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Build Instructions (Chromium OS on Linux)

Chromium on Chromium OS is built on a mix of code sourced from Chromium on Linux and Chromium on Windows. Much of the user interface code is shared with Chromium on Windows. As such, if you make a change to Chromium on Windows you may find your changes affect Chromium on Chromium OS. Fortunately to test the effect of your changes you don't have to build all of Chromium OS, you can just build Chromium for Chromium OS directly on Linux.

First, follow the normal Linux build instructions as usual to get a Chromium checkout.

Running Chromium on your local machine

If you plan to test the Chromium build on your dev machine and not a Chromium OS device run:

export GYP_DEFINES="chromeos=1"
gclient runhooks

Now, once you build, you will build with Chromium OS features turned on.

Notes

  • When you build Chromium OS Chromium, you'll be using the TOOLKIT_VIEWS front-end just like Windows, so the files you'll probably want are in src/ui/views and src/chrome/browser/ui/views.
  • If chromeos=1 is specified, then toolkit_views=0 must not be specified.
  • The Chromium OS build requires a functioning GL so if you plan on testing it through Chromium Remote Desktop you might face drawing problems (e.g. Aura window not painting anything). Possible remedies:
    • --ui-enable-software-compositing --ui-disable-threaded-compositing
    • --use-gl=osmesa, but it's ultra slow, and you'll have to build osmesa yourself.
    • ... or just don't use Remote Desktop. :)
  • Note the underscore in the GYP_DEFINES variable name, as people sometimes mistakenly write it GYPDEFINES.

To specify a logged in user:

  • For first run, add the following options to the command line: --user-data-dir=/tmp/chrome --login-manager
  • Go through the out-of-the-box UX and sign in as username@gmail.com
  • For subsequent runs, add the following to the command line: --user-data-dir=/tmp/chrome --login-user=username@gmail.com.
  • To run in guest mode instantly, you can run add the arguments --user-data-dir=/tmp/chrome --bwsi --incognito --login-user='$guest' --login-profile=user

Signing in as a specific user is useful for debugging features like sync that require a logged in user.

Compile Testing Chromium with the Chromium OS SDK (quick version)

Note: These instructions are intended for Chromium developers trying to diagnose compile issues on Chromium OS, which can block changes in the CQ. See the full documentation for more information about building & testing chromium for Chromium OS. 

To do a build of Chromium that can run on Chromium OS itself, the Chromium OS SDK must be used. The SDK provides all of chromium's dependencies as they are distributed with Chromium OS (as opposed to other distributions such as Ubuntu).

To enter the SDK build environment, run the following command (replace the value of the --board flag with the name of the configuration you want to test).

cros chrome-sdk --board=amd64-generic --use-external-config

Once in the SDK build environment, build using the normal linux workflow (except for a different build directory):

gclient runhooks
ninja -C out_amd64-generic/Release chromium_builder_tests

The current configurations verified by the CQ are:

 Board Flag Build DirectoryCPU architecture 
 amd64-generic out_amd64-generic 64-bit Intel
 x86-generic out_x86-generic 32-bit Intel
 daisy out_daisy 32-bit ARM

Running Chromium on a Chromium OS device

Look at the Chromium OS documentation for the official flow for doing this.