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bitbake: user-manual-bitbakecommand: Various edits/cleanups

(Bitbake rev: f079e0886b1b191d84621057f9752cc32bfabb44)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
This commit is contained in:
Richard Purdie
2014-01-18 16:25:25 +00:00
parent 5cce95c602
commit bd4140578e
@@ -2,16 +2,16 @@
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<chapter> <chapter>
<title>The BitBake command</title> <title>The BitBake Command</title>
<section id='bitbake-command-introduction'> <section id='bitbake-command-introduction'>
<title>Introduction</title> <title>Introduction</title>
<para> <para>
bitbake is the primary command in the system. Bitbake is the primary command in the system.
It facilitates executing tasks in a single .bb It facilitates executing tasks in a single <filename>.bb</filename>
file, or executing a given task on a set of multiple file, or executing a given task on a set of multiple
.bb files, accounting for interdependencies <filename>.bb</filename> files, accounting for interdependencies
amongst them. amongst them.
</para> </para>
</section> </section>
@@ -20,8 +20,9 @@
<title>Usage and syntax</title> <title>Usage and syntax</title>
<para> <para>
Following is the usage and syntax for BitBake:
<literallayout class='monospaced'> <literallayout class='monospaced'>
<prompt>$ </prompt>bitbake --help $ bitbake -h
Usage: bitbake [options] [recipename/target ...] Usage: bitbake [options] [recipename/target ...]
Executes the specified task (default is 'build') for a given set of target recipes (.bb files). Executes the specified task (default is 'build') for a given set of target recipes (.bb files).
@@ -99,23 +100,30 @@ Options:
<section id='bitbake-examples'> <section id='bitbake-examples'>
<title>Examples</title> <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'> <section id='example-executing-a-task-against-a-single-recipe'>
<title>Executing a task against a single .bb</title> <title>Executing a Task Against a Single Recipe</title>
<para> <para>
Executing tasks for a single file is relatively simple. Executing tasks for a single recipe file is relatively simple.
You specify the file in question, and BitBake parses You specify the file in question, and BitBake parses
it and executes the specified task (or <quote>build</quote> by default). it and executes the specified task (or “build” by default).
It obeys intertask dependencies when doing so. BitBake obeys inter-task dependencies when doing
so.
</para> </para>
<para> <para>
<para><quote>clean</quote> task:</para> The following command runs the clean task on the
<filename>foo_1.0.bb</filename> recipe file:
<literallayout class='monospaced'> <literallayout class='monospaced'>
$ bitbake -b foo.bb -c clean $ bitbake -b foo.bb -c clean
</literallayout> </literallayout>
The following command runs the build task, which is
<para><quote>build</quote> task:</para> the default task, on the <filename>foo_1.0.bb</filename>
recipe file:
<literallayout class='monospaced'> <literallayout class='monospaced'>
$ bitbake -b foo_1.0.bb $ bitbake -b foo_1.0.bb
</literallayout> </literallayout>
@@ -123,20 +131,21 @@ Options:
</section> </section>
<section id='executing-tasks-against-a-set-of-recipe-files'> <section id='executing-tasks-against-a-set-of-recipe-files'>
<title>Executing tasks against a set of .bb files</title> <title>Executing Tasks Against a Set of Recipe Files</title>
<para> <para>
There are a number of additional complexities introduced There are a number of additional complexities introduced
when one wants to manage multiple .bb when one wants to manage multiple <filename>.bb</filename>
files. files.
Clearly there needs to be a way to tell BitBake what Clearly there needs to be a way to tell BitBake what
files are available, and of those, which we files are available, and of those, which we
want to execute at this time want to execute at this time.
There also needs to be a way for each .bb There also needs to be a way for each <filename>.bb</filename>
to express its dependencies, both for build time and to express its dependencies, both for build-time and
runtime. runtime.
There must be a way for the user to express their preferences There must be a way for the user to express their preferences
when multiple .bb's provide the same functionality, or when when multiple recipes provide the same functionality, or when
there are multiple versions of a .bb. there are multiple versions of a <filename>.bb</filename> file.
</para> </para>
<para> <para>
@@ -144,10 +153,10 @@ Options:
</para> </para>
<para> <para>
Note that the bitbake command, when not using The <filename>bitbake</filename> command, when not using
--buildfile, accepts a <varname>PROVIDER</varname>, not a filename or "--buildfile", accepts a PROVIDER, not a filename or
anything else. anything else.
By default, a .bb generally PROVIDES its By default, a <filename>.bb</filename> generally PROVIDES its
packagename, packagename-version, and packagename-version-revision. packagename, packagename-version, and packagename-version-revision.
<literallayout class='monospaced'> <literallayout class='monospaced'>
$ bitbake foo $ bitbake foo
@@ -166,22 +175,23 @@ Options:
</section> </section>
<section id='generating-dependency-graphs'> <section id='generating-dependency-graphs'>
<title>Generating dependency graphs</title> <title>Generating Dependency Graphs</title>
<para>
BitBake is able to generate dependency graphs using <para>
BitBake is able to generate dependency graphs using
the dot syntax. the dot syntax.
These graphs can be converted to images using the <application>dot</application> These graphs can be converted to images using the dot
application from application from
<ulink url="http://www.graphviz.org">Graphviz</ulink>. <ulink url='http://www.graphviz.org'>Graphviz</ulink>.
Two files will be written into the current working directory, Two files will be written into the current working directory:
<emphasis>depends.dot</emphasis> containing dependency information <filename>depends.dot</filename> containing dependency information
at the package level and <emphasis>task-depends.dot</emphasis> at the package level and <filename>task-depends.dot</filename>
containing a breakdown of the dependencies at the task level. containing a breakdown of the dependencies at the task level.
To stop depending on common depends, one can use the <prompt>-I depend</prompt> To stop depending on common depends, one can use the "-I" depend
to omit these from the graph. option to omit these from the graph.
This can lead to more readable graphs. This can lead to more readable graphs.
This way, <varname>DEPENDS</varname> from inherited classes This way, <filename>DEPENDS</filename> from inherited classes
such as base.bbclass can be removed from the such as <filename>base.bbclass</filename> can be removed from the
graph. graph.
<literallayout class='monospaced'> <literallayout class='monospaced'>
$ bitbake -g foo $ bitbake -g foo
@@ -193,14 +203,14 @@ Options:
</section> </section>
<section id='special-variables'> <section id='special-variables'>
<title>Special variables</title> <title>Special Variables</title>
<para> <para>
Certain variables affect BitBake operation: Certain variables affect BitBake operation:
</para> </para>
<section id='bb-number-threads'> <section id='bb-number-threads'>
<title><varname>BB_NUMBER_THREADS</varname></title> <title><filename>BB_NUMBER_THREADS</filename></title>
<para> <para>
The number of threads BitBake should run at once (default: 1). The number of threads BitBake should run at once (default: 1).
@@ -211,34 +221,35 @@ Options:
<section id='bitbake-command-metadata'> <section id='bitbake-command-metadata'>
<title>Metadata</title> <title>Metadata</title>
<para> <para>
As you may have seen in the usage information, or in the As you may have seen in the usage information, or in the
information about .bb files, the information about <filename>.bb</filename> files, the
<varname>BBFILES</varname> variable is how the BitBake <filename>BBFILES</filename> variable is how the BitBake
tool locates its files. tool locates its files.
This variable is a space separated list of files This variable is a space-separated list of files
that are available, and supports wildcards. that are available, and supports wildcards.
</para> </para>
<section id='setting-bbfiles'> <section id='setting-bbfiles'>
<title>Setting BBFILES</title> <title>Setting <filename>BBFILES</filename></title>
<para> <para>
<literallayout class='monospaced'> <literallayout class='monospaced'>
BBFILES = "/path/to/bbfiles/*.bb" BBFILES = "/path/to/bbfiles/*.bb"
</literallayout> </literallayout>
With regard to dependencies, it expects the With regard to dependencies, it expects the
.bb to define a <filename>.bb</filename> to define a
<varname>DEPENDS</varname> variable, which contains a <filename>DEPENDS</filename> variable, which contains a
space separated list of <quote>package names</quote>, which themselves space separated list of package names, which themselves
are the <varname>PN</varname> variable. The are the <filename>PN</filename> variable. The
<varname>PN</varname> variable is, in general, <filename>PN</filename> variable is, in general,
set to a component of the .bb set to a component of the <filename>.bb</filename>
filename by default. filename by default.
</para> </para>
</section> </section>
<section id='depending-on-another-recipe-file'> <section id='depending-on-another-recipe-file'>
<title>Depending on another .bb</title> <title>Depending on Another Recipe File</title>
<para> <para>
<literallayout class='monospaced'> <literallayout class='monospaced'>
@@ -255,10 +266,13 @@ Options:
</section> </section>
<section id='using-provides'> <section id='using-provides'>
<title>Using PROVIDES</title> <title>Using <filename>PROVIDES</filename></title>
<para> <para>
This example shows the usage of the <varname>PROVIDES</varname> variable, which allows a given .bb to specify what functionality it provides. This example shows the usage of the
<filename>PROVIDES</filename> variable, which allows a
given <filename>.bb</filename> to specify what
functionality it provides.
<literallayout class='monospaced'> <literallayout class='monospaced'>
package1.bb: package1.bb:
@@ -273,7 +287,7 @@ This example shows the usage of the <varname>PROVIDES</varname> variable, which
PROVIDES += "virtual/package" PROVIDES += "virtual/package"
</literallayout> </literallayout>
As you can see, we have two different As you can see, we have two different
.bb's that provide the same functionality recipes that provide the same functionality
(virtual/package). (virtual/package).
Clearly, there needs to be a way for the person running Clearly, there needs to be a way for the person running
BitBake to control which of those providers BitBake to control which of those providers
@@ -282,7 +296,8 @@ This example shows the usage of the <varname>PROVIDES</varname> variable, which
</para> </para>
<para> <para>
The following would go into a .conf file, to select package1: The following would go into a <filename>.conf</filename>
file, to select package1:
<literallayout class='monospaced'> <literallayout class='monospaced'>
PREFERRED_PROVIDER_virtual/package = "package1" PREFERRED_PROVIDER_virtual/package = "package1"
</literallayout> </literallayout>
@@ -290,27 +305,27 @@ The following would go into a .conf file, to select package1:
</section> </section>
<section id='specifying-version-preference'> <section id='specifying-version-preference'>
<title>Specifying version preference</title> <title>Specifying Version Preference</title>
<para> <para>
When there are multiple <quote>versions</quote> of a given package, When there are multiple “versions” of a given package,
BitBake defaults to selecting the most recent version, BitBake defaults to selecting the most recent
unless otherwise specified. version, unless otherwise specified.
If the .bb in question has a If the <filename>.bb</filename> in question has a
<varname>DEFAULT_PREFERENCE</varname> set lower than <filename>DEFAULT_PREFERENCE</filename> set lower than
the other .bb's (default is 0), then it will not be the other recipes (default is 0), then it will not be
selected. selected.
This allows the person or persons maintaining This allows the person or persons maintaining
the repository of .bb files to specify the repository of <filename>.bb</filename> files to specify
their preference for the default selected version. their preference for the default selected version.
In addition, the user can specify their preferred version. In addition, the user can specify their preferred version.
</para> </para>
<para> <para>
If the first .bb is named If the first <filename>.bb</filename> is named
<filename>a_1.1.bb</filename>, then the <filename>a_1.1.bb</filename>, then the
<varname>PN</varname> variable will be set to <filename>PN</filename> variable will be set to
<quote>a</quote>, and the <varname>PV</varname> variable will be “a”, and the <filename>PV</filename> variable will be
set to 1.1. set to 1.1.
</para> </para>
@@ -318,27 +333,26 @@ The following would go into a .conf file, to select package1:
If we then have an <filename>a_1.2.bb</filename>, BitBake If we then have an <filename>a_1.2.bb</filename>, BitBake
will choose 1.2 by default. will choose 1.2 by default.
However, if we define the following variable in a However, if we define the following variable in a
.conf that BitBake parses, we <filename>.conf</filename> file that BitBake parses, we
can change that. can change that.
<literallayout class='monospaced'> <literallayout class='monospaced'>
PREFERRED_VERSION_a = "1.1" PREFERRED_VERSION_a = "1.1"
</literallayout> </literallayout>
</para> </para>
</section> </section>
<section id='using-recipe-file-collections'> <section id='using-recipe-file-collections'>
<title>Using <quote>bbfile collections</quote></title> <title>Using Recipe File Collections</title>
<para> <para>
bbfile collections exist to allow the user to Recipe file collections exist to allow the user to
have multiple repositories of have multiple repositories of
bbfiles that contain the same <filename>.bb</filename> files that contain the same
exact package. exact package.
For example, one could easily use them to make one's For example, one could easily use them to make one's
own local copy of an upstream repository, but with own local copy of an upstream repository, but with
custom modifications that one does not want upstream. custom modifications that one does not want upstream.
Usage: Here is an example:
<literallayout class='monospaced'> <literallayout class='monospaced'>
BBFILES = "/stuff/openembedded/*/*.bb /stuff/openembedded.modified/*/*.bb" BBFILES = "/stuff/openembedded/*/*.bb /stuff/openembedded.modified/*/*.bb"
BBFILE_COLLECTIONS = "upstream local" BBFILE_COLLECTIONS = "upstream local"