686 lines
33 KiB
XML
686 lines
33 KiB
XML
<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
|
|
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
|
|
|
|
<chapter id="bitbake-user-manual-intro">
|
|
<title>Overview</title>
|
|
|
|
<para>
|
|
Welcome to the BitBake User Manual.
|
|
This manual provides information on the BitBake tool.
|
|
The information attempts to be as independent as possible regarding
|
|
systems that use BitBake, such as OpenEmbedded and the
|
|
Yocto Project.
|
|
In some cases, scenarios or examples within the context of
|
|
a build system are used in the manual to help with understanding.
|
|
For these cases, the manual clearly states the context.
|
|
</para>
|
|
|
|
<section id="intro">
|
|
<title>Introduction</title>
|
|
|
|
<para>
|
|
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.
|
|
One of BitBake's main users, OpenEmbedded, takes this core
|
|
and builds embedded Linux software stacks using
|
|
a task-oriented approach.
|
|
</para>
|
|
|
|
<para>
|
|
Conceptually, BitBake is similar to GNU Make in
|
|
some regards but has significant differences:
|
|
<itemizedlist>
|
|
<listitem><para>
|
|
BitBake executes tasks according to provided
|
|
metadata that builds up the tasks.
|
|
Metadata is stored in recipe (<filename>.bb</filename>)
|
|
and related recipe "append" (<filename>.bbappend</filename>)
|
|
files, configuration (<filename>.conf</filename>) and
|
|
underlying include (<filename>.inc</filename>) files, and
|
|
in class (<filename>.bbclass</filename>) files.
|
|
The metadata provides
|
|
BitBake with instructions on what tasks to run and
|
|
the dependencies between those tasks.
|
|
</para></listitem>
|
|
<listitem><para>
|
|
BitBake includes a fetcher library for obtaining source
|
|
code from various places such as local files, source control
|
|
systems, or websites.
|
|
</para></listitem>
|
|
<listitem><para>
|
|
The instructions for each unit to be built (e.g. a piece
|
|
of software) are known as "recipe" files and
|
|
contain all the information about the unit
|
|
(dependencies, source file locations, checksums, description
|
|
and so on).
|
|
</para></listitem>
|
|
<listitem><para>
|
|
BitBake includes a client/server abstraction and can
|
|
be used from a command line or used as a service over
|
|
XML-RPC and has several different user interfaces.
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
</section>
|
|
|
|
<section id="history-and-goals">
|
|
<title>History and Goals</title>
|
|
|
|
<para>
|
|
BitBake was originally a part of the OpenEmbedded project.
|
|
It was inspired by the Portage package management system
|
|
used by the Gentoo Linux distribution.
|
|
On December 7, 2004, OpenEmbedded project team member
|
|
Chris Larson split the project into two distinct pieces:
|
|
<itemizedlist>
|
|
<listitem><para>BitBake, a generic task executor</para></listitem>
|
|
<listitem><para>OpenEmbedded, a metadata set utilized by
|
|
BitBake</para></listitem>
|
|
</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 Linux
|
|
distributions such as the
|
|
<ulink url='http://www.angstrom-distribution.org/'>Angstrom Distribution</ulink>,
|
|
and which is also being used as the build tool for Linux projects
|
|
such as the
|
|
<ulink url='http://www.yoctoproject.org'>Yocto Project</ulink>.
|
|
</para>
|
|
|
|
<para>
|
|
Prior to BitBake, no other build tool adequately met the needs of
|
|
an aspiring embedded Linux distribution.
|
|
All of the build systems used by traditional desktop Linux
|
|
distributions lacked important functionality, and none of the
|
|
ad hoc Buildroot-based systems, prevalent in the
|
|
embedded space, were scalable or maintainable.
|
|
</para>
|
|
|
|
<para>
|
|
Some important original goals for BitBake were:
|
|
<itemizedlist>
|
|
<listitem><para>
|
|
Handle cross-compilation.
|
|
</para></listitem>
|
|
<listitem><para>
|
|
Handle inter-package dependencies (build time on
|
|
target architecture, build time on native
|
|
architecture, and runtime).
|
|
</para></listitem>
|
|
<listitem><para>
|
|
Support running any number of tasks within a given
|
|
package, including, but not limited to, fetching
|
|
upstream sources, unpacking them, patching them,
|
|
configuring them, and so forth.
|
|
</para></listitem>
|
|
<listitem><para>
|
|
Be Linux distribution agnostic for both build and
|
|
target systems.
|
|
</para></listitem>
|
|
<listitem><para>
|
|
Be architecture agnostic.
|
|
</para></listitem>
|
|
<listitem><para>
|
|
Support multiple build and target operating systems
|
|
(e.g. Cygwin, the BSDs, and so forth).
|
|
</para></listitem>
|
|
<listitem><para>
|
|
Be self contained, rather than tightly
|
|
integrated into the build machine's root
|
|
filesystem.
|
|
</para></listitem>
|
|
<listitem><para>
|
|
Handle conditional metadata on the target architecture,
|
|
operating system, distribution, and machine.
|
|
</para></listitem>
|
|
<listitem><para>
|
|
Be easy to use the tools to supply local metadata and packages
|
|
against which to operate.
|
|
</para></listitem>
|
|
<listitem><para>
|
|
Be easy to use BitBake to collaborate between multiple
|
|
projects for their builds.
|
|
</para></listitem>
|
|
<listitem><para>
|
|
Provide an inheritance mechanism to share
|
|
common metadata between many packages.
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
Over time it became apparent that some further requirements
|
|
were necessary:
|
|
<itemizedlist>
|
|
<listitem><para>
|
|
Handle variants of a base recipe (e.g. native, sdk,
|
|
and multilib).
|
|
</para></listitem>
|
|
<listitem><para>
|
|
Split metadata into layers and allow layers
|
|
to enhance or override other layers.
|
|
</para></listitem>
|
|
<listitem><para>
|
|
Allow representation of a given set of input variables
|
|
to a task as a checksum.
|
|
Based on that checksum, allow acceleration of builds
|
|
with prebuilt components.
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
BitBake satisfies all the original requirements and many more
|
|
with extensions being made to the basic functionality to
|
|
reflect the additional requirements.
|
|
Flexibility and power have always been the priorities.
|
|
BitBake is highly extensible and supports embedded Python code and
|
|
execution of any arbitrary tasks.
|
|
</para>
|
|
</section>
|
|
|
|
<section id="Concepts">
|
|
<title>Concepts</title>
|
|
|
|
<para>
|
|
BitBake is a program written in the Python language.
|
|
At the highest level, BitBake interprets metadata, decides
|
|
what tasks are required to run, and executes those tasks.
|
|
Similar to GNU Make, BitBake controls how software is
|
|
built.
|
|
GNU Make achieves its control through "makefiles", while
|
|
BitBake uses "recipes".
|
|
</para>
|
|
|
|
<para>
|
|
BitBake extends the capabilities of a simple
|
|
tool like GNU Make by allowing for the definition of much more
|
|
complex tasks, such as assembling entire embedded Linux
|
|
distributions.
|
|
</para>
|
|
|
|
<para>
|
|
The remainder of this section introduces several concepts
|
|
that should be understood in order to better leverage
|
|
the power of BitBake.
|
|
</para>
|
|
|
|
<section id='recipes'>
|
|
<title>Recipes</title>
|
|
|
|
<para>
|
|
BitBake Recipes, which are denoted by the file extension
|
|
<filename>.bb</filename>, are the most basic metadata files.
|
|
These recipe files provide BitBake with the following:
|
|
<itemizedlist>
|
|
<listitem><para>Descriptive information about the
|
|
package (author, homepage, license, and so on)</para></listitem>
|
|
<listitem><para>The version of the recipe</para></listitem>
|
|
<listitem><para>Existing dependencies (both build
|
|
and runtime dependencies)</para></listitem>
|
|
<listitem><para>Where the source code resides and
|
|
how to fetch it</para></listitem>
|
|
<listitem><para>Whether the source code requires
|
|
any patches, where to find them, and how to apply
|
|
them</para></listitem>
|
|
<listitem><para>How to configure and compile the
|
|
source code</para></listitem>
|
|
<listitem><para>Where on the target machine to install the
|
|
package or packages created</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
|
|
<para>
|
|
Within the context of BitBake, or any project utilizing BitBake
|
|
as its build system, files with the <filename>.bb</filename>
|
|
extension are referred to as recipes.
|
|
<note>
|
|
The term "package" is also commonly used to describe recipes.
|
|
However, since the same word is used to describe packaged
|
|
output from a project, it is best to maintain a single
|
|
descriptive term - "recipes".
|
|
Put another way, a single "recipe" file is quite capable
|
|
of generating a number of related but separately installable
|
|
"packages".
|
|
In fact, that ability is fairly common.
|
|
</note>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='configuration-files'>
|
|
<title>Configuration Files</title>
|
|
|
|
<para>
|
|
Configuration files, which are denoted by the
|
|
<filename>.conf</filename> extension, define
|
|
various configuration variables that govern the project's build
|
|
process.
|
|
These files fall into several areas that define
|
|
machine configuration options, distribution configuration
|
|
options, compiler tuning options, general common
|
|
configuration options, and user configuration options.
|
|
The main configuration file is the sample
|
|
<filename>bitbake.conf</filename> file, which is
|
|
located within the BitBake source tree
|
|
<filename>conf</filename> directory.
|
|
</para>
|
|
</section>
|
|
|
|
<section id='classes'>
|
|
<title>Classes</title>
|
|
|
|
<para>
|
|
Class files, which are denoted by the
|
|
<filename>.bbclass</filename> extension, contain
|
|
information that is useful to share between metadata files.
|
|
The BitBake source tree currently comes with one class metadata file
|
|
called <filename>base.bbclass</filename>.
|
|
You can find this file in the
|
|
<filename>classes</filename> directory.
|
|
The <filename>base.bbclass</filename> class files 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
|
|
default) and packaging (empty by default).
|
|
These tasks are often overridden or extended by other classes
|
|
added during the project development process.
|
|
</para>
|
|
</section>
|
|
|
|
<section id='layers'>
|
|
<title>Layers</title>
|
|
|
|
<para>
|
|
Layers allow you to isolate different types of
|
|
customizations from each other.
|
|
While you might find it tempting to keep everything in one layer
|
|
when working on a single project, the more modular you organize
|
|
your metadata, the easier it is to cope with future changes.
|
|
</para>
|
|
|
|
<para>
|
|
To illustrate how you can use layers to keep things modular,
|
|
consider customizations you might make to support a specific target machine.
|
|
These types of customizations typically reside in a special layer,
|
|
rather than a general layer, called a Board Support Package (BSP)
|
|
Layer.
|
|
Furthermore, the machine customizations should be isolated from
|
|
recipes and metadata that support a new GUI environment, for
|
|
example.
|
|
This situation gives you a couple of layers: one for the machine
|
|
configurations and one for the GUI environment.
|
|
It is important to understand, however, that the BSP layer can still
|
|
make machine-specific additions to recipes within
|
|
the GUI environment layer without polluting the GUI layer itself
|
|
with those machine-specific changes.
|
|
You can accomplish this through a recipe that is a BitBake append
|
|
(<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, extend or
|
|
override information in 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 extends or
|
|
overrides the information in the underlying,
|
|
similarly-named recipe files.
|
|
</para>
|
|
|
|
<para>
|
|
When you name an append file, you can use the
|
|
wildcard character (%) to allow for matching recipe names.
|
|
For example, suppose you have an append file named
|
|
as follows:
|
|
<literallayout class='monospaced'>
|
|
busybox_1.21.%.bbappend
|
|
</literallayout>
|
|
That append file would match any <filename>busybox_1.21.x.bb</filename>
|
|
version of the recipe.
|
|
So, the append file would match the following recipe names:
|
|
<literallayout class='monospaced'>
|
|
busybox_1.21.1.bb
|
|
busybox_1.21.2.bb
|
|
busybox_1.21.3.bb
|
|
</literallayout>
|
|
If the <filename>busybox</filename> recipe was updated to
|
|
<filename>busybox_1.3.0.bb</filename>, the append name would not
|
|
match.
|
|
However, if you named the append file
|
|
<filename>busybox_1.%.bbappend</filename>, then you would have a match.
|
|
</para>
|
|
|
|
<para>
|
|
In the most general case, you could name the append file something as
|
|
simple as <filename>busybox_%.bbappend</filename> to be entirely
|
|
version independent.
|
|
</para>
|
|
</section>
|
|
</section>
|
|
|
|
<section id='obtaining-bitbake'>
|
|
<title>Obtaining BitBake</title>
|
|
|
|
<para>
|
|
You can obtain BitBake several different ways:
|
|
<itemizedlist>
|
|
<listitem><para><emphasis>Cloning BitBake:</emphasis>
|
|
Using Git to clone the BitBake source code repository
|
|
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>
|
|
This command clones the BitBake Git repository into a
|
|
directory called <filename>bitbake</filename>.
|
|
Alternatively, you can
|
|
designate a directory after the
|
|
<filename>git clone</filename> command
|
|
if you want to call the new directory something
|
|
other than <filename>bitbake</filename>.
|
|
Here is an example that names the directory
|
|
<filename>bbdev</filename>:
|
|
<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.
|
|
<note>
|
|
Cloning the Git repository, as described earlier,
|
|
is the preferred method for getting BitBake.
|
|
Cloning the repository makes it easier to update as
|
|
patches are added to the stable branches.
|
|
</note></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>Using the BitBake that Comes With Your
|
|
Build Checkout:</emphasis>
|
|
A final possibility for getting a copy of BitBake is that it
|
|
already comes with your checkout of a larger Bitbake-based build
|
|
system, such as Poky or Yocto Project.
|
|
Rather than manually checking out individual layers and
|
|
gluing them together yourself, you can check
|
|
out an entire build system.
|
|
The checkout will already include a version of BitBake that
|
|
has been thoroughly tested for compatibility with the other
|
|
components.
|
|
For information on how to check out a particular BitBake-based
|
|
build system, consult that build system's supporting documentation.
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
</section>
|
|
|
|
<section id="bitbake-user-manual-command">
|
|
<title>The BitBake Command</title>
|
|
|
|
<para>
|
|
The <filename>bitbake</filename> command is the primary interface
|
|
to the BitBake tool.
|
|
This section presents the BitBake command syntax and provides
|
|
several execution examples.
|
|
</para>
|
|
|
|
<section id='usage-and-syntax'>
|
|
<title>Usage and syntax</title>
|
|
|
|
<para>
|
|
Following is the usage and syntax for BitBake:
|
|
<literallayout class='monospaced'>
|
|
$ bitbake -h
|
|
Usage: bitbake [options] [recipename/target ...]
|
|
|
|
Executes the specified task (default is 'build') for a given set of target recipes (.bb files).
|
|
It is assumed there is a conf/bblayers.conf available in cwd or in BBPATH which
|
|
will provide the layer, BBFILES and other configuration information.
|
|
|
|
Options:
|
|
--version show program's version number and exit
|
|
-h, --help show this help message and exit
|
|
-b BUILDFILE, --buildfile=BUILDFILE
|
|
Execute tasks from a specific .bb recipe directly.
|
|
WARNING: Does not handle any dependencies from other
|
|
recipes.
|
|
-k, --continue Continue as much as possible after an error. While the
|
|
target that failed and anything depending on it cannot
|
|
be built, as much as possible will be built before
|
|
stopping.
|
|
-a, --tryaltconfigs Continue with builds by trying to use alternative
|
|
providers where possible.
|
|
-f, --force Force the specified targets/task to run (invalidating
|
|
any existing stamp file).
|
|
-c CMD, --cmd=CMD Specify the task to execute. The exact options
|
|
available depend on the metadata. Some examples might
|
|
be 'compile' or 'populate_sysroot' or 'listtasks' may
|
|
give a list of the tasks available.
|
|
-C INVALIDATE_STAMP, --clear-stamp=INVALIDATE_STAMP
|
|
Invalidate the stamp for the specified task such as
|
|
'compile' and then run the default task for the
|
|
specified target(s).
|
|
-r PREFILE, --read=PREFILE
|
|
Read the specified file before bitbake.conf.
|
|
-R POSTFILE, --postread=POSTFILE
|
|
Read the specified file after bitbake.conf.
|
|
-v, --verbose Output more log message data to the terminal.
|
|
-D, --debug Increase the debug level. You can specify this more
|
|
than once.
|
|
-n, --dry-run Don't execute, just go through the motions.
|
|
-S SIGNATURE_HANDLER, --dump-signatures=SIGNATURE_HANDLER
|
|
Dump out the signature construction information, with
|
|
no task execution. The SIGNATURE_HANDLER parameter is
|
|
passed to the handler. Two common values are none and
|
|
printdiff but the handler may define more/less. none
|
|
means only dump the signature, printdiff means compare
|
|
the dumped signature with the cached one.
|
|
-p, --parse-only Quit after parsing the BB recipes.
|
|
-s, --show-versions Show current and preferred versions of all recipes.
|
|
-e, --environment Show the global or per-recipe environment complete
|
|
with information about where variables were
|
|
set/changed.
|
|
-g, --graphviz Save dependency tree information for the specified
|
|
targets in the dot syntax.
|
|
-I EXTRA_ASSUME_PROVIDED, --ignore-deps=EXTRA_ASSUME_PROVIDED
|
|
Assume these dependencies don't exist and are already
|
|
provided (equivalent to ASSUME_PROVIDED). Useful to
|
|
make dependency graphs more appealing
|
|
-l DEBUG_DOMAINS, --log-domains=DEBUG_DOMAINS
|
|
Show debug logging for the specified logging domains
|
|
-P, --profile Profile the command and save reports.
|
|
-u UI, --ui=UI The user interface to use (e.g. knotty, hob, depexp).
|
|
-t SERVERTYPE, --servertype=SERVERTYPE
|
|
Choose which server to use, process or xmlrpc.
|
|
--token=XMLRPCTOKEN Specify the connection token to be used when
|
|
connecting to a remote server.
|
|
--revisions-changed Set the exit code depending on whether upstream
|
|
floating revisions have changed or not.
|
|
--server-only Run bitbake without a UI, only starting a server
|
|
(cooker) process.
|
|
-B BIND, --bind=BIND The name/address for the bitbake server to bind to.
|
|
--no-setscene Do not run any setscene tasks. sstate will be ignored
|
|
and everything needed, built.
|
|
--remote-server=REMOTE_SERVER
|
|
Connect to the specified server.
|
|
-m, --kill-server Terminate the remote server.
|
|
--observe-only Connect to a server as an observing-only client.
|
|
--status-only Check the status of the remote bitbake server.
|
|
</literallayout>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='bitbake-examples'>
|
|
<title>Examples</title>
|
|
|
|
<para>
|
|
This section presents some examples showing how to use BitBake.
|
|
</para>
|
|
|
|
<section id='example-executing-a-task-against-a-single-recipe'>
|
|
<title>Executing a Task Against a Single Recipe</title>
|
|
|
|
<para>
|
|
Executing tasks for a single recipe file is relatively simple.
|
|
You specify the file in question, and BitBake parses
|
|
it and executes the specified task.
|
|
If you do not specify a task, BitBake executes the default
|
|
task, which is "build”.
|
|
BitBake obeys inter-task dependencies when doing
|
|
so.
|
|
</para>
|
|
|
|
<para>
|
|
The following command runs the build task, which is
|
|
the default task, on the <filename>foo_1.0.bb</filename>
|
|
recipe file:
|
|
<literallayout class='monospaced'>
|
|
$ bitbake -b foo_1.0.bb
|
|
</literallayout>
|
|
The following command runs the clean task on the
|
|
<filename>foo.bb</filename> recipe file:
|
|
<literallayout class='monospaced'>
|
|
$ bitbake -b foo.bb -c clean
|
|
</literallayout>
|
|
<note>
|
|
The "-b" option explicitly does not handle recipe
|
|
dependencies.
|
|
Other than for debugging purposes, it is instead
|
|
recommended that you use the syntax presented in the
|
|
next section.
|
|
</note>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='executing-tasks-against-a-set-of-recipe-files'>
|
|
<title>Executing Tasks Against a Set of Recipe Files</title>
|
|
|
|
<para>
|
|
There are a number of additional complexities introduced
|
|
when one wants to manage multiple <filename>.bb</filename>
|
|
files.
|
|
Clearly there needs to be a way to tell BitBake what
|
|
files are available and, of those, which you
|
|
want to execute.
|
|
There also needs to be a way for each recipe
|
|
to express its dependencies, both for build-time and
|
|
runtime.
|
|
There must be a way for you to express recipe preferences
|
|
when multiple recipes provide the same functionality, or when
|
|
there are multiple versions of a recipe.
|
|
</para>
|
|
|
|
<para>
|
|
The <filename>bitbake</filename> command, when not using
|
|
"--buildfile" or "-b" only accepts a "PROVIDES".
|
|
You cannot provide anything else.
|
|
By default, a recipe file generally "PROVIDES" its
|
|
"packagename" as shown in the following example:
|
|
<literallayout class='monospaced'>
|
|
$ bitbake foo
|
|
</literallayout>
|
|
This next example "PROVIDES" the package name and also uses
|
|
the "-c" option to tell BitBake to just execute the
|
|
<filename>do_clean</filename> task:
|
|
<literallayout class='monospaced'>
|
|
$ bitbake -c clean foo
|
|
</literallayout>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='generating-dependency-graphs'>
|
|
<title>Generating Dependency Graphs</title>
|
|
|
|
<para>
|
|
BitBake is able to generate dependency graphs using
|
|
the <filename>dot</filename> syntax.
|
|
You can convert these graphs into images using the
|
|
<filename>dot</filename> tool from
|
|
<ulink url='http://www.graphviz.org'>Graphviz</ulink>.
|
|
</para>
|
|
|
|
<para>
|
|
When you generate a dependency graph, BitBake writes four files
|
|
to the current working directory:
|
|
<itemizedlist>
|
|
<listitem><para><emphasis><filename>package-depends.dot</filename>:</emphasis>
|
|
Shows BitBake's knowledge of dependencies between
|
|
runtime targets.
|
|
</para></listitem>
|
|
<listitem><para><emphasis><filename>pn-depends.dot</filename>:</emphasis>
|
|
Shows dependencies between build-time targets
|
|
(i.e. recipes).
|
|
</para></listitem>
|
|
<listitem><para><emphasis><filename>task-depends.dot</filename>:</emphasis>
|
|
Shows dependencies between tasks.
|
|
</para></listitem>
|
|
<listitem><para><emphasis><filename>pn-buildlist</filename>:</emphasis>
|
|
Shows a simple list of targets that are to be built.
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
|
|
<para>
|
|
To stop depending on common depends, use the "-I" depend
|
|
option and BitBake omits them from the graph.
|
|
Leaving this information out can produce more readable graphs.
|
|
This way, you can remove from the graph
|
|
<filename>DEPENDS</filename> from inherited classes
|
|
such as <filename>base.bbclass</filename>.
|
|
</para>
|
|
|
|
<para>
|
|
Here are two examples that create dependency graphs.
|
|
The second example omits depends common in OpenEmbedded from
|
|
the graph:
|
|
<literallayout class='monospaced'>
|
|
$ bitbake -g foo
|
|
|
|
$ bitbake -g -I virtual/kernel -I eglibc foo
|
|
</literallayout>
|
|
</para>
|
|
</section>
|
|
</section>
|
|
</section>
|
|
</chapter>
|