Docker on Riotboard using Buildroot

Getting buildroot

Buildroot version used: 2019.02.9.

Link: https://buildroot.org/downloads/buildroot-2019.02.9.tar.gz

wget https://buildroot.org/downloads/buildroot-2019.02.9.tar.gz
tar -xzf buildroot-2019.02.9.tar.gz

Buildroot using BR2_EXTERNAL

One note on BR2_EXTERNAL: The path to a br2-external tree can be either absolute or relative. If it is passed as a relative path, it is important to note that it is interpreted relative to the main Buildroot source directory, not to the Buildroot output directory

cd buildroot-2019.02.9/

export BR2_EXTERNAL="../riotboard-docker"
export BR2_JLEVEL=24
export O="../riotboard-docker.build"

make riotboard_docker_defconfig
make menuconfig

Before trying to compile, check that that the following buildroot config options are set:

• BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE which depends on BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG

• BR2_PACKAGE_BUSYBOX_CONFIG

These variables contain the full path to the linux kernel defconfig & busybox config.

The values for these vars should be as following:

• BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="${BR2_EXTERNAL}/board/embest/riotboard/linux.config"

• BR2_PACKAGE_BUSYBOX_CONFIG="${BR2_EXTERNAL}/board/embest/riotboard/busybox.config"

Now you should be ready to build.

Note: You should never use make -jN with Buildroot: top-level parallel make is currently not supported. Instead, use the BR2_JLEVEL option to tell Buildroot to run the compilation of each individual package with make -jN.

make

Buildroot configuration tips

• make linux-update-defconfig saves the linux configuration to the path specified by BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE. It simplifies the config file by removing default values. However, this only works with kernels starting from 2.6.33. For earlier kernels, use make linux-update-config.
• make busybox-update-config saves the busybox configuration to the path specified by BR2_PACKAGE_BUSYBOX_CONFIG.
• make uclibc-update-config saves the uClibc configuration to the path specified by BR2_UCLIBC_CONFIG.
• make barebox-update-defconfig saves the barebox configuration to the path specified by BR2_TARGET_BAREBOX_CUSTOM_CONFIG_FILE.
• make uboot-update-defconfig saves the U-Boot configuration to the path specified by BR2_TARGET_UBOOT_CUSTOM_CONFIG_FILE.

More details in Buildroot documentation, Chapter 9.

After making a change into Buildroot using make menuconfig, you can save the changes into a defconfig file like this:

make savedefconfig BR2_DEFCONFIG=<path to defconfig file>

Or, if you want to always overwrite your board defconfig:

export BR2_DEFCONFIG="${BR2_EXTERNAL}/configs/riotboard_docker_defconfig"
make savedefconfig

Riotboard boot switches

SD card
1   0  1   0   0  1   0  1
ON OFF ON OFF OFF ON OFF ON

microSD card
1   0  1   0   0  1   1  0
ON OFF ON OFF OFF ON OFF ON

OS image

The final built image should be at output/images/sdcard.img. However, it seems that when you change the default of BR2_TARGET_ROOTFS_EXT2_SIZE, the build system breaks the sdcard.img rootfs partition, which leads to a kernel panic. To overcome this issue, you should resize the SD card partition, and flash only rootfs.ext4 to the first partition using dd.

Firewalld rules for build host to act as router

Remember to add --permanent flag to make it persistent (requires --reload afterwards)

eth_ext="ens1"
eth_int="eno1"

sudo firewall-cmd --direct --permanent --add-rule ipv4 nat POSTROUTING 0 -o $eth_ext -j MASQUERADE
sudo firewall-cmd --direct --permanent --add-rule ipv4 filter FORWARD 0 -i $eth_int -o $eth_ext -j ACCEPT
sudo firewall-cmd --direct --permanent --add-rule ipv4 filter FORWARD 0 -i $eth_ext -o $eth_int -m state --state RELATED,ESTABLISHED -j ACCEPT

Fetch home assistant docker

More detailed info here: https://www.home-assistant.io/docs/installation/docker/

# docker-compose.yml:

version: '3'
services:
  homeassistant:
    container_name: home-assistant
    image: homeassistant/home-assistant:stable
    volumes:
      - /PATH_TO_YOUR_CONFIG:/config
    environment:
      - TZ=America/New_York
    restart: always
    network_mode: host
	ports:
	  - 8123:8123

To start and refresh the container:

# start
docker-compose up -d

# reload configuration
docker-compose restart