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diff --git a/import-layers/yocto-poky/documentation/kernel-dev/kernel-dev-intro.xml b/import-layers/yocto-poky/documentation/kernel-dev/kernel-dev-intro.xml new file mode 100644 index 000000000..263e50098 --- /dev/null +++ b/import-layers/yocto-poky/documentation/kernel-dev/kernel-dev-intro.xml @@ -0,0 +1,149 @@ +<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" +"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" +[<!ENTITY % poky SYSTEM "../poky.ent"> %poky; ] > + +<chapter id='kernel-dev-intro'> +<title>Introduction</title> + +<!-- +<para> + <emphasis>AR - Darren Hart:</emphasis> See if the concepts in these + three bullets are adequately covered in somewhere in this manual: + <itemizedlist> + <listitem><para>Do we convey that our kernel Git repositories + have a clear and continuous history, similar to the way the + kernel Git repositories for <filename>kernel.org</filename> + do. + </para></listitem> + <listitem><para>Does the manual note that Yocto Project delivers + a key set of supported kernel types, where + each type is tailored to meet a specific use (e.g. networking, + consumer, devices, and so forth).</para></listitem> + <listitem><para>Do we convey that the Yocto Project uses a + Git branching strategy that, from a + developer's point of view, results in a linear path from the + baseline kernel.org, through a select group of features and + ends with their BSP-specific commits.</para></listitem> + </itemizedlist> +</para> +--> + + <section id='kernel-dev-overview'> + <title>Overview</title> + + <para> + Regardless of how you intend to make use of the Yocto Project, + chances are you will work with the Linux kernel. + This manual provides background information on the Yocto Linux kernel + <ulink url='&YOCTO_DOCS_DEV_URL;#metadata'>Metadata</ulink>, + describes common tasks you can perform using the kernel tools, + and shows you how to use the kernel Metadata needed to work with + the kernel inside the Yocto Project. + </para> + + <para> + Each Yocto Project release has a set of linux-yocto recipes, whose + Git repositories you can view in the Yocto + <ulink url='&YOCTO_GIT_URL;'>Source Repositories</ulink> under + the "Yocto Linux Kernel" heading. + New recipes for the release track the latest upstream developments + and introduce newly-supported platforms. + Previous recipes in the release are refreshed and supported for at + least one additional release. + As they align, these previous releases are updated to include the + latest from the + <ulink url='&YOCTO_HOME_URL;/organization/long-term-support-initiative-ltsi'>Long Term Support Initiative</ulink> + (LTSI) project. + Also included is a linux-yocto development recipe + (<filename>linux-yocto-dev.bb</filename>) should you want to work + with the very latest in upstream Linux kernel development and + kernel Metadata development. + </para> + + <para> + The Yocto Project also provides a powerful set of kernel + tools for managing Linux kernel sources and configuration data. + You can use these tools to make a single configuration change, + apply multiple patches, or work with your own kernel sources. + </para> + + <para> + In particular, the kernel tools allow you to generate configuration + fragments that specify only what you must, and nothing more. + Configuration fragments only need to contain the highest level + visible <filename>CONFIG</filename> options as presented by the Linux + kernel <filename>menuconfig</filename> system. + Contrast this against a complete Linux kernel + <filename>.config</filename>, which includes all the automatically + selected <filename>CONFIG</filename> options. + This efficiency reduces your maintenance effort and allows you + to further separate your configuration in ways that make sense for + your project. + A common split separates policy and hardware. + For example, all your kernels might support + the <filename>proc</filename> and <filename>sys</filename> filesystems, + but only specific boards require sound, USB, or specific drivers. + Specifying these configurations individually allows you to aggregate + them together as needed, but maintains them in only one place. + Similar logic applies to separating source changes. + </para> + + <para> + If you do not maintain your own kernel sources and need to make + only minimal changes to the sources, the released recipes provide a + vetted base upon which to layer your changes. + Doing so allows you to benefit from the continual kernel + integration and testing performed during development of the + Yocto Project. + </para> + + <para> + If, instead, you have a very specific Linux kernel source tree + and are unable to align with one of the official linux-yocto + recipes, an alternative exists by which you can use the Yocto + Project Linux kernel tools with your own kernel sources. + </para> + </section> + + <section id='kernel-dev-other-resources'> + <title>Other Resources</title> + + <para> + The sections that follow provide instructions for completing + specific Linux kernel development tasks. + These instructions assume you are comfortable working with + <ulink url='http://openembedded.org/wiki/Bitbake'>BitBake</ulink> + recipes and basic open-source development tools. + Understanding these concepts will facilitate the process of working + with the kernel recipes. + If you find you need some additional background, please be sure to + review and understand the following documentation: + <itemizedlist> + <listitem><para><ulink url='&YOCTO_DOCS_QS_URL;'>Yocto Project Quick Start</ulink> + </para></listitem> + <listitem><para>The "<ulink url='&YOCTO_DOCS_DEV_URL;#dev-modifying-source-code'>Modifying Source Code</ulink>" + section in the Yocto Project Development Manual + </para></listitem> + <listitem><para>The "<ulink url='&YOCTO_DOCS_DEV_URL;#understanding-and-creating-layers'>Understanding and Creating Layers</ulink>" section + in the Yocto Project Development Manual</para></listitem> + <listitem><para>The "<ulink url='&YOCTO_DOCS_DEV_URL;#modifying-the-kernel'>Modifying the Kernel</ulink>" section + in the Yocto Project Development Manual.</para></listitem> + </itemizedlist> + </para> + + <para> + Finally, while this document focuses on the manual creation of + recipes, patches, and configuration files, the Yocto Project + Board Support Package (BSP) tools are available to automate + this process with existing content and work well to create the + initial framework and boilerplate code. + For details on these tools, see the + "<ulink url='&YOCTO_DOCS_BSP_URL;#using-the-yocto-projects-bsp-tools'>Using the Yocto Project's BSP Tools</ulink>" + section in the Yocto Project Board Support Package (BSP) Developer's + Guide. + </para> + </section> +</chapter> +<!-- +vim: expandtab tw=80 ts=4 +--> |
