https://www.chromium.org/chromium-os/quick-start-guide

root
adduser --disabled-login chromiumos
sudo apt-get install git-core gitk git-gui subversion curl lvm2 thin-provisioning-tools python-pkg-resources python-virtualenv python-oauth2client
cd /tmp
cat > ./sudo_editor <<EOF
#!/bin/sh
echo Defaults \!tty_tickets > \$1          # Entering your password in one shell affects all shells
echo Defaults timestamp_timeout=180 >> \$1 # Time between re-requesting your password, in minutes
EOF
chmod +x ./sudo_editor
sudo EDITOR=./sudo_editor visudo -f /etc/sudoers.d/relax_requirements

Per visudo hinzufügen:

chromiumos ALL=(ALL) NOPASSWD: ALL

chromiumos
git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git
echo "# depot_tools
if [ -d "$HOME/depot_tools" ] ; then
    PATH="$HOME/depot_tools:$PATH"
fi" >> ~/.profile
source ~/.profile
mkdir chromiumos
repo init -u https://chromium.googlesource.com/chromiumos/manifest.git
repo sync
export BOARD=amd64-generic
cros_sdk -- ./build_packages --board=${BOARD}
cros_sdk -- ./build_image --board=${BOARD}

Das Ergebnis liegt dann unter ./src/build/images/amd64-generic/latest/

./src/scripts/image_to_vm.sh --from=./../../src/build/images/amd64-generic/latest/ --board=amd64-generic