Building Zephyr Out-of-Chroot

It is possible to build Zephyr outside of the Chromium OS chroot, albeit with additional steps.

Note: These steps are maintained on a best-effort basis, and may not be accurate depending on your Linux distribution and your system's specific environment.

Remove west, if installed b/184654974

Zephyr‘s Cmake system will try to attach itself to the west tool if it finds it installed, conflicting with manual cmake invocations. If you installed west, you’ll need to remove it:

python3 -m pip uninstall west

Install zmake

You can install zmake with pip:

cd ~/chromiumos/src/platform/ec
python3 -m pip install -e zephyr/zmake --user

Ensure that ~/.local/bin is in your PATH.

You may also need to install these items:

sudo apt-get install cmake ninja-build python3-pyelftools gcc-multilib \
    python3-pykwalify python3-colorama python3-testfixtures

Install binman

First build pylibfdt:

cd somewhere
sudo apt-get install flex bison swig
git clone git://git.kernel.org/pub/scm/utils/dtc/dtc.git
cd dtc
make
make install PREFIX=~/.local         # You can install this where it suits

If you have a Chromium OS checkout then you should do:

cd ~/.local/bin
ln -s ~/chromiumos/src/third_party/u-boot/files/tools/binman/binman

otherwise:

cd somewhere
git clone https://source.denx.de/u-boot/u-boot.git
cd ~/.local/bin
ln -s somewhere/u-boot/tools/binman/binman

Install Zephyr toolchain

If using the Zephyr toolchain (-t zephyr), follow the upstream documentation to install the Zephyr build tools.