%poky; ] > This chapter provides procedures related to getting set up to use the Yocto Project. For a more front-to-end process that takes you from minimally preparing a build host through building an image, see the Yocto Project Quick Start.

This section provides procedures to set up your development host to use the Yocto Project. For a Linux system to use the Yocto Project, you need to be sure you are running a supported Linux distribution and have the proper host packages installed. If you are using CROPS that leverages Docker Containers, host setup differs from that of a native Linux machine.

Need text - Following is some basics for a Linux host system. This information needs to be worked in. Setup consists of making sure you have a supported operating system, installing host packages, and Here is what you need to use the Yocto Project: Host System: You should have a reasonably current Linux-based host system. You will have the best results with a recent release of Fedora, openSUSE, Debian, Ubuntu, or CentOS as these releases are frequently tested against the Yocto Project and officially supported. For a list of the distributions under validation and their status, see the "Supported Linux Distributions" section in the Yocto Project Reference Manual and the wiki page at Distribution Support. You should also have about 50 Gbytes of free disk space for building images. Packages: The OpenEmbedded build system requires that certain packages exist on your development system (e.g. Python 2.7). See the "Build Host Packages" section in the Yocto Project Quick Start and the "Required Packages for the Host Development System" section in the Yocto Project Reference Manual for the exact package requirements and the installation commands to install them for the supported distributions.

Need text. With CROPS, not sure what the basic package requirements are. Need to find this out.

This section describes how to set up a layer for a Board Support Package (BSP). For structural information on BSPs, see the Yocto Project Board Support Package (BSP) Developer's Guide. Determine the BSP Layer You Want: The Yocto Project supports many BSPs, which are maintained in their own layers or in layers designed to contain several BSPs. To get an idea of machine support through BSP layers, you can look at the index of machines for the release. The Yocto Project uses the following BSP layer naming scheme: meta-bsp_name where bsp_name is the recognized BSP name. Here is an example: meta-raspberrypi See the "BSP Layers" section in the Yocto Project Board Support Package (BSP) Developer's Guide for more information on BSP Layers. Optionally Set Up the meta-intel BSP Layer: If your hardware is based on current Intel CPUs and devices, you can leverage this BSP layer. For details on the meta-intel BSP layer, see the layer's README file. Navigate to Your Source Directory: Typically, you set up the meta-intel Git repository inside the Source Directory (e.g. poky). Clone the Layer: $ git clone git://git.yoctoproject.org/meta-intel.git Cloning into 'meta-intel'... remote: Counting objects: 14224, done. remote: Compressing objects: 100% (4591/4591), done. remote: Total 14224 (delta 8245), reused 13985 (delta 8006) Receiving objects: 100% (14224/14224), 4.29 MiB | 2.90 MiB/s, done. Resolving deltas: 100% (8245/8245), done. Checking connectivity... done. Check Out the Proper Branch: The branch you check out for meta-intel must match the same branch you are using for the Yocto Project release (e.g. &DISTRO_NAME_NO_CAP;): $ git checkout branch_name For an example on how to discover branch names and checkout on a branch, see the "Checking Out By Branch in Poky" section. Optionally Set Up an Alternative BSP Layer: If your hardware can be more closely leveraged to an existing BSP not within the meta-intel BSP layer, you can clone that BSP layer. The process is identical to the process used for the meta-intel layer except for the layer's name. For example, if you determine that your hardware most closely matches the meta-minnow, clone that layer: $ git clone git://git.yoctoproject.org/meta-minnow Cloning into 'meta-minnow'... remote: Counting objects: 456, done. remote: Compressing objects: 100% (283/283), done. remote: Total 456 (delta 163), reused 384 (delta 91) Receiving objects: 100% (456/456), 96.74 KiB | 0 bytes/s, done. Resolving deltas: 100% (163/163), done. Checking connectivity... done.

Kernel development is best accomplished using the devtool tool and not through traditional kernel workflow methods. This section provides procedures for both.

Need the updated wiki stuff here

For traditional kernel development using the Yocto Project, you need to establish local copies of the kernel source. You can find Git repositories of supported Yocto Project kernels organized under "Yocto Linux Kernel" in the Yocto Project Source Repositories at . This setup can involve creating a bare clone of the Yocto Project kernel and then copying that cloned repository. You can create the bare clone and the copy of the bare clone anywhere you like. For simplicity, it is recommended that you create these structures outside of the Source Directory, which is usually named poky. The following steps show how to create a bare clone of the linux-yocto-4.4 kernel and then create a copy of that clone: When you have a local Yocto Project kernel Git repository, you can reference that repository rather than the upstream Git repository as part of the clone command. Doing so can speed up the process. Create the Bare Clone: In the following example, the bare clone is named linux-yocto-4.4.git: $ git clone ‐‐bare git://git.yoctoproject.org/linux-yocto-4.4 linux-yocto-4.4.git Cloning into bare repository 'linux-yocto-4.4.git'... remote: Counting objects: 4543903, done. remote: Compressing objects: 100% (695618/695618), done. remote: Total 4543903 (delta 3818435), reused 4541724 (delta 3816256) Receiving objects: 100% (4543903/4543903), 801.08 MiB | 6.55 MiB/s, done. Resolving deltas: 100% (3818435/3818435), done. Checking connectivity... done. Create the Copy of the Bare Clone: In the following command, the copy of the bare clone is named my-linux-yocto-4.4-work: $ git clone linux-yocto-4.4.git my-linux-yocto-4.4-work Cloning into 'my-linux-yocto-4.4-work'... done. Checking out files: 100% (52221/52221), done. Cloning the meta-yocto-kernel-extras Repository: The meta-yocto-kernel-extras Git repository contains Metadata needed only if you are modifying and building the kernel image. In particular, it contains the kernel BitBake append (.bbappend) files that you edit to point to your locally modified kernel source files and to build the kernel image. Pointing to these local files is much more efficient than requiring a download of the kernel's source files from upstream each time you make changes to the kernel. You can find the meta-yocto-kernel-extras Git Repository in the "Yocto Metadata Layers" area of the Yocto Project Source Repositories at . It is good practice to create this Git repository inside the Source Directory. Following is an example that creates the meta-yocto-kernel-extras Git repository inside the Source Directory, which is named poky, in this case: $ cd ~/poky $ git clone git://git.yoctoproject.org/meta-yocto-kernel-extras meta-yocto-kernel-extras Cloning into 'meta-yocto-kernel-extras'... remote: Counting objects: 727, done. remote: Compressing objects: 100% (452/452), done. remote: Total 727 (delta 260), reused 719 (delta 252) Receiving objects: 100% (727/727), 536.36 KiB | 0 bytes/s, done. Resolving deltas: 100% (260/260), done. Checking connectivity... done.

This section presents the steps needed to set up your host if you are going to be using the popular Eclipse IDE. The steps in this procedure are links to sections in the Yocto Project Software Development Kit (SDK) Developer's Guide that provide detailed procedures given the Neon version of Eclipse. For procedures on the entire development process using Eclipse, see the "Developing Applications Using Eclipse" section in the Yocto Project Software Development Kit (SDK) Developer's Guide. Install Eclipse: See the "Installing the Neon Eclipse IDE" section. Configure Eclipse: See the "Configuring the Neon Eclipse IDE" section. Configure Eclipse: See the "Installing or Accessing the Neon Eclipse Yocto Plug-in" section. Configure Eclipse: See the "Configuring the Neon Eclipse Yocto Plug-in" section.

This section contains procedures related to locating and securing Yocto Project files. You establish and use these local files to work on projects. For concepts and introductory information about Git as it is used in the Yocto Project, see the "Git" section in the Yocto Project Reference Manual. For concepts on Yocto Project source repositories, see the "Yocto Project Source Repositories" section in the Yocto Project Reference Manual."

Yocto Project maintains upstream Git Source Repositories that you can examine and access using a browser-based UI: Open a browser and go to to access the GUI-based interface into the Yocto Project source repositories. Click on any repository in which you are interested (e.g. poky). At the bottom of the page, note the URL used to clone that repository (e.g. &YOCTO_GIT_URL;/poky). At the top of the page, click on any branch in which you might be interested (e.g. &DISTRO_NAME_NO_CAP;). You can then view the commit log or tree view for that development branch.

Yocto Project maintains an Index of Releases area that contains related files that contribute to the Yocto Project. Rather than Git repositories, these files represent snapshot tarballs. The recommended method for accessing Yocto Project components is to use Git to clone a repository and work from within that local repository. The procedure in this section exists should you desire a tarball snapshot of any given component. Open a browser and go to to access the Index of Releases. The list represents released components (e.g. eclipse-plugin, sato, and so on). The yocto directory contains the full array of released Poky tarballs. The poky directory in the Index of Releases was historically used for very early releases and exists for retroactive completeness only. Click on any released component in which you are interested (e.g. yocto). Drill down to find the associated tarball. For example, click on yocto-2.3 to view files associated with the Yocto Project 2.3 release (e.g. poky-pyro-17.0.0tar.bz2, which is the released Poky tarball). Click a tarball to download and save a snapshot of a given component.

The Yocto Project Website uses a "Downloads" area from which you can locate and download tarballs of any Yocto Project release. Rather than Git repositories, these files represent snapshot tarballs. The recommended method for accessing Yocto Project components is to use Git to clone a repository and work from within that local repository. The procedure in this section exists should you desire a tarball snapshot of any given component. Open The Yocto Project Website in your browser. Click the "Downloads" tab. Click the type of files you want (i.e "Build System", "Tools", or "Board Support Packages (BSPs)". Locate the release. Click the download link to get your files.

To use the Yocto Project, you need a release of the Yocto Project locally installed on your development system. The locally installed set of files is referred to as the Source Directory in the Yocto Project documentation. You create your Source Directory by using Git to clone a local copy of the upstream poky repository. The preferred method of getting the Yocto Project Source Directory set up is to clone the repository. Working from a copy of the upstream repository allows you to contribute back into the Yocto Project or simply work with the latest software on a development branch. Because Git maintains and creates an upstream repository with a complete history of changes and you are working with a local clone of that repository, you have access to all the Yocto Project development branches and tag names used in the upstream repository. Follow these steps to create a local version of the upstream poky Git repository. Set Your Directory: Be in the directory where you want to create your local copy of poky. Clone the Repository: The following command clones the repository and uses the default name "poky" for your local repository: $ git clone git://git.yoctoproject.org/poky Cloning into 'poky'... remote: Counting objects: 367178, done. remote: Compressing objects: 100% (88161/88161), done. remote: Total 367178 (delta 272761), reused 366942 (delta 272525) Receiving objects: 100% (367178/367178), 133.26 MiB | 6.40 MiB/s, done. Resolving deltas: 100% (272761/272761), done. Checking connectivity... done. Once the repository is created, you can change to that directory and check its status and list its branches: $ cd ~/poky $ git status On branch master Your branch is up-to-date with 'origin/master'. nothing to commit, working directory clean $ git branch * master Your local repository of poky is identical to the upstream poky repository at the time from which it was cloned. By default, Git creates the "master" branch and checks it out.

When you clone the upstream poky repository, you have access to all its development branches. Each development branch in a repository is unique as it forks off the repositories "master" branch. To see and use the files of any branch locally, you need to know the branch name and then checkout the branch. Switch to the Poky Directory: If you have a local poky Git repository, switch to that directory. If you do not have the local copy of poky, see the "Cloning the poky Repository" section. Determine Existing Branch Names: $ git branch -a * master remotes/origin/1.1_M1 remotes/origin/1.1_M2 remotes/origin/1.1_M3 remotes/origin/1.1_M4 remotes/origin/1.2_M1 remotes/origin/1.2_M2 remotes/origin/1.2_M3 . . . remotes/origin/master-next remotes/origin/master-next2 remotes/origin/morty remotes/origin/pinky remotes/origin/purple remotes/origin/pyro Checkout the Branch: Checkout the branch in which you want to work. For example, to access the files for the Yocto Project 2.3 Release (Pyro), use the following command: $ git checkout -b pyro origin/pyro Branch pyro set up to track remote branch pyro from origin. Switched to a new branch 'pyro' The previous command checks out the "pyro" branch and reports that the branch is tracking the upstream "origin/pyro" branch. The following command displays the branches that are now part of your local poky repository. The asterisk character indicates the branch that is currently checked out for work: $ git branch master * pyro

Similar to branches, the upstream repository has tags used to mark significant commits such as a completed release or stage of a release. You might want to set up a local branch based on one of those points in the repository. The process is similar to checking out by branch name except you use tag names. Switch to the Poky Directory: If you have a local poky Git repository, switch to that directory. If you do not have the local copy of poky, see the "Cloning the poky Repository" section. Fetch the Tag Names: To checkout the branch based on a tag name, you need to fetch the upstream tags into your local repository: $ git fetch --tags $ List the Tag Names: You can list the tag names now: $ git tag 1.1_M1.final 1.1_M1.rc1 1.1_M1.rc2 1.1_M2.final 1.1_M2.rc1 . . . yocto-2.2 yocto-2.2.1 yocto-2.3 yocto_1.5_M5.rc8 Checkout the Branch: $ git checkout tags/2.2_M2 -b my_yocto_2.2_M2 Switched to a new branch 'my_yocto_2.2_M2' $ git branch master * my_yocto_2.2_M2 The previous command creates and checks out a local branch named "my_yocto_2.2_M2", which is based on the commit in the upstream poky repository that has the same tag. The files you have available locally when you are checked out to that branch are a snapshot of the "morty" development branch at the point where milestone two was reached.

The build process creates an entire Linux distribution, including the toolchain, from source. For more information on this topic, see the "Building Images" section in the Yocto Project Quick Start. Following are the high-level steps for performing a simple build using the Yocto Project: Set Up Your Source Directories: Make sure you have set up the Source Directory described in the "Cloning the poky Repository" section. Initialize the Build Environment: Initialize the build environment by sourcing a build environment script (i.e. &OE_INIT_FILE; or oe-init-build-env-memres). Make Sure Your local.conf File is Correct: Ensure the conf/local.conf configuration file, which is found in the Build Directory, is set up how you want it. This file defines many aspects of the build environment including the target machine architecture through the MACHINE variable, the packaging format used during the build (PACKAGE_CLASSES), and a centralized tarball download directory through the DL_DIR variable. Build the Image: Build the image using the bitbake command. For example, the following command builds the core-image-minimal image: $ bitbake core-image-minimal For information on BitBake, see the BitBake User Manual.

Another option you have to get started is to use pre-built binaries. The Yocto Project provides many types of binaries with each release. See the "Images" chapter in the Yocto Project Reference Manual for descriptions of the types of binaries that ship with a Yocto Project release. Using a pre-built binary is ideal for developing software applications to run on your target hardware. To do this, you need to be able to access the appropriate cross-toolchain tarball for the architecture on which you are developing. If you are using an SDK type image, the image ships with the complete toolchain native to the architecture (i.e. a toolchain designed to run on the SDKMACHINE). If you are not using an SDK type image, you need to separately download and install the stand-alone Yocto Project cross-toolchain tarball. See the "Obtaining the SDK" appendix in the Yocto Project Software Development Kit (SDK) Developer's Guide for more information on locating and installing cross-toolchains. Regardless of the type of image you are using, you need to download the pre-built kernel that you will boot in the QEMU emulator and then download and extract the target root filesystem for your target machine’s architecture. You can get architecture-specific binaries and file systems from machines. You can get installation scripts for stand-alone toolchains from toolchains. Once you have all your files, you set up the environment to emulate the hardware by sourcing an environment setup script. Finally, you start the QEMU emulator. You can find details on all these steps in the Yocto Project Software Development Kit (SDK) Developer's Guide. You can learn more about using QEMU with the Yocto Project in the "Using the Quick EMUlator (QEMU)" section. Using QEMU to emulate your hardware can result in speed issues depending on the target and host architecture mix. For example, using the qemux86 image in the emulator on an Intel-based 32-bit (x86) host machine is fast because the target and host architectures match. On the other hand, using the qemuarm image on the same Intel-based host can be slower. But, you still achieve faithful emulation of ARM-specific issues. To speed things up, the QEMU images support using distcc to call a cross-compiler outside the emulated system. If you used runqemu to start QEMU, and the distccd application is present on the host system, any BitBake cross-compiling toolchain available from the build system is automatically used from within QEMU simply by calling distcc. You can accomplish this by defining the cross-compiler variable (e.g. export CC="distcc"). Alternatively, if you are using a suitable SDK image or the appropriate stand-alone toolchain is present, the toolchain is also automatically used. Several mechanisms exist that let you connect to the system running on the QEMU emulator: QEMU provides a framebuffer interface that makes standard consoles available. Generally, headless embedded devices have a serial port. If so, you can configure the operating system of the running image to use that port to run a console. The connection uses standard IP networking. SSH servers exist in some QEMU images. The core-image-sato QEMU image has a Dropbear secure shell (SSH) server that runs with the root password disabled. The core-image-full-cmdline and core-image-lsb QEMU images have OpenSSH instead of Dropbear. Including these SSH servers allow you to use standard ssh and scp commands. The core-image-minimal QEMU image, however, contains no SSH server. You can use a provided, user-space NFS server to boot the QEMU session using a local copy of the root filesystem on the host. In order to make this connection, you must extract a root filesystem tarball by using the runqemu-extract-sdk command. After running the command, you must then point the runqemu script to the extracted directory instead of a root filesystem image file.