The Yocto Project team is continually verifying more and more Linux distributions with each release. In general, if you have the current release minus one of the following distributions you should have no problems.

For a more detailed list of distributions that support the Yocto Project, see the "Supported Linux Distributions" section in the Yocto Project Reference Manual.

The OpenEmbedded build system should be able to run on any modern distribution that has the following versions for Git, tar, and Python.

Earlier releases of Python are known to not work and the system does not support Python 3 at this time. If your system does not meet any of these three listed version requirements, you can take steps to prepare the system so that you can still use the build system. See the "Required Git, tar, and Python Versions" section in the Yocto Project Reference Manual for information.

This document assumes you are running one of the previously noted distributions on your Linux-based host systems.

Packages and package installation vary depending on your development system and on your intent. For example, if you want to build an image that can run on QEMU in graphical mode (a minimal, basic build requirement), then the number of packages is different than if you want to build an image on a headless system or build out the Yocto Project documentation set. Collectively, the number of required packages is large if you want to be able to cover all cases.

The next few sections list, by supported Linux Distributions, the required packages needed to build an image that runs on QEMU in graphical mode (e.g. essential plus graphics support).

For lists of required packages for other scenarios, see the "Required Packages for the Host Development System" section in the Yocto Project Reference Manual.

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

     $ sudo yum install gawk make wget tar bzip2 gzip python unzip perl patch \
     diffutils diffstat git cpp gcc gcc-c++ glibc-devel texinfo chrpath \
     ccache perl-Data-Dumper perl-Text-ParseWords perl-Thread-Queue SDL-devel xterm
                

     $ sudo zypper install python gcc gcc-c++ git chrpath make wget python-xml \
     diffstat texinfo python-curses patch libSDL-devel xterm
                

     $ sudo yum install gawk make wget tar bzip2 gzip python unzip perl patch \
     diffutils diffstat git cpp gcc gcc-c++ glibc-devel texinfo chrpath SDL-devel xterm
                

It is recommended that you get the latest Yocto Project files by setting up (cloning in Git terms) a local copy of the poky Git repository on your host development system. Doing so allows you to contribute back to the Yocto Project project. For information on how to get set up using this method, see the "Yocto Project Release" item in the Yocto Project Development Manual.

You can also get the Yocto Project Files by downloading Yocto Project releases from the Yocto Project website. From the website, you just click "Downloads" in the navigation pane to the left to display all Yocto Project downloads. Current and archived releases are available for download. Nightly and developmental builds are also maintained at http://autobuilder.yoctoproject.org/nightly/. However, for this document a released version of Yocto Project is used.

In the development environment you will need to build an image whenever you change hardware support, add or change system libraries, or add or change services that have dependencies.

Building an Image

Use the following commands to build your image. The OpenEmbedded build process creates an entire Linux distribution, including the toolchain, from source.

     $ git clone http://git.yoctoproject.org/git/poky
     $ cd poky
     $ git checkout -b daisy origin/daisy
     $ source oe-init-build-env
             

     INHERIT += "rm_work"
                 

Take some time to examine your local.conf file in your project's configuration directory, which is found in the Build Directory. The defaults in that file should work fine. However, there are some variables of interest at which you might look.

By default, the target architecture for the build is qemux86, which produces an image that can be used in the QEMU emulator and is targeted at an Intel® 32-bit based architecture. To change this default, edit the value of the MACHINE variable in the configuration file before launching the build.

Another couple of variables of interest are the BB_NUMBER_THREADS and the PARALLEL_MAKE variables. By default, these variables are set to how ever many processor cores your build host uses. However, if your build host uses multiple processor cores, you should increase these settings to twice the number of cores used. Doing so can significantly shorten your build time.

Another consideration before you build is the package manager used when creating the image. By default, the OpenEmbedded build system uses the RPM package manager. You can control this configuration by using the PACKAGE_CLASSES variable. For additional package manager selection information, see the "package*.bbclass" section in the Yocto Project Reference Manual.

Continue with the following command to build an OS image for the target, which is core-image-sato in this example. For information on the -k option use the bitbake --help command, see the "BitBake" section in the Yocto Project Reference Manual, or see the "BitBake Command" section in the BitBake User Manual.

     $ bitbake -k core-image-sato
             

The final command runs the image:

     $ runqemu qemux86
             

If hardware, libraries and services are stable, you can get started by using a pre-built binary of the filesystem image, kernel, and toolchain and run it using the QEMU emulator. This scenario is useful for developing application software.

Using a Pre-Built Image

For this scenario, you need to do several things:

     poky-eglibc-<host_system>-<image_type>-<arch>-toolchain-<release_version>.sh

     Where:
         <host_system> is a string representing your development system:

                    i686 or x86_64.

         <image_type> is a string representing the image you wish to
                develop a Software Development Toolkit (SDK) for use against.
                The Yocto Project builds toolchain installers using the
                following BitBake command:

                    bitbake core-image-sato -c populate_sdk

         <arch> is a string representing the tuned target architecture:

                    i586, x86_64, powerpc, mips, armv7a or armv5te

         <release_version> is a string representing the release number of the
                Yocto Project:

                    1.6.1, 1.6.1+snapshot
            

     poky-eglibc-x86_64-core-image-sato-i586-toolchain-1.6.1.sh
                

     $ ~/Downloads/poky-eglibc-x86_64-core-image-sato-i586-toolchain-1.6.1.sh
                

     *zImage-qemu<arch>.bin
     vmlinux-qemu<arch>.bin

     Where:
         <arch> is a string representing the target architecture:
                x86, x86-64, ppc, mips, or arm.
                

     core-image-<profile>-qemu<arch>.ext3
     core-image-<profile>-qemu<arch>.tar.bz2

     Where:
         <profile> is the filesystem image's profile:
                   lsb, lsb-dev, lsb-sdk, lsb-qt3, minimal, minimal-dev, sato,
                   sato-dev, or sato-sdk. For information on these types of image
                   profiles, see the "Images" chapter in the Yocto Project
                   Reference Manual.

         <arch> is a string representing the target architecture:
                x86, x86-64, ppc, mips, or arm.
                

     $ source /opt/poky/1.6.1/environment-setup-<arch>-poky-linux-<if>

     Where:
         <arch> is a string representing the target architecture:
                i586, x86_64, ppc603e, mips, or armv5te.

         <if> is a string representing an embedded application binary interface.
              Not all setup scripts include this string.
                

     $ runqemu <qemuarch> <kernel-image> <filesystem-image>

     Where:
         <qemuarch> is a string representing the target architecture: qemux86, qemux86-64,
                    qemuppc, qemumips, or qemuarm.

         <kernel-image> is the architecture-specific kernel image.

         <filesystem-image> is the .ext3 filesystem image.

                

     $ cd $HOME
     $ source /opt/poky/1.6.1/environment-setup-i586-poky-linux
     $ runqemu qemux86 bzImage-qemux86.bin \
     core-image-sato-qemux86.ext3
                

Set up your Source Directory by using Git to clone the poky repository and then check out the release branch:

     $ cd ~
     $ git clone git://git.yoctoproject.org/poky
     $ cd poky
     $ git checkout -b daisy origin/daisy
            

You need some packages for everything to work. Rather than duplicate them here, look at the "The Packages" section earlier in this quick start.

From the root directory of your Source Directory, initialize your environment and provide a meaningful Build Directory name:

     $ source oe-init-build-env mybuilds
            

At this point, the mybuilds directory has been created for you and it is now your current working directory. If you do not provide your own directory name, it defaults to build, which is inside the Source Directory.

Initializing the build environment creates a conf/local.conf configuration file in the Build Directory. You need to manually edit this file to specify the machine you are building and to optimize your build time. Here are the minimal changes to make:

     BB_NUMBER_THREADS = "8"
     PARALLEL_MAKE = "-j 8"
     MACHINE ?= "beaglebone"
            

Briefly, set BB_NUMBER_THREADS and PARALLEL_MAKE to twice your host processor's number of cores.

A good deal that goes into a Yocto Project build is simply downloading all of the source tarballs. Maybe you have been working with another build system (OpenEmbedded or Angstrom) for which you have built up a sizable directory of source tarballs. Or, perhaps someone else has such a directory for which you have read access. If so, you can save time by adding statements to your configuration file so that the build process checks local directories first for existing tarballs before checking the Internet. Here is an efficient way to set it up in your local.conf file:

     SOURCE_MIRROR_URL ?= "file:///home/you/your-download-dir/"
     INHERIT += "own-mirrors"
     BB_GENERATE_MIRROR_TARBALLS = "1"
     # BB_NO_NETWORK = "1"
            

In the previous example, the BB_GENERATE_MIRROR_TARBALLS variable causes the OpenEmbedded build system to generate tarballs of the Git repositories and store them in the DL_DIR directory. Due to performance reasons, generating and storing these tarballs is not the build system's default behavior.

You can also use the PREMIRRORS variable. For an example, see the variable's glossary entry in the Yocto Project Reference Manual.

At this point, you need to select an image to build for the Beaglebone hardware. If this is your first build using the Yocto Project, you should try the smallest and simplest image:

     $ bitbake core-image-minimal
            

Now you just wait for the build to finish.

Here are some variations on the build process that could be helpful:

Once you have your image, you can take steps to load and boot it on the target hardware.

You can learn about BitBake in general by reading the BitBake User Manual.