<title>Introduction</title>
<para>
- fundamentally, BitBake is a generic task execution
+ Fundamentally, BitBake is a generic task execution
engine that allows shell and Python tasks to be run
efficiently and in parallel while working within
complex inter-task dependency constraints.
</itemizedlist>
Today, BitBake is the primary basis of the
<ulink url="http://www.openembedded.org/">OpenEmbedded</ulink>
- project, which is being used to build and maintain a
- number of projects and embedded Linux distributions
- such as the Angstrom Distribution and the Yocto
- Project.
+ project, which is being used to build and maintain Linux
+ distributions such as the Angstrom Distribution and which is used
+ as the build tool for Linux projects such as the Yocto Project.
</para>
<para>
<para>
BitBake Recipes, which are denoted by the file extension
<filename>.bb</filename>, are the most basic metadata files.
- These recipe files provide BitBake the following:
+ These recipe files provide BitBake with the following:
<itemizedlist>
<listitem><para>Descriptive information about the package</para></listitem>
<listitem><para>The version of the recipe</para></listitem>
- <listitem><para>When dependencies exist</para></listitem>
+ <listitem><para>Existing Dependencies</para></listitem>
<listitem><para>Where the source code resides</para></listitem>
<listitem><para>Whether the source code requires any patches</para></listitem>
<listitem><para>How to compile the source code</para></listitem>
</para>
</section>
- <section id='append-bbappend-files'>
- <title>Append Files</title>
-
- <para>
- Append files, which are files that have the
- <filename>.bbappend</filename> file extension, add or
- extend build information to an existing
- recipe file.
- </para>
-
- <para>
- BitBake expects every append file to have a corresponding recipe file.
- Furthermore, the append file and corresponding recipe file
- must use the same root filename.
- The filenames can differ only in the file type suffix used
- (e.g. <filename>formfactor_0.0.bb</filename> and
- <filename>formfactor_0.0.bbappend</filename>).
- </para>
-
- <para>
- Information in append files overrides the information in the
- similarly-named recipe file.
- </para>
- </section>
-
<section id='configuration-files'>
<title>Configuration Files</title>
called <filename>base.bbclass</filename>.
You can find this file in the
<filename>classes</filename> directory.
- The <filename>base.bbclass</filename> is special in that any
- new classes that a developer adds to a project are required to
- inherit <filename>base.bbclass</filename> automatically.
+ The <filename>base.bbclass</filename> is special since it
+ is always included automatically for all recipes
+ and classes.
This class contains definitions for standard basic tasks such
as fetching, unpacking, configuring (empty by default),
compiling (runs any Makefile present), installing (empty by
(<filename>.bbappend</filename>) file.
</para>
</section>
+
+ <section id='append-bbappend-files'>
+ <title>Append Files</title>
+
+ <para>
+ Append files, which are files that have the
+ <filename>.bbappend</filename> file extension, add or
+ extend build information to an existing
+ recipe file.
+ </para>
+
+ <para>
+ BitBake expects every append file to have a corresponding recipe file.
+ Furthermore, the append file and corresponding recipe file
+ must use the same root filename.
+ The filenames can differ only in the file type suffix used
+ (e.g. <filename>formfactor_0.0.bb</filename> and
+ <filename>formfactor_0.0.bbappend</filename>).
+ </para>
+
+ <para>
+ Information in append files overrides the information in the
+ similarly-named recipe file.
+ </para>
+ </section>
</section>
<section id='obtaining-bitbake'>
<para>
You can obtain BitBake several different ways:
<itemizedlist>
- <listitem><para><emphasis>Installation using your Distribution
- Package Management System:</emphasis>
- This method is not
- recommended because the BitBake version, in most
- cases provided by your distribution, is several
- releases behind a snapshot of the BitBake repository.
- </para></listitem>
- <listitem><para><emphasis>Taking a snapshot of BitBake:</emphasis>
- Downloading a snapshot of BitBake from the
- source code repository is the recommended method
- as you are assured of having the most recent stable
- BitBake release.</para>
- <para>The following example downloads a snapshot of
- BitBake version 1.17.0:
- <literallayout class='monospaced'>
- $ wget http://git.openembedded.org/bitbake/snapshot/bitbake-1.17.0.tar.gz
- $ tar zxpvf bitbake-1.17.0.tar.gz
- </literallayout>
- After extraction of the tarball using the tar utility,
- you have a directory entitled
- <filename>bitbake-1.17.0</filename>.
- </para></listitem>
<listitem><para><emphasis>Cloning BitBake:</emphasis>
Using Git to clone the BitBake source code repository
- is also a recommended method when you need the absolute latest
- BitBake source.
- Realize that using this method could expose you to areas of
- BitBake that are under development.</para>
- <para>Here is an example:
+ is the recommended method for obtaining BitBake.
+ Cloning the repository makes it easy to get bug fixes
+ and have access to stable branches and the master
+ branch.
+ Once you have cloned BitBake, you should use
+ the latest stable
+ branch for development since the master branch is for
+ BitBake development and might contain less stable changes.
+ </para>
+ <para>You usually need a version of BitBake
+ that matches the metadata you are using.
+ The metadata is generally backwards compatible but
+ not forward compatible.</para>
+ <para>Here is an example that clones the BitBake repository:
<literallayout class='monospaced'>
$ git clone git://git.openembedded.org/bitbake
</literallayout>
<literallayout class='monospaced'>
$ git clone git://git.openembedded.org/bitbake bbdev
</literallayout></para></listitem>
+ <listitem><para><emphasis>Installation using your Distribution
+ Package Management System:</emphasis>
+ This method is not
+ recommended because the BitBake version that is
+ provided by your distribution, in most cases,
+ is several
+ releases behind a snapshot of the BitBake repository.
+ </para></listitem>
+ <listitem><para><emphasis>Taking a snapshot of BitBake:</emphasis>
+ Downloading a snapshot of BitBake from the
+ source code repository gives you access to a known
+ branch or release of BitBake.</para>
+ <para>The following example downloads a snapshot of
+ BitBake version 1.17.0:
+ <literallayout class='monospaced'>
+ $ wget http://git.openembedded.org/bitbake/snapshot/bitbake-1.17.0.tar.gz
+ $ tar zxpvf bitbake-1.17.0.tar.gz
+ </literallayout>
+ After extraction of the tarball using the tar utility,
+ you have a directory entitled
+ <filename>bitbake-1.17.0</filename>.
+ </para></listitem>
</itemizedlist>
</para>
</section>
projects / thirdparty / openembedded / openembedded-core-contrib.git / commitdiff
