generic-poky/documentation/yocto-project-qs/yocto-project-qs.xml

336 lines
13 KiB
XML
Raw Normal View History

<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<article id='intro'>
<imagedata fileref="figures/yocto-project-transp.png" width="6in" depth="1in" align="right" scale="25" />
<section id='fake-title'>
<title>Yocto Project Quick Start</title>
</section>
<section id='welcome'>
<title>Welcome!</title>
<para>
Welcome to the Yocto Project!
The Yocto Project (YP) is an open-source collaboration project focused on embedded Linux
developers.
Amongst other things, YP uses the Poky build tool to construct complete Linux images.
</para>
<para>
This short document will give you some basic information about the environment as well
as let you experience it in its simplest form.
After reading this document you will have a basic understanding of what the Yocto Project is
and how to use some of its core components.
This document steps you through a simple example showing you how to build a small image
and run it using the QEMU emulator.
</para>
<para>
For complete information on the Yocto Project you should check out the
<ulink url='http://www.yoctoproject.org'>Yocto Project Website</ulink>.
You can find the latest builds, breaking news, full development documentation, and a
rich Yocto Project Development Community into which you can tap.
</para>
</section>
<section id='yp-intro'>
<title>Introducing the Yocto Project Development Environment</title>
<para>
The Yocto Project through the Poky build tool provides an open source development
environment targeting the ARM, MIPS, PowerPC and x86 architectures for a variety of
platforms including x86-64 and emulated ones.
You can use components from the the Yocto Project to design, develop, build, debug, simulate,
and test the complete software stack using Linux, the X Window System, GNOME Mobile-based
application frameworks, and Qt frameworks.
</para>
<para></para>
<para></para>
<mediaobject>
<imageobject>
<imagedata fileref="figures/yocto-environment.png" format="PNG" align='center' scalefit='1'/>
</imageobject>
<caption>
<para>The Yocto Project Development Environment</para>
</caption>
</mediaobject>
<para>
Yocto Project:
</para>
<itemizedlist>
<listitem>
<para>Provides a recent Linux kernel along with a set of system commands and libraries suitable for the embedded environment.</para>
</listitem>
<listitem>
<para>Makes available system components such as X11, Matchbox, GTK+, Pimlico, Clutter,
GuPNP and Qt (among others) so you can create a richer user interface experience on
devices that use displays or have a GUI.
For devices that don't have a GUI or display you simply would not employ these
components.</para>
</listitem>
<listitem>
<para>Creates a focused and stable core compatible with the OpenEmbedded
project with which you can easily and reliably build and develop.</para>
</listitem>
<listitem>
<para>Fully supports a wide range of hardware and device emulation through the QEMU
Emulator.</para>
</listitem>
</itemizedlist>
<para>
Yocto Project can generate images for many kinds of devices.
However, the standard example machines target QEMU full system emulation for x86, ARM, MIPS,
and PPC based architectures as well as specific hardware such as the Intel Desktop Board
DH55TC.
Because an image developed with Yocto Project can boot inside a QEMU emulator, the
development environment works nicely as a test platform for developing embedded software.
</para>
<para>
Another important Yocto Project feature is the Sato reference User Interface.
This optional GNOME mobile-based UI, which is intended for devices with
resolution but restricted size screens, sits neatly on top of a device using the
GNOME Mobile Stack providing a well defined user experience.
Implemented in its own layer, it makes it clear to developers how they can implement
their own UIs on top of Yocto Linux.
</para>
</section>
<section id='resources'>
<title>What You Need and How You Get It</title>
<para>
You need these things to develop in the Yocto Project environment:
</para>
<itemizedlist>
<listitem>
<para>A host system running a supported Linux distribution (i.e. recent releases of
Fedora, OpenSUSE, Debian, and Ubuntu).</para>
</listitem>
<listitem>
<para>The right packages.</para>
</listitem>
<listitem>
<para>A release of Yocto Project.</para>
</listitem>
</itemizedlist>
<section id='the-linux-distro'>
<title>The Linux Distribution</title>
<para>
While this document assumes a Debian-based host system you can develop in the Yocto Linux environment using many other Linux distributions.
For Debian-based systems we recommend you use the Ubuntu Release 10.04 or later.
</para>
</section>
<section id='packages'>
<title>The Packages</title>
<para>
The packages you need for a Debian-based host are shown in the following command:
</para>
<literallayout class='monospaced'>
$ sudo apt-get install sed wget cvs subversion git-core coreutils \
unzip texi2html texinfo libsdll.2-dev docbook-utils gawk \
python-pysqlite2 diffstat help2man make gcc build-essential \
g++ desktop-file-utils chrpath libgl1-mesa-dev libglu1-mesa-dev \
libsdl1.2-dev
</literallayout>
<para>
<emphasis>NOTE:</emphasis> Packages vary in number and name for other Linux distributions.
For package requirements on other Linux distributions refer to the information found at <ulink url='http://wiki.openembedded.net/index.php/OEandYourDistro'>http://wiki.openembedded.net/index.php/OEandYourDistro</ulink>.
</para>
</section>
<section id='releases'>
<title>Yocto Project Release</title>
<para>
The latest release images for the Yocto Project are kept at
<ulink url="http://yoctoproject.org/downloads/yoctolinux-0.9/"></ulink>.
Nightly and developmental builds are also maintained. However, for this
document a released version of Yocto Project is used.
</para>
</section>
</section>
<section id='test-run'>
<title>A Quick Test Run</title>
<para>
Now that you have your system requirements in order you can give Yocto Project a try.
This section presents some steps that let you do the following:
</para>
<itemizedlist>
<listitem>
<para>Build an image and run it in the emulator</para>
</listitem>
<listitem>
<para>Or, use a pre-built image and run it in the emulator</para>
</listitem>
</itemizedlist>
<section id='building-image'>
<title>Building an Image</title>
<para>
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.
</para>
<mediaobject>
<imageobject>
<imagedata fileref="figures/building-an-image.png" format="PNG" align='center' scalefit='1'/>
</imageobject>
<caption>
<para>Building an Image</para>
</caption>
</mediaobject>
<para>
Use the following commands from a shell on your Debian-based host to build your image.
The build creates an entire Linux system including the Toolchain from the source.
</para>
<para><emphasis>NOTE:</emphasis> The build process using Sato currently consumes 50GB of disk space.
To allow for variations in the build process and for future package expansion we recommend 100GB of free disk space.
</para>
<para>
<literallayout class='monospaced'>
$ wget http://www.yoctoproject.org/downloads/poky/poky-laverne-4.0.tar.bz2
$ tar xjf poky-laverne-4.0.tar.bz2
$ source poky-4.0/poky-init-build-env poky-4.0-build
$ cd poky-4.0-build
$ bitbake poky-image-sato
$ poky-qemu qemux86
</literallayout>
</para>
<para>
Here is some explanation for these commands:
</para>
<itemizedlist>
<listitem>
<para>
The first two commands extract the Yocto Project files from the release area and place them into your build area (<command>poky-4.0-build</command> in this example).
</para>
</listitem>
<listitem>
<para>
The next two commands create the directory and place you there.
The build directory contains all the object files used during the build.
The default build directory is <command>poky-dir/build</command>.
Note that you can change the target architecture by editing the
<command>&lt;build_directory&gt;/conf/local.conf</command> file.
By default the target architecture is qemux86.
</para>
</listitem>
<listitem>
<para>
The <command>$bitbake</command> command builds the OS image for the target.
Here poky-image-sato is the name of the target.
</para>
</listitem>
<listitem>
<para>
Finally, the <command>$poky-qemu</command> command launches the customized QEMU.
</para>
</listitem>
</itemizedlist>
</section>
<section id='using-pre-built'>
<title>Using a Pre-Built Linux Kernel for QEMU</title>
<para>
If hardware, libraries and services are stable you can use a pre-built image of the kernel and just run it on the target using the emulator QEMU.
This situation is perfect for developing application software.
</para>
<para></para>
<para></para>
<para></para>
<mediaobject>
<imageobject>
<imagedata fileref="figures/using-a-pre-built-image.png" format="PNG" align='center' scalefit='1'/>
</imageobject>
<caption>
<para>Using a Pre-Built Image</para>
</caption>
</mediaobject>
<para>
For this scenario you need to do three things:
</para>
<itemizedlist>
<listitem>
<para>
Install the Yocto Project Scripts
</para>
</listitem>
<listitem>
<para>
Download the pre-built kernel that will run on QEMU.
You need to be sure to get the QEMU image that matches your target machines architecture (e.g. x86, ARM, etc.).
</para>
</listitem>
<listitem>
<para>
Download and decompress the file image system.
</para>
</listitem>
</itemizedlist>
<para>
Use this command to install the patched Yocto Project QEMU scripts:
</para>
<para>
<literallayout class='monospaced'>
$ apt-get install qemu poky-scripts
</literallayout>
</para>
<para>
You can download the pre-built Linux kernel and the file image system from <ulink url='http://yoctoproject.org/downloads/yoctolinux-0.9/'></ulink>.
The kernel and file image system have the following forms, respectively:
</para>
<literallayout class='monospaced'>
*zImage*qemu*.bin
poky-image-*-qemu*.ext2.bz2
</literallayout>
<para>
You must decompress the file image system using the following command:
</para>
<literallayout class='monospaced'>
$ bzip2 -d
</literallayout>
<para>
You can now start the emulator using this command:
</para>
<literallayout class='monospaced'>
$ poky-qemu &lt;<emphasis>kernel</emphasis>&gt; &lt;<emphasis>image</emphasis>&gt;
</literallayout>
</section>
</section>
</article>
<!--
vim: expandtab tw=80 ts=4
-->