Setting up a ChromiumOS dev environment


Setting up a fully functional ChromiumOS development environment on actual Chromebook hardware

Set up environment

export DEV_DIR="/opt"
mkdir -p $DEV_DIR
export CHROMIUM_DIR="$DEV_DIR/chromiumos"
mkdir -p $CHROMIUM_DIR
export PATH="$DEV_DIR/depot_tools:$PATH"

# The BOARD variable used here is specific for the Chromebook that is
# being targeted, a more generic target like "amd64-generic" could
# be more useful for you needs.
export BOARD=chell

# The USB_DEVICE variable refers to the USB device that will be used
# for flashing ChromiumOS onto a Chromebook.
# Make sure that this device does not contain anything important!
export USB_DEVICE="/dev/sda"

Install dependencies

sudo apt install git-core gitk git-gui subversion curl
git clone

Get ChromiumOS source

repo init -u
repo sync -j25

Build ChromiumOS

cros_sdk -- ./build_packages --board=${BOARD}
cros_sdk -- ./build_image --board=${BOARD}

Flash ChromiumOS to storage medium

cros_sdk -- cros flash --board=${BOARD} usb:/$USB_DEVICE

Install ChromiumOS on Chromebook

Enter Chromebook into dev-mode

This part is highly device specific, and depends on how the manufacturer of your device has chosen to implement the dev-mode switch.

A partial list of devices and how to enter them into dev-mode can be found here.

Flash ChromiumOS to Chromebook

Fire up your Chrombook device and hit Ctrl+Alt+Back, followed by 'chronos' and hit enter. Followed by the below command to install the ChromiumOS build that was just flashed.


Debug an application

On Chromebook

Again fire up your Chrombook device and hit Ctrl+Alt+Back, followed by 'chronos' and hit enter.

# Remount the root drive read / write
sudo mount -o remount,rw /

# Open port so that gdbserver can be reached
sudo /sbin/iptables -A INPUT  -p tcp --dport 1234 -j ACCEPT

# Run gdb server, listening on port 1234 (opened in iptables command above)
sudo gdbserver :1234 chrome

On dev machine

# On x86
cros_sdk -- sudo USE=expat emerge cross-i686-pc-linux-gnu/gdb
# On ARMv7
cros_sdk -- sudo USE=expat emerge cross-armv7a-cros-linux-gnueabi/gdb

cros_sdk -- i686-pc-linux-gnu-gdb "/build/$BOARD/opt/google/chrome/chrome"
(gdb) set sysroot /build/$BOARD/
(gdb) target remote IP_ADDR_CHROMEBOOK:1234
(gdb) continue


This is a bit of a rough outline, and is only suitable for Chromebook devices that already are in dev-mode.


This post has been a part of work undertaken by my employer Collabora.


ChromiumOS Depo Tools
ChromiumOS Quick Start
ChromiumOS Dev Mode
ChromiumOS Debug

Tags: linux · chromiumos · chromebook · collabora