Bare-metal CI

The bare-metal scripts run on a system with gitlab-runner and Docker, connected to potentially multiple bare-metal boards that run tests of Mesa. Currently only “fastboot” and “ChromeOS Servo” devices are supported.

In comparison with LAVA, this doesn’t involve maintaining a separate web service with its own job scheduler and replicating jobs between the two. It also places more of the board support in Git, instead of web service configuration. On the other hand, the serial interactions and bootloader support are more primitive.

Requirements (fastboot)

This testing requires power control of the DUTs by the gitlab-runner machine, since this is what we use to reset the system and get back to a pristine state at the start of testing.

We require access to the console output from the gitlab-runner system, since that is how we get the final results back from the tests. You should probably have the console on a serial connection, so that you can see bootloader progress.

The boards need to be able to have a kernel/initramfs supplied by the gitlab-runner system, since the initramfs is what contains the Mesa testing payload.

The boards should have networking, so that we can extract the dEQP .xml results to artifacts on GitLab.

Requirements (servo)

For servo-connected boards, we can use the EC connection for power control to reboot the board. However, loading a kernel is not as easy as fastboot, so we assume your bootloader can do TFTP, and that your gitlab-runner mounts the runner’s tftp directory specific to the board at /tftp in the container.

Since we’re going the TFTP route, we also use NFS root. This avoids packing the rootfs and sending it to the board as a ramdisk, which means we can support larger rootfses (for piglit testing), at the cost of needing more storage on the runner.

Telling the board about where its TFTP and NFS should come from is done using dnsmasq on the runner host. For example, this snippet in the dnsmasq.conf.d in the google farm, with the gitlab-runner host we call “servo”:

dhcp-host=1c:69:7a:0d:a3:d3,10.42.0.10,set:servo

# Fixed dhcp addresses for my sanity, and setting a tag for
# specializing other DHCP options
dhcp-host=a0:ce:c8:c8:d9:5d,10.42.0.11,set:cheza1
dhcp-host=a0:ce:c8:c8:d8:81,10.42.0.12,set:cheza2

# Specify the next server, watch out for the double ',,'.  The
# filename didn't seem to get picked up by the bootloader, so we use
# tftp-unique-root and mount directories like
# /srv/tftp/10.42.0.11/jwerner/cheza as /tftp in the job containers.
tftp-unique-root
dhcp-boot=tag:cheza1,cheza1/vmlinuz,,10.42.0.10
dhcp-boot=tag:cheza2,cheza2/vmlinuz,,10.42.0.10

dhcp-option=tag:cheza1,option:root-path,/srv/nfs/cheza1
dhcp-option=tag:cheza2,option:root-path,/srv/nfs/cheza2

Setup

Each board will be registered in fd.o GitLab. You’ll want something like this to register a fastboot board:

sudo gitlab-runner register \
     --url https://gitlab.freedesktop.org \
     --registration-token $1 \
     --name MY_BOARD_NAME \
     --tag-list MY_BOARD_TAG \
     --executor docker \
     --docker-image "alpine:latest" \
     --docker-volumes "/dev:/dev" \
     --docker-network-mode "host" \
     --docker-privileged \
     --non-interactive

For a servo board, you’ll need to also volume mount the board’s NFS root dir at /nfs and TFTP kernel directory at /tftp.

The registration token has to come from a fd.o GitLab admin going to https://gitlab.freedesktop.org/admin/runners

The name scheme for Google’s lab is google-freedreno-boardname-n, and our tag is something like google-freedreno-db410c. The tag is what identifies a board type so that board-specific jobs can be dispatched into that pool.

We need privileged mode and the /dev bind mount in order to get at the serial console and fastboot USB devices (–device arguments don’t apply to devices that show up after container start, which is the case with fastboot, and the servo serial devices are actually links to /dev/pts). We use host network mode so that we can spin up a nginx server to collect XML results for fastboot.

Once you’ve added your boards, you’re going to need to add a little more customization in /etc/gitlab-runner/config.toml. First, add concurrent = <number of boards> at the top (“we should have up to this many jobs running managed by this gitlab-runner”). Then for each board’s runner, set limit = 1 (“only 1 job served by this board at a time”). Finally, add the board-specific environment variables required by your bare-metal script, something like:

[[runners]]
  name = "google-freedreno-db410c-1"
  environment = ["BM_SERIAL=/dev/ttyDB410c8", "BM_POWERUP=google-power-up.sh 8", "BM_FASTBOOT_SERIAL=15e9e390", "FDO_CI_CONCURRENT=4"]

The FDO_CI_CONCURRENT variable should be set to the number of CPU threads on the board, which is used for auto-tuning of job parallelism.

If you want to collect the results for fastboot you need to add the following two board-specific environment variables BM_WEBDAV_IP and BM_WEBDAV_PORT. These represent the IP address of the Docker host and the board specific port number that gets used to start a nginx server.

Once you’ve updated your runners’ configs, restart with sudo service gitlab-runner restart