buildroot_elixir

This is an example of using the Buildroot embedded Linux build system to run an Elixir app.

It has support for building in Docker and GitHub Actions CI.

Running in Docker

Create an .env file:

IMAGE_NAME="foo-app"
IMAGE_OWNER="cogini"

Build dev image:

docker compose build

Run dev image:

docker compose run buildroot-dev

Inside the container

[ -d /opt/buildroot/.git ] || git clone $BUILDROOT_GIT_REPO /opt/buildroot
git checkout $BUILDROOT_TAG && \
git pull origin $BUILDROOT_TAG
make BR2_EXTERNAL="/buildroot" $BUILDROOT_DEFCONFIG
make
cp /opt/buildroot/output/images/sdcard.img /tmp/output

Useful buildroot commands

Configure buildroot:

make menuconfig

Save buildroot config to buildroot_ec2/configs/ec2_defconfig:

make savedefconfig

Use a different kernel config:

cp ~/nixos-4.14.32.config output/build/linux-4.16.13/.config

Configure Linux kernel

make linux-menuconfig

Save to .config, then save the kernel config back to buildroot_ec2/board/ec2/linux.config:

make linux-savedefconfig

See the available buildroot configs

make list-defconfigs