VS Code + DevContainer

Here’s a guide for using Visual Studio Code (VS Code) to develop with Yocto in a containerized environment.

Linux distribution

When using a containerized environment for building yocto, the host does not have to be a Yocto-supported distro.

Requirements

Before you start, make sure you have:

The following instructions assume that you are working in a Linux environment.

Get the repo tool

Download and activate the repo tool:

mkdir ~/bin
curl https://storage.googleapis.com/git-repo-downloads/repo > ~/bin/repo
chmod a+x ~/bin/repo
export PATH=~/bin:$PATH

Get the BSP

First get the BSP for your STM, Renesas module (Mainline BSP) or NXP module (NXP BSP).

The repo tool is used to initialize the BSP folder locally.

BSP

Command

Mainline

 
repo init -u https://github.com/karo-electronics/karo-bsp.git -b <branch>

NXP

 
repo init -u https://github.com/karo-electronics/karo-nxp-bsp.git -b <branch>

Next synchronize the sources with:

repo sync

After this step, the Yocto BSP sources are ready on your machine.

Dev Container setup

  1. Open the BSP root folder with VS Code.

    • Starting from the scarthgap branch, VS Code should directly prompt you to reopen the current directory in a Container. If that is the case, skip to step 4.

  2. Create the folder:

    .devcontainer

  3. Add these files inside .devcontainer:

    • devcontainer.json:

      In devcontainer.json replace the <YOCTO_VERSION> placeholder with the codename of the Yocto version used.

    • Dockerfile:

      In Dockerfile replace the <SUPPORTED_DISTRO> placeholder with a supported Ubuntu Version of the used Yocto version.

Shared Yocto files

This setups uses shared docker volumes for Yocto cache files. For each Yocto release (e.g. mickledore, scarthgap) a different volume needs to be used to avoid cache corruption between versions.

  1. In VS Code reopen the folder in a Container. If not prompted, search for Dev Container: Reopen in Container command using strg + shift + P.

Inside the Dev Container

The container is setup automatically to be able to build Yocto. Furthermore it configures VS Code and the Environment to develop with Yocto more easily. Key aspects include:

  • Supported Linux distribution for building with Yocto

  • Shared Yocto downloads and sstate-cache in docker volume.

  • Yocto Project BitBake VS Code Extension

  • Pre-configured VS Code for Yocto Development

The build directory can be setup using the karo-setup-release.sh script, e.g.:

DISTRO=<DISTRO> MACHINE=<MACHINE> source karo-setup-release.sh

This creates the folder build-karo and instantiates the configuration for the selected DISTRO and MACHINE. Furthermore it activates the build environment, which makes the bitbake tool available.

Now to build a Yocto image, you can use the following command:

bitbake karo-image-minimal

This example requires the karo-minimal DISTRO. For more info on how to use the karo-setup-release.sh, see the quickguides at Getting Started and/or further chapters in the Yocto Guide.

Yocto Project BitBake Extension

The Dev Container comes with the Yocto Project BitBake VS Code Extension preinstalled. It is configured to automatically detect the build folder by the name build-karo. The extension provides a GUI to manage, build and develop recipes.

A devtool workspace can be created to directly edit a recipe’s source and also create patches automatically. For more information on how to use the Yocto Project Extension see Yocto Project BitBake.

  • The Yocto Project extension is configured to use build-karo as the build directory. If needed change it in the extension settings. It is also possible to define multiple build-directories, see official documentation.

  • When creating a new devtool workspace via the Yocto Project extension, skip SDK toolkit configuration for now, as it may cause errors in this setup.

  • If a build fails while using a devtool workspace, try adding the following in the local.conf:

    PACKAGE_DEBUG_SPLIT_STYLE = "debug-without-src"