The Yocto Project on Raspberry Pi 5: Create a New Layer, a New Recipe (.bb) and .bbappend

In episode 7 of the tutorials about the Yocto Project and OpenEmbedded for Raspberry Pi 5, we will cover how to create a new layer, write a new recipe, and extend an existing recipe using a .bbappend file. All examples are based on the Yocto LTS release, Scarthgap.

Steps:

• Initialize the build environment:

  source oe-init-build-env

• Create a new layer:

  bitbake-layers create-layer ../meta-leon

• Add the new layer to conf/bblayers.conf:

  bitbake-layers add-layer ../meta-leon

• Open another terminal and navigate to the newly created layer:

  cd meta-leon

• Create a directory for the "Hello, World" recipe:

  mkdir -p recipes-apps/hello/

• Create the recipe file recipes-apps/hello/hello_git.bb with the following content:

  DESCRIPTION = "Hello World"
  HOMEPAGE = "https://github.com/leon-anavi/hello-world"
  SECTION = "console/utils"
  LICENSE = "MIT"
  
  LIC_FILES_CHKSUM = "file://LICENSE;md5=f388cad0df1af35e3626518d587c0cb6"
  
  SRC_URI = "git://github.com/leon-anavi/hello-world.git;branch=master;protocol=https"
  SRCREV = "f66f58e7bcdcc834568d8c7c6fc51e30765befad"
  
  S = "${WORKDIR}/git"
  
  inherit autotools

• Create a directory in the layer to extend core-image-base:

  mkdir -p recipes-core/images/

• Create the file recipes-core/images/core-image-base.bbappend and add the following line to install the hello recipe from the meta-leon layer into core-image-base:

  IMAGE_INSTALL:append = " hello"

• Return to the terminal where the build environment was initialized and build the new image:

  bitbake core-image-base

• Flash core-image-base-raspberrypi5.rootfs.wic.bz2 to a microSD card.

• Boot the Raspberry Pi 5 from the microSD card and run hello to verify that the "Hello, World" application has been successfully built and included in the image.