Docker based development environment for Yocto / OpenSTLinux on STM32MP1

Tested with a STM32MP157C-DK2.

Scripts

• build-docker-image.sh
  • builds a Docker image locally, based on docker/Dockerfile
  • run this once, or when you change the Dockerfile
• start.sh
  • starts the Docker container
  • exit with ctrl+D
    • destroys the container
    • data in directories mounted as volumes (e.g. home, workspace) will be persisted
• clone-layers.sh
  • clones the Yocto layers needed by your project
  • run once inside the Docker container
• init-env
  • initializes the environment variables, so you can issue commands like bitbake etc.
  • source it every time you start the container: source ./init-env
• create-sdcard.sh
  • creates a raw file which can be written to an SD card
• serial.sh
  • connects to the board's serial port (via /dev/ttyACM0)

Directories

• cache
  • contains the locations used as Docker volume targets for the Yocto DL_DIR and SSTATE_DIR variables
  • set them in conf/local.conf:

      DL_DIR = /opt/yocto/cache/downloads
      SSTATE_DIR = /opt/yocto/cache/sstate
  

  • ignored by git
• home
  • Docker volume target for the home directory of the yocto user
  • allows you to add persistence for bash and git configuration, history, ssh keys etc.
  • is ignored by git, so to add something, you need to use git add --force <file>
• conf
  • create this directory to add Yocto config files (build/conf/*.conf) to source control
  • if it exists, init-env adds it to the workspace via symlink
• workspace
  • contains layers downloaded by clone-layers.sh, Yocto artifacts built by bitbake, (a symlink to) the configuration directory etc.
  • ignored by git

Environment Setup

Make sure you have Ubuntu 18.04 or 16.04, other distros may or may not work.

Install Docker (see docs on the Docker site) and make sure you can start containers as non-root user:

docker run --rm hello-world

Optional:

• add the layers your project depends on to clone-layers.sh
  • you'll eventually have to add them to conf/bblayers.conf, too
• check init-env: make sure the right environment init script is sourced
  • see https://wiki.st.com/stm32mpu/wiki/STM32MP1_Distribution_Package

Finally, proceed with the following (as a non-root user):

./build-docker-image.sh
./start.sh
./clone-layers.sh
. ./init-env
# now you can run bitbake

Copy conf from workspace/build to the project's root dir, in order to add local.conf, bblayers.conf etc. to the git repo.

Working with the Docker Environment

./start.sh
. ./init-env
bitbake st-image-core-min

Creating an SD Card Image

./create-sdcard.sh

This creates a file flashlayout_st-image-core-min_FlashLayout_sdcard_stm32mp157c-dk2-basic.raw in workspace/build/tmp-glibc/deploy/images/stm32mp1/scripts. Use dd or (safer) balenaEtcher to write it to an SD card.

Connect to the board via USB, then use serial.sh to watch it boot.