mResultHandlerQ.IsEmpty()) {
+        RefPtr<GonkSensorsResultHandler> res = mResultHandlerQ.ElementAt(0);
+        mResultHandlerQ.RemoveElementAt(0);
+        if (res) {
+          res->Disconnect();
+        }
+      }
+      break;
+  }
+
+  /* For recovery make sure all sockets disconnected, in order to avoid
+   * the remaining disconnects interfere with the restart procedure.
+   */
+  if (mNotificationHandler && mResultHandlerQ.IsEmpty()) {
+    if (mListenSocket->GetConnectionStatus() == SOCKET_DISCONNECTED &&
+        mDataSocket->GetConnectionStatus() == SOCKET_DISCONNECTED) {
+      // Recovery, step 2: Notify the caller to prepare the restart procedure.
+      mNotificationHandler->BackendErrorNotification(true);
+      mNotificationHandler = nullptr;
+    }
+  }
+}
+
+} // namespace hal
+} // namespace mozilla
diff --git a/hal/gonk/GonkSensorsInterface.h b/hal/gonk/GonkSensorsInterface.h
new file mode 100644
index 000000000..6e356dc36
--- /dev/null
+++ b/hal/gonk/GonkSensorsInterface.h
@@ -0,0 +1,191 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * The sensors interface gives you access to the low-level sensors code
+ * in a platform-independent manner. The interfaces in this file allow
+ * for starting an stopping the sensors driver. Specific functionality
+ * is implemented in sub-interfaces.
+ */
+
+#ifndef hal_gonk_GonkSensorsInterface_h
+#define hal_gonk_GonkSensorsInterface_h
+
+#include <mozilla/ipc/DaemonSocketConsumer.h>
+#include <mozilla/ipc/DaemonSocketMessageHandlers.h>
+#include <mozilla/ipc/ListenSocketConsumer.h>
+#include <mozilla/UniquePtr.h>
+#include "SensorsTypes.h"
+
+namespace mozilla {
+namespace ipc {
+
+class DaemonSocket;
+class ListenSocket;
+
+}
+}
+
+namespace mozilla {
+namespace hal {
+
+class GonkSensorsPollInterface;
+class GonkSensorsProtocol;
+class GonkSensorsRegistryInterface;
+
+/**
+ * This class is the result-handler interface for the Sensors
+ * interface. Methods always run on the main thread.
+ */
+class GonkSensorsResultHandler
+  : public mozilla::ipc::DaemonSocketResultHandler
+{
+public:
+
+  /**
+   * Called if a command failed.
+   *
+   * @param aError The error code.
+   */
+  virtual void OnError(SensorsError aError);
+
+  /**
+   * The callback method for |GonkSensorsInterface::Connect|.
+   */
+  virtual void Connect();
+
+  /**
+   * The callback method for |GonkSensorsInterface::Connect|.
+   */
+  virtual void Disconnect();
+
+protected:
+  virtual ~GonkSensorsResultHandler();
+};
+
+/**
+ * This is the notification-handler interface. Implement this classes
+ * methods to handle event and notifications from the sensors daemon.
+ * All methods run on the main thread.
+ */
+class GonkSensorsNotificationHandler
+{
+public:
+
+  /**
+   * This notification is called when the backend code fails
+   * unexpectedly. Save state in the high-level code and restart
+   * the driver.
+   *
+   * @param aCrash True is the sensors driver crashed.
+   */
+  virtual void BackendErrorNotification(bool aCrashed);
+
+protected:
+  virtual ~GonkSensorsNotificationHandler();
+};
+
+/**
+ * This class implements the public interface to the Sensors functionality
+ * and driver. Use |GonkSensorsInterface::GetInstance| to retrieve an instance.
+ * All methods run on the main thread.
+ */
+class GonkSensorsInterface final
+  : public mozilla::ipc::DaemonSocketConsumer
+  , public mozilla::ipc::ListenSocketConsumer
+{
+public:
+  /**
+   * Returns an instance of the Sensors backend. This code can return
+   * |nullptr| if no Sensors backend is available.
+   *
+   * @return An instance of |GonkSensorsInterface|.
+   */
+  static GonkSensorsInterface* GetInstance();
+
+  /**
+   * This method sets the notification handler for sensor notifications. Call
+   * this method immediately after retreiving an instance of the class, or you
+   * won't be able able to receive notifications. You may not free the handler
+   * class while the Sensors backend is connected.
+   *
+   * @param aNotificationHandler An instance of a notification handler.
+   */
+  void SetNotificationHandler(
+    GonkSensorsNotificationHandler* aNotificationHandler);
+
+  /**
+   * This method starts the Sensors backend and establishes ad connection
+   * with Gecko. This is a multi-step process and errors are signalled by
+   * |GonkSensorsNotificationHandler::BackendErrorNotification|. If you see
+   * this notification before the connection has been established, it's
+   * certainly best to assume the Sensors backend to be not evailable.
+   *
+   * @param aRes The result handler.
+   */
+  void Connect(GonkSensorsNotificationHandler* aNotificationHandler,
+               GonkSensorsResultHandler* aRes);
+
+  /**
+   * This method disconnects Gecko from the Sensors backend and frees
+   * the backend's resources. This will invalidate all interfaces and
+   * state. Don't use any sensors functionality without reconnecting
+   * first.
+   *
+   * @param aRes The result handler.
+   */
+  void Disconnect(GonkSensorsResultHandler* aRes);
+
+  /**
+   * Returns the Registry interface for the connected Sensors backend.
+   *
+   * @return An instance of the Sensors Registry interface.
+   */
+  GonkSensorsRegistryInterface* GetSensorsRegistryInterface();
+
+  /**
+   * Returns the Poll interface for the connected Sensors backend.
+   *
+   * @return An instance of the Sensors Poll interface.
+   */
+  GonkSensorsPollInterface* GetSensorsPollInterface();
+
+private:
+  enum Channel {
+    LISTEN_SOCKET,
+    DATA_SOCKET
+  };
+
+  GonkSensorsInterface();
+  ~GonkSensorsInterface();
+
+  void DispatchError(GonkSensorsResultHandler* aRes, SensorsError aError);
+  void DispatchError(GonkSensorsResultHandler* aRes, nsresult aRv);
+
+  // Methods for |DaemonSocketConsumer| and |ListenSocketConsumer|
+  //
+
+  void OnConnectSuccess(int aIndex) override;
+  void OnConnectError(int aIndex) override;
+  void OnDisconnect(int aIndex) override;
+
+  nsCString mListenSocketName;
+  RefPtr<mozilla::ipc::ListenSocket> mListenSocket;
+  RefPtr<mozilla::ipc::DaemonSocket> mDataSocket;
+  UniquePtr<GonkSensorsProtocol> mProtocol;
+
+  nsTArray<RefPtr<GonkSensorsResultHandler> > mResultHandlerQ;
+
+  GonkSensorsNotificationHandler* mNotificationHandler;
+
+  UniquePtr<GonkSensorsRegistryInterface> mRegistryInterface;
+  UniquePtr<GonkSensorsPollInterface> mPollInterface;
+};
+
+} // namespace hal
+} // namespace mozilla
+
+#endif // hal_gonk_GonkSensorsInterface_h
diff --git a/hal/gonk/GonkSensorsPollInterface.cpp b/hal/gonk/GonkSensorsPollInterface.cpp
new file mode 100644
index 000000000..d4edc2e7a
--- /dev/null
+++ b/hal/gonk/GonkSensorsPollInterface.cpp
@@ -0,0 +1,431 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "GonkSensorsPollInterface.h"
+#include "HalLog.h"
+#include <mozilla/UniquePtr.h>
+
+namespace mozilla {
+namespace hal {
+
+using namespace mozilla::ipc;
+
+//
+// GonkSensorsPollResultHandler
+//
+
+void
+GonkSensorsPollResultHandler::OnError(SensorsError aError)
+{
+  HAL_ERR("Received error code %d", static_cast<int>(aError));
+}
+
+void
+GonkSensorsPollResultHandler::EnableSensor()
+{ }
+
+void
+GonkSensorsPollResultHandler::DisableSensor()
+{ }
+
+void
+GonkSensorsPollResultHandler::SetPeriod()
+{ }
+
+GonkSensorsPollResultHandler::~GonkSensorsPollResultHandler()
+{ }
+
+//
+// GonkSensorsPollNotificationHandler
+//
+
+void
+GonkSensorsPollNotificationHandler::ErrorNotification(SensorsError aError)
+{
+  HAL_ERR("Received error code %d", static_cast<int>(aError));
+}
+
+void
+GonkSensorsPollNotificationHandler::SensorDetectedNotification(
+  int32_t aId,
+  SensorsType aType,
+  float aRange,
+  float aResolution,
+  float aPower,
+  int32_t aMinPeriod,
+  int32_t aMaxPeriod,
+  SensorsTriggerMode aTriggerMode,
+  SensorsDeliveryMode aDeliveryMode)
+{ }
+
+void
+GonkSensorsPollNotificationHandler::SensorLostNotification(int32_t aId)
+{ }
+
+void
+GonkSensorsPollNotificationHandler::EventNotification(int32_t aId,
+                                                  const SensorsEvent& aEvent)
+{ }
+
+GonkSensorsPollNotificationHandler::~GonkSensorsPollNotificationHandler()
+{ }
+
+//
+// GonkSensorsPollModule
+//
+
+GonkSensorsPollModule::GonkSensorsPollModule()
+  : mProtocolVersion(0)
+{ }
+
+GonkSensorsPollModule::~GonkSensorsPollModule()
+{ }
+
+nsresult
+GonkSensorsPollModule::SetProtocolVersion(unsigned long aProtocolVersion)
+{
+  if ((aProtocolVersion < MIN_PROTOCOL_VERSION) ||
+      (aProtocolVersion > MAX_PROTOCOL_VERSION)) {
+    HAL_ERR("Sensors Poll protocol version %lu not supported",
+            aProtocolVersion);
+    return NS_ERROR_ILLEGAL_VALUE;
+  }
+  mProtocolVersion = aProtocolVersion;
+  return NS_OK;
+}
+
+void
+GonkSensorsPollModule::HandleSvc(const DaemonSocketPDUHeader& aHeader,
+                             DaemonSocketPDU& aPDU,
+                             DaemonSocketResultHandler* aRes)
+{
+  static void (GonkSensorsPollModule::* const HandleOp[])(
+    const DaemonSocketPDUHeader&, DaemonSocketPDU&,
+    DaemonSocketResultHandler*) = {
+    [0] = &GonkSensorsPollModule::HandleRsp,
+    [1] = &GonkSensorsPollModule::HandleNtf
+  };
+
+  MOZ_ASSERT(!NS_IsMainThread()); // I/O thread
+
+  // Negate twice to map bit to 0/1
+  unsigned long isNtf = !!(aHeader.mOpcode & 0x80);
+
+  (this->*(HandleOp[isNtf]))(aHeader, aPDU, aRes);
+}
+
+// Commands
+//
+
+nsresult
+GonkSensorsPollModule::EnableSensorCmd(int32_t aId, GonkSensorsPollResultHandler* aRes)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  UniquePtr<DaemonSocketPDU> pdu =
+    MakeUnique<DaemonSocketPDU>(SERVICE_ID, OPCODE_ENABLE_SENSOR, 0);
+
+  nsresult rv = PackPDU(aId, *pdu);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  rv = Send(pdu.get(), aRes);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  Unused << pdu.release();
+  return NS_OK;
+}
+
+nsresult
+GonkSensorsPollModule::DisableSensorCmd(int32_t aId, GonkSensorsPollResultHandler* aRes)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  UniquePtr<DaemonSocketPDU> pdu =
+    MakeUnique<DaemonSocketPDU>(SERVICE_ID, OPCODE_DISABLE_SENSOR, 0);
+
+  nsresult rv = PackPDU(aId, *pdu);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  rv = Send(pdu.get(), aRes);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  Unused << pdu.release();
+  return NS_OK;
+}
+
+nsresult
+GonkSensorsPollModule::SetPeriodCmd(int32_t aId, uint64_t aPeriod,
+                                GonkSensorsPollResultHandler* aRes)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  UniquePtr<DaemonSocketPDU> pdu =
+    MakeUnique<DaemonSocketPDU>(SERVICE_ID, OPCODE_SET_PERIOD, 0);
+
+  nsresult rv = PackPDU(aId, *pdu);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  rv = PackPDU(aPeriod, *pdu);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  rv = Send(pdu.get(), aRes);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  Unused << pdu.release();
+  return NS_OK;
+}
+
+// Responses
+//
+
+void
+GonkSensorsPollModule::ErrorRsp(
+  const DaemonSocketPDUHeader& aHeader,
+  DaemonSocketPDU& aPDU, GonkSensorsPollResultHandler* aRes)
+{
+  ErrorRunnable::Dispatch(
+    aRes, &GonkSensorsPollResultHandler::OnError, UnpackPDUInitOp(aPDU));
+}
+
+void
+GonkSensorsPollModule::EnableSensorRsp(
+  const DaemonSocketPDUHeader& aHeader, DaemonSocketPDU& aPDU,
+  GonkSensorsPollResultHandler* aRes)
+{
+  ResultRunnable::Dispatch(
+    aRes, &GonkSensorsPollResultHandler::EnableSensor, UnpackPDUInitOp(aPDU));
+}
+
+void
+GonkSensorsPollModule::DisableSensorRsp(
+  const DaemonSocketPDUHeader& aHeader, DaemonSocketPDU& aPDU,
+  GonkSensorsPollResultHandler* aRes)
+{
+  ResultRunnable::Dispatch(
+    aRes, &GonkSensorsPollResultHandler::DisableSensor, UnpackPDUInitOp(aPDU));
+}
+
+void
+GonkSensorsPollModule::SetPeriodRsp(
+  const DaemonSocketPDUHeader& aHeader, DaemonSocketPDU& aPDU,
+  GonkSensorsPollResultHandler* aRes)
+{
+  ResultRunnable::Dispatch(
+    aRes, &GonkSensorsPollResultHandler::SetPeriod, UnpackPDUInitOp(aPDU));
+}
+
+void
+GonkSensorsPollModule::HandleRsp(
+  const DaemonSocketPDUHeader& aHeader, DaemonSocketPDU& aPDU,
+  DaemonSocketResultHandler* aRes)
+{
+  static void (GonkSensorsPollModule::* const sHandleRsp[])(
+    const DaemonSocketPDUHeader&, DaemonSocketPDU&,
+    GonkSensorsPollResultHandler*) = {
+    [OPCODE_ERROR] = &GonkSensorsPollModule::ErrorRsp,
+    [OPCODE_ENABLE_SENSOR] = &GonkSensorsPollModule::EnableSensorRsp,
+    [OPCODE_DISABLE_SENSOR] = &GonkSensorsPollModule::DisableSensorRsp,
+    [OPCODE_SET_PERIOD] = &GonkSensorsPollModule::SetPeriodRsp,
+  };
+
+  MOZ_ASSERT(!NS_IsMainThread()); // I/O thread
+
+  if (!(aHeader.mOpcode < MOZ_ARRAY_LENGTH(sHandleRsp)) ||
+      !sHandleRsp[aHeader.mOpcode]) {
+    HAL_ERR("Sensors poll response opcode %d unknown", aHeader.mOpcode);
+    return;
+  }
+
+  RefPtr<GonkSensorsPollResultHandler> res =
+    static_cast<GonkSensorsPollResultHandler*>(aRes);
+
+  if (!res) {
+    return; // Return early if no result handler has been set for response
+  }
+
+  (this->*(sHandleRsp[aHeader.mOpcode]))(aHeader, aPDU, res);
+}
+
+// Notifications
+//
+
+// Returns the current notification handler to a notification runnable
+class GonkSensorsPollModule::NotificationHandlerWrapper final
+{
+public:
+  typedef GonkSensorsPollNotificationHandler ObjectType;
+
+  static ObjectType* GetInstance()
+  {
+    MOZ_ASSERT(NS_IsMainThread());
+
+    return sNotificationHandler;
+  }
+
+  static GonkSensorsPollNotificationHandler* sNotificationHandler;
+};
+
+GonkSensorsPollNotificationHandler*
+  GonkSensorsPollModule::NotificationHandlerWrapper::sNotificationHandler;
+
+void
+GonkSensorsPollModule::ErrorNtf(
+  const DaemonSocketPDUHeader& aHeader, DaemonSocketPDU& aPDU)
+{
+  ErrorNotification::Dispatch(
+    &GonkSensorsPollNotificationHandler::ErrorNotification,
+    UnpackPDUInitOp(aPDU));
+}
+
+void
+GonkSensorsPollModule::SensorDetectedNtf(
+  const DaemonSocketPDUHeader& aHeader, DaemonSocketPDU& aPDU)
+{
+  SensorDetectedNotification::Dispatch(
+    &GonkSensorsPollNotificationHandler::SensorDetectedNotification,
+    UnpackPDUInitOp(aPDU));
+}
+
+void
+GonkSensorsPollModule::SensorLostNtf(
+  const DaemonSocketPDUHeader& aHeader, DaemonSocketPDU& aPDU)
+{
+  SensorLostNotification::Dispatch(
+    &GonkSensorsPollNotificationHandler::SensorLostNotification,
+    UnpackPDUInitOp(aPDU));
+}
+
+void
+GonkSensorsPollModule::EventNtf(
+  const DaemonSocketPDUHeader& aHeader, DaemonSocketPDU& aPDU)
+{
+  EventNotification::Dispatch(
+    &GonkSensorsPollNotificationHandler::EventNotification,
+    UnpackPDUInitOp(aPDU));
+}
+
+void
+GonkSensorsPollModule::HandleNtf(
+  const DaemonSocketPDUHeader& aHeader, DaemonSocketPDU& aPDU,
+  DaemonSocketResultHandler* aRes)
+{
+  static void (GonkSensorsPollModule::* const sHandleNtf[])(
+    const DaemonSocketPDUHeader&, DaemonSocketPDU&) = {
+    [0] = &GonkSensorsPollModule::ErrorNtf,
+    [1] = &GonkSensorsPollModule::SensorDetectedNtf,
+    [2] = &GonkSensorsPollModule::SensorLostNtf,
+    [3] = &GonkSensorsPollModule::EventNtf
+  };
+
+  MOZ_ASSERT(!NS_IsMainThread());
+
+  uint8_t index = aHeader.mOpcode - 0x80;
+
+  if (!(index < MOZ_ARRAY_LENGTH(sHandleNtf)) || !sHandleNtf[index]) {
+    HAL_ERR("Sensors poll notification opcode %d unknown", aHeader.mOpcode);
+    return;
+  }
+
+  (this->*(sHandleNtf[index]))(aHeader, aPDU);
+}
+
+//
+// GonkSensorsPollInterface
+//
+
+GonkSensorsPollInterface::GonkSensorsPollInterface(
+  GonkSensorsPollModule* aModule)
+  : mModule(aModule)
+{ }
+
+GonkSensorsPollInterface::~GonkSensorsPollInterface()
+{ }
+
+void
+GonkSensorsPollInterface::SetNotificationHandler(
+  GonkSensorsPollNotificationHandler* aNotificationHandler)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  GonkSensorsPollModule::NotificationHandlerWrapper::sNotificationHandler =
+    aNotificationHandler;
+}
+
+nsresult
+GonkSensorsPollInterface::SetProtocolVersion(unsigned long aProtocolVersion)
+{
+  MOZ_ASSERT(mModule);
+
+  return mModule->SetProtocolVersion(aProtocolVersion);
+}
+
+void
+GonkSensorsPollInterface::EnableSensor(int32_t aId,
+                                       GonkSensorsPollResultHandler* aRes)
+{
+  MOZ_ASSERT(mModule);
+
+  nsresult rv = mModule->EnableSensorCmd(aId, aRes);
+  if (NS_FAILED(rv)) {
+    DispatchError(aRes, rv);
+  }
+}
+
+void
+GonkSensorsPollInterface::DisableSensor(int32_t aId,
+                                        GonkSensorsPollResultHandler* aRes)
+{
+  MOZ_ASSERT(mModule);
+
+  nsresult rv = mModule->DisableSensorCmd(aId, aRes);
+  if (NS_FAILED(rv)) {
+    DispatchError(aRes, rv);
+  }
+}
+
+void
+GonkSensorsPollInterface::SetPeriod(int32_t aId, uint64_t aPeriod,
+                                    GonkSensorsPollResultHandler* aRes)
+{
+  MOZ_ASSERT(mModule);
+
+  nsresult rv = mModule->SetPeriodCmd(aId, aPeriod, aRes);
+  if (NS_FAILED(rv)) {
+    DispatchError(aRes, rv);
+  }
+}
+
+void
+GonkSensorsPollInterface::DispatchError(
+  GonkSensorsPollResultHandler* aRes, SensorsError aError)
+{
+  DaemonResultRunnable1<GonkSensorsPollResultHandler, void,
+                        SensorsError, SensorsError>::Dispatch(
+    aRes, &GonkSensorsPollResultHandler::OnError,
+    ConstantInitOp1<SensorsError>(aError));
+}
+
+void
+GonkSensorsPollInterface::DispatchError(
+  GonkSensorsPollResultHandler* aRes, nsresult aRv)
+{
+  SensorsError error;
+
+  if (NS_FAILED(Convert(aRv, error))) {
+    error = SENSORS_ERROR_FAIL;
+  }
+  DispatchError(aRes, error);
+}
+
+} // namespace hal
+} // namespace mozilla
diff --git a/hal/gonk/GonkSensorsPollInterface.h b/hal/gonk/GonkSensorsPollInterface.h
new file mode 100644
index 000000000..89381a9bd
--- /dev/null
+++ b/hal/gonk/GonkSensorsPollInterface.h
@@ -0,0 +1,340 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * The poll interface gives yo access to the Sensors daemon's Poll service,
+ * which handles sensors. The poll service will inform you when sensors are
+ * detected or removed from the system. You can activate (or deactivate)
+ * existing sensors and poll will deliver the sensors' events.
+ *
+ * All public methods and callback methods run on the main thread.
+ */
+
+#ifndef hal_gonk_GonkSensorsPollInterface_h
+#define hal_gonk_GonkSensorsPollInterface_h
+
+#include <mozilla/ipc/DaemonRunnables.h>
+#include <mozilla/ipc/DaemonSocketMessageHandlers.h>
+#include "SensorsTypes.h"
+
+namespace mozilla {
+namespace ipc {
+
+class DaemonSocketPDU;
+class DaemonSocketPDUHeader;
+
+}
+}
+
+namespace mozilla {
+namespace hal {
+
+class SensorsInterface;
+
+using mozilla::ipc::DaemonSocketPDU;
+using mozilla::ipc::DaemonSocketPDUHeader;
+using mozilla::ipc::DaemonSocketResultHandler;
+
+/**
+ * This class is the result-handler interface for the Sensors
+ * Poll interface. Methods always run on the main thread.
+ */
+class GonkSensorsPollResultHandler : public DaemonSocketResultHandler
+{
+public:
+
+  /**
+   * Called if a poll command failed.
+   *
+   * @param aError The error code.
+   */
+  virtual void OnError(SensorsError aError);
+
+  /**
+   * The callback method for |GonkSensorsPollInterface::EnableSensor|.
+   */
+  virtual void EnableSensor();
+
+  /**
+   * The callback method for |GonkSensorsPollInterface::DisableSensor|.
+   */
+  virtual void DisableSensor();
+
+  /**
+   * The callback method for |GonkSensorsPollInterface::SetPeriod|.
+   */
+  virtual void SetPeriod();
+
+protected:
+  virtual ~GonkSensorsPollResultHandler();
+};
+
+/**
+ * This is the notification-handler interface. Implement this classes
+ * methods to handle event and notifications from the sensors daemon.
+ */
+class GonkSensorsPollNotificationHandler
+{
+public:
+
+  /**
+   * The notification handler for errors. You'll receive this call if
+   * there's been a critical error in the daemon. Either try to handle
+   * the error, or restart the daemon.
+   *
+   * @param aError The error code.
+   */
+  virtual void ErrorNotification(SensorsError aError);
+
+  /**
+   * This methods gets call when a new sensor has been detected.
+   *
+   * @param aId The sensor's id.
+   * @param aType The sensor's type.
+   * @param aRange The sensor's maximum value.
+   * @param aResolution The minimum difference between two consecutive values.
+   * @param aPower The sensor's power consumption (in mA).
+   * @param aMinPeriod The minimum time between two events (in ns).
+   * @param aMaxPeriod The maximum time between two events (in ns).
+   * @param aTriggerMode The sensor's mode for triggering events.
+   * @param aDeliveryMode The sensor's urgency for event delivery.
+   */
+  virtual void SensorDetectedNotification(int32_t aId, SensorsType aType,
+                                          float aRange, float aResolution,
+                                          float aPower, int32_t aMinPeriod,
+                                          int32_t aMaxPeriod,
+                                          SensorsTriggerMode aTriggerMode,
+                                          SensorsDeliveryMode aDeliveryMode);
+
+  /**
+   * This methods gets call when an existing sensor has been removed.
+   *
+   * @param aId The sensor's id.
+   */
+  virtual void SensorLostNotification(int32_t aId);
+
+  /**
+   * This is the callback methods for sensor events. Only activated sensors
+   * generate events. All sensors are disabled by default. The actual data
+   * of the event depends on the sensor type.
+   *
+   * @param aId The sensor's id.
+   * @param aEvent The event's data.
+   */
+  virtual void EventNotification(int32_t aId, const SensorsEvent& aEvent);
+
+protected:
+  virtual ~GonkSensorsPollNotificationHandler();
+};
+
+/**
+ * This is the module class for the Sensors poll component. It handles PDU
+ * packing and unpacking. Methods are either executed on the main thread or
+ * the I/O thread.
+ *
+ * This is an internal class, use |GonkSensorsPollInterface| instead.
+ */
+class GonkSensorsPollModule
+{
+public:
+  class NotificationHandlerWrapper;
+
+  enum {
+    SERVICE_ID = 0x01
+  };
+
+  enum {
+    OPCODE_ERROR = 0x00,
+    OPCODE_ENABLE_SENSOR = 0x01,
+    OPCODE_DISABLE_SENSOR = 0x02,
+    OPCODE_SET_PERIOD = 0x03
+  };
+
+  enum {
+    MIN_PROTOCOL_VERSION = 1,
+    MAX_PROTOCOL_VERSION = 1
+  };
+
+  virtual nsresult Send(DaemonSocketPDU* aPDU,
+                        DaemonSocketResultHandler* aRes) = 0;
+
+  nsresult SetProtocolVersion(unsigned long aProtocolVersion);
+
+  //
+  // Commands
+  //
+
+  nsresult EnableSensorCmd(int32_t aId,
+                           GonkSensorsPollResultHandler* aRes);
+
+  nsresult DisableSensorCmd(int32_t aId,
+                            GonkSensorsPollResultHandler* aRes);
+
+  nsresult SetPeriodCmd(int32_t aId, uint64_t aPeriod,
+                        GonkSensorsPollResultHandler* aRes);
+
+protected:
+  GonkSensorsPollModule();
+  virtual ~GonkSensorsPollModule();
+
+  void HandleSvc(const DaemonSocketPDUHeader& aHeader,
+                 DaemonSocketPDU& aPDU,
+                 DaemonSocketResultHandler* aRes);
+
+private:
+
+  //
+  // Responses
+  //
+
+  typedef mozilla::ipc::DaemonResultRunnable0<
+    GonkSensorsPollResultHandler, void>
+    ResultRunnable;
+
+  typedef mozilla::ipc::DaemonResultRunnable1<
+    GonkSensorsPollResultHandler, void, SensorsError, SensorsError>
+    ErrorRunnable;
+
+  void ErrorRsp(const DaemonSocketPDUHeader& aHeader,
+                DaemonSocketPDU& aPDU,
+                GonkSensorsPollResultHandler* aRes);
+
+  void EnableSensorRsp(const DaemonSocketPDUHeader& aHeader,
+                       DaemonSocketPDU& aPDU,
+                       GonkSensorsPollResultHandler* aRes);
+
+  void DisableSensorRsp(const DaemonSocketPDUHeader& aHeader,
+                        DaemonSocketPDU& aPDU,
+                        GonkSensorsPollResultHandler* aRes);
+
+  void SetPeriodRsp(const DaemonSocketPDUHeader& aHeader,
+                    DaemonSocketPDU& aPDU,
+                    GonkSensorsPollResultHandler* aRes);
+
+  void HandleRsp(const DaemonSocketPDUHeader& aHeader,
+                 DaemonSocketPDU& aPDU,
+                 DaemonSocketResultHandler* aRes);
+
+  //
+  // Notifications
+  //
+
+  typedef mozilla::ipc::DaemonNotificationRunnable1<
+    NotificationHandlerWrapper, void, SensorsError>
+    ErrorNotification;
+
+  typedef mozilla::ipc::DaemonNotificationRunnable9<
+    NotificationHandlerWrapper, void, int32_t, SensorsType,
+    float, float, float, int32_t, int32_t, SensorsTriggerMode,
+    SensorsDeliveryMode>
+    SensorDetectedNotification;
+
+  typedef mozilla::ipc::DaemonNotificationRunnable1<
+    NotificationHandlerWrapper, void, int32_t>
+    SensorLostNotification;
+
+  typedef mozilla::ipc::DaemonNotificationRunnable2<
+    NotificationHandlerWrapper, void, int32_t, SensorsEvent, int32_t,
+    const SensorsEvent&>
+    EventNotification;
+
+  class SensorDetectedInitOp;
+  class SensorLostInitOp;
+  class EventInitOp;
+
+  void ErrorNtf(const DaemonSocketPDUHeader& aHeader,
+                DaemonSocketPDU& aPDU);
+
+  void SensorDetectedNtf(const DaemonSocketPDUHeader& aHeader,
+                         DaemonSocketPDU& aPDU);
+
+  void SensorLostNtf(const DaemonSocketPDUHeader& aHeader,
+                     DaemonSocketPDU& aPDU);
+
+  void EventNtf(const DaemonSocketPDUHeader& aHeader,
+                DaemonSocketPDU& aPDU);
+
+  void HandleNtf(const DaemonSocketPDUHeader& aHeader,
+                 DaemonSocketPDU& aPDU,
+                 DaemonSocketResultHandler* aRes);
+
+private:
+  unsigned long mProtocolVersion;
+};
+
+/**
+ * This class implements the public interface to the Sensors poll
+ * component. Use |SensorsInterface::GetPollInterface| to retrieve
+ * an instance. All methods run on the main thread.
+ */
+class GonkSensorsPollInterface final
+{
+public:
+  GonkSensorsPollInterface(GonkSensorsPollModule* aModule);
+  ~GonkSensorsPollInterface();
+
+  /**
+   * This method sets the notification handler for poll notifications. Call
+   * this method immediately after registering the module. Otherwise you won't
+   * be able able to receive poll notifications. You may not free the handler
+   * class while the poll component is regsitered.
+   *
+   * @param aNotificationHandler An instance of a poll notification handler.
+   */
+  void SetNotificationHandler(
+    GonkSensorsPollNotificationHandler* aNotificationHandler);
+
+  /**
+   * This method sets the protocol version. You should set it to the
+   * value that has been returned from the backend when registering the
+   * Poll service. You cannot send or receive messages before setting
+   * the protocol version.
+   *
+   * @param aProtocolVersion
+   * @return NS_OK for supported versions, or an XPCOM error code otherwise.
+   */
+  nsresult SetProtocolVersion(unsigned long aProtocolVersion);
+
+  /**
+   * Enables an existing sensor. The sensor id will have been delivered in
+   * a SensorDetectedNotification.
+   *
+   * @param aId The sensor's id.
+   * @param aRes The result handler.
+   */
+  void EnableSensor(int32_t aId, GonkSensorsPollResultHandler* aRes);
+
+  /**
+   * Disables an existing sensor. The sensor id will have been delivered in
+   * a SensorDetectedNotification.
+   *
+   * @param aId The sensor's id.
+   * @param aRes The result handler.
+   */
+  void DisableSensor(int32_t aId, GonkSensorsPollResultHandler* aRes);
+
+  /**
+   * Sets the period for a sensor. The sensor id will have been delivered in
+   * a SensorDetectedNotification. The value for the period should be between
+   * the sensor's minimum and maximum period.
+   *
+   * @param aId The sensor's id.
+   * @param aPeriod The sensor's new period.
+   * @param aRes The result handler.
+   */
+  void SetPeriod(int32_t aId, uint64_t aPeriod, GonkSensorsPollResultHandler* aRes);
+
+private:
+  void DispatchError(GonkSensorsPollResultHandler* aRes, SensorsError aError);
+  void DispatchError(GonkSensorsPollResultHandler* aRes, nsresult aRv);
+
+  GonkSensorsPollModule* mModule;
+};
+
+} // hal
+} // namespace mozilla
+
+#endif // hal_gonk_GonkSensorsPollInterface_h
diff --git a/hal/gonk/GonkSensorsRegistryInterface.cpp b/hal/gonk/GonkSensorsRegistryInterface.cpp
new file mode 100644
index 000000000..601dc7a2a
--- /dev/null
+++ b/hal/gonk/GonkSensorsRegistryInterface.cpp
@@ -0,0 +1,213 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "GonkSensorsRegistryInterface.h"
+#include "GonkSensorsHelpers.h"
+#include "HalLog.h"
+#include <mozilla/UniquePtr.h>
+
+namespace mozilla {
+namespace hal {
+
+using namespace mozilla::ipc;
+
+//
+// GonkSensorsRegistryResultHandler
+//
+
+void
+GonkSensorsRegistryResultHandler::OnError(SensorsError aError)
+{
+  HAL_ERR("Received error code %d", static_cast<int>(aError));
+}
+
+void
+GonkSensorsRegistryResultHandler::RegisterModule(uint32_t aProtocolVersion)
+{ }
+
+void
+GonkSensorsRegistryResultHandler::UnregisterModule()
+{ }
+
+GonkSensorsRegistryResultHandler::~GonkSensorsRegistryResultHandler()
+{ }
+
+//
+// GonkSensorsRegistryModule
+//
+
+GonkSensorsRegistryModule::~GonkSensorsRegistryModule()
+{ }
+
+void
+GonkSensorsRegistryModule::HandleSvc(const DaemonSocketPDUHeader& aHeader,
+                                     DaemonSocketPDU& aPDU,
+                                     DaemonSocketResultHandler* aRes)
+{
+  static void (GonkSensorsRegistryModule::* const HandleRsp[])(
+    const DaemonSocketPDUHeader&,
+    DaemonSocketPDU&,
+    GonkSensorsRegistryResultHandler*) = {
+    [OPCODE_ERROR] = &GonkSensorsRegistryModule::ErrorRsp,
+    [OPCODE_REGISTER_MODULE] = &GonkSensorsRegistryModule::RegisterModuleRsp,
+    [OPCODE_UNREGISTER_MODULE] = &GonkSensorsRegistryModule::UnregisterModuleRsp
+  };
+
+  if ((aHeader.mOpcode >= MOZ_ARRAY_LENGTH(HandleRsp)) ||
+      !HandleRsp[aHeader.mOpcode]) {
+    HAL_ERR("Sensors registry response opcode %d unknown", aHeader.mOpcode);
+    return;
+  }
+
+  RefPtr<GonkSensorsRegistryResultHandler> res =
+    static_cast<GonkSensorsRegistryResultHandler*>(aRes);
+
+  if (!res) {
+    return; // Return early if no result handler has been set
+  }
+
+  (this->*(HandleRsp[aHeader.mOpcode]))(aHeader, aPDU, res);
+}
+
+// Commands
+//
+
+nsresult
+GonkSensorsRegistryModule::RegisterModuleCmd(
+  uint8_t aId, GonkSensorsRegistryResultHandler* aRes)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  UniquePtr<DaemonSocketPDU> pdu =
+    MakeUnique<DaemonSocketPDU>(SERVICE_ID, OPCODE_REGISTER_MODULE, 0);
+
+  nsresult rv = PackPDU(aId, *pdu);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  rv = Send(pdu.get(), aRes);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  Unused << pdu.release();
+  return NS_OK;
+}
+
+nsresult
+GonkSensorsRegistryModule::UnregisterModuleCmd(
+  uint8_t aId, GonkSensorsRegistryResultHandler* aRes)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  UniquePtr<DaemonSocketPDU> pdu =
+    MakeUnique<DaemonSocketPDU>(SERVICE_ID, OPCODE_UNREGISTER_MODULE, 0);
+
+  nsresult rv = PackPDU(aId, *pdu);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  rv = Send(pdu.get(), aRes);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  Unused << pdu.release();
+  return NS_OK;
+}
+
+// Responses
+//
+
+void
+GonkSensorsRegistryModule::ErrorRsp(
+  const DaemonSocketPDUHeader& aHeader,
+  DaemonSocketPDU& aPDU, GonkSensorsRegistryResultHandler* aRes)
+{
+  ErrorRunnable::Dispatch(
+    aRes, &GonkSensorsRegistryResultHandler::OnError, UnpackPDUInitOp(aPDU));
+}
+
+void
+GonkSensorsRegistryModule::RegisterModuleRsp(
+  const DaemonSocketPDUHeader& aHeader, DaemonSocketPDU& aPDU,
+  GonkSensorsRegistryResultHandler* aRes)
+{
+  Uint32ResultRunnable::Dispatch(
+    aRes,
+    &GonkSensorsRegistryResultHandler::RegisterModule,
+    UnpackPDUInitOp(aPDU));
+}
+
+void
+GonkSensorsRegistryModule::UnregisterModuleRsp(
+  const DaemonSocketPDUHeader& aHeader, DaemonSocketPDU& aPDU,
+  GonkSensorsRegistryResultHandler* aRes)
+{
+  ResultRunnable::Dispatch(
+    aRes,
+    &GonkSensorsRegistryResultHandler::UnregisterModule,
+    UnpackPDUInitOp(aPDU));
+}
+
+//
+// GonkSensorsRegistryInterface
+//
+
+GonkSensorsRegistryInterface::GonkSensorsRegistryInterface(
+  GonkSensorsRegistryModule* aModule)
+  : mModule(aModule)
+{ }
+
+GonkSensorsRegistryInterface::~GonkSensorsRegistryInterface()
+{ }
+
+void
+GonkSensorsRegistryInterface::RegisterModule(
+  uint8_t aId, GonkSensorsRegistryResultHandler* aRes)
+{
+  MOZ_ASSERT(mModule);
+
+  nsresult rv = mModule->RegisterModuleCmd(aId, aRes);
+  if (NS_FAILED(rv)) {
+    DispatchError(aRes, rv);
+  }
+}
+
+void
+GonkSensorsRegistryInterface::UnregisterModule(
+  uint8_t aId, GonkSensorsRegistryResultHandler* aRes)
+{
+  MOZ_ASSERT(mModule);
+
+  nsresult rv = mModule->UnregisterModuleCmd(aId, aRes);
+  if (NS_FAILED(rv)) {
+    DispatchError(aRes, rv);
+  }
+}
+
+void
+GonkSensorsRegistryInterface::DispatchError(
+  GonkSensorsRegistryResultHandler* aRes, SensorsError aError)
+{
+  DaemonResultRunnable1<GonkSensorsRegistryResultHandler, void,
+                        SensorsError, SensorsError>::Dispatch(
+    aRes, &GonkSensorsRegistryResultHandler::OnError,
+    ConstantInitOp1<SensorsError>(aError));
+}
+
+void
+GonkSensorsRegistryInterface::DispatchError(
+  GonkSensorsRegistryResultHandler* aRes, nsresult aRv)
+{
+  SensorsError error;
+
+  if (NS_FAILED(Convert(aRv, error))) {
+    error = SENSORS_ERROR_FAIL;
+  }
+  DispatchError(aRes, error);
+}
+
+} // namespace hal
+} // namespace mozilla
diff --git a/hal/gonk/GonkSensorsRegistryInterface.h b/hal/gonk/GonkSensorsRegistryInterface.h
new file mode 100644
index 000000000..a9d98d653
--- /dev/null
+++ b/hal/gonk/GonkSensorsRegistryInterface.h
@@ -0,0 +1,182 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * The registry interface gives yo access to the Sensors daemon's Registry
+ * service. The purpose of the service is to register and setup all other
+ * services, and make them available.
+ *
+ * All public methods and callback methods run on the main thread.
+ */
+
+#ifndef hal_gonk_GonkSensorsRegistryInterface_h
+#define hal_gonk_GonkSensorsRegistryInterface_h
+
+#include <mozilla/ipc/DaemonRunnables.h>
+#include <mozilla/ipc/DaemonSocketMessageHandlers.h>
+#include "SensorsTypes.h"
+
+namespace mozilla {
+namespace ipc {
+
+class DaemonSocketPDU;
+class DaemonSocketPDUHeader;
+
+}
+}
+
+namespace mozilla {
+namespace hal {
+
+class SensorsInterface;
+
+using mozilla::ipc::DaemonSocketPDU;
+using mozilla::ipc::DaemonSocketPDUHeader;
+using mozilla::ipc::DaemonSocketResultHandler;
+
+/**
+ * This class is the result-handler interface for the Sensors
+ * Registry interface. Methods always run on the main thread.
+ */
+class GonkSensorsRegistryResultHandler : public DaemonSocketResultHandler
+{
+public:
+
+  /**
+   * Called if a registry command failed.
+   *
+   * @param aError The error code.
+   */
+  virtual void OnError(SensorsError aError);
+
+  /**
+   * The callback method for |GonkSensorsRegistryInterface::RegisterModule|.
+   *
+   * @param aProtocolVersion The daemon's protocol version. Make sure it's
+   *                         compatible with Gecko's implementation.
+   */
+  virtual void RegisterModule(uint32_t aProtocolVersion);
+
+  /**
+   * The callback method for |SensorsRegsitryInterface::UnregisterModule|.
+   */
+  virtual void UnregisterModule();
+
+protected:
+  virtual ~GonkSensorsRegistryResultHandler();
+};
+
+/**
+ * This is the module class for the Sensors registry component. It handles
+ * PDU packing and unpacking. Methods are either executed on the main thread
+ * or the I/O thread.
+ *
+ * This is an internal class, use |GonkSensorsRegistryInterface| instead.
+ */
+class GonkSensorsRegistryModule
+{
+public:
+  enum {
+    SERVICE_ID = 0x00
+  };
+
+  enum {
+    OPCODE_ERROR = 0x00,
+    OPCODE_REGISTER_MODULE = 0x01,
+    OPCODE_UNREGISTER_MODULE = 0x02
+  };
+
+  virtual nsresult Send(DaemonSocketPDU* aPDU,
+                        DaemonSocketResultHandler* aRes) = 0;
+
+  //
+  // Commands
+  //
+
+  nsresult RegisterModuleCmd(uint8_t aId,
+                             GonkSensorsRegistryResultHandler* aRes);
+
+  nsresult UnregisterModuleCmd(uint8_t aId,
+                               GonkSensorsRegistryResultHandler* aRes);
+
+protected:
+  virtual ~GonkSensorsRegistryModule();
+
+  void HandleSvc(const DaemonSocketPDUHeader& aHeader,
+                 DaemonSocketPDU& aPDU, DaemonSocketResultHandler* aRes);
+
+  //
+  // Responses
+  //
+
+  typedef mozilla::ipc::DaemonResultRunnable0<
+    GonkSensorsRegistryResultHandler, void>
+    ResultRunnable;
+
+  typedef mozilla::ipc::DaemonResultRunnable1<
+    GonkSensorsRegistryResultHandler, void, uint32_t, uint32_t>
+    Uint32ResultRunnable;
+
+  typedef mozilla::ipc::DaemonResultRunnable1<
+    GonkSensorsRegistryResultHandler, void, SensorsError, SensorsError>
+    ErrorRunnable;
+
+  void ErrorRsp(const DaemonSocketPDUHeader& aHeader,
+                DaemonSocketPDU& aPDU,
+                GonkSensorsRegistryResultHandler* aRes);
+
+  void RegisterModuleRsp(const DaemonSocketPDUHeader& aHeader,
+                         DaemonSocketPDU& aPDU,
+                         GonkSensorsRegistryResultHandler* aRes);
+
+  void UnregisterModuleRsp(const DaemonSocketPDUHeader& aHeader,
+                           DaemonSocketPDU& aPDU,
+                           GonkSensorsRegistryResultHandler* aRes);
+};
+
+/**
+ * This class implements the public interface to the Sensors Registry
+ * component. Use |SensorsInterface::GetRegistryInterface| to retrieve
+ * an instance. All methods run on the main thread.
+ */
+class GonkSensorsRegistryInterface final
+{
+public:
+  GonkSensorsRegistryInterface(GonkSensorsRegistryModule* aModule);
+  ~GonkSensorsRegistryInterface();
+
+  /**
+   * Sends a RegisterModule command to the Sensors daemon. When the
+   * result handler's |RegisterModule| method gets called, the service
+   * has been registered successfully and can be used.
+   *
+   * @param aId The id of the service that is to be registered.
+   * @param aRes The result handler.
+   */
+  void RegisterModule(uint8_t aId, GonkSensorsRegistryResultHandler* aRes);
+
+  /**
+   * Sends an UnregisterModule command to the Sensors daemon. The service
+   * should not be used afterwards until it has been registered again.
+   *
+   * @param aId The id of the service that is to be unregistered.
+   * @param aRes The result handler.
+   */
+  void UnregisterModule(uint8_t aId, GonkSensorsRegistryResultHandler* aRes);
+
+private:
+  void DispatchError(GonkSensorsRegistryResultHandler* aRes,
+                     SensorsError aError);
+  void DispatchError(GonkSensorsRegistryResultHandler* aRes,
+                     nsresult aRv);
+
+  GonkSensorsRegistryModule* mModule;
+};
+
+} // namespace hal
+} // namespace mozilla
+
+#endif // hal_gonk_GonkSensorsRegistryInterface_h
diff --git a/hal/gonk/GonkSwitch.cpp b/hal/gonk/GonkSwitch.cpp
new file mode 100644
index 000000000..b2c31c973
--- /dev/null
+++ b/hal/gonk/GonkSwitch.cpp
@@ -0,0 +1,479 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* Copyright 2012 Mozilla Foundation and Mozilla contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <fcntl.h>
+#include <sysutils/NetlinkEvent.h>
+
+#include "base/message_loop.h"
+#include "base/task.h"
+
+#include "Hal.h"
+#include "HalLog.h"
+#include "mozilla/FileUtils.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/Monitor.h"
+#include "nsPrintfCString.h"
+#include "nsXULAppAPI.h"
+#include "nsThreadUtils.h"
+#include "UeventPoller.h"
+
+using namespace mozilla::hal;
+
+#define SWITCH_HEADSET_DEVPATH "/devices/virtual/switch/h2w"
+#define SWITCH_USB_DEVPATH_GB  "/devices/virtual/switch/usb_configuration"
+#define SWITCH_USB_DEVPATH_ICS "/devices/virtual/android_usb/android0"
+
+namespace mozilla {
+namespace hal_impl {
+/**
+ * The uevent for a usb on GB insertion looks like:
+ *
+ *  change@/devices/virtual/switch/usb_configuration
+ *    ACTION=change
+ *    DEVPATH=/devices/virtual/switch/usb_configuration
+ *    SUBSYSTEM=switch
+ *    SWITCH_NAME=usb_configuration
+ *    SWITCH_STATE=0
+ *    SEQNUM=5038
+ */
+class SwitchHandler
+{
+public:
+  NS_INLINE_DECL_REFCOUNTING(SwitchHandler)
+
+  SwitchHandler(const char* aDevPath, SwitchDevice aDevice)
+    : mDevPath(aDevPath),
+      mState(SWITCH_STATE_UNKNOWN),
+      mDevice(aDevice)
+  {
+    GetInitialState();
+  }
+
+  bool CheckEvent(NetlinkEvent* aEvent)
+  {
+    if (strcmp(GetSubsystem(), aEvent->getSubsystem()) ||
+        strcmp(mDevPath, aEvent->findParam("DEVPATH"))) {
+        return false;
+    }
+
+    mState = ConvertState(GetStateString(aEvent));
+    return mState != SWITCH_STATE_UNKNOWN;
+  }
+
+  SwitchState GetState()
+  {
+    return mState;
+  }
+
+  SwitchDevice GetType()
+  {
+    return mDevice;
+  }
+protected:
+  virtual ~SwitchHandler()
+  {
+  }
+
+  virtual const char* GetSubsystem()
+  {
+    return "switch";
+  }
+
+  virtual const char* GetStateString(NetlinkEvent* aEvent)
+  {
+    return aEvent->findParam("SWITCH_STATE");
+  }
+
+  void GetInitialState()
+  {
+    nsPrintfCString statePath("/sys%s/state", mDevPath);
+    int fd = open(statePath.get(), O_RDONLY);
+    if (fd <= 0) {
+      return;
+    }
+
+    ScopedClose autoClose(fd);
+    char state[16];
+    ssize_t bytesRead = read(fd, state, sizeof(state));
+    if (bytesRead < 0) {
+      HAL_ERR("Read data from %s fails", statePath.get());
+      return;
+    }
+
+    if (state[bytesRead - 1] == '\n') {
+      bytesRead--;
+    }
+
+    state[bytesRead] = '\0';
+    mState = ConvertState(state);
+  }
+
+  virtual SwitchState ConvertState(const char* aState)
+  {
+    MOZ_ASSERT(aState);
+    return aState[0] == '0' ? SWITCH_STATE_OFF : SWITCH_STATE_ON;
+  }
+
+  const char* mDevPath;
+  SwitchState mState;
+  SwitchDevice mDevice;
+};
+
+/**
+ * The uevent delivered for the USB configuration under ICS looks like,
+ *
+ *  change@/devices/virtual/android_usb/android0
+ *    ACTION=change
+ *    DEVPATH=/devices/virtual/android_usb/android0
+ *    SUBSYSTEM=android_usb
+ *    USB_STATE=CONFIGURED
+ *    SEQNUM=1802
+ */
+class SwitchHandlerUsbIcs: public SwitchHandler
+{
+public:
+  SwitchHandlerUsbIcs(const char* aDevPath) : SwitchHandler(aDevPath, SWITCH_USB)
+  {
+    SwitchHandler::GetInitialState();
+  }
+
+  virtual ~SwitchHandlerUsbIcs() { }
+
+protected:
+  virtual const char* GetSubsystem()
+  {
+    return "android_usb";
+  }
+
+  virtual const char* GetStateString(NetlinkEvent* aEvent)
+  {
+    return aEvent->findParam("USB_STATE");
+  }
+
+  SwitchState ConvertState(const char* aState)
+  {
+    MOZ_ASSERT(aState);
+    return strcmp(aState, "CONFIGURED") == 0 ? SWITCH_STATE_ON : SWITCH_STATE_OFF;
+  }
+};
+
+/**
+ * The uevent delivered for the headset under ICS looks like,
+ *
+ * change@/devices/virtual/switch/h2w
+ *   ACTION=change
+ *   DEVPATH=/devices/virtual/switch/h2w
+ *   SUBSYSTEM=switch
+ *   SWITCH_NAME=h2w
+ *   SWITCH_STATE=2 // Headset with no mic
+ *   SEQNUM=2581
+ * On Otoro, SWITCH_NAME could be Headset/No Device when plug/unplug.
+ * change@/devices/virtual/switch/h2w
+ *   ACTION=change
+ *   DEVPATH=/devices/virtual/switch/h2w
+ *   SUBSYSTEM=switch
+ *   SWITCH_NAME=Headset
+ *   SWITCH_STATE=1 // Headset with mic
+ *   SEQNUM=1602
+ */
+class SwitchHandlerHeadphone: public SwitchHandler
+{
+public:
+  SwitchHandlerHeadphone(const char* aDevPath) :
+    SwitchHandler(aDevPath, SWITCH_HEADPHONES)
+  {
+    SwitchHandler::GetInitialState();
+  }
+
+  virtual ~SwitchHandlerHeadphone() { }
+
+protected:
+  SwitchState ConvertState(const char* aState)
+  {
+    MOZ_ASSERT(aState);
+
+    return aState[0] == '0' ? SWITCH_STATE_OFF :
+      (aState[0] == '1' ? SWITCH_STATE_HEADSET : SWITCH_STATE_HEADPHONE);
+  }
+};
+
+
+typedef nsTArray<RefPtr<SwitchHandler> > SwitchHandlerArray;
+
+class SwitchEventRunnable : public Runnable
+{
+public:
+  SwitchEventRunnable(SwitchEvent& aEvent) : mEvent(aEvent)
+  {
+  }
+
+  NS_IMETHOD Run() override
+  {
+    NotifySwitchChange(mEvent);
+    return NS_OK;
+  }
+private:
+  SwitchEvent mEvent;
+};
+
+class SwitchEventObserver final : public IUeventObserver
+{
+  ~SwitchEventObserver()
+  {
+    mHandler.Clear();
+  }
+
+public:
+  NS_INLINE_DECL_REFCOUNTING(SwitchEventObserver)
+  SwitchEventObserver()
+    : mEnableCount(0),
+    mHeadphonesFromInputDev(false)
+  {
+    Init();
+  }
+
+  int GetEnableCount()
+  {
+    return mEnableCount;
+  }
+
+  void EnableSwitch(SwitchDevice aDevice)
+  {
+    mEventInfo[aDevice].mEnabled = true;
+    mEnableCount++;
+  }
+
+  void DisableSwitch(SwitchDevice aDevice)
+  {
+    mEventInfo[aDevice].mEnabled = false;
+    mEnableCount--;
+  }
+
+  void Notify(const NetlinkEvent& aEvent)
+  {
+    SwitchState currState;
+
+    SwitchDevice device = GetEventInfo(aEvent, currState);
+    if (device == SWITCH_DEVICE_UNKNOWN) {
+      return;
+    }
+
+    EventInfo& info = mEventInfo[device];
+    if (currState == info.mEvent.status()) {
+      return;
+    }
+
+    info.mEvent.status() = currState;
+
+    if (info.mEnabled) {
+      NS_DispatchToMainThread(new SwitchEventRunnable(info.mEvent));
+    }
+  }
+
+  void Notify(SwitchDevice aDevice, SwitchState aState)
+  {
+    EventInfo& info = mEventInfo[aDevice];
+    if (aState == info.mEvent.status()) {
+      return;
+    }
+
+    info.mEvent.status() = aState;
+
+    if (info.mEnabled) {
+      NS_DispatchToMainThread(new SwitchEventRunnable(info.mEvent));
+    }
+  }
+
+  SwitchState GetCurrentInformation(SwitchDevice aDevice)
+  {
+    return mEventInfo[aDevice].mEvent.status();
+  }
+
+  void NotifyAnEvent(SwitchDevice aDevice)
+  {
+    EventInfo& info = mEventInfo[aDevice];
+    if (info.mEvent.status() != SWITCH_STATE_UNKNOWN) {
+      NS_DispatchToMainThread(new SwitchEventRunnable(info.mEvent));
+    }
+  }
+
+  bool GetHeadphonesFromInputDev()
+  {
+    return mHeadphonesFromInputDev;
+  }
+
+private:
+  class EventInfo
+  {
+  public:
+    EventInfo() : mEnabled(false)
+    {
+      mEvent.status() = SWITCH_STATE_UNKNOWN;
+      mEvent.device() = SWITCH_DEVICE_UNKNOWN;
+    }
+    SwitchEvent mEvent;
+    bool mEnabled;
+  };
+
+  EventInfo mEventInfo[NUM_SWITCH_DEVICE];
+  size_t mEnableCount;
+  SwitchHandlerArray mHandler;
+  bool mHeadphonesFromInputDev;
+
+  // This function might also get called on the main thread
+  // (from IsHeadphoneEventFromInputDev)
+  void Init()
+  {
+    RefPtr<SwitchHandlerHeadphone> switchHeadPhone =
+      new SwitchHandlerHeadphone(SWITCH_HEADSET_DEVPATH);
+
+    // If the initial state is unknown, it means the headphone event is from input dev
+    mHeadphonesFromInputDev = switchHeadPhone->GetState() == SWITCH_STATE_UNKNOWN ? true : false;
+
+    if (!mHeadphonesFromInputDev) {
+      mHandler.AppendElement(switchHeadPhone);
+    } else {
+      // If headphone status will be notified from input dev then initialize
+      // status to "off" and wait for event notification.
+      mEventInfo[SWITCH_HEADPHONES].mEvent.device() = SWITCH_HEADPHONES;
+      mEventInfo[SWITCH_HEADPHONES].mEvent.status() = SWITCH_STATE_OFF;
+    }
+    mHandler.AppendElement(new SwitchHandler(SWITCH_USB_DEVPATH_GB, SWITCH_USB));
+    mHandler.AppendElement(new SwitchHandlerUsbIcs(SWITCH_USB_DEVPATH_ICS));
+
+    SwitchHandlerArray::index_type handlerIndex;
+    SwitchHandlerArray::size_type numHandlers = mHandler.Length();
+
+    for (handlerIndex = 0; handlerIndex < numHandlers; handlerIndex++) {
+      SwitchState state = mHandler[handlerIndex]->GetState();
+      if (state == SWITCH_STATE_UNKNOWN) {
+        continue;
+      }
+
+      SwitchDevice device = mHandler[handlerIndex]->GetType();
+      mEventInfo[device].mEvent.device() = device;
+      mEventInfo[device].mEvent.status() = state;
+    }
+  }
+
+  SwitchDevice GetEventInfo(const NetlinkEvent& aEvent, SwitchState& aState)
+  {
+    //working around the android code not being const-correct
+    NetlinkEvent *e = const_cast<NetlinkEvent*>(&aEvent);
+
+    for (size_t i = 0; i < mHandler.Length(); i++) {
+      if (mHandler[i]->CheckEvent(e)) {
+        aState = mHandler[i]->GetState();
+        return mHandler[i]->GetType();
+      }
+    }
+    return SWITCH_DEVICE_UNKNOWN;
+  }
+};
+
+static RefPtr<SwitchEventObserver> sSwitchObserver;
+
+static void
+InitializeResourceIfNeed()
+{
+  if (!sSwitchObserver) {
+    sSwitchObserver = new SwitchEventObserver();
+    RegisterUeventListener(sSwitchObserver);
+  }
+}
+
+static void
+ReleaseResourceIfNeed()
+{
+  if (sSwitchObserver->GetEnableCount() == 0) {
+    UnregisterUeventListener(sSwitchObserver);
+    sSwitchObserver = nullptr;
+  }
+}
+
+static void
+EnableSwitchNotificationsIOThread(SwitchDevice aDevice, Monitor *aMonitor)
+{
+  InitializeResourceIfNeed();
+  sSwitchObserver->EnableSwitch(aDevice);
+  {
+    MonitorAutoLock lock(*aMonitor);
+    lock.Notify();
+  }
+
+  // Notify the latest state if IO thread has the information.
+  if (sSwitchObserver->GetEnableCount() > 1) {
+    sSwitchObserver->NotifyAnEvent(aDevice);
+  }
+}
+
+void
+EnableSwitchNotifications(SwitchDevice aDevice)
+{
+  Monitor monitor("EnableSwitch.monitor");
+  {
+    MonitorAutoLock lock(monitor);
+    XRE_GetIOMessageLoop()->PostTask(
+        NewRunnableFunction(EnableSwitchNotificationsIOThread, aDevice, &monitor));
+    lock.Wait();
+  }
+}
+
+static void
+DisableSwitchNotificationsIOThread(SwitchDevice aDevice)
+{
+  MOZ_ASSERT(sSwitchObserver->GetEnableCount());
+  sSwitchObserver->DisableSwitch(aDevice);
+  ReleaseResourceIfNeed();
+}
+
+void
+DisableSwitchNotifications(SwitchDevice aDevice)
+{
+  XRE_GetIOMessageLoop()->PostTask(
+      NewRunnableFunction(DisableSwitchNotificationsIOThread, aDevice));
+}
+
+SwitchState
+GetCurrentSwitchState(SwitchDevice aDevice)
+{
+  MOZ_ASSERT(sSwitchObserver && sSwitchObserver->GetEnableCount());
+  return sSwitchObserver->GetCurrentInformation(aDevice);
+}
+
+static void
+NotifySwitchStateIOThread(SwitchDevice aDevice, SwitchState aState)
+{
+  InitializeResourceIfNeed();
+  sSwitchObserver->Notify(aDevice, aState);
+}
+
+void NotifySwitchStateFromInputDevice(SwitchDevice aDevice, SwitchState aState)
+{
+  XRE_GetIOMessageLoop()->PostTask(
+      NewRunnableFunction(NotifySwitchStateIOThread, aDevice, aState));
+}
+
+bool IsHeadphoneEventFromInputDev()
+{
+  // Instead of calling InitializeResourceIfNeed, create new SwitchEventObserver
+  // to prevent calling RegisterUeventListener in main thread.
+  RefPtr<SwitchEventObserver> switchObserver = new SwitchEventObserver();
+  return switchObserver->GetHeadphonesFromInputDev();
+}
+
+} // hal_impl
+} //mozilla
diff --git a/hal/gonk/SensorsTypes.h b/hal/gonk/SensorsTypes.h
new file mode 100644
index 000000000..35c852f5a
--- /dev/null
+++ b/hal/gonk/SensorsTypes.h
@@ -0,0 +1,140 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef hal_gonk_SensorsTypes_h
+#define hal_gonk_SensorsTypes_h
+
+namespace mozilla {
+namespace hal {
+
+enum SensorsDeliveryMode {
+  SENSORS_DELIVERY_MODE_BEST_EFFORT,
+  SENSORS_DELIVERY_MODE_IMMEDIATE
+};
+
+enum SensorsError {
+  SENSORS_ERROR_NONE,
+  SENSORS_ERROR_FAIL,
+  SENSORS_ERROR_NOT_READY,
+  SENSORS_ERROR_NOMEM,
+  SENSORS_ERROR_BUSY,
+  SENSORS_ERROR_DONE,
+  SENSORS_ERROR_UNSUPPORTED,
+  SENSORS_ERROR_PARM_INVALID
+};
+
+enum SensorsStatus {
+  SENSORS_STATUS_NO_CONTACT,
+  SENSORS_STATUS_UNRELIABLE,
+  SENSORS_STATUS_ACCURACY_LOW,
+  SENSORS_STATUS_ACCURACY_MEDIUM,
+  SENSORS_STATUS_ACCURACY_HIGH
+};
+
+enum SensorsTriggerMode {
+  SENSORS_TRIGGER_MODE_CONTINUOUS,
+  SENSORS_TRIGGER_MODE_ON_CHANGE,
+  SENSORS_TRIGGER_MODE_ONE_SHOT,
+  SENSORS_TRIGGER_MODE_SPECIAL
+};
+
+enum SensorsType {
+  SENSORS_TYPE_ACCELEROMETER,
+  SENSORS_TYPE_GEOMAGNETIC_FIELD,
+  SENSORS_TYPE_ORIENTATION,
+  SENSORS_TYPE_GYROSCOPE,
+  SENSORS_TYPE_LIGHT,
+  SENSORS_TYPE_PRESSURE,
+  SENSORS_TYPE_TEMPERATURE,
+  SENSORS_TYPE_PROXIMITY,
+  SENSORS_TYPE_GRAVITY,
+  SENSORS_TYPE_LINEAR_ACCELERATION,
+  SENSORS_TYPE_ROTATION_VECTOR,
+  SENSORS_TYPE_RELATIVE_HUMIDITY,
+  SENSORS_TYPE_AMBIENT_TEMPERATURE,
+  SENSORS_TYPE_MAGNETIC_FIELD_UNCALIBRATED,
+  SENSORS_TYPE_GAME_ROTATION_VECTOR,
+  SENSORS_TYPE_GYROSCOPE_UNCALIBRATED,
+  SENSORS_TYPE_SIGNIFICANT_MOTION,
+  SENSORS_TYPE_STEP_DETECTED,
+  SENSORS_TYPE_STEP_COUNTER,
+  SENSORS_TYPE_GEOMAGNETIC_ROTATION_VECTOR,
+  SENSORS_TYPE_HEART_RATE,
+  SENSORS_TYPE_TILT_DETECTOR,
+  SENSORS_TYPE_WAKE_GESTURE,
+  SENSORS_TYPE_GLANCE_GESTURE,
+  SENSORS_TYPE_PICK_UP_GESTURE,
+  SENSORS_TYPE_WRIST_TILT_GESTURE,
+  SENSORS_NUM_TYPES
+};
+
+struct SensorsEvent {
+  SensorsType mType;
+  SensorsStatus mStatus;
+  SensorsDeliveryMode mDeliveryMode;
+  int64_t mTimestamp;
+  union {
+    float mFloat[6];
+    uint64_t mUint[1];
+  } mData;
+};
+
+/**
+ * |SensorsSensor| represents a device sensor; either single or composite.
+ */
+struct SensorsSensor {
+  SensorsSensor(int32_t aId, SensorsType aType,
+                float aRange, float aResolution,
+                float aPower, int32_t aMinPeriod,
+                int32_t aMaxPeriod,
+                SensorsTriggerMode aTriggerMode,
+                SensorsDeliveryMode aDeliveryMode)
+    : mId(aId)
+    , mType(aType)
+    , mRange(aRange)
+    , mResolution(aResolution)
+    , mPower(aPower)
+    , mMinPeriod(aMinPeriod)
+    , mMaxPeriod(aMaxPeriod)
+    , mTriggerMode(aTriggerMode)
+    , mDeliveryMode(aDeliveryMode)
+  { }
+
+  int32_t mId;
+  SensorsType mType;
+  float mRange;
+  float mResolution;
+  float mPower;
+  int32_t mMinPeriod;
+  int32_t mMaxPeriod;
+  SensorsTriggerMode mTriggerMode;
+  SensorsDeliveryMode mDeliveryMode;
+};
+
+/**
+ * |SensorClass| represents the status of a specific sensor type.
+ */
+struct SensorsSensorClass {
+  SensorsSensorClass()
+    : mActivated(0)
+    , mMinValue(0)
+    , mMaxValue(0)
+  { }
+
+  void UpdateFromSensor(const SensorsSensor& aSensor)
+  {
+    mMaxValue = std::max(aSensor.mRange, mMaxValue);
+  }
+
+  uint32_t mActivated;
+  float mMinValue;
+  float mMaxValue;
+};
+
+} // namespace hal
+} // namespace mozilla
+
+#endif // hal_gonk_SensorsTypes_h
diff --git a/hal/gonk/SystemService.cpp b/hal/gonk/SystemService.cpp
new file mode 100644
index 000000000..2b98f5fdd
--- /dev/null
+++ b/hal/gonk/SystemService.cpp
@@ -0,0 +1,131 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et ft=cpp : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Hal.h"
+
+#include <cutils/properties.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "HalLog.h"
+#include "nsITimer.h"
+#include "mozilla/Unused.h"
+
+namespace mozilla {
+namespace hal_impl {
+
+static const int sRetryInterval = 100; // ms
+
+bool
+SystemServiceIsRunning(const char* aSvcName)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  char key[PROPERTY_KEY_MAX];
+  auto res = snprintf(key, sizeof(key), "init.svc.%s", aSvcName);
+
+  if (res < 0) {
+    HAL_ERR("snprintf: %s", strerror(errno));
+    return false;
+  } else if (static_cast<size_t>(res) >= sizeof(key)) {
+    HAL_ERR("snprintf: trunctated service name %s", aSvcName);
+    return false;
+  }
+
+  char value[PROPERTY_VALUE_MAX];
+  Unused << NS_WARN_IF(property_get(key, value, "") < 0);
+
+  return !strcmp(value, "running");
+}
+
+class StartSystemServiceTimerCallback final : public nsITimerCallback
+{
+  NS_DECL_THREADSAFE_ISUPPORTS;
+
+public:
+  StartSystemServiceTimerCallback(const char* aSvcName, const char* aArgs)
+    : mSvcName(aSvcName)
+    , mArgs(aArgs)
+  {
+    MOZ_COUNT_CTOR_INHERITED(StartSystemServiceTimerCallback,
+                             nsITimerCallback);
+  }
+
+  NS_IMETHOD Notify(nsITimer* aTimer) override
+  {
+    MOZ_ASSERT(NS_IsMainThread());
+
+    return StartSystemService(mSvcName.get(), mArgs.get());
+  }
+
+protected:
+  ~StartSystemServiceTimerCallback()
+  {
+    MOZ_COUNT_DTOR_INHERITED(StartSystemServiceTimerCallback,
+                             nsITimerCallback);
+  }
+
+private:
+  nsCString mSvcName;
+  nsCString mArgs;
+};
+
+NS_IMPL_ISUPPORTS0(StartSystemServiceTimerCallback);
+
+nsresult
+StartSystemService(const char* aSvcName, const char* aArgs)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  char value[PROPERTY_VALUE_MAX];
+  auto res = snprintf(value, sizeof(value), "%s:%s", aSvcName, aArgs);
+
+  if (res < 0) {
+    HAL_ERR("snprintf: %s", strerror(errno));
+    return NS_ERROR_FAILURE;
+  } else if (static_cast<size_t>(res) >= sizeof(value)) {
+    HAL_ERR("snprintf: trunctated service name %s", aSvcName);
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  if (NS_WARN_IF(property_set("ctl.start", value) < 0)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  /* If the system service is not running, re-try later to start it.
+   *
+   * This condition happens when we restart a service immediately
+   * after it crashed, as the service state remains 'stopping'
+   * instead of 'stopped'. Due to the limitation of property service,
+   * hereby add delay. See Bug 1143925 Comment 41.
+   */
+  if (!SystemServiceIsRunning(aSvcName)) {
+    nsCOMPtr<nsITimer> timer = do_CreateInstance("@mozilla.org/timer;1");
+    if (!timer) {
+      return NS_ERROR_FAILURE;
+    }
+
+    RefPtr<StartSystemServiceTimerCallback> timerCallback =
+      new StartSystemServiceTimerCallback(aSvcName, aArgs);
+
+    timer->InitWithCallback(timerCallback,
+                            sRetryInterval,
+                            nsITimer::TYPE_ONE_SHOT);
+  }
+
+  return NS_OK;
+}
+
+void
+StopSystemService(const char* aSvcName)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  Unused << NS_WARN_IF(property_set("ctl.stop", aSvcName));
+}
+
+} // namespace hal_impl
+} // namespace mozilla
diff --git a/hal/gonk/UeventPoller.cpp b/hal/gonk/UeventPoller.cpp
new file mode 100644
index 000000000..3fbe850ed
--- /dev/null
+++ b/hal/gonk/UeventPoller.cpp
@@ -0,0 +1,312 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* Copyright 2012 Mozilla Foundation and Mozilla contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <pthread.h>
+#include <signal.h>
+#include <string.h>
+#include <strings.h>
+#include <unistd.h>
+
+#include <arpa/inet.h>
+#include <linux/types.h>
+#include <linux/netlink.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+
+#include "HalLog.h"
+#include "nsDebug.h"
+#include "base/message_loop.h"
+#include "base/task.h"
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/FileUtils.h"
+#include "mozilla/Monitor.h"
+#include "nsThreadUtils.h"
+#include "nsXULAppAPI.h"
+
+#include "UeventPoller.h"
+
+using namespace mozilla;
+
+namespace mozilla {
+namespace hal_impl {
+
+static void ShutdownUevent();
+
+class NetlinkPoller : public MessageLoopForIO::Watcher
+{
+public:
+  NetlinkPoller() : mSocket(-1),
+                    mIOLoop(MessageLoopForIO::current())
+  {
+  }
+
+  virtual ~NetlinkPoller() {}
+
+  bool OpenSocket();
+
+  virtual void OnFileCanReadWithoutBlocking(int fd);
+
+  // no writing to the netlink socket
+  virtual void OnFileCanWriteWithoutBlocking(int fd)
+  {
+    MOZ_CRASH("Must not write to netlink socket");
+  }
+
+  MessageLoopForIO *GetIOLoop () const { return mIOLoop; }
+  void RegisterObserver(IUeventObserver *aObserver)
+  {
+    mUeventObserverList.AddObserver(aObserver);
+  }
+
+  void UnregisterObserver(IUeventObserver *aObserver)
+  {
+    mUeventObserverList.RemoveObserver(aObserver);
+    if (mUeventObserverList.Length() == 0) {
+      ShutdownUevent();  // this will destroy self
+    }
+  }
+
+private:
+  ScopedClose mSocket;
+  MessageLoopForIO* mIOLoop;
+  MessageLoopForIO::FileDescriptorWatcher mReadWatcher;
+
+  const static int kBuffsize = 64 * 1024;
+  uint8_t mBuffer [kBuffsize];
+
+  typedef ObserverList<NetlinkEvent> UeventObserverList;
+  UeventObserverList mUeventObserverList;
+};
+
+bool
+NetlinkPoller::OpenSocket()
+{
+  mSocket.rwget() = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
+  if (mSocket.get() < 0) {
+    return false;
+  }
+
+  int sz = kBuffsize;
+
+  if (setsockopt(mSocket.get(), SOL_SOCKET, SO_RCVBUFFORCE, &sz,
+                 sizeof(sz)) < 0) {
+    return false;
+  }
+
+  // add FD_CLOEXEC flag
+  int flags = fcntl(mSocket.get(), F_GETFD);
+  if (flags == -1) {
+      return false;
+  }
+  flags |= FD_CLOEXEC;
+  if (fcntl(mSocket.get(), F_SETFD, flags) == -1) {
+    return false;
+  }
+
+  // set non-blocking
+  if (fcntl(mSocket.get(), F_SETFL, O_NONBLOCK) == -1) {
+    return false;
+  }
+
+  struct sockaddr_nl saddr;
+  bzero(&saddr, sizeof(saddr));
+  saddr.nl_family = AF_NETLINK;
+  saddr.nl_groups = 1;
+  saddr.nl_pid = gettid();
+
+  do {
+    if (bind(mSocket.get(), (struct sockaddr *)&saddr, sizeof(saddr)) == 0) {
+      break;
+    }
+
+    if (errno != EADDRINUSE) {
+      return false;
+    }
+
+    if (saddr.nl_pid == 0) {
+      return false;
+    }
+
+    // Once there was any other place in the same process assigning saddr.nl_pid by
+    // gettid(), we can detect it and print warning message.
+    HAL_LOG("The netlink socket address saddr.nl_pid=%u is in use. "
+            "Let the kernel re-assign.\n", saddr.nl_pid);
+    saddr.nl_pid = 0;
+  } while (true);
+
+  if (!mIOLoop->WatchFileDescriptor(mSocket.get(),
+                                    true,
+                                    MessageLoopForIO::WATCH_READ,
+                                    &mReadWatcher,
+                                    this)) {
+      return false;
+  }
+
+  return true;
+}
+
+static StaticAutoPtr<NetlinkPoller> sPoller;
+
+class UeventInitTask : public Runnable
+{
+  NS_IMETHOD Run() override
+  {
+    if (!sPoller) {
+      return NS_OK;
+    }
+    if (sPoller->OpenSocket()) {
+      return NS_OK;
+    }
+    sPoller->GetIOLoop()->PostDelayedTask(MakeAndAddRef<UeventInitTask>(),
+                                          1000);
+    return NS_OK;
+  }
+};
+
+void
+NetlinkPoller::OnFileCanReadWithoutBlocking(int fd)
+{
+  MOZ_ASSERT(fd == mSocket.get());
+  while (true) {
+    int ret = read(fd, mBuffer, kBuffsize);
+    if (ret == -1) {
+      if (errno == EAGAIN || errno == EWOULDBLOCK) {
+        return;
+      }
+      if (errno == EINTR) {
+        continue;
+      }
+    }
+    if (ret <= 0) {
+      // fatal error on netlink socket which should not happen
+      _exit(1);
+    }
+    NetlinkEvent netlinkEvent;
+    netlinkEvent.decode(reinterpret_cast<char*>(mBuffer), ret);
+    mUeventObserverList.Broadcast(netlinkEvent);
+  }
+}
+
+static bool sShutdown = false;
+
+class ShutdownNetlinkPoller;
+static StaticAutoPtr<ShutdownNetlinkPoller> sShutdownPoller;
+static Monitor* sMonitor = nullptr;
+
+class ShutdownNetlinkPoller {
+public:
+  ~ShutdownNetlinkPoller()
+  {
+    // This is called from KillClearOnShutdown() on the main thread.
+    MOZ_ASSERT(NS_IsMainThread());
+    MOZ_ASSERT(XRE_GetIOMessageLoop());
+
+    {
+      MonitorAutoLock lock(*sMonitor);
+
+      XRE_GetIOMessageLoop()->PostTask(
+          NewRunnableFunction(ShutdownUeventIOThread));
+
+      while (!sShutdown) {
+        lock.Wait();
+      }
+    }
+
+    sShutdown = true;
+    delete sMonitor;
+  }
+
+  static void MaybeInit()
+  {
+    MOZ_ASSERT(MessageLoop::current() == XRE_GetIOMessageLoop());
+    if (sShutdown || sMonitor) {
+      // Don't init twice or init after shutdown.
+      return;
+    }
+
+    sMonitor = new Monitor("ShutdownNetlinkPoller.monitor");
+    {
+      ShutdownNetlinkPoller* shutdownPoller = new ShutdownNetlinkPoller();
+
+      nsCOMPtr<nsIRunnable> runnable = NS_NewRunnableFunction([=] () -> void
+      {
+        sShutdownPoller = shutdownPoller;
+        ClearOnShutdown(&sShutdownPoller); // Must run on the main thread.
+      });
+      MOZ_ASSERT(runnable);
+      MOZ_ALWAYS_SUCCEEDS(
+        NS_DispatchToMainThread(runnable, NS_DISPATCH_NORMAL));
+    }
+  }
+private:
+  ShutdownNetlinkPoller() = default;
+  static void ShutdownUeventIOThread()
+  {
+    MonitorAutoLock l(*sMonitor);
+    ShutdownUevent(); // Must run on the IO thread.
+    sShutdown = true;
+    l.NotifyAll();
+  }
+};
+
+static void
+InitializeUevent()
+{
+  MOZ_ASSERT(!sPoller);
+  sPoller = new NetlinkPoller();
+  sPoller->GetIOLoop()->PostTask(MakeAndAddRef<UeventInitTask>());
+
+  ShutdownNetlinkPoller::MaybeInit();
+}
+
+static void
+ShutdownUevent()
+{
+  sPoller = nullptr;
+}
+
+void
+RegisterUeventListener(IUeventObserver *aObserver)
+{
+  MOZ_ASSERT(MessageLoop::current() == XRE_GetIOMessageLoop());
+
+  if (sShutdown) {
+    return;
+  }
+
+  if (!sPoller) {
+    InitializeUevent();
+  }
+  sPoller->RegisterObserver(aObserver);
+}
+
+void
+UnregisterUeventListener(IUeventObserver *aObserver)
+{
+  MOZ_ASSERT(MessageLoop::current() == XRE_GetIOMessageLoop());
+
+  if (sShutdown) {
+    return;
+  }
+
+  sPoller->UnregisterObserver(aObserver);
+}
+
+} // hal_impl
+} // mozilla
+
diff --git a/hal/gonk/UeventPoller.h b/hal/gonk/UeventPoller.h
new file mode 100644
index 000000000..ba121cec2
--- /dev/null
+++ b/hal/gonk/UeventPoller.h
@@ -0,0 +1,49 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* Copyright 2012 Mozilla Foundation and Mozilla contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _mozilla_uevent_poller_h_
+#define _mozilla_uevent_poller_h_
+
+#include <sysutils/NetlinkEvent.h>
+#include "mozilla/Observer.h"
+
+class NetlinkEvent;
+
+namespace mozilla {
+namespace hal_impl {
+
+typedef mozilla::Observer<NetlinkEvent> IUeventObserver;
+
+/**
+ * Register for uevent notification. Note that the method should run on the
+ * <b> IO Thread </b>
+ * @aObserver the observer to be added. The observer's Notify() is only called
+ * on the <b> IO Thread </b>
+ */
+void RegisterUeventListener(IUeventObserver *aObserver);
+
+/**
+ * Unregister for uevent notification. Note that the method should run on the
+ * <b> IO Thread </b>
+ * @aObserver the observer to be removed
+ */
+void UnregisterUeventListener(IUeventObserver *aObserver);
+
+}
+}
+
+#endif
+
diff --git a/hal/gonk/fanotify.h b/hal/gonk/fanotify.h
new file mode 100644
index 000000000..e715d3bf9
--- /dev/null
+++ b/hal/gonk/fanotify.h
@@ -0,0 +1,118 @@
+#ifndef _LINUX_FANOTIFY_H
+#define _LINUX_FANOTIFY_H
+
+/* This is a Linux header generated by "make headers_install" */
+
+#include <linux/types.h>
+
+/* the following events that user-space can register for */
+#define FAN_ACCESS		0x00000001	/* File was accessed */
+#define FAN_MODIFY		0x00000002	/* File was modified */
+#define FAN_CLOSE_WRITE		0x00000008	/* Writtable file closed */
+#define FAN_CLOSE_NOWRITE	0x00000010	/* Unwrittable file closed */
+#define FAN_OPEN		0x00000020	/* File was opened */
+
+#define FAN_Q_OVERFLOW		0x00004000	/* Event queued overflowed */
+
+#define FAN_OPEN_PERM		0x00010000	/* File open in perm check */
+#define FAN_ACCESS_PERM		0x00020000	/* File accessed in perm check */
+
+#define FAN_ONDIR		0x40000000	/* event occurred against dir */
+
+#define FAN_EVENT_ON_CHILD	0x08000000	/* interested in child events */
+
+/* helper events */
+#define FAN_CLOSE		(FAN_CLOSE_WRITE | FAN_CLOSE_NOWRITE) /* close */
+
+/* flags used for fanotify_init() */
+#define FAN_CLOEXEC		0x00000001
+#define FAN_NONBLOCK		0x00000002
+
+/* These are NOT bitwise flags.  Both bits are used togther.  */
+#define FAN_CLASS_NOTIF		0x00000000
+#define FAN_CLASS_CONTENT	0x00000004
+#define FAN_CLASS_PRE_CONTENT	0x00000008
+#define FAN_ALL_CLASS_BITS	(FAN_CLASS_NOTIF | FAN_CLASS_CONTENT | \
+				 FAN_CLASS_PRE_CONTENT)
+
+#define FAN_UNLIMITED_QUEUE	0x00000010
+#define FAN_UNLIMITED_MARKS	0x00000020
+
+#define FAN_ALL_INIT_FLAGS	(FAN_CLOEXEC | FAN_NONBLOCK | \
+				 FAN_ALL_CLASS_BITS | FAN_UNLIMITED_QUEUE |\
+				 FAN_UNLIMITED_MARKS)
+
+/* flags used for fanotify_modify_mark() */
+#define FAN_MARK_ADD		0x00000001
+#define FAN_MARK_REMOVE		0x00000002
+#define FAN_MARK_DONT_FOLLOW	0x00000004
+#define FAN_MARK_ONLYDIR	0x00000008
+#define FAN_MARK_MOUNT		0x00000010
+#define FAN_MARK_IGNORED_MASK	0x00000020
+#define FAN_MARK_IGNORED_SURV_MODIFY	0x00000040
+#define FAN_MARK_FLUSH		0x00000080
+
+#define FAN_ALL_MARK_FLAGS	(FAN_MARK_ADD |\
+				 FAN_MARK_REMOVE |\
+				 FAN_MARK_DONT_FOLLOW |\
+				 FAN_MARK_ONLYDIR |\
+				 FAN_MARK_MOUNT |\
+				 FAN_MARK_IGNORED_MASK |\
+				 FAN_MARK_IGNORED_SURV_MODIFY |\
+				 FAN_MARK_FLUSH)
+
+/*
+ * All of the events - we build the list by hand so that we can add flags in
+ * the future and not break backward compatibility.  Apps will get only the
+ * events that they originally wanted.  Be sure to add new events here!
+ */
+#define FAN_ALL_EVENTS (FAN_ACCESS |\
+			FAN_MODIFY |\
+			FAN_CLOSE |\
+			FAN_OPEN)
+
+/*
+ * All events which require a permission response from userspace
+ */
+#define FAN_ALL_PERM_EVENTS (FAN_OPEN_PERM |\
+			     FAN_ACCESS_PERM)
+
+#define FAN_ALL_OUTGOING_EVENTS	(FAN_ALL_EVENTS |\
+				 FAN_ALL_PERM_EVENTS |\
+				 FAN_Q_OVERFLOW)
+
+#define FANOTIFY_METADATA_VERSION	3
+
+struct fanotify_event_metadata {
+	__u32 event_len;
+	__u8 vers;
+	__u8 reserved;
+	__u16 metadata_len;
+	__u64 mask;
+	__s32 fd;
+	__s32 pid;
+};
+
+struct fanotify_response {
+	__s32 fd;
+	__u32 response;
+};
+
+/* Legit userspace responses to a _PERM event */
+#define FAN_ALLOW	0x01
+#define FAN_DENY	0x02
+/* No fd set in event */
+#define FAN_NOFD	-1
+
+/* Helper functions to deal with fanotify_event_metadata buffers */
+#define FAN_EVENT_METADATA_LEN (sizeof(struct fanotify_event_metadata))
+
+#define FAN_EVENT_NEXT(meta, len) ((len) -= (meta)->event_len, \
+				   (struct fanotify_event_metadata*)(((char *)(meta)) + \
+				   (meta)->event_len))
+
+#define FAN_EVENT_OK(meta, len)	((long)(len) >= (long)FAN_EVENT_METADATA_LEN && \
+				(long)(meta)->event_len >= (long)FAN_EVENT_METADATA_LEN && \
+				(long)(meta)->event_len <= (long)(len))
+
+#endif /* _LINUX_FANOTIFY_H */
diff --git a/hal/gonk/nsIRecoveryService.idl b/hal/gonk/nsIRecoveryService.idl
new file mode 100644
index 000000000..ecbb39c0e
--- /dev/null
+++ b/hal/gonk/nsIRecoveryService.idl
@@ -0,0 +1,39 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+[scriptable, uuid(bc24fb33-a0c1-49ca-aa43-05f167e02fb6)]
+interface nsIRecoveryService : nsISupports
+{
+  /**
+   * Possible values of fotaStatus.result. These should stay in sync with
+   * librecovery/librecovery.h
+   */
+  const long FOTA_UPDATE_UNKNOWN = 0;
+  const long FOTA_UPDATE_FAIL    = 1;
+  const long FOTA_UPDATE_SUCCESS = 2;
+
+  /**
+   * Uses recovery to wipe the data and cache partitions. If this call is
+   * successful, the device should reboot before the function call ever returns.
+   *
+   * @throws NS_ERROR_FAILURE when rebooting into recovery fails for some reason.
+   */
+  void factoryReset(in string reason);
+
+  /**
+   * Use recovery to install an OTA update.zip. If this call is
+   * successful, the device should reboot before the function call ever returns.
+   *
+   * @throws NS_ERROR_FAILURE when rebooting into recovery fails for some reason.
+   */
+  void installFotaUpdate(in string updatePath);
+
+  /**
+   * @return The status of the last FOTA update. One of FOTA_UPDATE_UNKNOWN,
+   *         FOTA_UPDATE_FAIL, FOTA_UPDATE_SUCCESS.
+   */
+  long getFotaUpdateStatus();
+};
diff --git a/hal/gonk/tavarua.h b/hal/gonk/tavarua.h
new file mode 100644
index 000000000..4eb3483a8
--- /dev/null
+++ b/hal/gonk/tavarua.h
@@ -0,0 +1,484 @@
+#ifndef __LINUX_TAVARUA_H
+#define __LINUX_TAVARUA_H
+
+/* This is a Linux header generated by "make headers_install" */
+
+#include <stdint.h>
+#include <linux/ioctl.h>
+#include <linux/videodev2.h>
+
+
+#undef FM_DEBUG
+
+/* constants */
+#define  RDS_BLOCKS_NUM             (4)
+#define BYTES_PER_BLOCK             (3)
+#define MAX_PS_LENGTH              (96)
+#define MAX_RT_LENGTH              (64)
+
+#define XFRDAT0                    (0x20)
+#define XFRDAT1                    (0x21)
+#define XFRDAT2                    (0x22)
+
+#define INTDET_PEEK_MSB            (0x88)
+#define INTDET_PEEK_LSB            (0x26)
+
+#define RMSSI_PEEK_MSB             (0x88)
+#define RMSSI_PEEK_LSB             (0xA8)
+
+#define MPX_DCC_BYPASS_POKE_MSB    (0x88)
+#define MPX_DCC_BYPASS_POKE_LSB    (0xC0)
+
+#define MPX_DCC_PEEK_MSB_REG1      (0x88)
+#define MPX_DCC_PEEK_LSB_REG1      (0xC2)
+
+#define MPX_DCC_PEEK_MSB_REG2      (0x88)
+#define MPX_DCC_PEEK_LSB_REG2      (0xC3)
+
+#define MPX_DCC_PEEK_MSB_REG3      (0x88)
+#define MPX_DCC_PEEK_LSB_REG3      (0xC4)
+
+#define ON_CHANNEL_TH_MSB          (0x0B)
+#define ON_CHANNEL_TH_LSB          (0xA8)
+
+#define OFF_CHANNEL_TH_MSB         (0x0B)
+#define OFF_CHANNEL_TH_LSB         (0xAC)
+
+#define ENF_200Khz                    (1)
+#define SRCH200KHZ_OFFSET             (7)
+#define SRCH_MASK                  (1 << SRCH200KHZ_OFFSET)
+
+/* Standard buffer size */
+#define STD_BUF_SIZE               (128)
+/* Search direction */
+#define SRCH_DIR_UP                 (0)
+#define SRCH_DIR_DOWN               (1)
+
+/* control options */
+#define CTRL_ON                     (1)
+#define CTRL_OFF                    (0)
+
+#define US_LOW_BAND                (87.5)
+#define US_HIGH_BAND               (108)
+
+/* constant for Tx */
+
+#define MASK_PI                    (0x0000FFFF)
+#define MASK_PI_MSB                (0x0000FF00)
+#define MASK_PI_LSB                (0x000000FF)
+#define MASK_PTY                   (0x0000001F)
+#define MASK_TXREPCOUNT            (0x0000000F)
+
+#undef FMDBG
+#ifdef FM_DEBUG
+  #define FMDBG(fmt, args...) printk(KERN_INFO "tavarua_radio: " fmt, ##args)
+#else
+  #define FMDBG(fmt, args...)
+#endif
+
+#undef FMDERR
+#define FMDERR(fmt, args...) printk(KERN_INFO "tavarua_radio: " fmt, ##args)
+
+#undef FMDBG_I2C
+#ifdef FM_DEBUG_I2C
+  #define FMDBG_I2C(fmt, args...) printk(KERN_INFO "fm_i2c: " fmt, ##args)
+#else
+  #define FMDBG_I2C(fmt, args...)
+#endif
+
+/* function declarations */
+/* FM Core audio paths. */
+#define TAVARUA_AUDIO_OUT_ANALOG_OFF	(0)
+#define TAVARUA_AUDIO_OUT_ANALOG_ON	(1)
+#define TAVARUA_AUDIO_OUT_DIGITAL_OFF	(0)
+#define TAVARUA_AUDIO_OUT_DIGITAL_ON	(1)
+
+int tavarua_set_audio_path(int digital_on, int analog_on);
+
+/* defines and enums*/
+
+#define MARIMBA_A0	0x01010013
+#define MARIMBA_2_1	0x02010204
+#define BAHAMA_1_0	0x0302010A
+#define BAHAMA_2_0	0x04020205
+#define WAIT_TIMEOUT 2000
+#define RADIO_INIT_TIME 15
+#define TAVARUA_DELAY 10
+/*
+ * The frequency is set in units of 62.5 Hz when using V4L2_TUNER_CAP_LOW,
+ * 62.5 kHz otherwise.
+ * The tuner is able to have a channel spacing of 50, 100 or 200 kHz.
+ * tuner->capability is therefore set to V4L2_TUNER_CAP_LOW
+ * The FREQ_MUL is then: 1 MHz / 62.5 Hz = 16000
+ */
+#define FREQ_MUL (1000000 / 62.5)
+
+enum v4l2_cid_private_tavarua_t {
+	V4L2_CID_PRIVATE_TAVARUA_SRCHMODE = (V4L2_CID_PRIVATE_BASE + 1),
+	V4L2_CID_PRIVATE_TAVARUA_SCANDWELL,
+	V4L2_CID_PRIVATE_TAVARUA_SRCHON,
+	V4L2_CID_PRIVATE_TAVARUA_STATE,
+	V4L2_CID_PRIVATE_TAVARUA_TRANSMIT_MODE,
+	V4L2_CID_PRIVATE_TAVARUA_RDSGROUP_MASK,
+	V4L2_CID_PRIVATE_TAVARUA_REGION,
+	V4L2_CID_PRIVATE_TAVARUA_SIGNAL_TH,
+	V4L2_CID_PRIVATE_TAVARUA_SRCH_PTY,
+	V4L2_CID_PRIVATE_TAVARUA_SRCH_PI,
+	V4L2_CID_PRIVATE_TAVARUA_SRCH_CNT,
+	V4L2_CID_PRIVATE_TAVARUA_EMPHASIS,
+	V4L2_CID_PRIVATE_TAVARUA_RDS_STD,
+	V4L2_CID_PRIVATE_TAVARUA_SPACING,
+	V4L2_CID_PRIVATE_TAVARUA_RDSON,
+	V4L2_CID_PRIVATE_TAVARUA_RDSGROUP_PROC,
+	V4L2_CID_PRIVATE_TAVARUA_LP_MODE,
+	V4L2_CID_PRIVATE_TAVARUA_ANTENNA,
+	V4L2_CID_PRIVATE_TAVARUA_RDSD_BUF,
+	V4L2_CID_PRIVATE_TAVARUA_PSALL,
+	/*v4l2 Tx controls*/
+	V4L2_CID_PRIVATE_TAVARUA_TX_SETPSREPEATCOUNT,
+	V4L2_CID_PRIVATE_TAVARUA_STOP_RDS_TX_PS_NAME,
+	V4L2_CID_PRIVATE_TAVARUA_STOP_RDS_TX_RT,
+	V4L2_CID_PRIVATE_TAVARUA_IOVERC,
+	V4L2_CID_PRIVATE_TAVARUA_INTDET,
+	V4L2_CID_PRIVATE_TAVARUA_MPX_DCC,
+	V4L2_CID_PRIVATE_TAVARUA_AF_JUMP,
+	V4L2_CID_PRIVATE_TAVARUA_RSSI_DELTA,
+	V4L2_CID_PRIVATE_TAVARUA_HLSI,
+
+	/*
+	* Here we have IOCTl's that are specific to IRIS
+	* (V4L2_CID_PRIVATE_BASE + 0x1E to V4L2_CID_PRIVATE_BASE + 0x28)
+	*/
+	V4L2_CID_PRIVATE_SOFT_MUTE,/* 0x800001E*/
+	V4L2_CID_PRIVATE_RIVA_ACCS_ADDR,
+	V4L2_CID_PRIVATE_RIVA_ACCS_LEN,
+	V4L2_CID_PRIVATE_RIVA_PEEK,
+	V4L2_CID_PRIVATE_RIVA_POKE,
+	V4L2_CID_PRIVATE_SSBI_ACCS_ADDR,
+	V4L2_CID_PRIVATE_SSBI_PEEK,
+	V4L2_CID_PRIVATE_SSBI_POKE,
+	V4L2_CID_PRIVATE_TX_TONE,
+	V4L2_CID_PRIVATE_RDS_GRP_COUNTERS,
+	V4L2_CID_PRIVATE_SET_NOTCH_FILTER,/* 0x8000028 */
+
+	V4L2_CID_PRIVATE_TAVARUA_SET_AUDIO_PATH,/* 0x8000029 */
+	V4L2_CID_PRIVATE_TAVARUA_DO_CALIBRATION,/* 0x800002A : IRIS */
+	V4L2_CID_PRIVATE_TAVARUA_SRCH_ALGORITHM,/* 0x800002B */
+	V4L2_CID_PRIVATE_IRIS_GET_SINR, /* 0x800002C : IRIS */
+	V4L2_CID_PRIVATE_INTF_LOW_THRESHOLD, /* 0x800002D */
+	V4L2_CID_PRIVATE_INTF_HIGH_THRESHOLD, /* 0x800002E */
+	V4L2_CID_PRIVATE_SINR_THRESHOLD,  /* 0x800002F : IRIS */
+	V4L2_CID_PRIVATE_SINR_SAMPLES,  /* 0x8000030 : IRIS */
+
+};
+
+enum tavarua_buf_t {
+	TAVARUA_BUF_SRCH_LIST,
+	TAVARUA_BUF_EVENTS,
+	TAVARUA_BUF_RT_RDS,
+	TAVARUA_BUF_PS_RDS,
+	TAVARUA_BUF_RAW_RDS,
+	TAVARUA_BUF_AF_LIST,
+	TAVARUA_BUF_MAX
+};
+
+enum tavarua_xfr_t {
+	TAVARUA_XFR_SYNC,
+	TAVARUA_XFR_ERROR,
+	TAVARUA_XFR_SRCH_LIST,
+	TAVARUA_XFR_RT_RDS,
+	TAVARUA_XFR_PS_RDS,
+	TAVARUA_XFR_AF_LIST,
+	TAVARUA_XFR_MAX
+};
+
+enum channel_spacing {
+	FM_CH_SPACE_200KHZ,
+	FM_CH_SPACE_100KHZ,
+	FM_CH_SPACE_50KHZ
+};
+
+enum step_size {
+	NO_SRCH200khz,
+	ENF_SRCH200khz
+};
+
+enum emphasis {
+	EMP_75,
+	EMP_50
+};
+
+enum rds_std {
+	RBDS_STD,
+	RDS_STD
+};
+
+/* offsets */
+#define RAW_RDS		0x0F
+#define RDS_BLOCK 	3
+
+/* registers*/
+#define MARIMBA_XO_BUFF_CNTRL 0x07
+#define RADIO_REGISTERS 0x30
+#define XFR_REG_NUM     16
+#define STATUS_REG_NUM 	3
+
+/* TX constants */
+#define HEADER_SIZE	4
+#define TX_ON		0x80
+#define TAVARUA_TX_RT	RDS_RT_0
+#define TAVARUA_TX_PS	RDS_PS_0
+
+enum register_t {
+	STATUS_REG1 = 0,
+	STATUS_REG2,
+	STATUS_REG3,
+	RDCTRL,
+	FREQ,
+	TUNECTRL,
+	SRCHRDS1,
+	SRCHRDS2,
+	SRCHCTRL,
+	IOCTRL,
+	RDSCTRL,
+	ADVCTRL,
+	AUDIOCTRL,
+	RMSSI,
+	IOVERC,
+	AUDIOIND = 0x1E,
+	XFRCTRL,
+	FM_CTL0 = 0xFF,
+	LEAKAGE_CNTRL = 0xFE,
+};
+#define BAHAMA_RBIAS_CTL1       0x07
+#define	BAHAMA_FM_MODE_REG      0xFD
+#define	BAHAMA_FM_CTL1_REG      0xFE
+#define	BAHAMA_FM_CTL0_REG      0xFF
+#define BAHAMA_FM_MODE_NORMAL   0x00
+#define BAHAMA_LDO_DREG_CTL0    0xF0
+#define BAHAMA_LDO_AREG_CTL0    0xF4
+
+/* Radio Control */
+#define RDCTRL_STATE_OFFSET	0
+#define RDCTRL_STATE_MASK	(3 << RDCTRL_STATE_OFFSET)
+#define RDCTRL_BAND_OFFSET	2
+#define RDCTRL_BAND_MASK	(1 << RDCTRL_BAND_OFFSET)
+#define RDCTRL_CHSPACE_OFFSET	3
+#define RDCTRL_CHSPACE_MASK	(3 << RDCTRL_CHSPACE_OFFSET)
+#define RDCTRL_DEEMPHASIS_OFFSET 5
+#define RDCTRL_DEEMPHASIS_MASK	(1 << RDCTRL_DEEMPHASIS_OFFSET)
+#define RDCTRL_HLSI_OFFSET	6
+#define RDCTRL_HLSI_MASK	(3 << RDCTRL_HLSI_OFFSET)
+#define RDSAF_OFFSET		6
+#define RDSAF_MASK		(1 << RDSAF_OFFSET)
+
+/* Tune Control */
+#define TUNE_STATION	0x01
+#define ADD_OFFSET	(1 << 1)
+#define SIGSTATE	(1 << 5)
+#define MOSTSTATE	(1 << 6)
+#define RDSSYNC		(1 << 7)
+/* Search Control */
+#define SRCH_MODE_OFFSET	0
+#define SRCH_MODE_MASK		(7 << SRCH_MODE_OFFSET)
+#define SRCH_DIR_OFFSET		3
+#define SRCH_DIR_MASK		(1 << SRCH_DIR_OFFSET)
+#define SRCH_DWELL_OFFSET	4
+#define SRCH_DWELL_MASK		(7 << SRCH_DWELL_OFFSET)
+#define SRCH_STATE_OFFSET	7
+#define SRCH_STATE_MASK		(1 << SRCH_STATE_OFFSET)
+
+/* I/O Control */
+#define IOC_HRD_MUTE	0x03
+#define IOC_SFT_MUTE    (1 << 2)
+#define IOC_MON_STR     (1 << 3)
+#define IOC_SIG_BLND    (1 << 4)
+#define IOC_INTF_BLND   (1 << 5)
+#define IOC_ANTENNA     (1 << 6)
+#define IOC_ANTENNA_OFFSET	6
+#define IOC_ANTENNA_MASK     	(1 << IOC_ANTENNA_OFFSET)
+
+/* RDS Control */
+#define RDS_ON		0x01
+#define RDSCTRL_STANDARD_OFFSET 1
+#define RDSCTRL_STANDARD_MASK	(1 << RDSCTRL_STANDARD_OFFSET)
+
+/* Advanced features controls */
+#define RDSRTEN		(1 << 3)
+#define RDSPSEN		(1 << 4)
+
+/* Audio path control */
+#define AUDIORX_ANALOG_OFFSET 	0
+#define AUDIORX_ANALOG_MASK 	(1 << AUDIORX_ANALOG_OFFSET)
+#define AUDIORX_DIGITAL_OFFSET 	1
+#define AUDIORX_DIGITAL_MASK 	(1 << AUDIORX_DIGITAL_OFFSET)
+#define AUDIOTX_OFFSET		2
+#define AUDIOTX_MASK		(1 << AUDIOTX_OFFSET)
+#define I2SCTRL_OFFSET		3
+#define I2SCTRL_MASK		(1 << I2SCTRL_OFFSET)
+
+/* Search options */
+enum search_t {
+	SEEK,
+	SCAN,
+	SCAN_FOR_STRONG,
+	SCAN_FOR_WEAK,
+	RDS_SEEK_PTY,
+	RDS_SCAN_PTY,
+	RDS_SEEK_PI,
+	RDS_AF_JUMP,
+};
+
+enum audio_path {
+	FM_DIGITAL_PATH,
+	FM_ANALOG_PATH
+};
+#define SRCH_MODE	0x07
+#define SRCH_DIR	0x08 /* 0-up 1-down */
+#define SCAN_DWELL	0x70
+#define SRCH_ON		0x80
+
+/* RDS CONFIG */
+#define RDS_CONFIG_PSALL 0x01
+
+#define FM_ENABLE	0x22
+#define SET_REG_FIELD(reg, val, offset, mask) \
+	(reg = (reg & ~mask) | (((val) << offset) & mask))
+#define GET_REG_FIELD(reg, offset, mask) ((reg & mask) >> offset)
+#define RSH_DATA(val, offset)    ((val) >> (offset))
+#define LSH_DATA(val, offset)    ((val) << (offset))
+#define GET_ABS_VAL(val)        ((val) & (0xFF))
+
+enum radio_state_t {
+	FM_OFF,
+	FM_RECV,
+	FM_TRANS,
+	FM_RESET,
+};
+
+#define XFRCTRL_WRITE   (1 << 7)
+
+/* Interrupt status */
+
+/* interrupt register 1 */
+#define	READY		(1 << 0) /* Radio ready after powerup or reset */
+#define	TUNE		(1 << 1) /* Tune completed */
+#define	SEARCH		(1 << 2) /* Search completed (read FREQ) */
+#define	SCANNEXT	(1 << 3) /* Scanning for next station */
+#define	SIGNAL		(1 << 4) /* Signal indicator change (read SIGSTATE) */
+#define	INTF		(1 << 5) /* Interference cnt has fallen outside range */
+#define	SYNC		(1 << 6) /* RDS sync state change (read RDSSYNC) */
+#define	AUDIO		(1 << 7) /* Audio Control indicator (read AUDIOIND) */
+
+/* interrupt register 2 */
+#define	RDSDAT		(1 << 0) /* New unread RDS data group available */
+#define	BLOCKB		(1 << 1) /* Block-B match condition exists */
+#define	PROGID		(1 << 2) /* Block-A or Block-C matched stored PI value*/
+#define	RDSPS		(1 << 3) /* New RDS Program Service Table available */
+#define	RDSRT		(1 << 4) /* New RDS Radio Text available */
+#define	RDSAF		(1 << 5) /* New RDS AF List available */
+#define	TXRDSDAT	(1 << 6) /* Transmitted an RDS group */
+#define	TXRDSDONE	(1 << 7) /* RDS raw group one-shot transmit completed */
+
+/* interrupt register 3 */
+#define	TRANSFER	(1 << 0) /* Data transfer (XFR) completed */
+#define	RDSPROC		(1 << 1) /* Dynamic RDS Processing complete */
+#define	ERROR		(1 << 7) /* Err occurred.Read code to determine cause */
+
+
+#define	FM_TX_PWR_LVL_0		0 /* Lowest power lvl that can be set for Tx */
+#define	FM_TX_PWR_LVL_MAX	7 /* Max power lvl for Tx */
+/* Transfer */
+enum tavarua_xfr_ctrl_t {
+	RDS_PS_0 = 0x01,
+	RDS_PS_1,
+	RDS_PS_2,
+	RDS_PS_3,
+	RDS_PS_4,
+	RDS_PS_5,
+	RDS_PS_6,
+	RDS_RT_0,
+	RDS_RT_1,
+	RDS_RT_2,
+	RDS_RT_3,
+	RDS_RT_4,
+	RDS_AF_0,
+	RDS_AF_1,
+	RDS_CONFIG,
+	RDS_TX_GROUPS,
+	RDS_COUNT_0,
+	RDS_COUNT_1,
+	RDS_COUNT_2,
+	RADIO_CONFIG,
+	RX_CONFIG,
+	RX_TIMERS,
+	RX_STATIONS_0,
+	RX_STATIONS_1,
+	INT_CTRL,
+	ERROR_CODE,
+	CHIPID,
+	CAL_DAT_0 = 0x20,
+	CAL_DAT_1,
+	CAL_DAT_2,
+	CAL_DAT_3,
+	CAL_CFG_0,
+	CAL_CFG_1,
+	DIG_INTF_0,
+	DIG_INTF_1,
+	DIG_AGC_0,
+	DIG_AGC_1,
+	DIG_AGC_2,
+	DIG_AUDIO_0,
+	DIG_AUDIO_1,
+	DIG_AUDIO_2,
+	DIG_AUDIO_3,
+	DIG_AUDIO_4,
+	DIG_RXRDS,
+	DIG_DCC,
+	DIG_SPUR,
+	DIG_MPXDCC,
+	DIG_PILOT,
+	DIG_DEMOD,
+	DIG_MOST,
+	DIG_TX_0,
+	DIG_TX_1,
+	PHY_TXGAIN = 0x3B,
+	PHY_CONFIG,
+	PHY_TXBLOCK,
+	PHY_TCB,
+	XFR_PEEK_MODE = 0x40,
+	XFR_POKE_MODE = 0xC0,
+	TAVARUA_XFR_CTRL_MAX
+};
+
+enum tavarua_evt_t {
+	TAVARUA_EVT_RADIO_READY,
+	TAVARUA_EVT_TUNE_SUCC,
+	TAVARUA_EVT_SEEK_COMPLETE,
+	TAVARUA_EVT_SCAN_NEXT,
+	TAVARUA_EVT_NEW_RAW_RDS,
+	TAVARUA_EVT_NEW_RT_RDS,
+	TAVARUA_EVT_NEW_PS_RDS,
+	TAVARUA_EVT_ERROR,
+	TAVARUA_EVT_BELOW_TH,
+	TAVARUA_EVT_ABOVE_TH,
+	TAVARUA_EVT_STEREO,
+	TAVARUA_EVT_MONO,
+	TAVARUA_EVT_RDS_AVAIL,
+	TAVARUA_EVT_RDS_NOT_AVAIL,
+	TAVARUA_EVT_NEW_SRCH_LIST,
+	TAVARUA_EVT_NEW_AF_LIST,
+	TAVARUA_EVT_TXRDSDAT,
+	TAVARUA_EVT_TXRDSDONE,
+	TAVARUA_EVT_RADIO_DISABLED
+};
+
+enum tavarua_region_t {
+	TAVARUA_REGION_US,
+	TAVARUA_REGION_EU,
+	TAVARUA_REGION_JAPAN,
+	TAVARUA_REGION_JAPAN_WIDE,
+	TAVARUA_REGION_OTHER
+};
+
+#endif /* __LINUX_TAVARUA_H */
diff --git a/hal/linux/LinuxMemory.cpp b/hal/linux/LinuxMemory.cpp
new file mode 100644
index 000000000..14ed63146
--- /dev/null
+++ b/hal/linux/LinuxMemory.cpp
@@ -0,0 +1,39 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: sw=2 ts=8 et :
+ */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <stdio.h>
+#include "Hal.h"
+
+namespace mozilla {
+namespace hal_impl {
+
+uint32_t
+GetTotalSystemMemory()
+{
+  static uint32_t sTotalMemory;
+  static bool sTotalMemoryObtained = false;
+
+  if (!sTotalMemoryObtained) {
+    sTotalMemoryObtained = true;
+
+    FILE* fd = fopen("/proc/meminfo", "r");
+    if (!fd) {
+      return 0;
+    }
+
+    int rv = fscanf(fd, "MemTotal: %i kB", &sTotalMemory);
+
+    if (fclose(fd) || rv != 1) {
+      return 0;
+    }
+  }
+
+  return sTotalMemory * 1024;
+}
+
+} // namespace hal_impl
+} // namespace mozilla
diff --git a/hal/linux/LinuxPower.cpp b/hal/linux/LinuxPower.cpp
new file mode 100644
index 000000000..70ab4a3f6
--- /dev/null
+++ b/hal/linux/LinuxPower.cpp
@@ -0,0 +1,167 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Hal.h"
+#include "HalLog.h"
+
+#include <unistd.h>
+#include <sys/reboot.h>
+#include "nsIObserverService.h"
+#include "mozilla/Services.h"
+#include "MainThreadUtils.h"
+
+#if defined(MOZ_WIDGET_GONK)
+#include "cutils/android_reboot.h"
+#include "cutils/properties.h"
+#endif
+
+namespace mozilla {
+namespace hal_impl {
+
+#if (defined(MOZ_WIDGET_GONK) && ANDROID_VERSION >= 19)
+static void
+PowerCtl(const char* aValue, int aCmd)
+{
+  // this invokes init's powerctl builtin via /init.rc
+  property_set("sys.powerctl", aValue);
+  // device should reboot in few moments, but if it doesn't - call
+  // android_reboot() to make sure that init isn't stuck somewhere
+  sleep(10);
+  HAL_LOG("Powerctl call takes too long, forcing %s.", aValue);
+  android_reboot(aCmd, 0, nullptr);
+}
+#endif
+
+void
+Reboot()
+{
+  if (NS_IsMainThread()) {
+    nsCOMPtr<nsIObserverService> obsServ = services::GetObserverService();
+    if (obsServ) {
+      obsServ->NotifyObservers(nullptr, "system-reboot", nullptr);
+    }
+  }
+
+#if !defined(MOZ_WIDGET_GONK)
+  sync();
+  reboot(RB_AUTOBOOT);
+#elif (ANDROID_VERSION < 19)
+  android_reboot(ANDROID_RB_RESTART, 0, nullptr);
+#else
+  PowerCtl("reboot", ANDROID_RB_RESTART);
+#endif
+}
+
+void
+PowerOff()
+{
+  if (NS_IsMainThread()) {
+    nsCOMPtr<nsIObserverService> obsServ = services::GetObserverService();
+    if (obsServ) {
+      obsServ->NotifyObservers(nullptr, "system-power-off", nullptr);
+    }
+  }
+
+#if !defined(MOZ_WIDGET_GONK)
+  sync();
+  reboot(RB_POWER_OFF);
+#elif (ANDROID_VERSION < 19)
+  android_reboot(ANDROID_RB_POWEROFF, 0, nullptr);
+#else
+  PowerCtl("shutdown", ANDROID_RB_POWEROFF);
+#endif
+}
+
+// Structure to specify how watchdog pthread is going to work.
+typedef struct watchdogParam
+{
+  hal::ShutdownMode mode; // Specify how to shutdown the system.
+  int32_t timeoutSecs;    // Specify the delayed seconds to shutdown the system.
+
+  watchdogParam(hal::ShutdownMode aMode, int32_t aTimeoutSecs)
+    : mode(aMode), timeoutSecs(aTimeoutSecs) {}
+} watchdogParam_t;
+
+// Function to complusively shut down the system with a given mode.
+static void
+QuitHard(hal::ShutdownMode aMode)
+{
+  switch (aMode)
+  {
+    case hal::eHalShutdownMode_PowerOff:
+      PowerOff();
+      break;
+    case hal::eHalShutdownMode_Reboot:
+      Reboot();
+      break;
+    case hal::eHalShutdownMode_Restart:
+      // Don't let signal handlers affect forced shutdown.
+      kill(0, SIGKILL);
+      // If we can't SIGKILL our process group, something is badly
+      // wrong.  Trying to deliver a catch-able signal to ourselves can
+      // invoke signal handlers and might cause problems.  So try
+      // _exit() and hope we go away.
+      _exit(1);
+      break;
+    default:
+      MOZ_CRASH();
+  }
+}
+
+// Function to complusively shut down the system with a given mode when timeout.
+static void*
+ForceQuitWatchdog(void* aParamPtr)
+{
+  watchdogParam_t* paramPtr = reinterpret_cast<watchdogParam_t*>(aParamPtr);
+  if (paramPtr->timeoutSecs > 0 && paramPtr->timeoutSecs <= 30) {
+    // If we shut down normally before the timeout, this thread will
+    // be harmlessly reaped by the OS.
+    TimeStamp deadline =
+      (TimeStamp::Now() + TimeDuration::FromSeconds(paramPtr->timeoutSecs));
+    while (true) {
+      TimeDuration remaining = (deadline - TimeStamp::Now());
+      int sleepSeconds = int(remaining.ToSeconds());
+      if (sleepSeconds <= 0) {
+        break;
+      }
+      sleep(sleepSeconds);
+    }
+  }
+  hal::ShutdownMode mode = paramPtr->mode;
+  delete paramPtr;
+  QuitHard(mode);
+  return nullptr;
+}
+
+void
+StartForceQuitWatchdog(hal::ShutdownMode aMode, int32_t aTimeoutSecs)
+{
+  // Force-quits are intepreted a little more ferociously on Gonk,
+  // because while Gecko is in the process of shutting down, the user
+  // can't call 911, for example.  And if we hang on shutdown, bad
+  // things happen.  So, make sure that doesn't happen.
+  if (aTimeoutSecs <= 0) {
+    return;
+  }
+
+  // Use a raw pthread here to insulate ourselves from bugs in other
+  // Gecko code that we're trying to protect!
+  // 
+  // Note that we let the watchdog in charge of releasing |paramPtr|
+  // if the pthread is successfully created.
+  watchdogParam_t* paramPtr = new watchdogParam_t(aMode, aTimeoutSecs);
+  pthread_t watchdog;
+  if (pthread_create(&watchdog, nullptr,
+                     ForceQuitWatchdog,
+                     reinterpret_cast<void*>(paramPtr))) {
+    // Better safe than sorry.
+    delete paramPtr;
+    QuitHard(aMode);
+  }
+  // The watchdog thread is off and running now.
+}
+
+} // hal_impl
+} // mozilla
diff --git a/hal/linux/UPowerClient.cpp b/hal/linux/UPowerClient.cpp
new file mode 100644
index 000000000..9f6e04379
--- /dev/null
+++ b/hal/linux/UPowerClient.cpp
@@ -0,0 +1,508 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Hal.h"
+#include "HalLog.h"
+#include <dbus/dbus-glib.h>
+#include <dbus/dbus-glib-lowlevel.h>
+#include <mozilla/Attributes.h>
+#include <mozilla/dom/battery/Constants.h>
+#include "nsAutoRef.h"
+#include <cmath>
+
+/*
+ * Helper that manages the destruction of glib objects as soon as they leave
+ * the current scope.
+ *
+ * We are specializing nsAutoRef class.
+ */
+
+template <>
+class nsAutoRefTraits<GHashTable> : public nsPointerRefTraits<GHashTable>
+{
+public:
+  static void Release(GHashTable* ptr) { g_hash_table_unref(ptr); }
+};
+
+using namespace mozilla::dom::battery;
+
+namespace mozilla {
+namespace hal_impl {
+
+/**
+ * This is the declaration of UPowerClient class. This class is listening and
+ * communicating to upower daemon through DBus.
+ * There is no header file because this class shouldn't be public.
+ */
+class UPowerClient
+{
+public:
+  static UPowerClient* GetInstance();
+
+  void BeginListening();
+  void StopListening();
+
+  double GetLevel();
+  bool   IsCharging();
+  double GetRemainingTime();
+
+  ~UPowerClient();
+
+private:
+  UPowerClient();
+
+  enum States {
+    eState_Unknown = 0,
+    eState_Charging,
+    eState_Discharging,
+    eState_Empty,
+    eState_FullyCharged,
+    eState_PendingCharge,
+    eState_PendingDischarge
+  };
+
+  /**
+   * Update the currently tracked device.
+   * @return whether everything went ok.
+   */
+  void UpdateTrackedDeviceSync();
+
+  /**
+   * Returns a hash table with the properties of aDevice.
+   * Note: the caller has to unref the hash table.
+   */
+  GHashTable* GetDevicePropertiesSync(DBusGProxy* aProxy);
+  void GetDevicePropertiesAsync(DBusGProxy* aProxy);
+  static void GetDevicePropertiesCallback(DBusGProxy* aProxy,
+                                          DBusGProxyCall* aCall,
+                                          void* aData);
+
+  /**
+   * Using the device properties (aHashTable), this method updates the member
+   * variable storing the values we care about.
+   */
+  void UpdateSavedInfo(GHashTable* aHashTable);
+
+  /**
+   * Callback used by 'DeviceChanged' signal.
+   */
+  static void DeviceChanged(DBusGProxy* aProxy, const gchar* aObjectPath,
+                            UPowerClient* aListener);
+
+  /**
+   * Callback used by 'PropertiesChanged' signal.
+   * This method is called when the the battery level changes.
+   * (Only with upower >= 0.99)
+   */
+  static void PropertiesChanged(DBusGProxy* aProxy, const gchar*,
+                                GHashTable*, char**,
+                                UPowerClient* aListener);
+
+  /**
+   * Callback called when mDBusConnection gets a signal.
+   */
+  static DBusHandlerResult ConnectionSignalFilter(DBusConnection* aConnection,
+                                                  DBusMessage* aMessage,
+                                                  void* aData);
+
+  // The DBus connection object.
+  DBusGConnection* mDBusConnection;
+
+  // The DBus proxy object to upower.
+  DBusGProxy* mUPowerProxy;
+
+  // The path of the tracked device.
+  gchar* mTrackedDevice;
+
+  // The DBusGProxy for the tracked device.
+  DBusGProxy* mTrackedDeviceProxy;
+
+  double mLevel;
+  bool mCharging;
+  double mRemainingTime;
+
+  static UPowerClient* sInstance;
+
+  static const guint sDeviceTypeBattery = 2;
+  static const guint64 kUPowerUnknownRemainingTime = 0;
+};
+
+/*
+ * Implementation of mozilla::hal_impl::EnableBatteryNotifications,
+ *                   mozilla::hal_impl::DisableBatteryNotifications,
+ *               and mozilla::hal_impl::GetCurrentBatteryInformation.
+ */
+
+void
+EnableBatteryNotifications()
+{
+  UPowerClient::GetInstance()->BeginListening();
+}
+
+void
+DisableBatteryNotifications()
+{
+  UPowerClient::GetInstance()->StopListening();
+}
+
+void
+GetCurrentBatteryInformation(hal::BatteryInformation* aBatteryInfo)
+{
+  UPowerClient* upowerClient = UPowerClient::GetInstance();
+
+  aBatteryInfo->level() = upowerClient->GetLevel();
+  aBatteryInfo->charging() = upowerClient->IsCharging();
+  aBatteryInfo->remainingTime() = upowerClient->GetRemainingTime();
+}
+
+/*
+ * Following is the implementation of UPowerClient.
+ */
+
+UPowerClient* UPowerClient::sInstance = nullptr;
+
+/* static */ UPowerClient*
+UPowerClient::GetInstance()
+{
+  if (!sInstance) {
+    sInstance = new UPowerClient();
+  }
+
+  return sInstance;
+}
+
+UPowerClient::UPowerClient()
+  : mDBusConnection(nullptr)
+  , mUPowerProxy(nullptr)
+  , mTrackedDevice(nullptr)
+  , mTrackedDeviceProxy(nullptr)
+  , mLevel(kDefaultLevel)
+  , mCharging(kDefaultCharging)
+  , mRemainingTime(kDefaultRemainingTime)
+{
+}
+
+UPowerClient::~UPowerClient()
+{
+  NS_ASSERTION(!mDBusConnection && !mUPowerProxy && !mTrackedDevice && !mTrackedDeviceProxy,
+               "The observers have not been correctly removed! "
+               "(StopListening should have been called)");
+}
+
+void
+UPowerClient::BeginListening()
+{
+  GError* error = nullptr;
+  mDBusConnection = dbus_g_bus_get(DBUS_BUS_SYSTEM, &error);
+
+  if (!mDBusConnection) {
+    HAL_LOG("Failed to open connection to bus: %s\n", error->message);
+    g_error_free(error);
+    return;
+  }
+
+  DBusConnection* dbusConnection =
+    dbus_g_connection_get_connection(mDBusConnection);
+
+  // Make sure we do not exit the entire program if DBus connection get lost.
+  dbus_connection_set_exit_on_disconnect(dbusConnection, false);
+
+  // Listening to signals the DBus connection is going to get so we will know
+  // when it is lost and we will be able to disconnect cleanly.
+  dbus_connection_add_filter(dbusConnection, ConnectionSignalFilter, this,
+                             nullptr);
+
+  mUPowerProxy = dbus_g_proxy_new_for_name(mDBusConnection,
+                                           "org.freedesktop.UPower",
+                                           "/org/freedesktop/UPower",
+                                           "org.freedesktop.UPower");
+
+  UpdateTrackedDeviceSync();
+
+  /*
+   * TODO: we should probably listen to DeviceAdded and DeviceRemoved signals.
+   * If we do that, we would have to disconnect from those in StopListening.
+   * It's not yet implemented because it requires testing hot plugging and
+   * removal of a battery.
+   */
+  dbus_g_proxy_add_signal(mUPowerProxy, "DeviceChanged", G_TYPE_STRING,
+                          G_TYPE_INVALID);
+  dbus_g_proxy_connect_signal(mUPowerProxy, "DeviceChanged",
+                              G_CALLBACK (DeviceChanged), this, nullptr);
+}
+
+void
+UPowerClient::StopListening()
+{
+  // If mDBusConnection isn't initialized, that means we are not really listening.
+  if (!mDBusConnection) {
+    return;
+  }
+
+  dbus_connection_remove_filter(
+      dbus_g_connection_get_connection(mDBusConnection),
+      ConnectionSignalFilter, this);
+
+  dbus_g_proxy_disconnect_signal(mUPowerProxy, "DeviceChanged",
+                                 G_CALLBACK (DeviceChanged), this);
+
+  g_free(mTrackedDevice);
+  mTrackedDevice = nullptr;
+
+  if (mTrackedDeviceProxy) {
+    dbus_g_proxy_disconnect_signal(mTrackedDeviceProxy, "PropertiesChanged",
+                                   G_CALLBACK (PropertiesChanged), this);
+
+    g_object_unref(mTrackedDeviceProxy);
+    mTrackedDeviceProxy = nullptr;
+  }
+
+  g_object_unref(mUPowerProxy);
+  mUPowerProxy = nullptr;
+
+  dbus_g_connection_unref(mDBusConnection);
+  mDBusConnection = nullptr;
+
+  // We should now show the default values, not the latest we got.
+  mLevel = kDefaultLevel;
+  mCharging = kDefaultCharging;
+  mRemainingTime = kDefaultRemainingTime;
+}
+
+void
+UPowerClient::UpdateTrackedDeviceSync()
+{
+  GType typeGPtrArray = dbus_g_type_get_collection("GPtrArray",
+                                                   DBUS_TYPE_G_OBJECT_PATH);
+  GPtrArray* devices = nullptr;
+  GError* error = nullptr;
+
+  // Reset the current tracked device:
+  g_free(mTrackedDevice);
+  mTrackedDevice = nullptr;
+
+  // Reset the current tracked device proxy:
+  if (mTrackedDeviceProxy) {
+    dbus_g_proxy_disconnect_signal(mTrackedDeviceProxy, "PropertiesChanged",
+                                   G_CALLBACK (PropertiesChanged), this);
+
+    g_object_unref(mTrackedDeviceProxy);
+    mTrackedDeviceProxy = nullptr;
+  }
+
+  // If that fails, that likely means upower isn't installed.
+  if (!dbus_g_proxy_call(mUPowerProxy, "EnumerateDevices", &error, G_TYPE_INVALID,
+                         typeGPtrArray, &devices, G_TYPE_INVALID)) {
+    HAL_LOG("Error: %s\n", error->message);
+    g_error_free(error);
+    return;
+  }
+
+  /*
+   * We are looking for the first device that is a battery.
+   * TODO: we could try to combine more than one battery.
+   */
+  for (guint i=0; i<devices->len; ++i) {
+    gchar* devicePath = static_cast<gchar*>(g_ptr_array_index(devices, i));
+
+    DBusGProxy* proxy = dbus_g_proxy_new_from_proxy(mUPowerProxy,
+                                                    "org.freedesktop.DBus.Properties",
+                                                    devicePath);
+
+    nsAutoRef<GHashTable> hashTable(GetDevicePropertiesSync(proxy));
+
+    if (g_value_get_uint(static_cast<const GValue*>(g_hash_table_lookup(hashTable, "Type"))) == sDeviceTypeBattery) {
+      UpdateSavedInfo(hashTable);
+      mTrackedDevice = devicePath;
+      mTrackedDeviceProxy = proxy;
+      break;
+    }
+
+    g_object_unref(proxy);
+    g_free(devicePath);
+  }
+
+  if (mTrackedDeviceProxy) {
+    dbus_g_proxy_add_signal(mTrackedDeviceProxy, "PropertiesChanged",
+                            G_TYPE_STRING,
+                            dbus_g_type_get_map("GHashTable", G_TYPE_STRING,
+                                                G_TYPE_VALUE),
+                            G_TYPE_STRV, G_TYPE_INVALID);
+    dbus_g_proxy_connect_signal(mTrackedDeviceProxy, "PropertiesChanged",
+                                G_CALLBACK (PropertiesChanged), this, nullptr);
+  }
+
+  g_ptr_array_free(devices, true);
+}
+
+/* static */ void
+UPowerClient::DeviceChanged(DBusGProxy* aProxy, const gchar* aObjectPath,
+                            UPowerClient* aListener)
+{
+  if (!aListener->mTrackedDevice) {
+    return;
+  }
+
+#if GLIB_MAJOR_VERSION >= 2 && GLIB_MINOR_VERSION >= 16
+  if (g_strcmp0(aObjectPath, aListener->mTrackedDevice)) {
+#else
+  if (g_ascii_strcasecmp(aObjectPath, aListener->mTrackedDevice)) {
+#endif
+    return;
+  }
+
+  aListener->GetDevicePropertiesAsync(aListener->mTrackedDeviceProxy);
+}
+
+/* static */ void
+UPowerClient::PropertiesChanged(DBusGProxy* aProxy, const gchar*, GHashTable*,
+                                char**, UPowerClient* aListener)
+{
+  aListener->GetDevicePropertiesAsync(aListener->mTrackedDeviceProxy);
+}
+
+/* static */ DBusHandlerResult
+UPowerClient::ConnectionSignalFilter(DBusConnection* aConnection,
+                                     DBusMessage* aMessage, void* aData)
+{
+  if (dbus_message_is_signal(aMessage, DBUS_INTERFACE_LOCAL, "Disconnected")) {
+    static_cast<UPowerClient*>(aData)->StopListening();
+    // We do not return DBUS_HANDLER_RESULT_HANDLED here because the connection
+    // might be shared and some other filters might want to do something.
+  }
+
+  return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
+}
+
+GHashTable*
+UPowerClient::GetDevicePropertiesSync(DBusGProxy* aProxy)
+{
+  GError* error = nullptr;
+  GHashTable* hashTable = nullptr;
+  GType typeGHashTable = dbus_g_type_get_map("GHashTable", G_TYPE_STRING,
+                                            G_TYPE_VALUE);
+  if (!dbus_g_proxy_call(aProxy, "GetAll", &error, G_TYPE_STRING,
+                         "org.freedesktop.UPower.Device", G_TYPE_INVALID,
+                         typeGHashTable, &hashTable, G_TYPE_INVALID)) {
+    HAL_LOG("Error: %s\n", error->message);
+    g_error_free(error);
+    return nullptr;
+  }
+
+  return hashTable;
+}
+
+/* static */ void
+UPowerClient::GetDevicePropertiesCallback(DBusGProxy* aProxy,
+                                          DBusGProxyCall* aCall, void* aData)
+{
+  GError* error = nullptr;
+  GHashTable* hashTable = nullptr;
+  GType typeGHashTable = dbus_g_type_get_map("GHashTable", G_TYPE_STRING,
+                                             G_TYPE_VALUE);
+  if (!dbus_g_proxy_end_call(aProxy, aCall, &error, typeGHashTable,
+                             &hashTable, G_TYPE_INVALID)) {
+    HAL_LOG("Error: %s\n", error->message);
+    g_error_free(error);
+  } else {
+    sInstance->UpdateSavedInfo(hashTable);
+    hal::NotifyBatteryChange(hal::BatteryInformation(sInstance->mLevel,
+                                                     sInstance->mCharging,
+                                                     sInstance->mRemainingTime));
+    g_hash_table_unref(hashTable);
+  }
+}
+
+void
+UPowerClient::GetDevicePropertiesAsync(DBusGProxy* aProxy)
+{
+  dbus_g_proxy_begin_call(aProxy, "GetAll", GetDevicePropertiesCallback, nullptr,
+                          nullptr, G_TYPE_STRING,
+                          "org.freedesktop.UPower.Device", G_TYPE_INVALID);
+}
+
+void
+UPowerClient::UpdateSavedInfo(GHashTable* aHashTable)
+{
+  bool isFull = false;
+
+  /*
+   * State values are confusing...
+   * First of all, after looking at upower sources (0.9.13), it seems that
+   * PendingDischarge and PendingCharge are not used.
+   * In addition, FullyCharged and Empty states are not clear because we do not
+   * know if the battery is actually charging or not. Those values come directly
+   * from sysfs (in the Linux kernel) which have four states: "Empty", "Full",
+   * "Charging" and "Discharging". In sysfs, "Empty" and "Full" are also only
+   * related to the level, not to the charging state.
+   * In this code, we are going to assume that Full means charging and Empty
+   * means discharging because if that is not the case, the state should not
+   * last a long time (actually, it should disappear at the following update).
+   * It might be even very hard to see real cases where the state is Empty and
+   * the battery is charging or the state is Full and the battery is discharging
+   * given that plugging/unplugging the battery should have an impact on the
+   * level.
+   */
+  switch (g_value_get_uint(static_cast<const GValue*>(g_hash_table_lookup(aHashTable, "State")))) {
+    case eState_Unknown:
+      mCharging = kDefaultCharging;
+      break;
+    case eState_FullyCharged:
+      isFull = true;
+      MOZ_FALLTHROUGH;
+    case eState_Charging:
+    case eState_PendingCharge:
+      mCharging = true;
+      break;
+    case eState_Discharging:
+    case eState_Empty:
+    case eState_PendingDischarge:
+      mCharging = false;
+      break;
+  }
+
+  /*
+   * The battery level might be very close to 100% (like 99%) without
+   * increasing. It seems that upower sets the battery state as 'full' in that
+   * case so we should trust it and not even try to get the value.
+   */
+  if (isFull) {
+    mLevel = 1.0;
+  } else {
+    mLevel = round(g_value_get_double(static_cast<const GValue*>(g_hash_table_lookup(aHashTable, "Percentage"))))*0.01;
+  }
+
+  if (isFull) {
+    mRemainingTime = 0;
+  } else {
+    mRemainingTime = mCharging ? g_value_get_int64(static_cast<const GValue*>(g_hash_table_lookup(aHashTable, "TimeToFull")))
+                               : g_value_get_int64(static_cast<const GValue*>(g_hash_table_lookup(aHashTable, "TimeToEmpty")));
+
+    if (mRemainingTime == kUPowerUnknownRemainingTime) {
+      mRemainingTime = kUnknownRemainingTime;
+    }
+  }
+}
+
+double
+UPowerClient::GetLevel()
+{
+  return mLevel;
+}
+
+bool
+UPowerClient::IsCharging()
+{
+  return mCharging;
+}
+
+double
+UPowerClient::GetRemainingTime()
+{
+  return mRemainingTime;
+}
+
+} // namespace hal_impl
+} // namespace mozilla
diff --git a/hal/moz.build b/hal/moz.build
new file mode 100644
index 000000000..c17379f22
--- /dev/null
+++ b/hal/moz.build
@@ -0,0 +1,185 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+XPIDL_SOURCES += [
+    'gonk/nsIRecoveryService.idl',
+]
+
+XPIDL_MODULE = 'hal'
+
+EXPORTS.mozilla += [
+    'Hal.h',
+    'HalImpl.h',
+    'HalSandbox.h',
+    'HalScreenConfiguration.h',
+    'HalSensor.h',
+    'HalTypes.h',
+    'HalWakeLock.h',
+]
+
+UNIFIED_SOURCES += [
+    'HalWakeLock.cpp',
+    'sandbox/SandboxHal.cpp',
+    'WindowIdentifier.cpp',
+]
+
+# Hal.cpp cannot be built in unified mode because it relies on HalImpl.h.
+SOURCES += [
+    'Hal.cpp',
+]
+
+if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'android':
+    LOCAL_INCLUDES += [
+        '/widget/android',
+    ]
+    UNIFIED_SOURCES += [
+        'android/AndroidAlarm.cpp',
+        'android/AndroidSensor.cpp',
+        'fallback/FallbackPower.cpp',
+        'linux/LinuxMemory.cpp',
+    ]
+    # AndroidHal.cpp cannot be built in unified mode because it relies on HalImpl.h.
+    SOURCES += [
+        'android/AndroidHal.cpp',
+    ]
+elif CONFIG['MOZ_WIDGET_TOOLKIT'] == 'gonk':
+    UNIFIED_SOURCES += [
+        'gonk/GonkDiskSpaceWatcher.cpp',
+        'gonk/GonkSensor.cpp',
+        'gonk/GonkSensorsHelpers.cpp',
+        'gonk/GonkSensorsInterface.cpp',
+        'gonk/GonkSensorsPollInterface.cpp',
+        'gonk/GonkSensorsRegistryInterface.cpp',
+        'gonk/GonkSwitch.cpp',
+        'gonk/SystemService.cpp',
+        'gonk/UeventPoller.cpp',
+        'linux/LinuxMemory.cpp',
+        'linux/LinuxPower.cpp',
+    ]
+    # GonkHal.cpp cannot be built in unified mode because it relies on HalImpl.h.
+    SOURCES += [
+        'gonk/GonkHal.cpp',
+    ]
+elif CONFIG['OS_TARGET'] == 'Linux':
+    UNIFIED_SOURCES += [
+        'fallback/FallbackAlarm.cpp',
+        'fallback/FallbackScreenConfiguration.cpp',
+        'fallback/FallbackSensor.cpp',
+        'fallback/FallbackVibration.cpp',
+        'linux/LinuxMemory.cpp',
+        'linux/LinuxPower.cpp',
+    ]
+    if CONFIG['MOZ_ENABLE_DBUS']:
+        UNIFIED_SOURCES += [
+            'linux/UPowerClient.cpp',
+        ]
+    else:
+        UNIFIED_SOURCES += [
+            'fallback/FallbackBattery.cpp',
+        ]
+elif CONFIG['OS_TARGET'] == 'WINNT':
+    UNIFIED_SOURCES += [
+        'fallback/FallbackAlarm.cpp',
+        'fallback/FallbackMemory.cpp',
+        'fallback/FallbackPower.cpp',
+        'fallback/FallbackScreenConfiguration.cpp',
+        'fallback/FallbackVibration.cpp',
+        'windows/WindowsSensor.cpp',
+    ]
+    # WindowsBattery.cpp cannot be built in unified mode because it relies on HalImpl.h.
+    SOURCES += [
+        'windows/WindowsBattery.cpp',
+    ]
+elif CONFIG['MOZ_WIDGET_TOOLKIT'] == 'cocoa':
+    UNIFIED_SOURCES += [
+        'cocoa/CocoaBattery.cpp',
+        'fallback/FallbackAlarm.cpp',
+        'fallback/FallbackMemory.cpp',
+        'fallback/FallbackPower.cpp',
+        'fallback/FallbackScreenConfiguration.cpp',
+        'fallback/FallbackVibration.cpp',
+    ]
+elif CONFIG['OS_TARGET'] in ('OpenBSD', 'NetBSD', 'FreeBSD', 'DragonFly'):
+    UNIFIED_SOURCES += [
+        'fallback/FallbackAlarm.cpp',
+        'fallback/FallbackMemory.cpp',
+        'fallback/FallbackPower.cpp',
+        'fallback/FallbackScreenConfiguration.cpp',
+        'fallback/FallbackSensor.cpp',
+        'fallback/FallbackVibration.cpp',
+    ]
+    if CONFIG['MOZ_ENABLE_DBUS']:
+        UNIFIED_SOURCES += [
+            'linux/UPowerClient.cpp',
+        ]
+    else:
+        UNIFIED_SOURCES += [
+            'fallback/FallbackBattery.cpp',
+        ]
+else:
+    UNIFIED_SOURCES += [
+        'fallback/FallbackAlarm.cpp',
+        'fallback/FallbackBattery.cpp',
+        'fallback/FallbackMemory.cpp',
+        'fallback/FallbackPower.cpp',
+        'fallback/FallbackScreenConfiguration.cpp',
+        'fallback/FallbackSensor.cpp',
+        'fallback/FallbackVibration.cpp',
+    ]
+
+# Fallbacks for backends implemented on Gonk only.
+if CONFIG['MOZ_WIDGET_TOOLKIT'] != 'gonk':
+    UNIFIED_SOURCES += [
+        'fallback/FallbackDiskSpaceWatcher.cpp',
+        'fallback/FallbackFactoryReset.cpp',
+        'fallback/FallbackProcessPriority.cpp',
+        'fallback/FallbackScreenPower.cpp',
+        'fallback/FallbackSwitch.cpp',
+        'fallback/FallbackSystemService.cpp',
+        'fallback/FallbackThreadPriority.cpp',
+        'fallback/FallbackTime.cpp',
+        'fallback/FallbackWakeLocks.cpp',
+    ]
+
+# Fallbacks for backends implemented on Android only.
+if CONFIG['MOZ_WIDGET_TOOLKIT'] != 'android':
+    UNIFIED_SOURCES += [
+        'fallback/FallbackNetwork.cpp',
+    ]
+
+if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'cocoa':
+    UNIFIED_SOURCES += [
+        'cocoa/CocoaSensor.mm',
+        'cocoa/smslib.mm',
+    ]
+
+IPDL_SOURCES = [
+    'sandbox/PHal.ipdl',
+]
+
+include('/ipc/chromium/chromium-config.mozbuild')
+
+FINAL_LIBRARY = 'xul'
+
+if CONFIG['MOZ_GAMEPAD']:
+    LOCAL_INCLUDES += [
+        '/dom/base',
+    ]
+
+if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'gonk':
+    # So that we can call nsScreenManagerGonk::GetConfiguration().
+    LOCAL_INCLUDES += [
+        '/widget',
+        '/widget/gonk',
+    ]
+
+if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'gonk':
+    LOCAL_INCLUDES += ['%' + '%s/hardware/libhardware_legacy/include' % CONFIG['ANDROID_SOURCE']]
+
+CFLAGS += CONFIG['GLIB_CFLAGS']
+CFLAGS += CONFIG['MOZ_DBUS_GLIB_CFLAGS']
+CXXFLAGS += CONFIG['GLIB_CFLAGS']
+CXXFLAGS += CONFIG['MOZ_DBUS_GLIB_CFLAGS']
diff --git a/hal/sandbox/PHal.ipdl b/hal/sandbox/PHal.ipdl
new file mode 100644
index 000000000..37b69f93f
--- /dev/null
+++ b/hal/sandbox/PHal.ipdl
@@ -0,0 +1,159 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et ft=cpp : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+include protocol PContent;
+include protocol PBrowser;
+
+include "mozilla/GfxMessageUtils.h";
+
+using mozilla::dom::ScreenOrientationInternal from "mozilla/dom/ScreenOrientation.h";
+using mozilla::hal::SensorType from "mozilla/HalSensor.h";
+using mozilla::hal::SensorAccuracyType from "mozilla/HalSensor.h";
+using mozilla::hal::WakeLockControl from "mozilla/HalTypes.h";
+using mozilla::hal::SwitchState from "mozilla/HalTypes.h";
+using mozilla::hal::SwitchDevice from "mozilla/HalTypes.h";
+using mozilla::hal::ProcessPriority from "mozilla/HalTypes.h";
+using nsIntRect from "nsRect.h";
+using PRTime from "prtime.h";
+
+namespace mozilla {
+
+namespace hal {
+struct BatteryInformation {
+  double level;
+  bool   charging;
+  double remainingTime;
+};
+
+struct SensorData {
+  SensorType sensor;
+  PRTime timestamp;
+  float[] values;
+  SensorAccuracyType accuracy;
+};
+
+struct NetworkInformation {
+  uint32_t type;
+  bool   isWifi;
+  uint32_t dhcpGateway;
+};
+
+struct SwitchEvent {
+  SwitchDevice device;
+  SwitchState status;
+};
+
+struct WakeLockInformation {
+  nsString topic;
+  uint32_t numLocks;
+  uint32_t numHidden;
+  uint64_t[] lockingProcesses;
+};
+
+struct ScreenConfiguration {
+  nsIntRect rect;
+  ScreenOrientationInternal orientation;
+  uint16_t angle;
+  uint32_t colorDepth;
+  uint32_t pixelDepth;
+};
+
+struct SystemTimezoneChangeInformation {
+  // These timezone offsets are relative to UTC in minutes and
+  // have already taken daylight saving time (DST) into account.
+  int32_t oldTimezoneOffsetMinutes;
+  int32_t newTimezoneOffsetMinutes;
+};
+
+} // namespace hal
+
+namespace hal_sandbox {
+
+nested(upto inside_cpow) sync protocol PHal {
+    manager PContent;
+
+child:
+    async NotifyBatteryChange(BatteryInformation aBatteryInfo);
+    async NotifyNetworkChange(NetworkInformation aNetworkInfo);
+    async NotifyWakeLockChange(WakeLockInformation aWakeLockInfo);
+    async NotifyScreenConfigurationChange(ScreenConfiguration aScreenOrientation);
+    async NotifySwitchChange(SwitchEvent aEvent);
+    async NotifySystemClockChange(int64_t aClockDeltaMS); 
+    async NotifySystemTimezoneChange(SystemTimezoneChangeInformation aSystemTimezoneChangeInfo); 
+
+parent:
+    async Vibrate(uint32_t[] pattern, uint64_t[] id, PBrowser browser);
+    async CancelVibrate(uint64_t[] id, PBrowser browser);
+
+    async EnableBatteryNotifications();
+    async DisableBatteryNotifications();
+    sync GetCurrentBatteryInformation()
+      returns (BatteryInformation aBatteryInfo);
+
+    async EnableNetworkNotifications();
+    async DisableNetworkNotifications();
+    sync GetCurrentNetworkInformation()
+      returns (NetworkInformation aNetworkInfo);
+
+    sync GetScreenEnabled() returns (bool enabled);
+    async SetScreenEnabled(bool aEnabled);
+
+    sync GetKeyLightEnabled() returns (bool enabled);
+    async SetKeyLightEnabled(bool aEnabled);
+
+    sync GetCpuSleepAllowed() returns (bool allowed);
+    async SetCpuSleepAllowed(bool aAllowed);
+
+    sync GetScreenBrightness() returns (double brightness);
+    async SetScreenBrightness(double aBrightness);
+
+    async AdjustSystemClock(int64_t aDeltaMilliseconds);
+    async SetTimezone(nsCString aTimezoneSpec);
+    sync GetTimezone()
+      returns (nsCString aTimezoneSpec);
+    sync GetTimezoneOffset()
+      returns (int32_t aTimezoneOffset);
+    async EnableSystemClockChangeNotifications();
+    async DisableSystemClockChangeNotifications();
+    async EnableSystemTimezoneChangeNotifications();
+    async DisableSystemTimezoneChangeNotifications();
+
+    async ModifyWakeLock(nsString aTopic,
+                         WakeLockControl aLockAdjust,
+                         WakeLockControl aHiddenAdjust,
+                         uint64_t aProcessID);
+    async EnableWakeLockNotifications();
+    async DisableWakeLockNotifications();
+    sync GetWakeLockInfo(nsString aTopic)
+      returns (WakeLockInformation aWakeLockInfo);
+
+    async EnableScreenConfigurationNotifications();
+    async DisableScreenConfigurationNotifications();
+    nested(inside_cpow) sync GetCurrentScreenConfiguration()
+      returns (ScreenConfiguration aScreenConfiguration);
+    sync LockScreenOrientation(ScreenOrientationInternal aOrientation)
+      returns (bool allowed);
+    async UnlockScreenOrientation();
+ 
+    async EnableSwitchNotifications(SwitchDevice aDevice);
+    async DisableSwitchNotifications(SwitchDevice aDevice);
+    sync GetCurrentSwitchState(SwitchDevice aDevice)
+      returns (SwitchState aState);
+
+    async FactoryReset(nsString aReason);
+
+child:
+    async NotifySensorChange(SensorData aSensorData);
+
+parent:
+    async EnableSensorNotifications(SensorType aSensor);
+    async DisableSensorNotifications(SensorType aSensor);
+
+    async __delete__();
+};
+
+} // namespace hal
+} // namespace mozilla
diff --git a/hal/sandbox/SandboxHal.cpp b/hal/sandbox/SandboxHal.cpp
new file mode 100644
index 000000000..d33a53a2f
--- /dev/null
+++ b/hal/sandbox/SandboxHal.cpp
@@ -0,0 +1,907 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et ft=cpp : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Hal.h"
+#include "HalLog.h"
+#include "mozilla/AppProcessChecker.h"
+#include "mozilla/dom/ContentChild.h"
+#include "mozilla/dom/ContentParent.h"
+#include "mozilla/hal_sandbox/PHalChild.h"
+#include "mozilla/hal_sandbox/PHalParent.h"
+#include "mozilla/dom/TabParent.h"
+#include "mozilla/dom/TabChild.h"
+#include "mozilla/dom/battery/Types.h"
+#include "mozilla/dom/network/Types.h"
+#include "mozilla/dom/ScreenOrientation.h"
+#include "mozilla/Observer.h"
+#include "mozilla/Unused.h"
+#include "nsAutoPtr.h"
+#include "WindowIdentifier.h"
+
+using namespace mozilla;
+using namespace mozilla::dom;
+using namespace mozilla::hal;
+
+namespace mozilla {
+namespace hal_sandbox {
+
+static bool sHalChildDestroyed = false;
+
+bool
+HalChildDestroyed()
+{
+  return sHalChildDestroyed;
+}
+
+static PHalChild* sHal;
+static PHalChild*
+Hal()
+{
+  if (!sHal) {
+    sHal = ContentChild::GetSingleton()->SendPHalConstructor();
+  }
+  return sHal;
+}
+
+void
+Vibrate(const nsTArray<uint32_t>& pattern, const WindowIdentifier &id)
+{
+  HAL_LOG("Vibrate: Sending to parent process.");
+
+  AutoTArray<uint32_t, 8> p(pattern);
+
+  WindowIdentifier newID(id);
+  newID.AppendProcessID();
+  Hal()->SendVibrate(p, newID.AsArray(), TabChild::GetFrom(newID.GetWindow()));
+}
+
+void
+CancelVibrate(const WindowIdentifier &id)
+{
+  HAL_LOG("CancelVibrate: Sending to parent process.");
+
+  WindowIdentifier newID(id);
+  newID.AppendProcessID();
+  Hal()->SendCancelVibrate(newID.AsArray(), TabChild::GetFrom(newID.GetWindow()));
+}
+
+void
+EnableBatteryNotifications()
+{
+  Hal()->SendEnableBatteryNotifications();
+}
+
+void
+DisableBatteryNotifications()
+{
+  Hal()->SendDisableBatteryNotifications();
+}
+
+void
+GetCurrentBatteryInformation(BatteryInformation* aBatteryInfo)
+{
+  Hal()->SendGetCurrentBatteryInformation(aBatteryInfo);
+}
+
+void
+EnableNetworkNotifications()
+{
+  Hal()->SendEnableNetworkNotifications();
+}
+
+void
+DisableNetworkNotifications()
+{
+  Hal()->SendDisableNetworkNotifications();
+}
+
+void
+GetCurrentNetworkInformation(NetworkInformation* aNetworkInfo)
+{
+  Hal()->SendGetCurrentNetworkInformation(aNetworkInfo);
+}
+
+void
+EnableScreenConfigurationNotifications()
+{
+  Hal()->SendEnableScreenConfigurationNotifications();
+}
+
+void
+DisableScreenConfigurationNotifications()
+{
+  Hal()->SendDisableScreenConfigurationNotifications();
+}
+
+void
+GetCurrentScreenConfiguration(ScreenConfiguration* aScreenConfiguration)
+{
+  Hal()->SendGetCurrentScreenConfiguration(aScreenConfiguration);
+}
+
+bool
+LockScreenOrientation(const dom::ScreenOrientationInternal& aOrientation)
+{
+  bool allowed;
+  Hal()->SendLockScreenOrientation(aOrientation, &allowed);
+  return allowed;
+}
+
+void
+UnlockScreenOrientation()
+{
+  Hal()->SendUnlockScreenOrientation();
+}
+
+bool
+GetScreenEnabled()
+{
+  bool enabled = false;
+  Hal()->SendGetScreenEnabled(&enabled);
+  return enabled;
+}
+
+void
+SetScreenEnabled(bool aEnabled)
+{
+  Hal()->SendSetScreenEnabled(aEnabled);
+}
+
+bool
+GetKeyLightEnabled()
+{
+  bool enabled = false;
+  Hal()->SendGetKeyLightEnabled(&enabled);
+  return enabled;
+}
+
+void
+SetKeyLightEnabled(bool aEnabled)
+{
+  Hal()->SendSetKeyLightEnabled(aEnabled);
+}
+
+bool
+GetCpuSleepAllowed()
+{
+  bool allowed = true;
+  Hal()->SendGetCpuSleepAllowed(&allowed);
+  return allowed;
+}
+
+void
+SetCpuSleepAllowed(bool aAllowed)
+{
+  Hal()->SendSetCpuSleepAllowed(aAllowed);
+}
+
+double
+GetScreenBrightness()
+{
+  double brightness = 0;
+  Hal()->SendGetScreenBrightness(&brightness);
+  return brightness;
+}
+
+void
+SetScreenBrightness(double aBrightness)
+{
+  Hal()->SendSetScreenBrightness(aBrightness);
+}
+
+void
+AdjustSystemClock(int64_t aDeltaMilliseconds)
+{
+  Hal()->SendAdjustSystemClock(aDeltaMilliseconds);
+}
+
+void
+SetTimezone(const nsCString& aTimezoneSpec)
+{
+  Hal()->SendSetTimezone(nsCString(aTimezoneSpec));
+}
+
+nsCString
+GetTimezone()
+{
+  nsCString timezone;
+  Hal()->SendGetTimezone(&timezone);
+  return timezone;
+}
+
+int32_t
+GetTimezoneOffset()
+{
+  int32_t timezoneOffset;
+  Hal()->SendGetTimezoneOffset(&timezoneOffset);
+  return timezoneOffset;
+}
+
+void
+EnableSystemClockChangeNotifications()
+{
+  Hal()->SendEnableSystemClockChangeNotifications();
+}
+
+void
+DisableSystemClockChangeNotifications()
+{
+  Hal()->SendDisableSystemClockChangeNotifications();
+}
+
+void
+EnableSystemTimezoneChangeNotifications()
+{
+  Hal()->SendEnableSystemTimezoneChangeNotifications();
+}
+
+void
+DisableSystemTimezoneChangeNotifications()
+{
+  Hal()->SendDisableSystemTimezoneChangeNotifications();
+}
+
+void
+Reboot()
+{
+  NS_RUNTIMEABORT("Reboot() can't be called from sandboxed contexts.");
+}
+
+void
+PowerOff()
+{
+  NS_RUNTIMEABORT("PowerOff() can't be called from sandboxed contexts.");
+}
+
+void
+StartForceQuitWatchdog(ShutdownMode aMode, int32_t aTimeoutSecs)
+{
+  NS_RUNTIMEABORT("StartForceQuitWatchdog() can't be called from sandboxed contexts.");
+}
+
+void
+EnableSensorNotifications(SensorType aSensor) {
+  Hal()->SendEnableSensorNotifications(aSensor);
+}
+
+void
+DisableSensorNotifications(SensorType aSensor) {
+  Hal()->SendDisableSensorNotifications(aSensor);
+}
+
+void
+EnableWakeLockNotifications()
+{
+  Hal()->SendEnableWakeLockNotifications();
+}
+
+void
+DisableWakeLockNotifications()
+{
+  Hal()->SendDisableWakeLockNotifications();
+}
+
+void
+ModifyWakeLock(const nsAString &aTopic,
+               WakeLockControl aLockAdjust,
+               WakeLockControl aHiddenAdjust,
+               uint64_t aProcessID)
+{
+  MOZ_ASSERT(aProcessID != CONTENT_PROCESS_ID_UNKNOWN);
+  Hal()->SendModifyWakeLock(nsString(aTopic), aLockAdjust, aHiddenAdjust, aProcessID);
+}
+
+void
+GetWakeLockInfo(const nsAString &aTopic, WakeLockInformation *aWakeLockInfo)
+{
+  Hal()->SendGetWakeLockInfo(nsString(aTopic), aWakeLockInfo);
+}
+
+void
+EnableSwitchNotifications(SwitchDevice aDevice)
+{
+  Hal()->SendEnableSwitchNotifications(aDevice);
+}
+
+void
+DisableSwitchNotifications(SwitchDevice aDevice)
+{
+  Hal()->SendDisableSwitchNotifications(aDevice);
+}
+
+SwitchState
+GetCurrentSwitchState(SwitchDevice aDevice)
+{
+  SwitchState state;
+  Hal()->SendGetCurrentSwitchState(aDevice, &state);
+  return state;
+}
+
+void
+NotifySwitchStateFromInputDevice(SwitchDevice aDevice, SwitchState aState)
+{
+  Unused << aDevice;
+  Unused << aState;
+  NS_RUNTIMEABORT("Only the main process may notify switch state change.");
+}
+
+bool
+EnableAlarm()
+{
+  NS_RUNTIMEABORT("Alarms can't be programmed from sandboxed contexts.  Yet.");
+  return false;
+}
+
+void
+DisableAlarm()
+{
+  NS_RUNTIMEABORT("Alarms can't be programmed from sandboxed contexts.  Yet.");
+}
+
+bool
+SetAlarm(int32_t aSeconds, int32_t aNanoseconds)
+{
+  NS_RUNTIMEABORT("Alarms can't be programmed from sandboxed contexts.  Yet.");
+  return false;
+}
+
+void
+SetProcessPriority(int aPid, ProcessPriority aPriority, uint32_t aLRU)
+{
+  NS_RUNTIMEABORT("Only the main process may set processes' priorities.");
+}
+
+void
+SetCurrentThreadPriority(ThreadPriority aThreadPriority)
+{
+  NS_RUNTIMEABORT("Setting current thread priority cannot be called from sandboxed contexts.");
+}
+
+void
+SetThreadPriority(PlatformThreadId aThreadId,
+                  ThreadPriority aThreadPriority)
+{
+  NS_RUNTIMEABORT("Setting thread priority cannot be called from sandboxed contexts.");
+}
+
+void
+FactoryReset(FactoryResetReason& aReason)
+{
+  if (aReason == FactoryResetReason::Normal) {
+    Hal()->SendFactoryReset(NS_LITERAL_STRING("normal"));
+  } else if (aReason == FactoryResetReason::Wipe) {
+    Hal()->SendFactoryReset(NS_LITERAL_STRING("wipe"));
+  } else if (aReason == FactoryResetReason::Root) {
+    Hal()->SendFactoryReset(NS_LITERAL_STRING("root"));
+  }
+}
+
+void
+StartDiskSpaceWatcher()
+{
+  NS_RUNTIMEABORT("StartDiskSpaceWatcher() can't be called from sandboxed contexts.");
+}
+
+void
+StopDiskSpaceWatcher()
+{
+  NS_RUNTIMEABORT("StopDiskSpaceWatcher() can't be called from sandboxed contexts.");
+}
+
+bool IsHeadphoneEventFromInputDev()
+{
+  NS_RUNTIMEABORT("IsHeadphoneEventFromInputDev() cannot be called from sandboxed contexts.");
+  return false;
+}
+
+nsresult StartSystemService(const char* aSvcName, const char* aArgs)
+{
+  NS_RUNTIMEABORT("System services cannot be controlled from sandboxed contexts.");
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+void StopSystemService(const char* aSvcName)
+{
+  NS_RUNTIMEABORT("System services cannot be controlled from sandboxed contexts.");
+}
+
+bool SystemServiceIsRunning(const char* aSvcName)
+{
+  NS_RUNTIMEABORT("System services cannot be controlled from sandboxed contexts.");
+  return false;
+}
+
+class HalParent : public PHalParent
+                , public BatteryObserver
+                , public NetworkObserver
+                , public ISensorObserver
+                , public WakeLockObserver
+                , public ScreenConfigurationObserver
+                , public SwitchObserver
+                , public SystemClockChangeObserver
+                , public SystemTimezoneChangeObserver
+{
+public:
+  virtual void
+  ActorDestroy(ActorDestroyReason aWhy) override
+  {
+    // NB: you *must* unconditionally unregister your observer here,
+    // if it *may* be registered below.
+    hal::UnregisterBatteryObserver(this);
+    hal::UnregisterNetworkObserver(this);
+    hal::UnregisterScreenConfigurationObserver(this);
+    for (int32_t sensor = SENSOR_UNKNOWN + 1;
+         sensor < NUM_SENSOR_TYPE; ++sensor) {
+      hal::UnregisterSensorObserver(SensorType(sensor), this);
+    }
+    hal::UnregisterWakeLockObserver(this);
+    hal::UnregisterSystemClockChangeObserver(this);
+    hal::UnregisterSystemTimezoneChangeObserver(this);
+    for (int32_t switchDevice = SWITCH_DEVICE_UNKNOWN + 1;
+         switchDevice < NUM_SWITCH_DEVICE; ++switchDevice) {
+      hal::UnregisterSwitchObserver(SwitchDevice(switchDevice), this);
+    }
+  }
+
+  virtual bool
+  RecvVibrate(InfallibleTArray<unsigned int>&& pattern,
+              InfallibleTArray<uint64_t>&& id,
+              PBrowserParent *browserParent) override
+  {
+    // We give all content vibration permission.
+    //    TabParent *tabParent = TabParent::GetFrom(browserParent);
+    /* xxxkhuey wtf
+    nsCOMPtr<nsIDOMWindow> window =
+      do_QueryInterface(tabParent->GetBrowserDOMWindow());
+    */
+    WindowIdentifier newID(id, nullptr);
+    hal::Vibrate(pattern, newID);
+    return true;
+  }
+
+  virtual bool
+  RecvCancelVibrate(InfallibleTArray<uint64_t> &&id,
+                    PBrowserParent *browserParent) override
+  {
+    //TabParent *tabParent = TabParent::GetFrom(browserParent);
+    /* XXXkhuey wtf
+    nsCOMPtr<nsIDOMWindow> window =
+      tabParent->GetBrowserDOMWindow();
+    */
+    WindowIdentifier newID(id, nullptr);
+    hal::CancelVibrate(newID);
+    return true;
+  }
+
+  virtual bool
+  RecvEnableBatteryNotifications() override {
+    // We give all content battery-status permission.
+    hal::RegisterBatteryObserver(this);
+    return true;
+  }
+
+  virtual bool
+  RecvDisableBatteryNotifications() override {
+    hal::UnregisterBatteryObserver(this);
+    return true;
+  }
+
+  virtual bool
+  RecvGetCurrentBatteryInformation(BatteryInformation* aBatteryInfo) override {
+    // We give all content battery-status permission.
+    hal::GetCurrentBatteryInformation(aBatteryInfo);
+    return true;
+  }
+
+  void Notify(const BatteryInformation& aBatteryInfo) override {
+    Unused << SendNotifyBatteryChange(aBatteryInfo);
+  }
+
+  virtual bool
+  RecvEnableNetworkNotifications() override {
+    // We give all content access to this network-status information.
+    hal::RegisterNetworkObserver(this);
+    return true;
+  }
+
+  virtual bool
+  RecvDisableNetworkNotifications() override {
+    hal::UnregisterNetworkObserver(this);
+    return true;
+  }
+
+  virtual bool
+  RecvGetCurrentNetworkInformation(NetworkInformation* aNetworkInfo) override {
+    hal::GetCurrentNetworkInformation(aNetworkInfo);
+    return true;
+  }
+
+  void Notify(const NetworkInformation& aNetworkInfo) override {
+    Unused << SendNotifyNetworkChange(aNetworkInfo);
+  }
+
+  virtual bool
+  RecvEnableScreenConfigurationNotifications() override {
+    // Screen configuration is used to implement CSS and DOM
+    // properties, so all content already has access to this.
+    hal::RegisterScreenConfigurationObserver(this);
+    return true;
+  }
+
+  virtual bool
+  RecvDisableScreenConfigurationNotifications() override {
+    hal::UnregisterScreenConfigurationObserver(this);
+    return true;
+  }
+
+  virtual bool
+  RecvGetCurrentScreenConfiguration(ScreenConfiguration* aScreenConfiguration) override {
+    hal::GetCurrentScreenConfiguration(aScreenConfiguration);
+    return true;
+  }
+
+  virtual bool
+  RecvLockScreenOrientation(const dom::ScreenOrientationInternal& aOrientation, bool* aAllowed) override
+  {
+    // FIXME/bug 777980: unprivileged content may only lock
+    // orientation while fullscreen.  We should check whether the
+    // request comes from an actor in a process that might be
+    // fullscreen.  We don't have that information currently.
+    *aAllowed = hal::LockScreenOrientation(aOrientation);
+    return true;
+  }
+
+  virtual bool
+  RecvUnlockScreenOrientation() override
+  {
+    hal::UnlockScreenOrientation();
+    return true;
+  }
+
+  void Notify(const ScreenConfiguration& aScreenConfiguration) override {
+    Unused << SendNotifyScreenConfigurationChange(aScreenConfiguration);
+  }
+
+  virtual bool
+  RecvGetScreenEnabled(bool* aEnabled) override
+  {
+    if (!AssertAppProcessPermission(this, "power")) {
+      return false;
+    }
+    *aEnabled = hal::GetScreenEnabled();
+    return true;
+  }
+
+  virtual bool
+  RecvSetScreenEnabled(const bool& aEnabled) override
+  {
+    if (!AssertAppProcessPermission(this, "power")) {
+      return false;
+    }
+    hal::SetScreenEnabled(aEnabled);
+    return true;
+  }
+
+  virtual bool
+  RecvGetKeyLightEnabled(bool* aEnabled) override
+  {
+    if (!AssertAppProcessPermission(this, "power")) {
+      return false;
+    }
+    *aEnabled = hal::GetKeyLightEnabled();
+    return true;
+  }
+
+  virtual bool
+  RecvSetKeyLightEnabled(const bool& aEnabled) override
+  {
+    if (!AssertAppProcessPermission(this, "power")) {
+      return false;
+    }
+    hal::SetKeyLightEnabled(aEnabled);
+    return true;
+  }
+
+  virtual bool
+  RecvGetCpuSleepAllowed(bool* aAllowed) override
+  {
+    if (!AssertAppProcessPermission(this, "power")) {
+      return false;
+    }
+    *aAllowed = hal::GetCpuSleepAllowed();
+    return true;
+  }
+
+  virtual bool
+  RecvSetCpuSleepAllowed(const bool& aAllowed) override
+  {
+    if (!AssertAppProcessPermission(this, "power")) {
+      return false;
+    }
+    hal::SetCpuSleepAllowed(aAllowed);
+    return true;
+  }
+
+  virtual bool
+  RecvGetScreenBrightness(double* aBrightness) override
+  {
+    if (!AssertAppProcessPermission(this, "power")) {
+      return false;
+    }
+    *aBrightness = hal::GetScreenBrightness();
+    return true;
+  }
+
+  virtual bool
+  RecvSetScreenBrightness(const double& aBrightness) override
+  {
+    if (!AssertAppProcessPermission(this, "power")) {
+      return false;
+    }
+    hal::SetScreenBrightness(aBrightness);
+    return true;
+  }
+
+  virtual bool
+  RecvAdjustSystemClock(const int64_t &aDeltaMilliseconds) override
+  {
+    if (!AssertAppProcessPermission(this, "time")) {
+      return false;
+    }
+    hal::AdjustSystemClock(aDeltaMilliseconds);
+    return true;
+  }
+
+  virtual bool
+  RecvSetTimezone(const nsCString& aTimezoneSpec) override
+  {
+    if (!AssertAppProcessPermission(this, "time")) {
+      return false;
+    }
+    hal::SetTimezone(aTimezoneSpec);
+    return true;
+  }
+
+  virtual bool
+  RecvGetTimezone(nsCString *aTimezoneSpec) override
+  {
+    if (!AssertAppProcessPermission(this, "time")) {
+      return false;
+    }
+    *aTimezoneSpec = hal::GetTimezone();
+    return true;
+  }
+
+  virtual bool
+  RecvGetTimezoneOffset(int32_t *aTimezoneOffset) override
+  {
+    if (!AssertAppProcessPermission(this, "time")) {
+      return false;
+    }
+    *aTimezoneOffset = hal::GetTimezoneOffset();
+    return true;
+  }
+
+  virtual bool
+  RecvEnableSystemClockChangeNotifications() override
+  {
+    hal::RegisterSystemClockChangeObserver(this);
+    return true;
+  }
+
+  virtual bool
+  RecvDisableSystemClockChangeNotifications() override
+  {
+    hal::UnregisterSystemClockChangeObserver(this);
+    return true;
+  }
+
+  virtual bool
+  RecvEnableSystemTimezoneChangeNotifications() override
+  {
+    hal::RegisterSystemTimezoneChangeObserver(this);
+    return true;
+  }
+
+  virtual bool
+  RecvDisableSystemTimezoneChangeNotifications() override
+  {
+    hal::UnregisterSystemTimezoneChangeObserver(this);
+    return true;
+  }
+
+  virtual bool
+  RecvEnableSensorNotifications(const SensorType &aSensor) override {
+    // We currently allow any content to register device-sensor
+    // listeners.
+    hal::RegisterSensorObserver(aSensor, this);
+    return true;
+  }
+
+  virtual bool
+  RecvDisableSensorNotifications(const SensorType &aSensor) override {
+    hal::UnregisterSensorObserver(aSensor, this);
+    return true;
+  }
+
+  void Notify(const SensorData& aSensorData) override {
+    Unused << SendNotifySensorChange(aSensorData);
+  }
+
+  virtual bool
+  RecvModifyWakeLock(const nsString& aTopic,
+                     const WakeLockControl& aLockAdjust,
+                     const WakeLockControl& aHiddenAdjust,
+                     const uint64_t& aProcessID) override
+  {
+    MOZ_ASSERT(aProcessID != CONTENT_PROCESS_ID_UNKNOWN);
+
+    // We allow arbitrary content to use wake locks.
+    hal::ModifyWakeLock(aTopic, aLockAdjust, aHiddenAdjust, aProcessID);
+    return true;
+  }
+
+  virtual bool
+  RecvEnableWakeLockNotifications() override
+  {
+    // We allow arbitrary content to use wake locks.
+    hal::RegisterWakeLockObserver(this);
+    return true;
+  }
+
+  virtual bool
+  RecvDisableWakeLockNotifications() override
+  {
+    hal::UnregisterWakeLockObserver(this);
+    return true;
+  }
+
+  virtual bool
+  RecvGetWakeLockInfo(const nsString &aTopic, WakeLockInformation *aWakeLockInfo) override
+  {
+    hal::GetWakeLockInfo(aTopic, aWakeLockInfo);
+    return true;
+  }
+
+  void Notify(const WakeLockInformation& aWakeLockInfo) override
+  {
+    Unused << SendNotifyWakeLockChange(aWakeLockInfo);
+  }
+
+  virtual bool
+  RecvEnableSwitchNotifications(const SwitchDevice& aDevice) override
+  {
+    // Content has no reason to listen to switch events currently.
+    hal::RegisterSwitchObserver(aDevice, this);
+    return true;
+  }
+
+  virtual bool
+  RecvDisableSwitchNotifications(const SwitchDevice& aDevice) override
+  {
+    hal::UnregisterSwitchObserver(aDevice, this);
+    return true;
+  }
+
+  void Notify(const SwitchEvent& aSwitchEvent) override
+  {
+    Unused << SendNotifySwitchChange(aSwitchEvent);
+  }
+
+  virtual bool
+  RecvGetCurrentSwitchState(const SwitchDevice& aDevice, hal::SwitchState *aState) override
+  {
+    // Content has no reason to listen to switch events currently.
+    *aState = hal::GetCurrentSwitchState(aDevice);
+    return true;
+  }
+
+  void Notify(const int64_t& aClockDeltaMS) override
+  {
+    Unused << SendNotifySystemClockChange(aClockDeltaMS);
+  }
+
+  void Notify(const SystemTimezoneChangeInformation& aSystemTimezoneChangeInfo) override
+  {
+    Unused << SendNotifySystemTimezoneChange(aSystemTimezoneChangeInfo);
+  }
+
+  virtual bool
+  RecvFactoryReset(const nsString& aReason) override
+  {
+    if (!AssertAppProcessPermission(this, "power")) {
+      return false;
+    }
+
+    FactoryResetReason reason = FactoryResetReason::Normal;
+    if (aReason.EqualsLiteral("normal")) {
+      reason = FactoryResetReason::Normal;
+    } else if (aReason.EqualsLiteral("wipe")) {
+      reason = FactoryResetReason::Wipe;
+    } else if (aReason.EqualsLiteral("root")) {
+      reason = FactoryResetReason::Root;
+    } else {
+      // Invalid factory reset reason. That should never happen.
+      return false;
+    }
+
+    hal::FactoryReset(reason);
+    return true;
+  }
+};
+
+class HalChild : public PHalChild {
+public:
+  virtual void
+  ActorDestroy(ActorDestroyReason aWhy) override
+  {
+    sHalChildDestroyed = true;
+  }
+
+  virtual bool
+  RecvNotifyBatteryChange(const BatteryInformation& aBatteryInfo) override {
+    hal::NotifyBatteryChange(aBatteryInfo);
+    return true;
+  }
+
+  virtual bool
+  RecvNotifySensorChange(const hal::SensorData &aSensorData) override;
+
+  virtual bool
+  RecvNotifyNetworkChange(const NetworkInformation& aNetworkInfo) override {
+    hal::NotifyNetworkChange(aNetworkInfo);
+    return true;
+  }
+
+  virtual bool
+  RecvNotifyWakeLockChange(const WakeLockInformation& aWakeLockInfo) override {
+    hal::NotifyWakeLockChange(aWakeLockInfo);
+    return true;
+  }
+
+  virtual bool
+  RecvNotifyScreenConfigurationChange(const ScreenConfiguration& aScreenConfiguration) override {
+    hal::NotifyScreenConfigurationChange(aScreenConfiguration);
+    return true;
+  }
+
+  virtual bool
+  RecvNotifySwitchChange(const mozilla::hal::SwitchEvent& aEvent) override {
+    hal::NotifySwitchChange(aEvent);
+    return true;
+  }
+
+  virtual bool
+  RecvNotifySystemClockChange(const int64_t& aClockDeltaMS) override {
+    hal::NotifySystemClockChange(aClockDeltaMS);
+    return true;
+  }
+
+  virtual bool
+  RecvNotifySystemTimezoneChange(
+    const SystemTimezoneChangeInformation& aSystemTimezoneChangeInfo) override {
+    hal::NotifySystemTimezoneChange(aSystemTimezoneChangeInfo);
+    return true;
+  }
+};
+
+bool
+HalChild::RecvNotifySensorChange(const hal::SensorData &aSensorData) {
+  hal::NotifySensorChange(aSensorData);
+
+  return true;
+}
+
+PHalChild* CreateHalChild() {
+  return new HalChild();
+}
+
+PHalParent* CreateHalParent() {
+  return new HalParent();
+}
+
+} // namespace hal_sandbox
+} // namespace mozilla
diff --git a/hal/sandbox/SandboxHal.h b/hal/sandbox/SandboxHal.h
new file mode 100644
index 000000000..0da2d41fb
--- /dev/null
+++ b/hal/sandbox/SandboxHal.h
@@ -0,0 +1,23 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et ft=cpp : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_SandboxHal_h
+#define mozilla_SandboxHal_h
+
+namespace mozilla {
+namespace hal_sandbox {
+
+class PHalChild;
+class PHalParent;
+
+PHalChild* CreateHalChild();
+
+PHalParent* CreateHalParent();
+
+} // namespace hal_sandbox
+} // namespace mozilla
+
+#endif  // mozilla_SandboxHal_h
diff --git a/hal/windows/WindowsBattery.cpp b/hal/windows/WindowsBattery.cpp
new file mode 100644
index 000000000..c1b9a31e6
--- /dev/null
+++ b/hal/windows/WindowsBattery.cpp
@@ -0,0 +1,190 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Hal.h"
+#include "HalImpl.h"
+#include "nsITimer.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/dom/battery/Constants.h"
+#include "nsComponentManagerUtils.h"
+
+#include <windows.h>
+#include "mozilla/WindowsVersion.h"
+
+using namespace mozilla::dom::battery;
+
+namespace mozilla {
+namespace hal_impl {
+
+static nsCOMPtr<nsITimer> sUpdateTimer;
+
+/* Power Event API is Vista or later */
+static decltype(RegisterPowerSettingNotification)* sRegisterPowerSettingNotification = nullptr;
+static decltype(UnregisterPowerSettingNotification)* sUnregisterPowerSettingNotification = nullptr;
+static HPOWERNOTIFY sPowerHandle = nullptr;
+static HPOWERNOTIFY sCapacityHandle = nullptr;
+static HWND sHWnd = nullptr;
+
+static void
+UpdateHandler(nsITimer* aTimer, void* aClosure) {
+  NS_ASSERTION(!IsVistaOrLater(),
+               "We shouldn't call this function for Vista or later version!");
+
+  static hal::BatteryInformation sLastInfo;
+  hal::BatteryInformation currentInfo;
+
+  hal_impl::GetCurrentBatteryInformation(&currentInfo);
+  if (sLastInfo.level() != currentInfo.level() ||
+      sLastInfo.charging() != currentInfo.charging() ||
+      sLastInfo.remainingTime() != currentInfo.remainingTime()) {
+    hal::NotifyBatteryChange(currentInfo);
+    sLastInfo = currentInfo;
+  }
+}
+
+static
+LRESULT CALLBACK
+BatteryWindowProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam) {
+  if (msg != WM_POWERBROADCAST || wParam != PBT_POWERSETTINGCHANGE) {
+    return DefWindowProc(hwnd, msg, wParam, lParam);
+  }
+
+  hal::BatteryInformation currentInfo;
+
+  // Since we need update remainingTime, we cannot use LPARAM.
+  hal_impl::GetCurrentBatteryInformation(&currentInfo);
+
+  hal::NotifyBatteryChange(currentInfo);
+  return TRUE;
+}
+
+void
+EnableBatteryNotifications()
+{
+  if (IsVistaOrLater()) {
+    // RegisterPowerSettingNotification is from Vista or later.
+    // Use this API if available.
+    HMODULE hUser32 = GetModuleHandleW(L"USER32.DLL");
+    if (!sRegisterPowerSettingNotification)
+      sRegisterPowerSettingNotification = (decltype(RegisterPowerSettingNotification)*)
+        GetProcAddress(hUser32, "RegisterPowerSettingNotification");
+    if (!sUnregisterPowerSettingNotification)
+      sUnregisterPowerSettingNotification = (decltype(UnregisterPowerSettingNotification)*)
+        GetProcAddress(hUser32, "UnregisterPowerSettingNotification");
+
+    if (!sRegisterPowerSettingNotification ||
+        !sUnregisterPowerSettingNotification) {
+      NS_ASSERTION(false, "Canot find PowerSettingNotification functions.");
+      return;
+    }
+
+    // Create custom window to watch battery event
+    // If we can get Gecko's window handle, this is unnecessary.
+
+    if (sHWnd == nullptr) {
+      WNDCLASSW wc;
+      HMODULE hSelf = GetModuleHandle(nullptr);
+
+      if (!GetClassInfoW(hSelf, L"MozillaBatteryClass", &wc)) {
+        ZeroMemory(&wc, sizeof(WNDCLASSW));
+        wc.hInstance = hSelf;
+        wc.lpfnWndProc = BatteryWindowProc;
+        wc.lpszClassName = L"MozillaBatteryClass";
+        RegisterClassW(&wc);
+      }
+
+      sHWnd = CreateWindowW(L"MozillaBatteryClass", L"Battery Watcher",
+                            0, 0, 0, 0, 0,
+                            nullptr, nullptr, hSelf, nullptr);
+    }
+
+    if (sHWnd == nullptr) {
+      return;
+    }
+
+    sPowerHandle =
+      sRegisterPowerSettingNotification(sHWnd,
+                                        &GUID_ACDC_POWER_SOURCE,
+                                        DEVICE_NOTIFY_WINDOW_HANDLE);
+    sCapacityHandle =
+      sRegisterPowerSettingNotification(sHWnd,
+                                        &GUID_BATTERY_PERCENTAGE_REMAINING,
+                                        DEVICE_NOTIFY_WINDOW_HANDLE);
+  } else
+  {
+    // for Windows XP.  If we remove Windows XP support,
+    // we should remove timer-based power notification
+    sUpdateTimer = do_CreateInstance(NS_TIMER_CONTRACTID);
+    if (sUpdateTimer) {
+      sUpdateTimer->InitWithFuncCallback(UpdateHandler,
+                                         nullptr,
+                                         Preferences::GetInt("dom.battery.timer",
+                                                             30000 /* 30s */),
+                                         nsITimer::TYPE_REPEATING_SLACK);
+    } 
+  }
+}
+
+void
+DisableBatteryNotifications()
+{
+  if (IsVistaOrLater()) {
+    if (sPowerHandle) {
+      sUnregisterPowerSettingNotification(sPowerHandle);
+      sPowerHandle = nullptr;
+    }
+
+    if (sCapacityHandle) {
+      sUnregisterPowerSettingNotification(sCapacityHandle);
+      sCapacityHandle = nullptr;
+    }
+
+    if (sHWnd) {
+      DestroyWindow(sHWnd);
+      sHWnd = nullptr;
+    }
+  } else
+  {
+    if (sUpdateTimer) {
+      sUpdateTimer->Cancel();
+      sUpdateTimer = nullptr;
+    }
+  }
+}
+
+void
+GetCurrentBatteryInformation(hal::BatteryInformation* aBatteryInfo)
+{
+  SYSTEM_POWER_STATUS status;
+  if (!GetSystemPowerStatus(&status)) {
+    aBatteryInfo->level() = kDefaultLevel;
+    aBatteryInfo->charging() = kDefaultCharging;
+    aBatteryInfo->remainingTime() = kDefaultRemainingTime;
+    return;
+  }
+
+  aBatteryInfo->level() =
+    status.BatteryLifePercent == 255 ? kDefaultLevel
+                                     : ((double)status.BatteryLifePercent) / 100.0;
+  aBatteryInfo->charging() = (status.ACLineStatus != 0);
+  if (status.ACLineStatus != 0) {
+    if (aBatteryInfo->level() == 1.0) {
+      // GetSystemPowerStatus API may returns -1 for BatteryFullLifeTime.
+      // So, if battery is 100%, set kDefaultRemainingTime at force.
+      aBatteryInfo->remainingTime() = kDefaultRemainingTime;
+    } else {
+      aBatteryInfo->remainingTime() =
+        status.BatteryFullLifeTime == (DWORD)-1 ? kUnknownRemainingTime
+                                                : status.BatteryFullLifeTime;
+    }
+  } else {
+    aBatteryInfo->remainingTime() =
+      status.BatteryLifeTime == (DWORD)-1 ? kUnknownRemainingTime
+                                          : status.BatteryLifeTime;
+  }
+}
+
+} // hal_impl
+} // mozilla
diff --git a/hal/windows/WindowsSensor.cpp b/hal/windows/WindowsSensor.cpp
new file mode 100644
index 000000000..302ad7c48
--- /dev/null
+++ b/hal/windows/WindowsSensor.cpp
@@ -0,0 +1,184 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Hal.h"
+
+#include <sensorsapi.h>
+#include <sensors.h>
+#include <portabledevicetypes.h>
+
+#define MEAN_GRAVITY 9.80665
+#define DEFAULT_SENSOR_POLL 100
+
+using namespace mozilla::hal;
+
+namespace mozilla {
+namespace hal_impl {
+
+static RefPtr<ISensor> sAccelerometer;
+
+class SensorEvent final : public ISensorEvents {
+public:
+  SensorEvent() : mCount(0) {
+  }
+
+  // IUnknown interface
+
+  STDMETHODIMP_(ULONG) AddRef() {
+    return InterlockedIncrement(&mCount);
+  }
+
+  STDMETHODIMP_(ULONG) Release() {
+    ULONG count = InterlockedDecrement(&mCount);
+    if (!count) {
+      delete this;
+      return 0;
+    }
+    return count;
+  }
+
+  STDMETHODIMP QueryInterface(REFIID iid, void** ppv) {
+    if (iid == IID_IUnknown) {
+      *ppv = static_cast<IUnknown*>(this);
+    } else if (iid == IID_ISensorEvents) {
+      *ppv = static_cast<ISensorEvents*>(this);
+    } else {
+      return E_NOINTERFACE;
+    }
+    AddRef();
+    return S_OK;
+  }
+
+  // ISensorEvents interface
+
+  STDMETHODIMP OnEvent(ISensor *aSensor, REFGUID aId, IPortableDeviceValues *aData) {
+    return S_OK;
+  }
+
+  STDMETHODIMP OnLeave(REFSENSOR_ID aId) {
+    return S_OK;
+  }
+
+  STDMETHODIMP OnStateChanged(ISensor *aSensor, SensorState state) {
+    return S_OK;
+  }
+
+  STDMETHODIMP OnDataUpdated(ISensor *aSensor, ISensorDataReport *aReport) {
+    PROPVARIANT v;
+    HRESULT hr;
+    InfallibleTArray<float> values;
+
+    // X-axis acceleration in g's
+    hr = aReport->GetSensorValue(SENSOR_DATA_TYPE_ACCELERATION_X_G, &v);
+    if (FAILED(hr)) {
+      return hr;
+    }
+    values.AppendElement(float(-v.dblVal * MEAN_GRAVITY));
+
+    // Y-axis acceleration in g's
+    hr = aReport->GetSensorValue(SENSOR_DATA_TYPE_ACCELERATION_Y_G, &v);
+    if (FAILED(hr)) {
+      return hr;
+    }
+    values.AppendElement(float(-v.dblVal * MEAN_GRAVITY));
+
+    // Z-axis acceleration in g's
+    hr = aReport->GetSensorValue(SENSOR_DATA_TYPE_ACCELERATION_Z_G, &v);
+    if (FAILED(hr)) {
+      return hr;
+    }
+    values.AppendElement(float(-v.dblVal * MEAN_GRAVITY));
+
+    hal::SensorData sdata(hal::SENSOR_ACCELERATION,
+                          PR_Now(),
+                          values,
+                          hal::SENSOR_ACCURACY_UNKNOWN);
+    hal::NotifySensorChange(sdata);
+
+    return S_OK;
+  }
+
+private:
+  ULONG mCount;
+};
+
+void
+EnableSensorNotifications(SensorType aSensor)
+{
+  if (aSensor != SENSOR_ACCELERATION) {
+    return;
+  }
+
+  if (sAccelerometer) {
+    return;
+  }
+
+  RefPtr<ISensorManager> manager;
+  if (FAILED(CoCreateInstance(CLSID_SensorManager, nullptr,
+                              CLSCTX_INPROC_SERVER,
+                              IID_ISensorManager, 
+                              getter_AddRefs(manager)))) {
+    return;
+  }
+
+  // accelerometer event
+
+  RefPtr<ISensorCollection> collection;
+  if (FAILED(manager->GetSensorsByType(SENSOR_TYPE_ACCELEROMETER_3D,
+                                       getter_AddRefs(collection)))) {
+    return;
+  }
+
+  ULONG count = 0;
+  collection->GetCount(&count);
+  if (!count) {
+    return;
+  }
+
+  RefPtr<ISensor> sensor;
+  collection->GetAt(0, getter_AddRefs(sensor));
+  if (!sensor) {
+    return;
+  }
+
+  // Set report interval to 100ms if possible. 
+  // Default value depends on drivers.
+  RefPtr<IPortableDeviceValues> values;
+  if (SUCCEEDED(CoCreateInstance(CLSID_PortableDeviceValues, nullptr,
+                                 CLSCTX_INPROC_SERVER,
+                                 IID_IPortableDeviceValues,
+                                 getter_AddRefs(values)))) {
+    if (SUCCEEDED(values->SetUnsignedIntegerValue(
+                    SENSOR_PROPERTY_CURRENT_REPORT_INTERVAL,
+                    DEFAULT_SENSOR_POLL))) {
+      RefPtr<IPortableDeviceValues> returns;
+      sensor->SetProperties(values, getter_AddRefs(returns));
+    }
+  }
+
+  RefPtr<SensorEvent> event = new SensorEvent();
+  RefPtr<ISensorEvents> sensorEvents;
+  if (FAILED(event->QueryInterface(IID_ISensorEvents,
+                                   getter_AddRefs(sensorEvents)))) {
+    return;
+  }
+
+  if (FAILED(sensor->SetEventSink(sensorEvents))) {
+    return;
+  }
+
+  sAccelerometer = sensor;
+}
+
+void
+DisableSensorNotifications(SensorType aSensor)
+{
+  if (aSensor == SENSOR_ACCELERATION && sAccelerometer) {
+    sAccelerometer->SetEventSink(nullptr);
+    sAccelerometer = nullptr;
+  }
+}
+
+} // hal_impl
+} // mozilla