Moved to https://chromium.googlesource.com/chromiumos/docs/+/master/simple_chrome_workflow.md
This workflow allows you to quickly build/deploy Chromium to any Chromium OS device without needing a Chromium OS checkout or chroot. It‘s useful for trying out your changes on a real device while you’re doing Chromium development. If you want your Chromium changes to be included when building a full Chromium OS image, see the instructions in the development guide.
At its core is the chrome-sdk shell which sets up the shell environment, and fetches the necessary SDK components (CrOS toolchain, sysroot, etc.).
Color Paths, files, and commands: green text on your build machine, outside the chroot purple text inside the chrome-sdk shell on your build machine Note: This is not the same thing as the cros-sdk chroot. crimson text on your Chromium OS device
First off make sure all preconditions are met:
In order to sign in to your Chromebook you must have Google API keys:
Run this from within your Chromium checkout (not the Chromium OS chroot):
Have you setup gsutil yet?
Steps below may run slow and fail with “Login Required” from gsutil. Use depot_tools/gsutil.py and run gsutil config to set the authentication token. (If you are a Googler, use your @google.com account)
NOTE: When prompted for a project ID, enter 134157665460 as your project ID (this is the Chrome OS project ID).
# Note: Replace $BOARD with a [Chromium OS board name](http://www.chromium.org/chromium-os/developer-information-for-chrome-os-devices) cros chrome-sdk --board=$BOARD
cros chrome-sdk will fetch the latest Chrome OS SDK for building Chrome, and put you in a shell (with a command prompt starting with (sdk BOARD VERSION).
cros chrome-sdk will also automatically install and start the Goma server, with the active server port stored in the $SDK_GOMA_PORT environment variable.
Tip: cros chrome-sdk will set up the environment to build external Chromium by default. To build the official Chrome, run with the --internal flag.
Note: There are no public builders yet for non-generic boards, so you'll have to use the generic or create your own local build. Star http://crbug.com/360342 for updates.
If you are making changes to Chromium OS and have a Chromium OS build inside a chroot that you want to build against, run cros chrome-sdk with the --chroot option.
cros chrome-sdk --board=$BOARD --chroot=/path/to/chromiumos/chroot
Create a GN build directory. Run the following inside the chrome-sdk shell:
$ gn gen out_$SDK_BOARD/Release --args=“$GN_ARGS”
This will generate out_$SDK_BOARD/Release/args.gn.
You can edit the args with:
$ gn args out_$SDK_BOARD/Release
You can replace Release with Debug (or something else) for different configurations. See “Debug build” below.
GN build configuration discusses various GN build configurations. For more info on GN, run gn help on the command line or read the quick start guide.
To build Chrome, run:
ninja -C out_${SDK_BOARD}/Release -j500 -l 10 chrome chrome_sandbox nacl_helper
This runs Goma with 500 concurrent jobs and a maximum load of 10. You can tweak this number to achieve optimal build performance. To watch the build progress, find out the Goma port (echo $SDK_GOMA_PORT) and open http://localhost:<port_number> in a browser.
IMPORTANT: Do not attempt to build targets other than chrome, chrome_sandbox, nacl_helper, or (optionally) chromiumos_preflight in Simple Chrome, they will likely fail.
Congratulations, you've now built Chromium for Chromium OS!
Once you've built Chromium the first time, you can build incrementally just using ninja, e.g.:
ninja -C out_${SDK_BOARD}/Release -j500 -l 10 chrome
Tip: The default extensions will be installed by the test image you use below.
Before you can deploy your build of Chromium to the device, it needs to have a test image loaded on it.
You will need a 4GiB USB stick (you can get one at the ChromeStop where you picked up your Chromebook).
Non-Googlers: Download a test image from the URL https://storage.cloud.google.com/chromeos-image-archive/$BOARD-release//chromiumos_test_image.tar.xz where $BOARD and version come from your SDK prompt. For example (sdk **lumpy** **R27-3789.0.0**) is the lumpy board using version R27-3789.0.0)
Googlers: Download an unsigned test image from https://cros-goldeneye.corp.google.com/console/listRelease. The latest dev channel is a good choice.
After you download the compressed tarball containing the test image (it should have “test” somewhere in the file name), extract the image by running:
tar xf chromiumos_test_image.tar.xz
Copy the image to your drive using cros flash
cros flash usb:// chromiumos_test_image.bin
If cros flash does not work you can do it the old fashioned way using dd. Where the X in sdX is the path to your usb key, and you can use dmesg to figure out the right path (it'll show when you plug it in). bs stands for block size, and was set to one gigabyte here. With the default value, the operation can be very slow. Make sure that the USB stick is not mounted before running this. You might have to turn of automounting in your operating system.
sudo dd if=chromiumos_test_image.bin of=/dev/sdX bs=1G
Follow the device-specific instructions to
sudo /usr/sbin/chromeos-installIMPORTANT NOTES:
To do this you will need a USB-to-ethernet dongle (you can find these at the techstop).
To deploy the build to a device, you will need direct ssh access to it from your computer. The scripts below handle everything else.
This also works both before and after login. Another option is to run ‘ifconfig’ from the shell (Ctrl-Alt-t -> shell) after guest login.
Just type deploy_chrome from with your chrome-sdk shell. It will use rsync to incrementally deploy to the device.
Specify the build output directory to deploy from using --build-dir, and the IP address of the target device (which must be ssh-able as user ‘root’) using --to, where %CHROME_DIR% is the path to your Chrome checkout:
cd %CHROME_DIR%/src
deploy_chrome --build-dir=out_${SDK_BOARD}/Release --to=172.11.11.11
Tip: deploy_chrome lives under $CHROME_DIR/src/third_party/chromite/bin. You can run deploy_chrome outside of a chrome-sdk shell as well.
Tip: Specify the --target-dir flag to deploy to a custom location on the target device.
NOTE for GN: The gn build outputs .so files (for component builds) and some test files in a different location than the gyp build. In order for deploy_chrome to successfully locate these files, it needs to know that chrome was built using gn. Currently cros chrome-sdk looks for GYP_CHROMIUM_NO_ACTION=1 as a hint to set USE=“gn” which will cause deploy_chrome to look for files in the correct place. If you do not have GYP_CHROMIUM_NO_ACTION=1 set or if you do but have build chrome with gyp, you can set USE=“gn” or USE="" to indicate where deploy_chrome should look for output files.
Other than the normal system output in /var/log/messages, you can find the output of Chrome itself in /var/log/ui/ui.LATEST. This is where vmodule output and such ends up.
If you want to tweak the command line of Chrome or its environment, you have to do this on the device itself.
Edit the /etc/chrome_dev.conf file. Instructions on using it are in the file itself.
Edit the /sbin/session_manager_setup.sh script. If you go to the end, you'll see where Chrome is invoked and where you can tweak the flags/env.
For cros chrome-sdk GN configurations, Release is the default. A debug build of Chrome will include useful tools like DCHECK and debug logs like DVLOG. For a Debug configuration, specify --args=“$GN_ARGS is_debug=true is_component_build = false”.
Alternately, you can just turn on DCHECKs for a release build. You can do this with --args=“$GN_ARGS dcheck_always_on=true”.
You need to add --nostrip to deploy_chrome because otherwise it will strip symbols even from a debug build. The rootfs will probably not be big enough to hold all the binaries so you need to put it on the stateful partition and bind mount over the real directory. Create the directory /usr/local/chrome on your device and run:
deploy_chrome --build-dir=out_$BOARD/Debug \ --to=<ip-address> \ --target-dir=/usr/local/chrome \ --mount-dir=/opt/google/chrome \ --nostrip
Notes:
Core dumps are disabled by defaul.t See additional debugging tips for how to enable core files.
On the target machine, open up a port for the gdb server to listen on, and attach the gdb server to the running chrome process.
sudo /sbin/iptables -A INPUT -p tcp --dport 1234 -j ACCEPT sudo gdbserver --attach :1234 $(pgrep chrome -P $(pgrep session_manager))
On your host machine (inside the chrome-sdk shell), run gdb and start the Python interpreter:
cd %CHROME_DIR%/src
gdb out_${SDK_BOARD}/Release/chrome
Reading symbols from /usr/local/google2/chromium2/src/out_link/Release/chrome...
(gdb) pi
>>>
Note: These instructions are for targeting an x86_64 device. For now, to target an ARM device, you need to run the cross-compiled gdb from within a chroot.
Then from within the Python interpreter, run these commands:
import os
sysroot = os.environ['SYSROOT']
gdb.execute('set sysroot %s' % sysroot)
gdb.execute('set solib-absolute-prefix %s' % sysroot)
gdb.execute('set debug-file-directory %s/usr/lib/debug' % sysroot)
gdb.execute('set solib-search-path out_%s/Release/lib' % os.environ['SDK_BOARD']) # Or "Debug" for a debug build
gdb.execute('target remote 12.34.56.78:1234')
If you wish, after you connect, you can Ctrl-D out of the Python shell.
Extra debugging instructions are located at http://www.chromium.org/chromium-os/how-tos-and-troubleshooting/debugging-tips.
When you invoke cros chrome-sdk, the script fetches the version of the SDK that corresponds to your Chrome checkout. To update the SDK, sync your Chrome checkout and re-run cros chrome-sdk.
IMPORTANT NOTES:
You can specify a version of Chrome OS to build against. This is handy for tracking down when a particular bug was introduced.
cros chrome-sdk --board=$BOARD --version=3680.0.0
Once you are finished testing the old version of the chrome-sdk, you can always start a new shell with the latest version again. Here's an example:
cros chrome-sdk --board=$BOARD
Tip: If you update Chrome inside the chrome-sdk, you may then be using an SDK that is out of date with the current Chrome. See Updating the version of the Chrome OS SDK above.
git rebase-update gclient sync
Since the gyp files don't define which targets get installed, that information is maintained in the chromite repo as part of Chromium OS. That repo is also integrated into the Chromium source tree via the DEPS file.
In order to add/remove a file from the installed list:
cros flash with xbuddy will automatically download an image and write it to USB for you. It's very convenient, but for now it requires a full Chrome OS checkout and must be run inside the Chrome OS chroot. (issue 437877)
cros flash usb:// xbuddy://remote/**$BOARD**/**<version>**/test
Replace $BOARD with and with the right values. Both can be seen in your SDK prompt (e.g. (sdk **lumpy** **R27-3789.0.0**) is the lumpy board using version R27-3789.0.0).
See the Cros Flash page for more details.
By default, cros chrome-sdk prepends something like ‘(sdk link R52-8315.0.0)’ to the prompt (with the version of the chromeos prebuilt being used).
If you prefer to colorize the prompt, you can set PS1 in ~/.chromite/chrome_sdk.bashrc, e.g. to prepend a yellow '(sdk link 8315.0.0)' to the prompt:
PS1='\[\033[01;33m\](sdk ${SDK_BOARD} ${SDK_VERSION})\[\033[00m\] \w \[\033[01;36m\]$(__git_ps1 "(%s)")\[\033[00m\] \$ '
NOTE: Currently the release version (e.g. 52) is not available as an environment variable.