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diff --git a/documentation/dev-manual/start.rst b/documentation/dev-manual/start.rst new file mode 100644 index 0000000000..85ec97b9e4 --- /dev/null +++ b/documentation/dev-manual/start.rst @@ -0,0 +1,915 @@ +.. SPDX-License-Identifier: CC-BY-SA-2.0-UK + +*********************************** +Setting Up to Use the Yocto Project +*********************************** + +This chapter provides guidance on how to prepare to use the Yocto +Project. You can learn about creating a team environment to develop +using the Yocto Project, how to set up a :ref:`build +host <dev-manual/start:preparing the build host>`, how to locate +Yocto Project source repositories, and how to create local Git +repositories. + +Creating a Team Development Environment +======================================= + +It might not be immediately clear how you can use the Yocto Project in a +team development environment, or how to scale it for a large team of +developers. You can adapt the Yocto Project to many different use cases +and scenarios; however, this flexibility could cause difficulties if you +are trying to create a working setup that scales effectively. + +To help you understand how to set up this type of environment, this +section presents a procedure that gives you information that can help +you get the results you want. The procedure is high-level and presents +some of the project's most successful experiences, practices, solutions, +and available technologies that have proved to work well in the past; +however, keep in mind, the procedure here is simply a starting point. +You can build off these steps and customize the procedure to fit any +particular working environment and set of practices. + +1. *Determine Who is Going to be Developing:* You first need to + understand who is going to be doing anything related to the Yocto + Project and determine their roles. Making this determination is + essential to completing subsequent steps, which are to get your + equipment together and set up your development environment's + hardware topology. + + The following roles exist: + + - *Application Developer:* This type of developer does application + level work on top of an existing software stack. + + - *Core System Developer:* This type of developer works on the + contents of the operating system image itself. + + - *Build Engineer:* This type of developer manages Autobuilders and + releases. Depending on the specifics of the environment, not all + situations might need a Build Engineer. + + - *Test Engineer:* This type of developer creates and manages + automated tests that are used to ensure all application and core + system development meets desired quality standards. + +2. *Gather the Hardware:* Based on the size and make-up of the team, + get the hardware together. Ideally, any development, build, or test + engineer uses a system that runs a supported Linux distribution. + These systems, in general, should be high performance (e.g. dual, + six-core Xeons with 24 Gbytes of RAM and plenty of disk space). You + can help ensure efficiency by having any machines used for testing + or that run Autobuilders be as high performance as possible. + + .. note:: + + Given sufficient processing power, you might also consider + building Yocto Project development containers to be run under + Docker, which is described later. + +3. *Understand the Hardware Topology of the Environment:* Once you + understand the hardware involved and the make-up of the team, you + can understand the hardware topology of the development environment. + You can get a visual idea of the machines and their roles across the + development environment. + +4. *Use Git as Your Source Control Manager (SCM):* Keeping your + :term:`Metadata` (i.e. recipes, + configuration files, classes, and so forth) and any software you are + developing under the control of an SCM system that is compatible + with the OpenEmbedded build system is advisable. Of all of the SCMs + supported by BitBake, the Yocto Project team strongly recommends using + :ref:`overview-manual/overview-manual-development-environment:git`. + Git is a distributed system + that is easy to back up, allows you to work remotely, and then + connects back to the infrastructure. + + .. note:: + + For information about BitBake, see the + :doc:`bitbake:index`. + + It is relatively easy to set up Git services and create + infrastructure like :yocto_git:`/`, which is based on + server software called ``gitolite`` with ``cgit`` being used to + generate the web interface that lets you view the repositories. The + ``gitolite`` software identifies users using SSH keys and allows + branch-based access controls to repositories that you can control as + little or as much as necessary. + + .. note:: + + The setup of these services is beyond the scope of this manual. + However, sites such as the following exist that describe how to + perform setup: + + - `Gitolite <https://gitolite.com>`__: Information for + ``gitolite``. + + - `Interfaces, frontends, and + tools <https://git.wiki.kernel.org/index.php/Interfaces,_frontends,_and_tools>`__: + Documentation on how to create interfaces and frontends for + Git. + +5. *Set up the Application Development Machines:* As mentioned earlier, + application developers are creating applications on top of existing + software stacks. Following are some best practices for setting up + machines used for application development: + + - Use a pre-built toolchain that contains the software stack + itself. Then, develop the application code on top of the stack. + This method works well for small numbers of relatively isolated + applications. + + - Keep your cross-development toolchains updated. You can do this + through provisioning either as new toolchain downloads or as + updates through a package update mechanism using ``opkg`` to + provide updates to an existing toolchain. The exact mechanics of + how and when to do this depend on local policy. + + - Use multiple toolchains installed locally into different + locations to allow development across versions. + +6. *Set up the Core Development Machines:* As mentioned earlier, core + developers work on the contents of the operating system itself. + Following are some best practices for setting up machines used for + developing images: + + - Have the :term:`OpenEmbedded Build System` available on + the developer workstations so developers can run their own builds + and directly rebuild the software stack. + + - Keep the core system unchanged as much as possible and do your + work in layers on top of the core system. Doing so gives you a + greater level of portability when upgrading to new versions of + the core system or Board Support Packages (BSPs). + + - Share layers amongst the developers of a particular project and + contain the policy configuration that defines the project. + +7. *Set up an Autobuilder:* Autobuilders are often the core of the + development environment. It is here that changes from individual + developers are brought together and centrally tested. Based on this + automated build and test environment, subsequent decisions about + releases can be made. Autobuilders also allow for "continuous + integration" style testing of software components and regression + identification and tracking. + + See ":yocto_ab:`Yocto Project Autobuilder <>`" for more + information and links to buildbot. The Yocto Project team has found + this implementation works well in this role. A public example of + this is the Yocto Project Autobuilders, which the Yocto Project team + uses to test the overall health of the project. + + The features of this system are: + + - Highlights when commits break the build. + + - Populates an :ref:`sstate + cache <overview-manual/overview-manual-concepts:shared state cache>` from which + developers can pull rather than requiring local builds. + + - Allows commit hook triggers, which trigger builds when commits + are made. + + - Allows triggering of automated image booting and testing under + the QuickEMUlator (QEMU). + + - Supports incremental build testing and from-scratch builds. + + - Shares output that allows developer testing and historical + regression investigation. + + - Creates output that can be used for releases. + + - Allows scheduling of builds so that resources can be used + efficiently. + +8. *Set up Test Machines:* Use a small number of shared, high + performance systems for testing purposes. Developers can use these + systems for wider, more extensive testing while they continue to + develop locally using their primary development system. + +9. *Document Policies and Change Flow:* The Yocto Project uses a + hierarchical structure and a pull model. Scripts exist to create and + send pull requests (i.e. ``create-pull-request`` and + ``send-pull-request``). This model is in line with other open source + projects where maintainers are responsible for specific areas of the + project and a single maintainer handles the final "top-of-tree" + merges. + + .. note:: + + You can also use a more collective push model. The ``gitolite`` + software supports both the push and pull models quite easily. + + As with any development environment, it is important to document the + policy used as well as any main project guidelines so they are + understood by everyone. It is also a good idea to have + well-structured commit messages, which are usually a part of a + project's guidelines. Good commit messages are essential when + looking back in time and trying to understand why changes were made. + + If you discover that changes are needed to the core layer of the + project, it is worth sharing those with the community as soon as + possible. Chances are if you have discovered the need for changes, + someone else in the community needs them also. + +10. *Development Environment Summary:* Aside from the previous steps, + some best practices exist within the Yocto Project development + environment. Consider the following: + + - Use :ref:`overview-manual/overview-manual-development-environment:git` as the source control + system. + + - Maintain your Metadata in layers that make sense for your + situation. See the ":ref:`overview-manual/overview-manual-yp-intro:the yocto project layer model`" + section in the Yocto Project Overview and Concepts Manual and the + ":ref:`dev-manual/common-tasks:understanding and creating layers`" + section for more information on layers. + + - Separate the project's Metadata and code by using separate Git + repositories. See the ":ref:`overview-manual/overview-manual-development-environment:yocto project source repositories`" + section in the Yocto Project Overview and Concepts Manual for + information on these repositories. See the "`Locating Yocto + Project Source Files <#locating-yocto-project-source-files>`__" + section for information on how to set up local Git repositories + for related upstream Yocto Project Git repositories. + + - Set up the directory for the shared state cache + (:term:`SSTATE_DIR`) where + it makes sense. For example, set up the sstate cache on a system + used by developers in the same organization and share the same + source directories on their machines. + + - Set up an Autobuilder and have it populate the sstate cache and + source directories. + + - The Yocto Project community encourages you to send patches to the + project to fix bugs or add features. If you do submit patches, + follow the project commit guidelines for writing good commit + messages. See the + ":ref:`dev-manual/common-tasks:submitting a change to the yocto project`" + section. + + - Send changes to the core sooner than later as others are likely + to run into the same issues. For some guidance on mailing lists + to use, see the list in the + ":ref:`dev-manual/common-tasks:submitting a change to the yocto project`" + section. For a description + of the available mailing lists, see the ":ref:`resources-mailinglist`" section in + the Yocto Project Reference Manual. + +Preparing the Build Host +======================== + +This section provides procedures to set up a system to be used as your +:term:`Build Host` for +development using the Yocto Project. Your build host can be a native +Linux machine (recommended), it can be a machine (Linux, Mac, or +Windows) that uses `CROPS <https://github.com/crops/poky-container>`__, +which leverages `Docker Containers <https://www.docker.com/>`__ or it +can be a Windows machine capable of running Windows Subsystem For Linux +v2 (WSL). + +.. note:: + + The Yocto Project is not compatible with + `Windows Subsystem for Linux v1 <https://en.wikipedia.org/wiki/Windows_Subsystem_for_Linux>`__. + It is compatible but not officially supported nor validated with + WSLv2. If you still decide to use WSL please upgrade to + `WSLv2 <https://docs.microsoft.com/en-us/windows/wsl/install-win10>`__. + +Once your build host is set up to use the Yocto Project, further steps +are necessary depending on what you want to accomplish. See the +following references for information on how to prepare for Board Support +Package (BSP) development and kernel development: + +- *BSP Development:* See the ":ref:`bsp-guide/bsp:preparing your build host to work with bsp layers`" + section in the Yocto Project Board Support Package (BSP) Developer's + Guide. + +- *Kernel Development:* See the ":ref:`kernel-dev/kernel-dev-common:preparing the build host to work on the kernel`" + section in the Yocto Project Linux Kernel Development Manual. + +Setting Up a Native Linux Host +------------------------------ + +Follow these steps to prepare a native Linux machine as your Yocto +Project Build Host: + +1. *Use a Supported Linux Distribution:* 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, RHEL 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 ":ref:`Supported Linux + Distributions <detailed-supported-distros>`" + section in the Yocto Project Reference Manual and the wiki page at + :yocto_wiki:`Distribution Support </Distribution_Support>`. + +2. *Have Enough Free Memory:* Your system should have at least 50 Gbytes + of free disk space for building images. + +3. *Meet Minimal Version Requirements:* The OpenEmbedded build system + should be able to run on any modern distribution that has the + following versions for Git, tar, Python and gcc. + + - Git 1.8.3.1 or greater + + - tar 1.28 or greater + + - Python 3.5.0 or greater. + + - gcc 5.0 or greater. + + If your build host 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 Yocto Project. See the + ":ref:`ref-manual/ref-system-requirements:required git, tar, python and gcc versions`" + section in the Yocto Project Reference Manual for information. + +4. *Install Development Host Packages:* Required development host + packages vary depending on your build host and what you want to do + with the Yocto Project. Collectively, the number of required packages + is large if you want to be able to cover all cases. + + For lists of required packages for all scenarios, see the + ":ref:`ref-manual/ref-system-requirements:required packages for the build host`" + section in the Yocto Project Reference Manual. + +Once you have completed the previous steps, you are ready to continue +using a given development path on your native Linux machine. If you are +going to use BitBake, see the +":ref:`dev-manual/start:cloning the \`\`poky\`\` repository`" +section. If you are going +to use the Extensible SDK, see the ":doc:`/sdk-manual/sdk-extensible`" Chapter in the Yocto +Project Application Development and the Extensible Software Development +Kit (eSDK) manual. If you want to work on the kernel, see the :doc:`/kernel-dev/index`. If you are going to use +Toaster, see the ":doc:`/toaster-manual/setup-and-use`" +section in the Toaster User Manual. + +Setting Up to Use CROss PlatformS (CROPS) +----------------------------------------- + +With `CROPS <https://github.com/crops/poky-container>`__, which +leverages `Docker Containers <https://www.docker.com/>`__, you can +create a Yocto Project development environment that is operating system +agnostic. You can set up a container in which you can develop using the +Yocto Project on a Windows, Mac, or Linux machine. + +Follow these general steps to prepare a Windows, Mac, or Linux machine +as your Yocto Project build host: + +1. *Determine What Your Build Host Needs:* + `Docker <https://www.docker.com/what-docker>`__ is a software + container platform that you need to install on the build host. + Depending on your build host, you might have to install different + software to support Docker containers. Go to the Docker installation + page and read about the platform requirements in "`Supported + Platforms <https://docs.docker.com/engine/install/#supported-platforms>`__" + your build host needs to run containers. + +2. *Choose What To Install:* Depending on whether or not your build host + meets system requirements, you need to install "Docker CE Stable" or + the "Docker Toolbox". Most situations call for Docker CE. However, if + you have a build host that does not meet requirements (e.g. + Pre-Windows 10 or Windows 10 "Home" version), you must install Docker + Toolbox instead. + +3. *Go to the Install Site for Your Platform:* Click the link for the + Docker edition associated with your build host's native software. For + example, if your build host is running Microsoft Windows Version 10 + and you want the Docker CE Stable edition, click that link under + "Supported Platforms". + +4. *Install the Software:* Once you have understood all the + pre-requisites, you can download and install the appropriate + software. Follow the instructions for your specific machine and the + type of the software you need to install: + + - Install `Docker CE for + Windows <https://docs.docker.com/docker-for-windows/install/#install-docker-desktop-on-windows>`__ + for Windows build hosts that meet requirements. + + - Install `Docker CE for + MacOs <https://docs.docker.com/docker-for-mac/install/#install-and-run-docker-desktop-on-mac>`__ + for Mac build hosts that meet requirements. + + - Install `Docker Toolbox for + Windows <https://docs.docker.com/toolbox/toolbox_install_windows/>`__ + for Windows build hosts that do not meet Docker requirements. + + - Install `Docker Toolbox for + MacOS <https://docs.docker.com/toolbox/toolbox_install_mac/>`__ + for Mac build hosts that do not meet Docker requirements. + + - Install `Docker CE for + CentOS <https://docs.docker.com/install/linux/docker-ce/centos/>`__ + for Linux build hosts running the CentOS distribution. + + - Install `Docker CE for + Debian <https://docs.docker.com/install/linux/docker-ce/debian/>`__ + for Linux build hosts running the Debian distribution. + + - Install `Docker CE for + Fedora <https://docs.docker.com/install/linux/docker-ce/fedora/>`__ + for Linux build hosts running the Fedora distribution. + + - Install `Docker CE for + Ubuntu <https://docs.docker.com/install/linux/docker-ce/ubuntu/>`__ + for Linux build hosts running the Ubuntu distribution. + +5. *Optionally Orient Yourself With Docker:* If you are unfamiliar with + Docker and the container concept, you can learn more here - + https://docs.docker.com/get-started/. + +6. *Launch Docker or Docker Toolbox:* You should be able to launch + Docker or the Docker Toolbox and have a terminal shell on your + development host. + +7. *Set Up the Containers to Use the Yocto Project:* Go to + https://github.com/crops/docker-win-mac-docs/wiki and follow + the directions for your particular build host (i.e. Linux, Mac, or + Windows). + + Once you complete the setup instructions for your machine, you have + the Poky, Extensible SDK, and Toaster containers available. You can + click those links from the page and learn more about using each of + those containers. + +Once you have a container set up, everything is in place to develop just +as if you were running on a native Linux machine. If you are going to +use the Poky container, see the +":ref:`dev-manual/start:cloning the \`\`poky\`\` repository`" +section. If you are going to use the Extensible SDK container, see the +":doc:`/sdk-manual/sdk-extensible`" Chapter in the Yocto +Project Application Development and the Extensible Software Development +Kit (eSDK) manual. If you are going to use the Toaster container, see +the ":doc:`/toaster-manual/setup-and-use`" +section in the Toaster User Manual. + +Setting Up to Use Windows Subsystem For Linux (WSLv2) +----------------------------------------------------- + +With `Windows Subsystem for Linux +(WSLv2) <https://docs.microsoft.com/en-us/windows/wsl/wsl2-about>`__, +you can create a Yocto Project development environment that allows you +to build on Windows. You can set up a Linux distribution inside Windows +in which you can develop using the Yocto Project. + +Follow these general steps to prepare a Windows machine using WSLv2 as +your Yocto Project build host: + +1. *Make sure your Windows 10 machine is capable of running WSLv2:* + WSLv2 is only available for Windows 10 builds > 18917. To check which + build version you are running, you may open a command prompt on + Windows and execute the command "ver". + :: + + C:\Users\myuser> ver + + Microsoft Windows [Version 10.0.19041.153] + + If your build is capable of running + WSLv2 you may continue, for more information on this subject or + instructions on how to upgrade to WSLv2 visit `Windows 10 + WSLv2 <https://docs.microsoft.com/en-us/windows/wsl/wsl2-install>`__ + +2. *Install the Linux distribution of your choice inside Windows 10:* + Once you know your version of Windows 10 supports WSLv2, you can + install the distribution of your choice from the Microsoft Store. + Open the Microsoft Store and search for Linux. While there are + several Linux distributions available, the assumption is that your + pick will be one of the distributions supported by the Yocto Project + as stated on the instructions for using a native Linux host. After + making your selection, simply click "Get" to download and install the + distribution. + +3. *Check your Linux distribution is using WSLv2:* Open a Windows + PowerShell and run: + :: + + C:\WINDOWS\system32> wsl -l -v + NAME STATE VERSION + *Ubuntu Running 2 + + Note the version column which says the WSL version + being used by your distribution, on compatible systems, this can be + changed back at any point in time. + +4. *Optionally Orient Yourself on WSL:* If you are unfamiliar with WSL, + you can learn more here - + https://docs.microsoft.com/en-us/windows/wsl/wsl2-about. + +5. *Launch your WSL Distibution:* From the Windows start menu simply + launch your WSL distribution just like any other application. + +6. *Optimize your WSLv2 storage often:* Due to the way storage is + handled on WSLv2, the storage space used by the undelying Linux + distribution is not reflected immedately, and since bitbake heavily + uses storage, after several builds, you may be unaware you are + running out of space. WSLv2 uses a VHDX file for storage, this issue + can be easily avoided by manually optimizing this file often, this + can be done in the following way: + + 1. *Find the location of your VHDX file:* First you need to find the + distro app package directory, to achieve this open a Windows + Powershell as Administrator and run: + :: + + C:\WINDOWS\system32> Get-AppxPackage -Name "*Ubuntu*" | Select PackageFamilyName + PackageFamilyName + ----------------- + CanonicalGroupLimited.UbuntuonWindows_79abcdefgh + + + You should now + replace the PackageFamilyName and your user on the following path + to find your VHDX file: + :: + + ls C:\Users\myuser\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79abcdefgh\LocalState\ + Mode LastWriteTime Length Name + -a---- 3/14/2020 9:52 PM 57418973184 ext4.vhdx + + Your VHDX file path is: + ``C:\Users\myuser\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79abcdefgh\LocalState\ext4.vhdx`` + + 2. *Optimize your VHDX file:* Open a Windows Powershell as + Administrator to optimize your VHDX file, shutting down WSL first: + :: + + C:\WINDOWS\system32> wsl --shutdown + C:\WINDOWS\system32> optimize-vhd -Path C:\Users\myuser\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79abcdefgh\LocalState\ext4.vhdx -Mode full + + A progress bar should be shown while optimizing the + VHDX file, and storage should now be reflected correctly on the + Windows Explorer. + +.. note:: + + The current implementation of WSLv2 does not have out-of-the-box + access to external devices such as those connected through a USB + port, but it automatically mounts your ``C:`` drive on ``/mnt/c/`` + (and others), which you can use to share deploy artifacts to be later + flashed on hardware through Windows, but your build directory should + not reside inside this mountpoint. + +Once you have WSLv2 set up, everything is in place to develop just as if +you were running on a native Linux machine. If you are going to use the +Extensible SDK container, see the ":doc:`/sdk-manual/sdk-extensible`" Chapter in the Yocto +Project Application Development and the Extensible Software Development +Kit (eSDK) manual. If you are going to use the Toaster container, see +the ":doc:`/toaster-manual/setup-and-use`" +section in the Toaster User Manual. + +Locating Yocto Project Source Files +=================================== + +This section shows you how to locate, fetch and configure the source +files you'll need to work with the Yocto Project. + +.. note:: + + - For concepts and introductory information about Git as it is used + in the Yocto Project, see the ":ref:`overview-manual/overview-manual-development-environment:git`" + section in the Yocto Project Overview and Concepts Manual. + + - For concepts on Yocto Project source repositories, see the + ":ref:`overview-manual/overview-manual-development-environment:yocto project source repositories`" + section in the Yocto Project Overview and Concepts Manual." + +Accessing Source Repositories +----------------------------- + +Working from a copy of the upstream :ref:`dev-manual/start:accessing source repositories` is the +preferred method for obtaining and using a Yocto Project release. You +can view the Yocto Project Source Repositories at +:yocto_git:`/`. In particular, you can find the ``poky`` +repository at :yocto_git:`/poky`. + +Use the following procedure to locate the latest upstream copy of the +``poky`` Git repository: + +1. *Access Repositories:* Open a browser and go to + :yocto_git:`/` to access the GUI-based interface into the + Yocto Project source repositories. + +2. *Select the Repository:* Click on the repository in which you are + interested (e.g. ``poky``). + +3. *Find the URL Used to Clone the Repository:* At the bottom of the + page, note the URL used to clone that repository + (e.g. :yocto_git:`/poky`). + + .. note:: + + For information on cloning a repository, see the + ":ref:`dev-manual/start:cloning the \`\`poky\`\` repository`" section. + +Accessing Index of Releases +--------------------------- + +Yocto Project maintains an Index of Releases area that contains related +files that contribute to the Yocto Project. Rather than Git +repositories, these files are tarballs that represent snapshots in time +of a given component. + +.. note:: + + The recommended method for accessing Yocto Project components is to + use Git to clone the upstream repository and work from within that + locally cloned repository. The procedure in this section exists + should you desire a tarball snapshot of any given component. + +Follow these steps to locate and download a particular tarball: + +1. *Access the Index of Releases:* Open a browser and go to + :yocto_dl:`Index of Releases </releases>`. The + list represents released components (e.g. ``bitbake``, ``sato``, and + so on). + + .. note:: + + 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 now only for + retroactive completeness. + +2. *Select a Component:* Click on any released component in which you + are interested (e.g. ``yocto``). + +3. *Find the Tarball:* Drill down to find the associated tarball. For + example, click on ``yocto-&DISTRO;`` to view files associated with the + Yocto Project &DISTRO; release (e.g. + ``&YOCTO_POKY;.tar.bz2``, which is the + released Poky tarball). + +4. *Download the Tarball:* Click the tarball to download and save a + snapshot of the given component. + +Using the Downloads Page +------------------------ + +The :yocto_home:`Yocto Project Website <>` uses a "DOWNLOADS" page +from which you can locate and download tarballs of any Yocto Project +release. Rather than Git repositories, these files represent snapshot +tarballs similar to the tarballs located in the Index of Releases +described in the "`Accessing Index of +Releases <#accessing-index-of-releases>`__" section. + +.. note:: + + 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. + +1. *Go to the Yocto Project Website:* Open The + :yocto_home:`Yocto Project Website <>` in your browser. + +2. *Get to the Downloads Area:* Select the "DOWNLOADS" item from the + pull-down "SOFTWARE" tab menu near the top of the page. + +3. *Select a Yocto Project Release:* Use the menu next to "RELEASE" to + display and choose a recent or past supported Yocto Project release + (e.g. &DISTRO_NAME_NO_CAP;, &DISTRO_NAME_NO_CAP_MINUS_ONE;, and so forth). + + .. note:: + + For a "map" of Yocto Project releases to version numbers, see the + :yocto_wiki:`Releases </Releases>` wiki page. + + You can use the "RELEASE ARCHIVE" link to reveal a menu of all Yocto + Project releases. + +4. *Download Tools or Board Support Packages (BSPs):* From the + "DOWNLOADS" page, you can download tools or BSPs as well. Just scroll + down the page and look for what you need. + +Accessing Nightly Builds +------------------------ + +Yocto Project maintains an area for nightly builds that contains tarball +releases at https://autobuilder.yocto.io//pub/nightly/. These builds include Yocto +Project releases ("poky"), toolchains, and builds for supported +machines. + +Should you ever want to access a nightly build of a particular Yocto +Project component, use the following procedure: + +1. *Locate the Index of Nightly Builds:* Open a browser and go to + https://autobuilder.yocto.io//pub/nightly/ to access the Nightly Builds. + +2. *Select a Date:* Click on the date in which you are interested. If + you want the latest builds, use "CURRENT". + +3. *Select a Build:* Choose the area in which you are interested. For + example, if you are looking for the most recent toolchains, select + the "toolchain" link. + +4. *Find the Tarball:* Drill down to find the associated tarball. + +5. *Download the Tarball:* Click the tarball to download and save a + snapshot of the given component. + +Cloning and Checking Out Branches +================================= + +To use the Yocto Project for development, you need a release locally +installed on your development system. This locally installed set of +files is referred to as the :term:`Source Directory` +in the Yocto Project documentation. + +The preferred method of creating your Source Directory is by using +:ref:`overview-manual/overview-manual-development-environment:git` to clone a local copy of the upstream +``poky`` repository. Working from a cloned copy of the upstream +repository allows you to contribute back into the Yocto Project or to +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. + +Cloning the ``poky`` Repository +------------------------------- + +Follow these steps to create a local version of the upstream +:term:`Poky` Git repository. + +1. *Set Your Directory:* Change your working directory to where you want + to create your local copy of ``poky``. + +2. *Clone the Repository:* The following example command clones the + ``poky`` repository and uses the default name "poky" for your local + repository: + :: + + $ git clone git://git.yoctoproject.org/poky + Cloning into 'poky'... + remote: Counting objects: 432160, done. + remote: Compressing objects: 100% (102056/102056), done. + remote: Total 432160 (delta 323116), reused 432037 (delta 323000) + Receiving objects: 100% (432160/432160), 153.81 MiB | 8.54 MiB/s, done. + Resolving deltas: 100% (323116/323116), done. + Checking connectivity... done. + + Unless you + specify a specific development branch or tag name, Git clones the + "master" branch, which results in a snapshot of the latest + development changes for "master". For information on how to check out + a specific development branch or on how to check out a local branch + based on a tag name, see the "`Checking Out By Branch in + Poky <#checking-out-by-branch-in-poky>`__" and `Checking Out By Tag + in Poky <#checkout-out-by-tag-in-poky>`__" sections, respectively. + + Once the local repository is created, you can change to that + directory and check its status. Here, the single "master" branch + exists on your system and by default, it is checked out: + :: + + $ 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. As you + work with the local branch, you can periodically use the + ``git pull --rebase`` command to be sure you are up-to-date + with the upstream branch. + +Checking Out by Branch in Poky +------------------------------ + +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 "master" branch. To see and use the files of a +particular development branch locally, you need to know the branch name +and then specifically check out that development branch. + +.. note:: + + Checking out an active development branch by branch name gives you a + snapshot of that particular branch at the time you check it out. + Further development on top of the branch that occurs after check it + out can occur. + +1. *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 + ":ref:`dev-manual/start:cloning the \`\`poky\`\` repository`" + section. + +2. *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/thud + remotes/origin/thud-next + remotes/origin/warrior + remotes/origin/warrior-next + remotes/origin/zeus + remotes/origin/zeus-next + ... and so on ... + +3. *Check out the Branch:* Check out the development branch in which you + want to work. For example, to access the files for the Yocto Project + &DISTRO; Release (&DISTRO_NAME;), use the following command: + :: + + $ git checkout -b &DISTRO_NAME_NO_CAP; origin/&DISTRO_NAME_NO_CAP; + Branch &DISTRO_NAME_NO_CAP; set up to track remote branch &DISTRO_NAME_NO_CAP; from origin. + Switched to a new branch '&DISTRO_NAME_NO_CAP;' + + The previous command checks out the "&DISTRO_NAME_NO_CAP;" development + branch and reports that the branch is tracking the upstream + "origin/&DISTRO_NAME_NO_CAP;" 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 + * &DISTRO_NAME_NO_CAP; + +Checking Out by Tag in Poky +--------------------------- + +Similar to branches, the upstream repository uses tags to mark specific +commits associated with significant points in a development branch (i.e. +a release point 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. + +.. note:: + + Checking out a branch based on a tag gives you a stable set of files + not affected by development on the branch above the tag. + +1. *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 + ":ref:`dev-manual/start:cloning the \`\`poky\`\` repository`" + section. + +2. *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 + $ + +3. *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-2.5 + yocto-2.5.1 + yocto-2.5.2 + yocto-2.5.3 + yocto-2.6 + yocto-2.6.1 + yocto-2.6.2 + yocto-2.7 + yocto_1.5_M5.rc8 + + +4. *Check out the Branch:* + :: + + $ git checkout tags/yocto-&DISTRO; -b my_yocto_&DISTRO; + Switched to a new branch 'my_yocto_&DISTRO;' + $ git branch + master + * my_yocto_&DISTRO; + + The previous command creates and + checks out a local branch named "my_yocto_&DISTRO;", which is based on + the commit in the upstream poky repository that has the same tag. In + this example, the files you have available locally as a result of the + ``checkout`` command are a snapshot of the "&DISTRO_NAME_NO_CAP;" + development branch at the point where Yocto Project &DISTRO; was + released. |