diff options
Diffstat (limited to 'third_party/rust/libc/ci/README.md')
| -rw-r--r-- | third_party/rust/libc/ci/README.md | 203 |
1 files changed, 0 insertions, 203 deletions
diff --git a/third_party/rust/libc/ci/README.md b/third_party/rust/libc/ci/README.md deleted file mode 100644 index 13c7c8da5..000000000 --- a/third_party/rust/libc/ci/README.md +++ /dev/null @@ -1,203 +0,0 @@ -The goal of the libc crate is to have CI running everywhere to have the -strongest guarantees about the definitions that this library contains, and as a -result the CI is pretty complicated and also pretty large! Hopefully this can -serve as a guide through the sea of scripts in this directory and elsewhere in -this project. - -# Files - -First up, let's talk about the files in this directory: - -* `run-travis.sh` - a shell script run by all Travis builders, this is - responsible for setting up the rest of the environment such as installing new - packages, downloading Rust target libraries, etc. - -* `run.sh` - the actual script which runs tests for a particular architecture. - Called from the `run-travis.sh` script this will run all tests for the target - specified. - -* `cargo-config` - Cargo configuration of linkers to use copied into place by - the `run-travis.sh` script before builds are run. - -* `dox.sh` - script called from `run-travis.sh` on only the linux 64-bit nightly - Travis bots to build documentation for this crate. - -* `landing-page-*.html` - used by `dox.sh` to generate a landing page for all - architectures' documentation. - -* `run-qemu.sh` - see discussion about QEMU below - -* `mips`, `rumprun` - instructions to build the docker image for each respective - CI target - -# CI Systems - -Currently this repository leverages a combination of Travis CI and AppVeyor for -running tests. The triples tested are: - -* AppVeyor - * `{i686,x86_64}-pc-windows-{msvc,gnu}` -* Travis - * `{i686,x86_64,mips,aarch64}-unknown-linux-gnu` - * `x86_64-unknown-linux-musl` - * `arm-unknown-linux-gnueabihf` - * `arm-linux-androideabi` - * `{i686,x86_64}-apple-{darwin,ios}` - * `x86_64-rumprun-netbsd` - * `x86_64-unknown-freebsd` - * `x86_64-unknown-openbsd` - -The Windows triples are all pretty standard, they just set up their environment -then run tests, no need for downloading any extra target libs (we just download -the right installer). The Intel Linux/OSX builds are similar in that we just -download the right target libs and run tests. Note that the Intel Linux/OSX -builds are run on stable/beta/nightly, but are the only ones that do so. - -The remaining architectures look like: - -* Android runs in a [docker image][android-docker] with an emulator, the NDK, - and the SDK already set up. The entire build happens within the docker image. -* The MIPS, ARM, and AArch64 builds all use the QEMU userspace emulator to run - the generated binary to actually verify the tests pass. -* The MUSL build just has to download a MUSL compiler and target libraries and - then otherwise runs tests normally. -* iOS builds need an extra linker flag currently, but beyond that they're built - as standard as everything else. -* The rumprun target builds an entire kernel from the test suite and then runs - it inside QEMU using the serial console to test whether it succeeded or - failed. -* The BSD builds, currently OpenBSD and FreeBSD, use QEMU to boot up a system - and compile/run tests. More information on that below. - -[android-docker]: https://github.com/rust-lang/rust-buildbot/blob/master/slaves/android/Dockerfile - -## QEMU - -Lots of the architectures tested here use QEMU in the tests, so it's worth going -over all the crazy capabilities QEMU has and the various flavors in which we use -it! - -First up, QEMU has userspace emulation where it doesn't boot a full kernel, it -just runs a binary from another architecture (using the `qemu-<arch>` wrappers). -We provide it the runtime path for the dynamically loaded system libraries, -however. This strategy is used for all Linux architectures that aren't intel. -Note that one downside of this QEMU system is that threads are barely -implemented, so we're careful to not spawn many threads. - -For the rumprun target the only output is a kernel image, so we just use that -plus the `rumpbake` command to create a full kernel image which is then run from -within QEMU. - -Finally, the fun part, the BSDs. Quite a few hoops are jumped through to get CI -working for these platforms, but the gist of it looks like: - -* Cross compiling from Linux to any of the BSDs seems to be quite non-standard. - We may be able to get it working but it might be difficult at that point to - ensure that the libc definitions align with what you'd get on the BSD itself. - As a result, we try to do compiles within the BSD distro. -* On Travis we can't run a VM-in-a-VM, so we resort to userspace emulation - (QEMU). -* Unfortunately on Travis we also can't use KVM, so the emulation is super slow. - -With all that in mind, the way BSD is tested looks like: - -1. Download a pre-prepared image for the OS being tested. -2. Generate the tests for the OS being tested. This involves running the `ctest` - library over libc to generate a Rust file and a C file which will then be - compiled into the final test. -3. Generate a disk image which will later be mounted by the OS being tested. - This image is mostly just the libc directory, but some modifications are made - to compile the generated files from step 2. -4. The kernel is booted in QEMU, and it is configured to detect the libc-test - image being available, run the test script, and then shut down afterwards. -5. Look for whether the tests passed in the serial console output of the kernel. - -There's some pretty specific instructions for setting up each image (detailed -below), but the main gist of this is that we must avoid a vanilla `cargo run` -inside of the `libc-test` directory (which is what it's intended for) because -that would compile `syntex_syntax`, a large library, with userspace emulation. -This invariably times out on Travis, so we can't do that. - -Once all those hoops are jumped through, however, we can be happy that we're -testing almost everything! - -Below are some details of how to set up the initial OS images which are -downloaded. Each image must be enabled have input/output over the serial -console, log in automatically at the serial console, detect if a second drive in -QEMU is available, and if so mount it, run a script (it'll specifically be -`run-qemu.sh` in this folder which is copied into the generated image talked -about above), and then shut down. - -### QEMU setup - FreeBSD - -1. Download CD installer (most minimal is fine) -2. `qemu-img create -f qcow2 foo.qcow2 2G` -3. `qemu -cdrom foo.iso -drive if=virtio,file=foo.qcow2 -net nic,model=virtio -net user` -4. run installer -5. `echo 'console="comconsole"' >> /boot/loader.conf` -6. `echo 'autoboot_delay="0"' >> /boot/loader.conf` -7. look at /etc/ttys, see what getty argument is for ttyu0 -8. edit /etc/gettytab, look for ttyu0 argument, prepend `:al=root` to line - beneath - -(note that the current image has a `freebsd` user, but this isn't really -necessary) - -Once that's done, arrange for this script to run at login: - -``` -#!/bin/sh - -sudo kldload ext2fs -[ -e /dev/vtbd1 ] || exit 0 -sudo mount -t ext2fs /dev/vtbd1 /mnt -sh /mnt/run.sh /mnt -sudo poweroff -``` - -Helpful links - -* https://en.wikibooks.org/wiki/QEMU/Images -* https://blog.nekoconeko.nl/blog/2015/06/04/creating-an-openstack-freebsd-image.html -* https://www.freebsd.org/doc/handbook/serialconsole-setup.html - - -### QEMU setup - OpenBSD - -1. Download CD installer -2. `qemu-img create -f qcow2 foo.qcow2 2G` -3. `qemu -cdrom foo.iso -drive if=virtio,file=foo.qcow2 -net nic,model=virtio -net user` -4. run installer -5. `echo 'set tty com0' >> /etc/boot.conf` -6. `echo 'boot' >> /etc/boot.conf` -7. Modify /etc/ttys, change the `tty00` at the end from 'unknown off' to - 'vt220 on secure' -8. Modify same line in /etc/ttys to have `"/root/foo.sh"` as the shell -9. Add this script to `/root/foo.sh` - -``` -#!/bin/sh -exec 1>/dev/tty00 -exec 2>&1 - -if mount -t ext2fs /dev/sd1c /mnt; then - sh /mnt/run.sh /mnt - shutdown -ph now -fi - -# limited shell... -exec /bin/sh < /dev/tty00 -``` - -10. `chmod +x /root/foo.sh` - -Helpful links: - -* https://en.wikibooks.org/wiki/QEMU/Images -* http://www.openbsd.org/faq/faq7.html#SerCon - -# Questions? - -Hopefully that's at least somewhat of an introduction to everything going on -here, and feel free to ping @alexcrichton with questions! - |