Building your own recipes from first principles

Overview

This walk-through has the aim of taking you from a clean system through to building and packaging a project for inclusion in an image.

You may already have Yocto installed and just be looking to work with recipes for the first time, in which case you can jump forward to the section you find most relevant.

The following assumptions are made. You are:

• familiar with basic Linux admin tasks
• using Ubuntu 12.04 LTS as your host build system
• working with Yocto 1.6 (daisy) release

Obtain the required packages for your host system to support Yocto

First we will install the required host packages for Ubuntu as detailed in the quickstart, i.e.

 $ sudo apt-get install gawk wget git-core diffstat unzip texinfo gcc-multilib build-essential chrpath libsdl1.2-dev xterm

Full details of system requirements and installation can be found in the Yocto Quickstart here

Download and extract the Yocto 1.6 release

At the time of writing, the current release of Yocto (1.6) can be found here

 $ cd ~
 $ mkdir yocto
 $ wget http://downloads.yoctoproject.org/releases/yocto/yocto-1.6/poky-daisy-11.0.0.tar.bz2
 $ tar xjvf poky-daisy-11.0.0.tar.bz2

This will get you the Yocto 1.6 base meta-data and the bitbake tool. You can also add in extra layers, usually of the form "meta-foo" to provide machine support and additional functionality.

Configure the build environment to build an emulator image

 $ cd ~/yocto/poky-daisy-11.0.0
 $ source oe-init-build-env build_qemux86

This will create a build tree in "build_qemux86" although you could use a different name if you so wish with no adverse effects.

It is entirely possible to have many build trees in parallel in different folders and to switch between them using oe-init-build-env.

[code]oe-init-build-env] will create a default configuration file in [code]conf/local/conf[/code] which will build an emulator image suitable for execution with [code]qemu[/code]

Build a baseline image

After configuring the environment you will be left in the build_qemux86 folder.

You should then build a baseline image, which will take some time (numbers of hours)

 $ bitbake core-image-minimal