The hps-firmware-images package installs signed HPS firmware images into the ChromiumOS disk image under /usr/lib/firmware/hps. This is the firmware which hpsd will load and run on the user’s Chromebook. “Releasing” new firmware therefore means updating the signed images in hps-firmware-images.
NOTE: since approximately OS version 15811, no new HPS firmware images are being built or signed. Releasing new images in the future will require re-enabling image building and signing, by reverting the changes in https://crrev.com/i/7027432 and https://crrev.com/c/5334546 or some other method that builds and signs the hps-firmware package automatically.
Follow these steps:
Choose a suitable brya-release build to take signed firmware from. Typically this would be the most recent successful dev-channel brya build, which contains HPS firmware built from the main branch. Use go/deneye to find the build number.
In the src/platform/hps-firmware-images directory, run the helper script to fetch the signed firmware. For example:
script/get_signed_binary.sh R105 14983.0.0
The helper script creates a git commit with the updated firmware. Use git commit --amend to reword the commit as necessary: update BUG= and TEST= and describe the changes included in the new firmware.
Test the new firmware on a DUT. You can use the standard cros workon and cros deploy workflows.
Upload your change for review using repo upload.