About the linux-firmware project

Please be aware that this project is not just a local Chrome OS project. It is actually intended to (roughly) match up with the upstream git repository hosted at:


As such we shouldn't just dump random binary files here. The flow should be like the Chrome OS kernel upstream process. In other words:

  • First, submit firmware to the upstream linux-firmware repo.
  • Second, pick the firmware to the Chrome OS tree, tagging it UPSTREAM.

If we have to (due to an urgent bugfix) we can make local (CHROMIUM) changes here but the policy is that things that get put here are on their way to the upstream linux-firmware project.

See also the README file here, which comes from upstream.

The WHENCE file

Presumably if you're landing your firmware in the upstream linux-firmware repository then upstream will make sure to remind folks to update the WHENCE file. You should make sure that you get relevant updates to the WHENCE file when you pick your firmware. If we need to do a local change, please make sure to confirm that the WHENCE file still makes sense.

Of special note is that the WHENCE says what license the binary was released under. See below.

NOTE: Run ‘make check’ to check that WHENCE is consistent with the repository contents.


When picking firmware, please confirm that the license is still right / sane. Licenses here have been copied to chromiumos-overlay:


You should confirm that:

  • The license here still matches the one in chromiumos-overlay.
  • The license here still matches upstream if you're picking a new firmware from upstream (use the upstream WHENCE to find the right license).

To figure out what license matches with the firmware, refer to the linux-firmware ebuild file. Figure out what LINUX_FIRMWARE flag chooses your firmware and then figure out what license the ebuild file matches it up with.

How firmware gets installed

Firmware is installed via the linux-firmware ebuild file. Board overlays specify LINUX_FIRMWARE in their make.defaults (or equivalent) and that tells the ebuild what to install.

Try to install only firmware you need

When thinking about getting firmware installed, remember that disk space is at a premium. Board overlays should specify exactly which firmware they need. In other words, say that you need firmware for a “Marvell 8897 SDIO WiFi” part, don't say you need firmware for “Marvell WiFi” or (even worse) that you need firmware for “Marvell”.

Will we ever do a wholesale rebase to ToT linux-firmware?

Probably not. See https://crbug.com/770230#c10. Specifically:

We will likely not do a wholesale uprev of the linux-firmware.git. Right now we are only picking a very small number of firmware files to install and we'll manage those manually. If this changes and we find some reason to install a whole pile of firmware files that are uprevving all the time, we can re-evaluate.

What about files that aren't appropriate for upstream linux-firmware?

If you have firmware that is not appropriate for the upstream linux-firmware project then this isn‘t the repository you’re looking for. In such a case you should find another place to put your firmware (probably in BCS since git isn't ideal for storing binaries) and have your own ebuild that installs the firmware.

Before trying to find another place for your firmware, however, please remember that there‘s a pretty big benefit to getting firmware landed in the upstream linux-firmware project. Notably we want upstream to be testing / using the same firmware that Chrome OS is using. This makes it more likely for our systems to keep working across kernel uprevs and also more likely that someone upstream will fix a problem and we’ll get the fix through stable merges.