Building Yocto for Raspberry Pi / Creating Embedded Linux for RPi using Yocto

For proceeding to this post: Setting up ubuntu development machine for Yocto is a prerequisite and make sure you have all those packages installed in ubuntu.

Note: This compilation is done for Yocto 2.6 i.e codenamed “thud” which is last known stable version available for RaspberryPi. Although currently Yocto 2.7 (codename – warrior) is available with Poky but meta-raspberrypi with “warrior” branch is not available.

Now, lets clone the poky and raspberry Pi metadata as,

 $ mkdir workspace

 $ cd workspace

 $ git clone git://git.yoctoproject.org/poky

 $ cd poky

 $ git checkout -b thud origin/thud

 $ cd workspace

 $ git clone git://git.yoctoproject.org/meta-raspberrypi

 $ cd meta-raspberrypi

 $ git checkout -b thud origin/thud

Now, we will have to initialize the environment variables to start compilation for kernel and filesystem as,

 $ cd workspace/poky

 $ source oe-init-build-env

Above command will initialize environment variables and create build directory and will go inside this build directory. The tree structure of the newly created “build” directory is like,

$ tree build/
build/
└── conf
    ├── bblayers.conf
    ├── local.conf
    └── templateconf.cfg

1 directory, 3 files

Now, we need to change bblayers.conf to add the path of meta-raspberrypi layer, hence open this file and append the path of meta-raspberrypi layer like below,

 $ vim conf/bblayers.conf

BBLAYERS ?= " \
  /home/myuser/workspace/poky/meta \
  /home/myuser/workspace/poky \
  /home/myuser/workspace/poky/meta-yocto-bsp \
  /home/myuser/workspace/meta-raspberrypi \
  "

Next, we need to edit “conf/local.conf” to add Raspberry Pi as machine,

$ vim conf/local.conf

and append following string,

 MACHINE = "raspberrypi3"

Now, lets start the compilation which will create the complete binary images required to boot Raspberry Pi,

 $ bitbake core-image-minimal