The Yocto Project on Raspberry Pi 5 Episode 7: Create a New Layer, a New Recipe (.bb) and .bbappend

This is episode 7 of our series on the Yocto Project and OpenEmbedded for Raspberry Pi 5, where we will discuss how to create a new layer, how to create a new recipe and how to extend an existing recipe using .bbappend file. All examples are based on the Yocto LTS release Scarthgap.

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 enter the layer created on the previous step:

cd meta-leon

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

mkdir -p recipes-apps/hello/

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

DESCRIPTION = "Hello World"
HOMEPAGE = "https://github.com/leon-anavi/hello-w..."
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 file recipes-core/images/core-image-base.bbappend and add in it the following line to install the hello recipe from layer meta-leon to core-image-base:

IMAGE_INSTALL:append = " hello"

Go back to the terminal where the build environment has been initialized and build the new image:

bitbake core-image-base

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

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

🔗 Related Videos
===
Episode 1: The Yocto Project on Raspberry Pi 5: Building an Embedded GNU Linux Distribution
   • The Yocto Project on Raspberry Pi 5 E...  
Episode 2: SSH for Remote Network Access
   • The Yocto Project on Raspberry Pi 5 E...  
Episode 3: Running Docker Containers
   • The Yocto Project on Raspberry Pi 5 E...  
Episode 4: U-Boot Bootloader
   • The Yocto Project on Raspberry Pi 5 E...  
Episode 5: Modifying U-Boot Environment in Linux with fw_setenv
   • The Yocto Project on Raspberry Pi 5 E...  
Episode 6: Runtime Package Management with apt and deb Packages
   • The Yocto Project on Raspberry Pi 5 E...  

📚 Useful Links
===
https://www.yoctoproject.org/
https://docs.yoctoproject.org/
https://www.openembedded.org/wiki/Mai...