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<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="chapter" title="Chapter 10. Variables Glossary">
<div class="titlepage"><div><div><h2 class="title">
<a name="ref-variables-glos"></a>Chapter 10. Variables Glossary</h2></div></div></div>
<div class="toc">
<p><b>Table of Contents</b></p>
<dl><dt><span class="glossary"><a href="ref-variables-glos.html#ref-variables-glossary">Glossary</a></span></dt></dl>
</div>
<p>
This chapter lists common variables used in the OpenEmbedded build system and gives an overview
of their function and contents.
</p>
<div class="glossary" title="Glossary">
<div class="titlepage"><div><div><h2 class="title">
<a name="ref-variables-glossary"></a>Glossary</h2></div></div></div>
<p>
<a class="link" href="ref-variables-glos.html#var-ALLOW_EMPTY" title="ALLOW_EMPTY">A</a>
<a class="link" href="ref-variables-glos.html#var-B" title="B">B</a>
<a class="link" href="ref-variables-glos.html#var-CFLAGS" title="CFLAGS">C</a>
<a class="link" href="ref-variables-glos.html#var-D" title="D">D</a>
<a class="link" href="ref-variables-glos.html#var-ENABLE_BINARY_LOCALE_GENERATION" title="ENABLE_BINARY_LOCALE_GENERATION">E</a>
<a class="link" href="ref-variables-glos.html#var-FILES" title="FILES">F</a>
<a class="link" href="ref-variables-glos.html#var-HOMEPAGE" title="HOMEPAGE">H</a>
<a class="link" href="ref-variables-glos.html#var-IMAGE_FEATURES" title="IMAGE_FEATURES">I</a>
<a class="link" href="ref-variables-glos.html#var-KBRANCH" title="KBRANCH">K</a>
<a class="link" href="ref-variables-glos.html#var-LAYERDIR" title="LAYERDIR">L</a>
<a class="link" href="ref-variables-glos.html#var-MACHINE" title="MACHINE">M</a>
<a class="link" href="ref-variables-glos.html#var-OE_TERMINAL" title="OE_TERMINAL">O</a>
<a class="link" href="ref-variables-glos.html#var-P" title="P">P</a>
<a class="link" href="ref-variables-glos.html#var-RCONFLICTS" title="RCONFLICTS">R</a>
<a class="link" href="ref-variables-glos.html#var-S" title="S">S</a>
<a class="link" href="ref-variables-glos.html#var-T" title="T">T</a>
<a class="link" href="ref-variables-glos.html#var-WORKDIR" title="WORKDIR">W</a>
</p>
<div class="glossdiv" title="A">
<h3 class="title">A</h3>
<dl>
<dt>
<a name="var-ALLOW_EMPTY"></a>ALLOW_EMPTY</dt>
<dd>
<p>
Specifies if an output package should still be produced if it is empty.
By default, BitBake does not produce empty packages.
This default behavior can cause issues when there is an
<a class="link" href="ref-variables-glos.html#var-RDEPENDS" title="RDEPENDS"><code class="filename">RDEPENDS</code></a> or
some other runtime hard-requirement on the existence of the package.
</p>
<p>
Like all package-controlling variables, you must always use them in
conjunction with a package name override.
Here is an example:
</p>
<pre class="literallayout">
ALLOW_EMPTY_${PN} = "1"
</pre>
<p>
</p>
</dd>
<dt>
<a name="var-AUTHOR"></a>AUTHOR</dt>
<dd><p>The email address used to contact the original author or authors in
order to send patches, forward bugs, etc.</p></dd>
<dt>
<a name="var-AUTOREV"></a>AUTOREV</dt>
<dd>
<p>When <code class="filename"><a class="link" href="ref-variables-glos.html#var-SRCREV" title="SRCREV">SRCREV</a></code>
is set to the value of this variable, it specifies that the latest
source revision in the repository should be used. Here is an example:
</p>
<pre class="literallayout">
SRCREV = "${AUTOREV}"
</pre>
<p>
</p>
</dd>
</dl>
</div>
<div class="glossdiv" title="B">
<h3 class="title">B</h3>
<dl>
<dt>
<a name="var-B"></a>B</dt>
<dd>
<p>
The <a class="link" href="../dev-manual/build-directory.html" target="_self">Build Directory</a>.
The OpenEmbedded build system places generated objects into the Build Directory
during a recipe's build process.
By default, this directory is the same as the <a class="link" href="ref-variables-glos.html#var-S" title="S"><code class="filename">S</code></a>
directory:
</p>
<pre class="literallayout">
B = ${WORKDIR}/${BPN}-{PV}/
</pre>
<p>
You can separate the (<code class="filename">S</code>) directory and the directory pointed to
by the <code class="filename">B</code> variable.
Most autotools-based recipes support separating these directories.
The build system defaults to using separate directories for <code class="filename">gcc</code>
and some kernel recipes.
</p>
</dd>
<dt>
<a name="var-BAD_RECOMMENDATIONS"></a>BAD_RECOMMENDATIONS</dt>
<dd><p>
A list of packages not to install despite being recommended by a recipe.
Support for this variable exists only when using the
<code class="filename">ipk</code> packaging backend.
</p></dd>
<dt>
<a name="var-BB_DISKMON_DIRS"></a>BB_DISKMON_DIRS</dt>
<dd>
<p>
Monitors disk space and available inodes during the build
and allows you to control the build based on these
parameters.
</p>
<p>
Disk space monitoring is disabled by default.
To enable monitoring, add the <code class="filename">BB_DISKMON_DIRS</code>
variable to your <code class="filename">conf/local.conf</code> file found in the
<a class="link" href="../dev-manual/build-directory.html" target="_self">Build Directory</a>.
Use the following form:
</p>
<pre class="literallayout">
BB_DISKMON_DIRS = "&lt;action&gt;,&lt;dir&gt;,&lt;threshold&gt; [...]"
where:
&lt;action&gt; is:
ABORT: Immediately abort the build when
a threshold is broken.
STOPTASKS: Stop the build after the currently
executing tasks have finished when
a threshold is broken.
WARN: Issue a warning but continue the
build when a threshold is broken.
Subsequent warnings are issued as
defined by the
<a class="link" href="ref-variables-glos.html#var-BB_DISKMON_WARNINTERVAL" title="BB_DISKMON_WARNINTERVAL">BB_DISKMON_WARNINTERVAL</a> variable,
which must be defined in the
conf/local.conf file.
&lt;dir&gt; is:
Any directory you choose. You can specify one or
more directories to monitor by separating the
groupings with a space. If two directories are
on the same device, only the first directory
is monitored.
&lt;threshold&gt; is:
Either the minimum available disk space,
the minimum number of free inodes, or
both. You must specify at least one. To
omit one or the other, simply omit the value.
Specify the threshold using G, M, K for Gbytes,
Mbytes, and Kbytes, respectively. If you do
not specify G, M, or K, Kbytes is assumed by
default. Do not use GB, MB, or KB.
</pre>
<p>
</p>
<p>
Here are some examples:
</p>
<pre class="literallayout">
BB_DISKMON_DIRS = "ABORT,${TMPDIR},1G,100K WARN,${SSTATE_DIR},1G,100K"
BB_DISKMON_DIRS = "STOPTASKS,${TMPDIR},1G"
BB_DISKMON_DIRS = "ABORT,${TMPDIR},,100K"
</pre>
<p>
The first example works only if you also provide
the <a class="link" href="ref-variables-glos.html#var-BB_DISKMON_WARNINTERVAL" title="BB_DISKMON_WARNINTERVAL"><code class="filename">BB_DISKMON_WARNINTERVAL</code></a> variable
in the <code class="filename">conf/local.conf</code>.
This example causes the build system to immediately
abort when either the disk space in <code class="filename">${TMPDIR}</code> drops
below 1 Gbyte or the available free inodes drops below
100 Kbytes.
Because two directories are provided with the variable, the
build system also issue a
warning when the disk space in the
<code class="filename">${SSTATE_DIR}</code> directory drops
below 1 Gbyte or the number of free inodes drops
below 100 Kbytes.
Subsequent warnings are issued during intervals as
defined by the <code class="filename">BB_DISKMON_WARNINTERVAL</code>
variable.
</p>
<p>
The second example stops the build after all currently
executing tasks complete when the minimum disk space
in the <code class="filename">${TMPDIR}</code> directory drops
below 1 Gbyte.
No disk monitoring occurs for the free inodes in this case.
</p>
<p>
The final example immediately aborts the build when the
number of free inodes in the <code class="filename">${TMPDIR}</code> directory
drops below 100 Kbytes.
No disk space monitoring for the directory itself occurs
in this case.
</p>
</dd>
<dt>
<a name="var-BB_DISKMON_WARNINTERVAL"></a>BB_DISKMON_WARNINTERVAL</dt>
<dd>
<p>
Defines the disk space and free inode warning intervals.
To set these intervals, define the variable in your
<code class="filename">conf/local.conf</code> file in the
<a class="link" href="../dev-manual/build-directory.html" target="_self">Build Directory</a>.
</p>
<p>
If you are going to use the
<code class="filename">BB_DISKMON_WARNINTERVAL</code> variable, you must
also use the
<a class="link" href="ref-variables-glos.html#var-BB_DISKMON_DIRS" title="BB_DISKMON_DIRS"><code class="filename">BB_DISKMON_DIRS</code></a> variable
and define its action as "WARN".
During the build, subsequent warnings are issued each time
disk space or number of free inodes further reduces by
the respective interval.
</p>
<p>
If you do not provide a <code class="filename">BB_DISKMON_WARNINTERVAL</code>
variable and you do use <code class="filename">BB_DISKMON_DIRS</code> with
the "WARN" action, the disk monitoring interval defaults to
the following:
</p>
<pre class="literallayout">
BB_DISKMON_WARNINTERVAL = "50M,5K"
</pre>
<p>
</p>
<p>
When specifying the variable in your configuration file,
use the following form:
</p>
<pre class="literallayout">
BB_DISKMON_WARNINTERVAL = "&lt;disk_space_interval&gt;,&lt;disk_inode_interval&gt;"
where:
&lt;disk_space_interval&gt; is:
An interval of memory expressed in either
G, M, or K for Gbytes, Mbytes, or Kbytes,
respectively. You cannot use GB, MB, or KB.
&lt;disk_inode_interval&gt; is:
An interval of free inodes expressed in either
G, M, or K for Gbytes, Mbytes, or Kbytes,
respectively. You cannot use GB, MB, or KB.
</pre>
<p>
</p>
<p>
Here is an example:
</p>
<pre class="literallayout">
BB_DISKMON_DIRS = "WARN,${SSTATE_DIR},1G,100K"
BB_DISKMON_WARNINTERVAL = "50M,5K"
</pre>
<p>
These variables cause the OpenEmbedded build system to
issue subsequent warnings each time the available
disk space further reduces by 50 Mbytes or the number
of free inodes further reduces by 5 Kbytes in the
<code class="filename">${SSTATE_DIR}</code> directory.
Subsequent warnings based on the interval occur each time
a respective interval is reached beyond the intial warning
(i.e. 1 Gbytes and 100 Kbytes).
</p>
</dd>
<dt>
<a name="var-BBCLASSEXTEND"></a>BBCLASSEXTEND</dt>
<dd>
<p>
Allows you to extend a recipe so that it builds variants of the software.
Common variants for recipes exist such as "natives" like <code class="filename">quilt-native</code>,
which is a copy of quilt built to run on the build system;
"crosses" such as <code class="filename">gcc-cross</code>,
which is a compiler built to run on the build machine but produces binaries
that run on the target <a class="link" href="ref-variables-glos.html#var-MACHINE" title="MACHINE"><code class="filename">MACHINE</code></a>;
"nativesdk", which targets the SDK machine instead of <code class="filename">MACHINE</code>;
and "mulitlibs" in the form "<code class="filename">multilib:&lt;multilib_name&gt;</code>".
</p>
<p>
To build a different variant of the recipe with a minimal amount of code, it usually
is as simple as adding the following to your recipe:
</p>
<pre class="literallayout">
BBCLASSEXTEND =+ "native nativesdk"
BBCLASSEXTEND =+ "multilib:&lt;multilib_name&gt;"
</pre>
<p>
</p>
</dd>
<dt>
<a name="var-BBMASK"></a>BBMASK</dt>
<dd>
<p>Prevents BitBake from processing recipes and recipe append files.
You can use the <code class="filename">BBMASK</code> variable to "hide"
these <code class="filename">.bb</code> and <code class="filename">.bbappend</code> files.
BitBake ignores any recipe or recipe append files that match the expression.
It is as if BitBake does not see them at all.
Consequently, matching files are not parsed or otherwise used by
BitBake.</p>
<p>The value you provide is passed to python's regular expression compiler.
For complete syntax information, see python's documentation at
<a class="ulink" href="http://docs.python.org/release/2.3/lib/re-syntax.html" target="_self">http://docs.python.org/release/2.3/lib/re-syntax.html</a>.
The expression is compared against the full paths to the files.
For example, the following uses a complete regular expression to tell
BitBake to ignore all recipe and recipe append files in the
<code class="filename">.*/meta-ti/recipes-misc/</code> directory:
</p>
<pre class="literallayout">
BBMASK = ".*/meta-ti/recipes-misc/"
</pre>
<p>Use the <code class="filename">BBMASK</code> variable from within the
<code class="filename">conf/local.conf</code> file found
in the <a class="link" href="../dev-manual/build-directory.html" target="_self">Build Directory</a>.</p>
</dd>
<dt>
<a name="var-BB_NUMBER_THREADS"></a>BB_NUMBER_THREADS</dt>
<dd><p>The maximum number of tasks BitBake should run in parallel at any one time.
If your host development system supports multiple cores a good rule of thumb
is to set this variable to twice the number of cores.</p></dd>
<dt>
<a name="var-BBFILE_COLLECTIONS"></a>BBFILE_COLLECTIONS</dt>
<dd><p>Lists the names of configured layers.
These names are used to find the other <code class="filename">BBFILE_*</code>
variables.
Typically, each layer will append its name to this variable in its
<code class="filename">conf/layer.conf</code> file.
</p></dd>
<dt>
<a name="var-BBFILE_PATTERN"></a>BBFILE_PATTERN</dt>
<dd><p>Variable that expands to match files from <code class="filename">BBFILES</code> in a particular layer.
This variable is used in the <code class="filename">conf/layer.conf</code> file and must
be suffixed with the name of the specific layer (e.g.
<code class="filename">BBFILE_PATTERN_emenlow</code>).</p></dd>
<dt>
<a name="var-BBFILE_PRIORITY"></a>BBFILE_PRIORITY</dt>
<dd>
<p>Assigns the priority for recipe files in each layer.</p>
<p>This variable is useful in situations where the same recipe appears in
more than one layer.
Setting this variable allows you to prioritize a
layer against other layers that contain the same recipe - effectively
letting you control the precedence for the multiple layers.
The precedence established through this variable stands regardless of a
recipe's version (<code class="filename">PV</code> variable).
For example, a layer that has a recipe with a higher <code class="filename">PV</code> value but for
which the <code class="filename">BBFILE_PRIORITY</code> is set to have a lower precedence still has a
lower precedence.</p>
<p>A larger value for the <code class="filename">BBFILE_PRIORITY</code> variable results in a higher
precedence.
For example, the value 6 has a higher precedence than the value 5.
If not specified, the <code class="filename">BBFILE_PRIORITY</code> variable is set based on layer
dependencies (see the
<code class="filename"><a class="link" href="ref-variables-glos.html#var-LAYERDEPENDS" title="LAYERDEPENDS">LAYERDEPENDS</a></code> variable for
more information.
The default priority, if unspecified
for a layer with no dependencies, is the lowest defined priority + 1
(or 1 if no priorities are defined).</p>
<div class="tip" title="Tip" style="margin-left: 0.5in; margin-right: 0.5in;">
<h3 class="title">Tip</h3>
You can use the command <code class="filename">bitbake-layers show_layers</code> to list
all configured layers along with their priorities.
</div>
</dd>
<dt>
<a name="var-BBFILES"></a>BBFILES</dt>
<dd><p>List of recipe files used by BitBake to build software</p></dd>
<dt>
<a name="var-BBPATH"></a>BBPATH</dt>
<dd><p>Used by BitBake to locate <code class="filename">.bbclass</code> and configuration files.
This variable is analogous to the <code class="filename">PATH</code> variable.</p></dd>
<dt>
<a name="var-BBINCLUDELOGS"></a>BBINCLUDELOGS</dt>
<dd><p>Variable that controls how BitBake displays logs on build failure.</p></dd>
<dt>
<a name="var-BBLAYERS"></a>BBLAYERS</dt>
<dd>
<p>Lists the layers to enable during the build.
This variable is defined in the <code class="filename">bblayers.conf</code> configuration
file in the <a class="link" href="../dev-manual/build-directory.html" target="_self">Build Directory</a>.
Here is an example:
</p>
<pre class="literallayout">
BBLAYERS = " \
/home/scottrif/poky/meta \
/home/scottrif/poky/meta-yocto \
/home/scottrif/poky/meta-yocto-bsp \
/home/scottrif/poky/meta-mykernel \
"
</pre>
<p>
This example enables four layers, one of which is a custom, user-defined layer
named <code class="filename">meta-mykernel</code>.
</p>
</dd>
<dt>
<a name="var-BP"></a>BP</dt>
<dd>
<p>The base recipe name and version but without any special
recipe name suffix (i.e. <code class="filename">-native</code>, <code class="filename">lib64-</code>,
and so forth).
<code class="filename">BP</code> is comprised of the following:
</p>
<pre class="literallayout">
${BPN}-${PV}
</pre>
</dd>
<dt>
<a name="var-BPN"></a>BPN</dt>
<dd><p>The bare name of the recipe.
This variable is a version of the <a class="link" href="ref-variables-glos.html#var-PN" title="PN"><code class="filename">PN</code></a> variable
but removes common suffixes such as "-native" and "-cross" as well
as removes common prefixes such as multilib's "lib64-" and "lib32-".
The exact list of suffixes removed is specified by the
<a class="link" href="ref-variables-glos.html#var-SPECIAL_PKGSUFFIX" title="SPECIAL_PKGSUFFIX"><code class="filename">SPECIAL_PKGSUFFIX</code></a> variable.
The exact list of prefixes removed is specified by the
<a class="link" href="ref-variables-glos.html#var-MLPREFIX" title="MLPREFIX"><code class="filename">MLPREFIX</code></a> variable.
Prefixes are removed for multilib and nativesdk cases.</p></dd>
</dl>
</div>
<div class="glossdiv" title="C">
<h3 class="title">C</h3>
<dl>
<dt>
<a name="var-CFLAGS"></a>CFLAGS</dt>
<dd><p>
Flags passed to C compiler for the target system.
This variable evaluates to the same as
<code class="filename"><a class="link" href="ref-variables-glos.html#var-TARGET_CFLAGS" title="TARGET_CFLAGS">TARGET_CFLAGS</a></code>.
</p></dd>
<dt>
<a name="var-COMBINED_FEATURES"></a>COMBINED_FEATURES</dt>
<dd><p>A set of features common between
<a class="link" href="ref-variables-glos.html#var-MACHINE_FEATURES" title="MACHINE_FEATURES"><code class="filename">MACHINE_FEATURES</code></a>
and <a class="link" href="ref-variables-glos.html#var-DISTRO_FEATURES" title="DISTRO_FEATURES"><code class="filename">DISTRO_FEATURES</code></a>.
See the glossary descriptions for these variables for more information.</p></dd>
<dt>
<a name="var-COMPATIBLE_MACHINE"></a>COMPATIBLE_MACHINE</dt>
<dd><p>A regular expression which evaluates to match the machines the recipe
works with.
It stops recipes being run on machines for which they are not compatible.
This is particularly useful with kernels.
It also helps to increase parsing speed as further parsing of the recipe is skipped
if it is found the current machine is not compatible.</p></dd>
<dt>
<a name="var-CONFFILES"></a>CONFFILES</dt>
<dd>
<p>
Identifies editable or configurable files that are part of a package.
If the Package Management System (PMS) is being used to update
packages on the target system, it is possible that
configuration files you have changed after the original installation
and that you now want to remain unchanged are overwritten.
In other words, editable files might exist in the package that you do not
want reset as part of the package update process.
You can use the <code class="filename">CONFFILES</code> variable to list the files in the
package that you wish to prevent the PMS from overwriting during this update process.
</p>
<p>
To use the <code class="filename">CONFFILES</code> variable, provide a package name
override that identifies the resulting package.
Then, provide a space-separated list of files.
Here is an example:
</p>
<pre class="literallayout">
CONFFILES_${PN} += "${sysconfdir}/file1 \
${sysconfdir}/file2 ${sysconfdir}/file3"
</pre>
<p>
</p>
<p>
A relationship exists between the <code class="filename">CONFFILES</code> and
<code class="filename"><a class="link" href="ref-variables-glos.html#var-FILES" title="FILES">FILES</a></code> variables.
The files listed within <code class="filename">CONFFILES</code> must be a subset of
the files listed within <code class="filename">FILES</code>.
Because the configuration files you provide with <code class="filename">CONFFILES</code>
are simply being identified so that the PMS will not overwrite them,
it makes sense that
the files must already be included as part of the package through the
<code class="filename">FILES</code> variable.
</p>
<div class="note" title="Note" style="margin-left: 0.5in; margin-right: 0.5in;">
<h3 class="title">Note</h3>
When specifying paths as part of the <code class="filename">CONFFILES</code> variable,
it is good practice to use appropriate path variables.
For example, <code class="filename">${sysconfdir}</code> rather than
<code class="filename">/etc</code> or <code class="filename">${bindir}</code> rather
than <code class="filename">/usr/bin</code>.
You can find a list of these variables at the top of the
<code class="filename">/meta/conf/bitbake.conf</code> file in the
<a class="link" href="../dev-manual/source-directory.html" target="_self">Source Directory</a>.
</div>
</dd>
<dt>
<a name="var-CONFIG_SITE"></a>CONFIG_SITE</dt>
<dd><p>
A list of files that contains <code class="filename">autoconf</code> test results relevant
to the current build.
This variable is used by the Autotools utilities when running
<code class="filename">configure</code>.
</p></dd>
<dt>
<a name="var-CORE_IMAGE_EXTRA_INSTALL"></a>CORE_IMAGE_EXTRA_INSTALL</dt>
<dd>
<p>
Specifies the list of packages to be added to the image.
This variable should only be set in the <code class="filename">local.conf</code>
configuration file found in the
<a class="link" href="../dev-manual/build-directory.html" target="_self">Build Directory</a>.
</p>
<p>
This variable replaces <code class="filename">POKY_EXTRA_INSTALL</code>, which is no longer supported.
</p>
</dd>
</dl>
</div>
<div class="glossdiv" title="D">
<h3 class="title">D</h3>
<dl>
<dt>
<a name="var-D"></a>D</dt>
<dd><p>The destination directory.</p></dd>
<dt>
<a name="var-DEBUG_BUILD"></a>DEBUG_BUILD</dt>
<dd><p>
Specifies to build packages with debugging information.
This influences the value of the
<code class="filename"><a class="link" href="ref-variables-glos.html#var-SELECTED_OPTIMIZATION" title="SELECTED_OPTIMIZATION">SELECTED_OPTIMIZATION</a></code>
variable.
</p></dd>
<dt>
<a name="var-DEBUG_OPTIMIZATION"></a>DEBUG_OPTIMIZATION</dt>
<dd><p>
The options to pass in
<code class="filename"><a class="link" href="ref-variables-glos.html#var-TARGET_CFLAGS" title="TARGET_CFLAGS">TARGET_CFLAGS</a></code>
and <code class="filename"><a class="link" href="ref-variables-glos.html#var-CFLAGS" title="CFLAGS">CFLAGS</a></code> when compiling
a system for debugging.
This variable defaults to "-O -fno-omit-frame-pointer -g".
</p></dd>
<dt>
<a name="var-DEFAULT_PREFERENCE"></a>DEFAULT_PREFERENCE</dt>
<dd><p>Specifies the priority of recipes.</p></dd>
<dt>
<a name="var-DEPENDS"></a>DEPENDS</dt>
<dd><p>
Lists a recipe's build-time dependencies
(i.e. other recipe files).
The system ensures that all the dependencies listed
have been built and have their contents in the appropriate
sysroots before the recipe's configure task is executed.
</p></dd>
<dt>
<a name="var-DESCRIPTION"></a>DESCRIPTION</dt>
<dd><p>The package description used by package managers.
If not set, <code class="filename">DESCRIPTION</code> takes
the value of the
<a class="link" href="ref-variables-glos.html#var-SUMMARY" title="SUMMARY"><code class="filename">SUMMARY</code></a>
variable.
</p></dd>
<dt>
<a name="var-DESTDIR"></a>DESTDIR</dt>
<dd><p>the destination directory.</p></dd>
<dt>
<a name="var-DISTRO"></a>DISTRO</dt>
<dd>
<p>
The short name of the distribution.
This variable corresponds to a file with the
extension <code class="filename">.conf</code>
located in a <code class="filename">conf/distro</code> directory
within the metadata that contains the distribution configuration.
The
value must not contain spaces, and is typically all lower-case.
</p>
<p>
If the variable is blank, a set of default configuration
will be used, which is specified
within <code class="filename">meta/conf/distro/defaultsetup.conf</code>.
</p>
</dd>
<dt>
<a name="var-DISTRO_EXTRA_RDEPENDS"></a>DISTRO_EXTRA_RDEPENDS</dt>
<dd><p>
Specifies a list of distro-specific packages to add to all images.
This variable takes affect through
<code class="filename">packagegroup-base</code> so the
variable only really applies to the more full-featured
images that include <code class="filename">packagegroup-base</code>.
You can use this variable to keep distro policy out of
generic images.
As with all other distro variables, you set this variable
in the distro <code class="filename">.conf</code> file.
</p></dd>
<dt>
<a name="var-DISTRO_EXTRA_RRECOMMENDS"></a>DISTRO_EXTRA_RRECOMMENDS</dt>
<dd><p>
Specifies a list of distro-specific packages to add to all images
if the packages exist.
The packages might not exist or be empty (e.g. kernel modules).
The list of packages are automatically installed but can be
removed by the user.
</p></dd>
<dt>
<a name="var-DISTRO_FEATURES"></a>DISTRO_FEATURES</dt>
<dd><p>The features enabled for the distribution.
For a list of features supported by the Yocto Project as shipped,
see the "<a class="link" href="ref-features-distro.html" title="9.1. Distro">Distro</a>"
section.
</p></dd>
<dt>
<a name="var-DISTRO_FEATURES_BACKFILL"></a>DISTRO_FEATURES_BACKFILL</dt>
<dd>
<p>Features to be added to
<code class="filename"><a class="link" href="ref-variables-glos.html#var-DISTRO_FEATURES" title="DISTRO_FEATURES">DISTRO_FEATURES</a></code>
if not also present in
<code class="filename"><a class="link" href="ref-variables-glos.html#var-DISTRO_FEATURES_BACKFILL_CONSIDERED" title="DISTRO_FEATURES_BACKFILL_CONSIDERED">DISTRO_FEATURES_BACKFILL_CONSIDERED</a></code>.
</p>
<p>
This variable is set in the <code class="filename">meta/conf/bitbake.conf</code> file.
It is not intended to be user-configurable.
It is best to just reference the variable to see which distro features are
being backfilled for all distro configurations.
See the <a class="link" href="ref-features-backfill.html" title="9.4. Feature Backfilling">Feature backfilling</a> section for
more information.
</p>
</dd>
<dt>
<a name="var-DISTRO_FEATURES_BACKFILL_CONSIDERED"></a>DISTRO_FEATURES_BACKFILL_CONSIDERED</dt>
<dd><p>Features from
<code class="filename"><a class="link" href="ref-variables-glos.html#var-DISTRO_FEATURES_BACKFILL" title="DISTRO_FEATURES_BACKFILL">DISTRO_FEATURES_BACKFILL</a></code>
that should not backfilled (i.e. added to
<code class="filename"><a class="link" href="ref-variables-glos.html#var-DISTRO_FEATURES" title="DISTRO_FEATURES">DISTRO_FEATURES</a></code>)
during the build.
See the "<a class="link" href="ref-features-backfill.html" title="9.4. Feature Backfilling">Feature Backfilling</a>" section for
more information.
</p></dd>
<dt>
<a name="var-DISTRO_NAME"></a>DISTRO_NAME</dt>
<dd><p>The long name of the distribution.</p></dd>
<dt>
<a name="var-DISTRO_PN_ALIAS"></a>DISTRO_PN_ALIAS</dt>
<dd>
<p>Alias names used for the recipe in various Linux distributions.</p>
<p>See the
"<a class="link" href="../dev-manual/usingpoky-configuring-DISTRO_PN_ALIAS.html" target="_self">Handling
a Package Name Alias</a>" section in the Yocto Project Development
Manual for more information.</p>
</dd>
<dt>
<a name="var-DISTRO_VERSION"></a>DISTRO_VERSION</dt>
<dd><p>the version of the distribution.</p></dd>
<dt>
<a name="var-DL_DIR"></a>DL_DIR</dt>
<dd>
<p>
The central download directory used by the build process to store downloads.
You can set this directory by defining the <code class="filename">DL_DIR</code>
variable in the <code class="filename">/conf/local.conf</code> file.
This directory is self-maintaining and you should not have
to touch it.
By default, the directory is <code class="filename">downloads</code> in the
<a class="link" href="../dev-manual/build-directory.html" target="_self">Build Directory</a>.
</p>
<pre class="literallayout">
#DL_DIR ?= "${TOPDIR}/downloads"
</pre>
<p>
To specify a different download directory, simply uncomment the line
and provide your directory.
</p>
<p>
During a first build, the system downloads many different source code
tarballs from various upstream projects.
Downloading can take a while, particularly if your network
connection is slow.
Tarballs are all stored in the directory defined by
<code class="filename">DL_DIR</code> and the build system looks there first
to find source tarballs.
</p>
<div class="note" title="Note" style="margin-left: 0.5in; margin-right: 0.5in;">
<h3 class="title">Note</h3>
When wiping and rebuilding, you can preserve this directory to speed
up this part of subsequent builds.
</div>
<p>
</p>
<p>
You can safely share this directory between multiple builds on the
same development machine.
For additional information on how the build process gets source files
when working behind a firewall or proxy server, see the
"<a class="link" href="faq.html#how-does-the-yocto-project-obtain-source-code-and-will-it-work-behind-my-firewall-or-proxy-server">FAQ</a>"
chapter.
</p>
</dd>
</dl>
</div>
<div class="glossdiv" title="E">
<h3 class="title">E</h3>
<dl>
<dt>
<a name="var-ENABLE_BINARY_LOCALE_GENERATION"></a>ENABLE_BINARY_LOCALE_GENERATION</dt>
<dd>
<p></p>
<p>Variable that controls which locales for <code class="filename">eglibc</code> are
to be generated during the build (useful if the target device has 64Mbytes
of RAM or less).</p>
</dd>
<dt>
<a name="var-EXTENDPE"></a>EXTENDPE</dt>
<dd>
<p>
Used with file and pathnames to create a prefix for a recipe's
version based on the recipe's
<a class="link" href="ref-variables-glos.html#var-PE" title="PE"><code class="filename">PE</code></a> value.
If <code class="filename">PE</code> is set and greater than zero for a recipe,
<code class="filename">EXTENDPE</code> becomes that value (e.g if
<code class="filename">PE</code> is equal to "1" then <code class="filename">EXTENDPE</code>
becomes "1_").
If a recipe's <code class="filename">PE</code> is not set (the default) or is equal to
zero, <code class="filename">EXTENDPE</code> becomes "".</p>
<p>See the <a class="link" href="ref-variables-glos.html#var-STAMP" title="STAMP"><code class="filename">STAMP</code></a>
variable for an example.
</p>
</dd>
<dt>
<a name="var-EXTRA_IMAGE_FEATURES"></a>EXTRA_IMAGE_FEATURES</dt>
<dd>
<p>Allows extra packages to be added to the generated images.
You set this variable in the <code class="filename">local.conf</code>
configuration file.
Note that some image features are also added using the
<code class="filename"><a class="link" href="ref-variables-glos.html#var-IMAGE_FEATURES" title="IMAGE_FEATURES">IMAGE_FEATURES</a></code>
variable generally configured in image recipes.
You can use this variable to add more features in addition to those.
Here are some examples of features you can add:</p>
<pre class="literallayout">
"dbg-pkgs" - Adds -dbg packages for all installed packages
including symbol information for debugging and
profiling.
"dev-pkgs" - Adds -dev packages for all installed packages.
This is useful if you want to develop against
the libraries in the image.
"tools-sdk" - Adds development tools such as gcc, make,
pkgconfig and so forth.
"tools-debug" - Adds debugging tools such as gdb and
strace.
"tools-profile" - Adds profiling tools such as oprofile,
exmap, lttng and valgrind (x86 only).
"tools-testapps" - Adds useful testing tools such as
ts_print, aplay, arecord and so
forth.
"debug-tweaks" - Makes an image suitable for development.
For example, ssh root access has a blank
password. You should remove this feature
before you produce a production image.
</pre>
<p>There are other valid features too, see the
<a class="link" href="ref-features-image.html" title="9.3. Images">Images</a>
section for more details.</p>
</dd>
<dt>
<a name="var-EXTRA_IMAGEDEPENDS"></a>EXTRA_IMAGEDEPENDS</dt>
<dd>
<p>A list of recipes to be built that do not provide packages to be installed in
the root filesystem.
</p>
<p>Sometimes a recipe is required to build the final image but is not
needed in the root filesystem.
You can use the <code class="filename">EXTRA_IMAGEDEPENDS</code> variable to
list these recipes and thus, specify the dependencies.
A typical example is a required bootloader in a machine configuration.
</p>
<div class="note" title="Note" style="margin-left: 0.5in; margin-right: 0.5in;">
<h3 class="title">Note</h3>
To add packages to the root filesystem, see the various
<code class="filename">*DEPENDS</code> and <code class="filename">*RECOMMENDS</code>
variables.
</div>
</dd>
<dt>
<a name="var-EXTRA_OECMAKE"></a>EXTRA_OECMAKE</dt>
<dd><p>Additional <code class="filename">cmake</code> options.</p></dd>
<dt>
<a name="var-EXTRA_OECONF"></a>EXTRA_OECONF</dt>
<dd><p>Additional <code class="filename">configure</code> script options.</p></dd>
<dt>
<a name="var-EXTRA_OEMAKE"></a>EXTRA_OEMAKE</dt>
<dd><p>Additional GNU <code class="filename">make</code> options.</p></dd>
</dl>
</div>
<div class="glossdiv" title="F">
<h3 class="title">F</h3>
<dl>
<dt>
<a name="var-FILES"></a>FILES</dt>
<dd>
<p>
The list of directories or files that are placed in packages.
</p>
<p>
To use the <code class="filename">FILES</code> variable, provide a package name
override that identifies the resulting package.
Then, provide a space-separated list of files or paths that identifies the
files you want included as part of the resulting package.
Here is an example:
</p>
<pre class="literallayout">
FILES_${PN} += "${bindir}/mydir1/ ${bindir}/mydir2/myfile"
</pre>
<p>
</p>
<div class="note" title="Note" style="margin-left: 0.5in; margin-right: 0.5in;">
<h3 class="title">Note</h3>
When specifying paths as part of the <code class="filename">FILES</code> variable,
it is good practice to use appropriate path variables.
For example, <code class="filename">${sysconfdir}</code> rather than
<code class="filename">/etc</code> or <code class="filename">${bindir}</code> rather
than <code class="filename">/usr/bin</code>.
You can find a list of these variables at the top of the
<code class="filename">/meta/conf/bitbake.conf</code> file in the
<a class="link" href="../dev-manual/source-directory.html" target="_self">Source Directory</a>.
</div>
<p>
If some of the files you provide with the <code class="filename">FILES</code> variable
are editable and you know they should not be
overwritten during the package update process by the Package Management
System (PMS), you can identify these files so that the PMS will not
overwrite them.
See the <code class="filename"><a class="link" href="ref-variables-glos.html#var-CONFFILES" title="CONFFILES">CONFFILES</a></code>
variable for information on how to identify these files to the PMS.
</p>
</dd>
<dt>
<a name="var-FILESEXTRAPATHS"></a>FILESEXTRAPATHS</dt>
<dd>
<p>
Extends the search path the OpenEmbedded build system uses when
looking for files and patches as it processes recipes.
The directories BitBake uses when it processes recipes is defined by the
<a class="link" href="ref-variables-glos.html#var-FILESPATH" title="FILESPATH"><code class="filename">FILESPATH</code></a> variable.
You can add directories to the search path by defining the
<code class="filename">FILESEXTRAPATHS</code> variable.
</p>
<p>
To add paths to the search order, provide a list of directories and separate
each path using a colon character as follows:
</p>
<pre class="literallayout">
FILESEXTRAPATHS_prepend := "path_1:path_2:path_3:"
</pre>
<p>
Typically, you want your directories search first.
To make sure that happens, use <code class="filename">_prepend</code> and
the immediate expansion (<code class="filename">:=</code>) operator as shown in the
previous example.
Finally, to maintain the integrity of the <code class="filename">FILESPATH</code> variable,
you must include the appropriate beginning or ending (as needed) colon character.
</p>
<p>
The <code class="filename">FILESEXTRAPATHS</code> variable is intended for use in
<code class="filename">.bbappend</code> files to include any additional files provided in that layer.
You typically accomplish this with the following:
</p>
<pre class="literallayout">
FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
</pre>
<p>
</p>
</dd>
<dt>
<a name="var-FILESPATH"></a>FILESPATH</dt>
<dd>
<p>
The default set of directories the OpenEmbedded build system uses
when searching for patches and files.
During the build process, BitBake searches each directory in
<code class="filename">FILESPATH</code> in the specified order when looking for
files and patches specified by each <code class="filename">file://</code> URI in a recipe.
</p>
<p>
The default value for the <code class="filename">FILESPATH</code> variable is defined
in the <code class="filename">base.bbclass</code> class found in
<code class="filename">meta/classes</code> in the
<a class="link" href="../dev-manual/source-directory.html" target="_self">Source Directory</a>:
</p>
<pre class="literallayout">
FILESPATH = "${@base_set_filespath([ "${FILE_DIRNAME}/${PF}", \
"${FILE_DIRNAME}/${P}", "${FILE_DIRNAME}/${PN}", \
"${FILE_DIRNAME}/${BP}", "${FILE_DIRNAME}/${BPN}", \
"${FILE_DIRNAME}/files", "${FILE_DIRNAME}" ], d)}"
</pre>
<p>
Do not hand-edit the <code class="filename">FILESPATH</code> variable.
If you want to extend the set of pathnames that BitBake uses when searching for
files and patches, use the
<a class="link" href="ref-variables-glos.html#var-FILESEXTRAPATHS" title="FILESEXTRAPATHS"><code class="filename">FILESEXTRAPATHS</code></a> variable.
</p>
</dd>
<dt>
<a name="var-FILESYSTEM_PERMS_TABLES"></a>FILESYSTEM_PERMS_TABLES</dt>
<dd>
<p>Allows you to define your own file permissions settings table as part of
your configuration for the packaging process.
For example, suppose you need a consistent set of custom permissions for
a set of groups and users across an entire work project.
It is best to do this in the packages themselves but this is not always
possible.
</p>
<p>
By default, the OpenEmbedded build system uses the <code class="filename">fs-perms.txt</code>, which
is located in the <code class="filename">meta/files</code> folder in the
<a class="link" href="../dev-manual/source-directory.html" target="_self">Source Directory</a>.
If you create your own file permissions setting table, you should place it in your
layer or the distros layer.
</p>
<p>
You define the <code class="filename">FILESYSTEM_PERMS_TABLES</code> variable in the
<code class="filename">conf/local.conf</code> file, which is found in the
<a class="link" href="../dev-manual/build-directory.html" target="_self">Build Directory</a>, to
point to your custom <code class="filename">fs-perms.txt</code>.
You can specify more than a single file permissions setting table.
The paths you specify to these files must be defined within the
<code class="filename">BBPATH</code> variable.
</p>
<p>
For guidance on how to create your own file permissions settings table file,
examine the existing <code class="filename">fs-perms.txt</code>.
</p>
</dd>
<dt>
<a name="var-FULL_OPTIMIZATION"></a>FULL_OPTIMIZATION</dt>
<dd><p>
The options to pass in
<code class="filename"><a class="link" href="ref-variables-glos.html#var-TARGET_CFLAGS" title="TARGET_CFLAGS">TARGET_CFLAGS</a></code>
and <code class="filename"><a class="link" href="ref-variables-glos.html#var-CFLAGS" title="CFLAGS">CFLAGS</a></code>
when compiling an optimized system.
This variable defaults to
"-fexpensive-optimizations -fomit-frame-pointer -frename-registers -O2".
</p></dd>
</dl>
</div>
<div class="glossdiv" title="H">
<h3 class="title">H</h3>
<dl>
<dt>
<a name="var-HOMEPAGE"></a>HOMEPAGE</dt>
<dd><p>Website where more information about the software the recipe is building
can be found.</p></dd>
</dl>
</div>
<div class="glossdiv" title="I">
<h3 class="title">I</h3>
<dl>
<dt>
<a name="var-IMAGE_FEATURES"></a>IMAGE_FEATURES</dt>
<dd><p>The list of features to include in an image.
Typically, you configure this variable in an image recipe.
Note that you can also add extra features to the image by using the
<code class="filename"><a class="link" href="ref-variables-glos.html#var-EXTRA_IMAGE_FEATURES" title="EXTRA_IMAGE_FEATURES">EXTRA_IMAGE_FEATURES</a></code> variable.
See the "<a class="link" href="ref-features-image.html" title="9.3. Images">Images</a>" section for the
full list of features that can be included in images built by the
OpenEmbedded build system.</p></dd>
<dt>
<a name="var-IMAGE_FSTYPES"></a>IMAGE_FSTYPES</dt>
<dd><p>Formats of root filesystem images that you want to have created.</p></dd>
<dt>
<a name="var-IMAGE_INSTALL"></a>IMAGE_INSTALL</dt>
<dd>
<p>
Specifies the packages to install into an image.
The <code class="filename">IMAGE_INSTALL</code> variable is a mechanism for an image
recipe and you should use it with care to avoid ordering issues.
</p>
<p>
Image recipes set <code class="filename">IMAGE_INSTALL</code> to specify the
packages to install into an image through <code class="filename">image.bbclass</code>.
Additionally, "helper" classes exist, such as <code class="filename">core-image.bbclass</code>,
that can take
<code class="filename"><a class="link" href="ref-variables-glos.html#var-IMAGE_FEATURES" title="IMAGE_FEATURES">IMAGE_FEATURES</a></code> lists
and turn these into auto-generated entries in
<code class="filename">IMAGE_INSTALL</code> in addition to its default contents.
</p>
<p>
Using <code class="filename">IMAGE_INSTALL</code> with the <code class="filename">+=</code>
operator from the <code class="filename">/conf/local.conf</code> file or from within
an image recipe is not recommended as it can cause ordering issues.
Since <code class="filename">core-image.bbclass</code> sets <code class="filename">IMAGE_INSTALL</code>
to a default value using the <code class="filename">?=</code> operator, using a
<code class="filename">+=</code> operation against <code class="filename">IMAGE_INSTALL</code>
will result in unexpected behavior when used in
<code class="filename">/conf/local.conf</code>.
Furthermore, the same operation from with an image recipe may or may not
succeed depending on the specific situation.
In both these cases, the behavior is contrary to how most users expect
the <code class="filename">+=</code> operator to work.
</p>
<p>
When you use this variable, it is best to use it as follows:
</p>
<pre class="literallayout">
IMAGE_INSTALL_append = " package-name"
</pre>
<p>
Be sure to include the space between the quotation character and the start of the
package name.
</p>
</dd>
<dt>
<a name="var-IMAGE_OVERHEAD_FACTOR"></a>IMAGE_OVERHEAD_FACTOR</dt>
<dd>
<p>
Defines a multiplier that the build system applies to the initial image
size for cases when the multiplier times the returned disk usage value
for the image is greater than the sum of
<code class="filename"><a class="link" href="ref-variables-glos.html#var-IMAGE_ROOTFS_SIZE" title="IMAGE_ROOTFS_SIZE">IMAGE_ROOTFS_SIZE</a></code>
and
<code class="filename"><a class="link" href="ref-variables-glos.html#var-IMAGE_ROOTFS_EXTRA_SPACE" title="IMAGE_ROOTFS_EXTRA_SPACE">IMAGE_ROOTFS_EXTRA_SPACE</a></code>.
The result of the multiplier applied to the initial image size creates
free disk space in the image as overhead.
By default, the build process uses a multiplier of 1.3 for this variable.
This default value results in 30% free disk space added to the image when this
method is used to determine the final generated image size.
You should be aware that post install scripts and the package management
system uses disk space inside this overhead area.
Consequently, the multiplier does not produce an image with
all the theoretical free disk space.
See <code class="filename"><a class="link" href="ref-variables-glos.html#var-IMAGE_ROOTFS_SIZE" title="IMAGE_ROOTFS_SIZE">IMAGE_ROOTFS_SIZE</a></code>
for information on how the build system determines the overall image size.
</p>
<p>
The default 30% free disk space typically gives the image enough room to boot
and allows for basic post installs while still leaving a small amount of
free disk space.
If 30% free space is inadequate, you can increase the default value.
For example, the following setting gives you 50% free space added to the image:
</p>
<pre class="literallayout">
IMAGE_OVERHEAD_FACTOR = "1.5"
</pre>
<p>
</p>
<p>
Alternatively, you can ensure a specific amount of free disk space is added
to the image by using
<code class="filename"><a class="link" href="ref-variables-glos.html#var-IMAGE_ROOTFS_EXTRA_SPACE" title="IMAGE_ROOTFS_EXTRA_SPACE">IMAGE_ROOTFS_EXTRA_SPACE</a></code>
the variable.
</p>
</dd>
<dt>
<a name="var-IMAGE_ROOTFS_EXTRA_SPACE"></a>IMAGE_ROOTFS_EXTRA_SPACE</dt>
<dd>
<p>
Defines additional free disk space created in the image in Kbytes.
By default, this variable is set to "0".
This free disk space is added to the image after the build system determines
the image size as described in
<code class="filename"><a class="link" href="ref-variables-glos.html#var-IMAGE_ROOTFS_SIZE" title="IMAGE_ROOTFS_SIZE">IMAGE_ROOTFS_SIZE</a></code>.
</p>
<p>
This variable is particularly useful when you want to ensure that a
specific amount of free disk space is available on a device after an image
is installed and running.
For example, to be sure 5 Gbytes of free disk space is available, set the
variable as follows:
</p>
<pre class="literallayout">
IMAGE_ROOTFS_EXTRA_SPACE = "5242880"
</pre>
<p>
</p>
</dd>
<dt>
<a name="var-IMAGE_ROOTFS_SIZE"></a>IMAGE_ROOTFS_SIZE</dt>
<dd>
<p>
Defines the size in Kbytes for the generated image.
The OpenEmbedded build system determines the final size for the generated
image using an algorithm that takes into account the initial disk space used
for the generated image, a requested size for the image, and requested
additional free disk space to be added to the image.
Programatically, the build system determines the final size of the
generated image as follows:
</p>
<pre class="literallayout">
if (image-du * overhead) &lt; rootfs-size:
internal-rootfs-size = rootfs-size + xspace
else:
internal-rootfs-size = (image-du * overhead) + xspace
where:
image-du = Returned value of the du command on
the image.
overhead = IMAGE_OVERHEAD_FACTOR
rootfs-size = IMAGE_ROOTFS_SIZE
internal-rootfs-size = Initial root filesystem
size before any modifications.
xspace = IMAGE_ROOTFS_EXTRA_SPACE
</pre>
<p>
</p>
</dd>
<dt>
<a name="var-INC_PR"></a>INC_PR</dt>
<dd>
<p>Helps define the recipe revision for recipes that share
a common <code class="filename">include</code> file.
You can think of this variable as part of the recipe revision
as set from within an include file.</p>
<p>Suppose, for example, you have a set of recipes that
are used across several projects.
And, within each of those recipes the revision
(its <code class="filename">PR</code> value) is set accordingly.
In this case, when the revision of those recipes changes
the burden is on you to find all those recipes and
be sure that they get changed to reflect the updated
version of the recipe.
In this scenario, it can get complicated when recipes
used in many places and that provide common functionality
are upgraded to a new revision.</p>
<p>A more efficient way of dealing with this situation is
to set the <code class="filename">INC_PR</code> variable inside
the <code class="filename">include</code> files that the recipes
share and then expand the <code class="filename">INC_PR</code>
variable within the recipes to help
define the recipe revision.
</p>
<p>
The following provides an example that shows how to use
the <code class="filename">INC_PR</code> variable
given a common <code class="filename">include</code> file that
defines the variable.
Once the variable is defined in the
<code class="filename">include</code> file, you can use the
variable to set the <code class="filename">PR</code> values in
each recipe.
You will notice that when you set a recipe's
<code class="filename">PR</code> you can provide more granular
revisioning by appending values to the
<code class="filename">INC_PR</code> variable:
</p>
<pre class="literallayout">
recipes-graphics/xorg-font/xorg-font-common.inc:INC_PR = "r2"
recipes-graphics/xorg-font/encodings_1.0.4.bb:PR = "${INC_PR}.1"
recipes-graphics/xorg-font/font-util_1.3.0.bb:PR = "${INC_PR}.0"
recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3"
</pre>
<p>
The first line of the example establishes the baseline
revision to be used for all recipes that use the
<code class="filename">include</code> file.
The remaining lines in the example are from individual
recipes and show how the <code class="filename">PR</code> value
is set.</p>
</dd>
<dt>
<a name="var-INHIBIT_PACKAGE_STRIP"></a>INHIBIT_PACKAGE_STRIP</dt>
<dd><p>
Causes the build to not strip binaries in resulting packages.
</p></dd>
<dt>
<a name="var-INHERIT"></a>INHERIT</dt>
<dd><p>
Causes the named class to be inherited at
this point during parsing.
The variable is only valid in configuration files.
</p></dd>
<dt>
<a name="var-INITSCRIPT_PACKAGES"></a>INITSCRIPT_PACKAGES</dt>
<dd>
<p>
A list of the packages that contain initscripts.
If multiple packages are specified, you need to append the package name
to the other <code class="filename">INITSCRIPT_*</code> as an override.</p>
<p>
This variable is used in recipes when using <code class="filename">update-rc.d.bbclass</code>.
The variable is optional and defaults to the <code class="filename">PN</code> variable.
</p>
</dd>
<dt>
<a name="var-INITSCRIPT_NAME"></a>INITSCRIPT_NAME</dt>
<dd>
<p>
The filename of the initscript (as installed to <code class="filename">${etcdir}/init.d)</code>.
</p>
<p>
This variable is used in recipes when using <code class="filename">update-rc.d.bbclass</code>.
The variable is Mandatory.
</p>
</dd>
<dt>
<a name="var-INITSCRIPT_PARAMS"></a>INITSCRIPT_PARAMS</dt>
<dd>
<p>
Specifies the options to pass to <code class="filename">update-rc.d</code>.
An example is <code class="filename">start 99 5 2 . stop 20 0 1 6 .</code>, which gives the script a
runlevel of 99, starts the script in initlevels 2 and 5, and
stops the script in levels 0, 1 and 6.
</p>
<p>
The variable is mandatory and is used in recipes when using
<code class="filename">update-rc.d.bbclass</code>.
</p>
</dd>
</dl>
</div>
<div class="glossdiv" title="K">
<h3 class="title">K</h3>
<dl>
<dt>
<a name="var-KBRANCH"></a>KBRANCH</dt>
<dd>
<p>
A regular expression used by the build process to explicitly identify the kernel
branch that is validated, patched and configured during a build.
The <code class="filename">KBRANCH</code> variable is optional.
You can use it to trigger checks to ensure the exact kernel branch you want is
being used by the build process.
</p>
<p>
Values for this variable are set in the kernel's recipe file and the kernel's
append file.
For example, if you are using the Yocto Project kernel that is based on the
Linux 3.4 kernel, the kernel recipe file is the
<code class="filename">meta/recipes-kernel/linux/linux-yocto_3.4.bb</code> file.
Following is the default value for <code class="filename">KBRANCH</code> and the default
override for the architectures the Yocto Project supports:
</p>
<pre class="literallayout">
KBRANCH_DEFAULT = "standard/base"
KBRANCH = "${KBRANCH_DEFAULT}"
</pre>
<p>
This branch exists in the <code class="filename">linux-yocto-3.4</code> kernel Git
repository <a class="ulink" href="http://git.yoctoproject.org/cgit.cgi/linux-yocto-3.4/refs/heads" target="_self">http://git.yoctoproject.org/cgit.cgi/linux-yocto-3.4/refs/heads</a>.
</p>
<p>
This variable is also used from the kernel's append file to identify the kernel
branch specific to a particular machine or target hardware.
The kernel's append file is located in the BSP layer for a given machine.
For example, the kernel append file for the Crown Bay BSP is in the
<code class="filename">meta-intel</code> Git repository and is named
<code class="filename">meta-crownbay/recipes-kernel/linux/linux-yocto_3.4.bbappend</code>.
Here are the related statements from the append file:
</p>
<pre class="literallayout">
COMPATIBLE_MACHINE_crownbay = "crownbay"
KMACHINE_crownbay = "crownbay"
KBRANCH_crownbay = "standard/crownbay"
COMPATIBLE_MACHINE_crownbay-noemgd = "crownbay-noemgd"
KMACHINE_crownbay-noemgd = "crownbay"
KBRANCH_crownbay-noemgd = "standard/crownbay"
</pre>
<p>
The <code class="filename">KBRANCH_*</code> statements identify the kernel branch to
use when building for the Crown Bay BSP.
In this case there are two identical statements: one for each type of
Crown Bay machine.
</p>
</dd>
<dt>
<a name="var-KERNEL_FEATURES"></a>KERNEL_FEATURES</dt>
<dd>
<p>Includes additional metadata from the Yocto Project kernel Git repository.
In the OpenEmbedded build system, the default Board Support Packages (BSPs)
metadata is provided through
the <code class="filename">KMACHINE</code> and <code class="filename">KBRANCH</code> variables.
You can use the <code class="filename">KERNEL_FEATURES</code> variable to further
add metadata for all BSPs.</p>
<p>The metadata you add through this variable includes config fragments and
features descriptions,
which usually includes patches as well as config fragments.
You typically override the <code class="filename">KERNEL_FEATURES</code> variable
for a specific machine.
In this way, you can provide validated, but optional, sets of kernel
configurations and features.</p>
<p>For example, the following adds <code class="filename">netfilter</code> to all
the Yocto Project kernels and adds sound support to the <code class="filename">qemux86</code>
machine:
</p>
<pre class="literallayout">
# Add netfilter to all linux-yocto kernels
KERNEL_FEATURES="features/netfilter"
# Add sound support to the qemux86 machine
KERNEL_FEATURES_append_qemux86=" cfg/sound"
</pre>
</dd>
<dt>
<a name="var-KERNEL_IMAGETYPE"></a>KERNEL_IMAGETYPE</dt>
<dd><p>The type of kernel to build for a device, usually set by the
machine configuration files and defaults to "zImage".
This variable is used
when building the kernel and is passed to <code class="filename">make</code> as the target to
build.</p></dd>
<dt>
<a name="var-KMACHINE"></a>KMACHINE</dt>
<dd>
<p>
The machine as known by the kernel.
Sometimes the machine name used by the kernel does not match the machine name
used by the OpenEmbedded build system.
For example, the machine name that the OpenEmbedded build system understands as
<code class="filename">qemuarm</code> goes by a different name in the Linux Yocto kernel.
The kernel understands that machine as <code class="filename">arm_versatile926ejs</code>.
For cases like these, the <code class="filename">KMACHINE</code> variable maps the
kernel machine name to the OpenEmbedded build system machine name.
</p>
<p>
Kernel machine names are initially defined in the
<a class="ulink" href="http://git.yoctoproject.org/cgit.cgi" target="_self">Yocto Linux Kernel</a> in
the <code class="filename">meta</code> branch.
From the <code class="filename">meta</code> branch, look in
the <code class="filename">meta/cfg/kernel-cache/bsp/&lt;bsp_name&gt;/&lt;bsp-name&gt;-&lt;kernel-type&gt;.scc</code> file.
For example, from the <code class="filename">meta</code> branch in the
<code class="filename">linux-yocto-3.0</code> kernel, the
<code class="filename">meta/cfg/kernel-cache/bsp/cedartrail/cedartrail-standard.scc</code> file
has the following:
</p>
<pre class="literallayout">
define KMACHINE cedartrail
define KTYPE standard
define KARCH i386
include ktypes/standard
branch cedartrail
include cedartrail.scc
</pre>
<p>
You can see that the kernel understands the machine name for the Cedar Trail BSP as
<code class="filename">cedartrail</code>.
</p>
<p>
If you look in the Cedar Trail BSP layer in the <code class="filename">meta-intel</code> source
repository at <code class="filename">meta-cedartrail/recipes-kernel/linux/linux-yocto_3.0.bbappend</code>,
you will find the following statements among others:
</p>
<pre class="literallayout">
COMPATIBLE_MACHINE_cedartrail = "cedartrail"
KMACHINE_cedartrail = "cedartrail"
KBRANCH_cedartrail = "yocto/standard/cedartrail"
KERNEL_FEATURES_append_cedartrail += "bsp/cedartrail/cedartrail-pvr-merge.scc"
KERNEL_FEATURES_append_cedartrail += "cfg/efi-ext.scc"
COMPATIBLE_MACHINE_cedartrail-nopvr = "cedartrail"
KMACHINE_cedartrail-nopvr = "cedartrail"
KBRANCH_cedartrail-nopvr = "yocto/standard/cedartrail"
KERNEL_FEATURES_append_cedartrail-nopvr += " cfg/smp.scc"
</pre>
<p>
The <code class="filename">KMACHINE</code> statements in the kernel's append file make sure that
the OpenEmbedded build system and the Yocto Linux kernel understand the same machine
names.
</p>
<p>
This append file uses two <code class="filename">KMACHINE</code> statements.
The first is not really necessary but does ensure that the machine known to the
OpenEmbedded build system as <code class="filename">cedartrail</code> maps to the machine
in the kernel also known as <code class="filename">cedartrail</code>:
</p>
<pre class="literallayout">
KMACHINE_cedartrail = "cedartrail"
</pre>
<p>
</p>
<p>
The second statement is a good example of why the <code class="filename">KMACHINE</code> variable
is needed.
In this example, the OpenEmbedded build system uses the <code class="filename">cedartrail-nopvr</code>
machine name to refer to the Cedar Trail BSP that does not support the propriatory
PowerVR driver.
The kernel, however, uses the machine name <code class="filename">cedartrail</code>.
Thus, the append file must map the <code class="filename">cedartrail-nopvr</code> machine name to
the kernel's <code class="filename">cedartrail</code> name:
</p>
<pre class="literallayout">
KMACHINE_cedartrail-nopvr = "cedartrail"
</pre>
<p>
</p>
<p>
BSPs that ship with the Yocto Project release provide all mappings between the Yocto
Project kernel machine names and the OpenEmbedded machine names.
Be sure to use the <code class="filename">KMACHINE</code> if you create a BSP and the machine
name you use is different than that used in the kernel.
</p>
</dd>
</dl>
</div>
<div class="glossdiv" title="L">
<h3 class="title">L</h3>
<dl>
<dt>
<a name="var-LAYERDEPENDS"></a>LAYERDEPENDS</dt>
<dd><p>Lists the layers that this recipe depends upon, separated by spaces.
Optionally, you can specify a specific layer version for a dependency
by adding it to the end of the layer name with a colon, (e.g. "anotherlayer:3"
to be compared against <code class="filename">LAYERVERSION_anotherlayer</code> in this case).
An error will be produced if any dependency is missing or
the version numbers do not match exactly (if specified).
This variable is used in the <code class="filename">conf/layer.conf</code> file
and must be suffixed with the name of the specific layer (e.g.
<code class="filename">LAYERDEPENDS_mylayer</code>).</p></dd>
<dt>
<a name="var-LAYERDIR"></a>LAYERDIR</dt>
<dd><p>When used inside the <code class="filename">layer.conf</code> configuration
file, this variable provides the path of the current layer.
This variable requires immediate expansion
(see the BitBake manual) as lazy expansion can result in
the expansion happening in the wrong directory and therefore
giving the wrong value.</p></dd>
<dt>
<a name="var-LAYERVERSION"></a>LAYERVERSION</dt>
<dd><p>Optionally specifies the version of a layer as a single number.
You can use this within <code class="filename">LAYERDEPENDS</code> for another layer in order to
depend on a specific version of the layer.
This variable is used in the <code class="filename">conf/layer.conf</code> file
and must be suffixed with the name of the specific layer (e.g.
<code class="filename">LAYERVERSION_mylayer</code>).</p></dd>
<dt>
<a name="var-LIC_FILES_CHKSUM"></a>LIC_FILES_CHKSUM</dt>
<dd>
<p>Checksums of the license text in the recipe source code.</p>
<p>This variable tracks changes in license text of the source
code files.
If the license text is changed, it will trigger a build
failure, which gives the developer an opportunity to review any
license change.</p>
<p>
This variable must be defined for all recipes (unless <code class="filename">LICENSE</code>
is set to "CLOSED")</p>
<p>For more information, see the
<a class="link" href="usingpoky-configuring-LIC_FILES_CHKSUM.html" title="3.4.1. Tracking License Changes">
Tracking License Changes</a> section</p>
</dd>
<dt>
<a name="var-LICENSE"></a>LICENSE</dt>
<dd>
<p>
The list of source licenses for the recipe.
Follow these rules:
</p>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem"><p>Do not use spaces within individual
license names.</p></li>
<li class="listitem"><p>Separate license names using
| (pipe) when there is a choice between licenses.
</p></li>
<li class="listitem"><p>Separate license names using
&amp; (ampersand) when multiple licenses exist
that cover different parts of the source.
</p></li>
<li class="listitem"><p>You can use spaces between license
names.</p></li>
</ul></div>
<p>
</p>
<p>
Here are some examples:
</p>
<pre class="literallayout">
LICENSE = "LGPLv2.1 | GPLv3"
LICENSE = "MPL-1 &amp; LGPLv2.1"
LICENSE = "GPLv2+"
</pre>
<p>
The first example is from the recipes for Qt, which the user
may choose to distribute under either the LGPL version
2.1 or GPL version 3.
The second example is from Cairo where two licenses cover
different parts of the source code.
The final example is from <code class="filename">sysstat</code>,
which presents a single license.
</p>
</dd>
<dt>
<a name="var-LICENSE_PATH"></a>LICENSE_PATH</dt>
<dd>
<p>Path to additional licenses used during the build.
By default, the OpenEmbedded build system uses <code class="filename">COMMON_LICENSE_DIR</code>
to define the directory that holds common license text used during the build.
The <code class="filename">LICENSE_PATH</code> variable allows you to extend that
location to other areas that have additional licenses:
</p>
<pre class="literallayout">
LICENSE_PATH += "/path/to/additional/common/licenses"
</pre>
</dd>
</dl>
</div>
<div class="glossdiv" title="M">
<h3 class="title">M</h3>
<dl>
<dt>
<a name="var-MACHINE"></a>MACHINE</dt>
<dd>
<p>
Specifies the target device for which the image is built.
You define <code class="filename">MACHINE</code> in the
<code class="filename">local.conf</code> file found in the
<a class="link" href="../dev-manual/build-directory.html" target="_self">Build Directory</a>.
By default, <code class="filename">MACHINE</code> is set to
"qemux86", which is an x86-based architecture machine to
be emulated using QEMU:
</p>
<pre class="literallayout">
MACHINE ?= "qemux86"
</pre>
<p>
The variable corresponds to a machine configuration file of the
same name, through which machine-specific configurations are set.
Thus, when <code class="filename">MACHINE</code> is set to "qemux86" there
exists the corresponding <code class="filename">qemux86.conf</code> machine
configuration file, which can be found in the
<a class="link" href="../dev-manual/source-directory.html" target="_self">Source Directory</a>
in <code class="filename">meta/conf/machine</code>.
</p>
<p>
The list of machines supported by the Yocto Project as
shipped include the following:
</p>
<pre class="literallayout">
MACHINE ?= "qemuarm"
MACHINE ?= "qemumips"
MACHINE ?= "qemuppc"
MACHINE ?= "qemux86"
MACHINE ?= "qemux86-64"
MACHINE ?= "atom-pc"
MACHINE ?= "beagleboard"
MACHINE ?= "mpc8315e-rdb"
MACHINE ?= "routerstationpro"
</pre>
<p>
The last four are Yocto Project reference hardware boards, which
are provided in the <code class="filename">meta-yocto-bsp</code> layer.
</p>
<div class="note" title="Note" style="margin-left: 0.5in; margin-right: 0.5in;">
<h3 class="title">Note</h3>Adding additional Board Support Package (BSP) layers
to your configuration adds new possible settings for
<code class="filename">MACHINE</code>.
</div>
<p>
</p>
</dd>
<dt>
<a name="var-MACHINE_ESSENTIAL_EXTRA_RDEPENDS"></a>MACHINE_ESSENTIAL_EXTRA_RDEPENDS</dt>
<dd>
<p></p>
<p>
A list of required machine-specific packages to install as part of
the image being built.
The build process depends on these packages being present.
Furthermore, because this is a "machine essential" variable, the list of
packages are essential for the machine to boot.
The impact of this variable affects images based on
<code class="filename">packagegroup-core-boot</code>,
including the <code class="filename">core-image-minimal</code> image.
</p>
<p>
This variable is similar to the
<code class="filename"><a class="link" href="ref-variables-glos.html#var-MACHINE_ESSENTIAL_EXTRA_RRECOMMENDS" title="MACHINE_ESSENTIAL_EXTRA_RRECOMMENDS">MACHINE_ESSENTIAL_EXTRA_RRECOMMENDS</a></code>
variable with the exception that the image being built has a build
dependency on the variable's list of packages.
In other words, the image will not build if a file in this list is not found.
</p>
<p>
As an example, suppose the machine for which you are building requires
<code class="filename">example-init</code> to be run during boot to initialize the hardware.
In this case, you would use the following in the machine's
<code class="filename">.conf</code> configuration file:
</p>
<pre class="literallayout">
MACHINE_ESSENTIAL_EXTRA_RDEPENDS += "example-init"
</pre>
<p>
</p>
</dd>
<dt>
<a name="var-MACHINE_ESSENTIAL_EXTRA_RRECOMMENDS"></a>MACHINE_ESSENTIAL_EXTRA_RRECOMMENDS</dt>
<dd>
<p></p>
<p>
A list of recommended machine-specific packages to install as part of
the image being built.
The build process does not depend on these packages being present.
However, because this is a "machine essential" variable, the list of
packages are essential for the machine to boot.
The impact of this variable affects images based on
<code class="filename">packagegroup-core-boot</code>,
including the <code class="filename">core-image-minimal</code> image.
</p>
<p>
This variable is similar to the
<code class="filename"><a class="link" href="ref-variables-glos.html#var-MACHINE_ESSENTIAL_EXTRA_RDEPENDS" title="MACHINE_ESSENTIAL_EXTRA_RDEPENDS">MACHINE_ESSENTIAL_EXTRA_RDEPENDS</a></code>
variable with the exception that the image being built does not have a build
dependency on the variable's list of packages.
In other words, the image will still build if a package in this list is not found.
Typically, this variable is used to handle essential kernel modules, whose
functionality may be selected to be built into the kernel rather than as a module,
in which case a package will not be produced.
</p>
<p>
Consider an example where you have a custom kernel where a specific touchscreen
driver is required for the machine to be usable.
However, the driver can be built as a module or
into the kernel depending on the kernel configuration.
If the driver is built as a module, you want it to be installed.
But, when the driver is built into the kernel, you still want the
build to succeed.
This variable sets up a "recommends" relationship so that in the latter case,
the build will not fail due to the missing package.
To accomplish this, assuming the package for the module was called
<code class="filename">kernel-module-ab123</code>, you would use the
following in the machine's <code class="filename">.conf</code> configuration
file:
</p>
<pre class="literallayout">
MACHINE_ESSENTIAL_EXTRA_RRECOMMENDS += "kernel-module-ab123"
</pre>
<p>
</p>
<p>
Some examples of these machine essentials are flash, screen, keyboard, mouse,
or touchscreen drivers (depending on the machine).
</p>
</dd>
<dt>
<a name="var-MACHINE_EXTRA_RDEPENDS"></a>MACHINE_EXTRA_RDEPENDS</dt>
<dd>
<p>
A list of machine-specific packages to install as part of the
image being built that are not essential for the machine to boot.
However, the build process for more fully-featured images
depends on the packages being present.
</p>
<p>
This variable affects all images based on
<code class="filename">packagegroup-base</code>, which does not include the
<code class="filename">core-image-minimal</code> or <code class="filename">core-image-basic</code>
images.
</p>
<p>
The variable is similar to the
<code class="filename"><a class="link" href="ref-variables-glos.html#var-MACHINE_EXTRA_RRECOMMENDS" title="MACHINE_EXTRA_RRECOMMENDS">MACHINE_EXTRA_RRECOMMENDS</a></code>
variable with the exception that the image being built has a build
dependency on the variable's list of packages.
In other words, the image will not build if a file in this list is not found.
</p>
<p>
An example is a machine that has WiFi capability but is not essential
For the machine to boot the image.
However, if you are building a more fully-featured image, you want to enable
the WiFi.
The package containing the firmware for the WiFi hardware is always
expected to exist, so it is acceptable for the build process to depend upon
finding the package.
In this case, assuming the package for the firmware was called
<code class="filename">wifidriver-firmware</code>, you would use the following in the
<code class="filename">.conf</code> file for the machine:
</p>
<pre class="literallayout">
MACHINE_EXTRA_RDEPENDS += "wifidriver-firmware"
</pre>
<p>
</p>
</dd>
<dt>
<a name="var-MACHINE_EXTRA_RRECOMMENDS"></a>MACHINE_EXTRA_RRECOMMENDS</dt>
<dd>
<p></p>
<p>
A list of machine-specific packages to install as part of the
image being built that are not essential for booting the machine.
The image being built has no build dependency on this list of packages.
</p>
<p>
This variable affects only images based on
<code class="filename">packagegroup-base</code>, which does not include the
<code class="filename">core-image-minimal</code> or <code class="filename">core-image-basic</code>
images.
</p>
<p>
This variable is similar to the
<code class="filename"><a class="link" href="ref-variables-glos.html#var-MACHINE_EXTRA_RDEPENDS" title="MACHINE_EXTRA_RDEPENDS">MACHINE_EXTRA_RDEPENDS</a></code>
variable with the exception that the image being built does not have a build
dependency on the variable's list of packages.
In other words, the image will build if a file in this list is not found.
</p>
<p>
An example is a machine that has WiFi capability but is not essential
For the machine to boot the image.
However, if you are building a more fully-featured image, you want to enable
WiFi.
In this case, the package containing the WiFi kernel module will not be produced
if the WiFi driver is built into the kernel, in which case you still want the
build to succeed instead of failing as a result of the package not being found.
To accomplish this, assuming the package for the module was called
<code class="filename">kernel-module-examplewifi</code>, you would use the
following in the <code class="filename">.conf</code> file for the machine:
</p>
<pre class="literallayout">
MACHINE_EXTRA_RRECOMMENDS += "kernel-module-examplewifi"
</pre>
<p>
</p>
</dd>
<dt>
<a name="var-MACHINE_FEATURES"></a>MACHINE_FEATURES</dt>
<dd>
<p>Specifies the list of hardware features the
<a class="link" href="ref-variables-glos.html#var-MACHINE" title="MACHINE">MACHINE</a> supports.
For example, including the "bluetooth" feature causes the
<code class="filename">bluez</code> bluetooth daemon to be built and
added to the image.
It also causes the <code class="filename">connman</code> recipe
to look at <code class="filename">MACHINE_FEATURES</code> and when it
finds "bluetooth" there it enables the bluetooth
support in ConnMan.
</p>
<p>
For a list of features supported by the Yocto Project as shipped,
see the "<a class="link" href="ref-features-machine.html" title="9.2. Machine">Machine</a>" section.
</p>
</dd>
<dt>
<a name="var-MACHINE_FEATURES_BACKFILL"></a>MACHINE_FEATURES_BACKFILL</dt>
<dd>
<p>Features to be added to
<code class="filename"><a class="link" href="ref-variables-glos.html#var-MACHINE_FEATURES" title="MACHINE_FEATURES">MACHINE_FEATURES</a></code>
if not also present in
<code class="filename"><a class="link" href="ref-variables-glos.html#var-MACHINE_FEATURES_BACKFILL_CONSIDERED" title="MACHINE_FEATURES_BACKFILL_CONSIDERED">MACHINE_FEATURES_BACKFILL_CONSIDERED</a></code>.
</p>
<p>
This variable is set in the <code class="filename">meta/conf/bitbake.conf</code> file.
It is not intended to be user-configurable.
It is best to just reference the variable to see which machine features are
being backfilled for all machine configurations.
See the <a class="link" href="ref-features-backfill.html" title="9.4. Feature Backfilling">Feature backfilling</a> section for
more information.
</p>
</dd>
<dt>
<a name="var-MACHINE_FEATURES_BACKFILL_CONSIDERED"></a>MACHINE_FEATURES_BACKFILL_CONSIDERED</dt>
<dd><p>Features from
<code class="filename"><a class="link" href="ref-variables-glos.html#var-MACHINE_FEATURES_BACKFILL" title="MACHINE_FEATURES_BACKFILL">MACHINE_FEATURES_BACKFILL</a></code>
that should not be backfilled (i.e. added to
<code class="filename"><a class="link" href="ref-variables-glos.html#var-MACHINE_FEATURES" title="MACHINE_FEATURES">MACHINE_FEATURES</a></code>)
during the build.
See the <a class="link" href="ref-features-backfill.html" title="9.4. Feature Backfilling">Feature backfilling</a> section for
more information.
</p></dd>
<dt>
<a name="var-MAINTAINER"></a>MAINTAINER</dt>
<dd><p>The email address of the distribution maintainer.</p></dd>
<dt>
<a name="var-MLPREFIX"></a>MLPREFIX</dt>
<dd><p>
Specifies a prefix has been added to
<a class="link" href="ref-variables-glos.html#var-PN" title="PN"><code class="filename">PN</code></a> to create a special version
of a recipe or package, such as a multilib version.
The variable is used in places where the prefix needs to be
added to or removed from a the name (e.g. the
<a class="link" href="ref-variables-glos.html#var-BPN" title="BPN"><code class="filename">BPN</code></a> variable).
<code class="filename">MLPREFIX</code> gets set when a prefix has been
added to <code class="filename">PN</code>.
</p></dd>
<dt>
<a name="var-MULTIMACH_TARGET_SYS"></a>MULTIMACH_TARGET_SYS</dt>
<dd><p>
Separates files for different machines such that you can build
for multiple target machines using the same output directories.
See the <a class="link" href="ref-variables-glos.html#var-STAMP" title="STAMP"><code class="filename">STAMP</code></a> variable
for an example.
</p></dd>
</dl>
</div>
<div class="glossdiv" title="O">
<h3 class="title">O</h3>
<dl>
<dt>
<a name="var-OE_TERMINAL"></a>OE_TERMINAL</dt>
<dd>
<p>
Controls how the OpenEmbedded build system spawns
interactive terminals on the host development system
(e.g. using the BitBake command with the
<code class="filename">-c devshell</code> command-line option).
For more information, see the
"<a class="link" href="../dev-manual/platdev-appdev-devshell.html" target="_self">Using a Development Shell</a>" section
in the Yocto Project Development Manual.
</p>
<p>
You can use the following values for the
<code class="filename">OE_TERMINAL</code> variable:
</p>
<pre class="literallayout">
auto
gnome
xfce
rxvt
screen
konsole
none
</pre>
<p>
</p>
<div class="note" title="Note" style="margin-left: 0.5in; margin-right: 0.5in;">
<h3 class="title">Note</h3>Konsole support only works for KDE 3.x.
Also, "auto" is the default behavior for
<code class="filename">OE_TERMINAL</code>
</div>
<p>
</p>
</dd>
</dl>
</div>
<div class="glossdiv" title="P">
<h3 class="title">P</h3>
<dl>
<dt>
<a name="var-P"></a>P</dt>
<dd>
<p>The recipe name and version.
<code class="filename">P</code> is comprised of the following:
</p>
<pre class="literallayout">
${PN}-${PV}
</pre>
</dd>
<dt>
<a name="var-PACKAGE_ARCH"></a>PACKAGE_ARCH</dt>
<dd><p>The architecture of the resulting package or packages.</p></dd>
<dt>
<a name="var-PACKAGE_BEFORE_PN"></a>PACKAGE_BEFORE_PN</dt>
<dd><p>Enables easily adding packages to
<code class="filename"><a class="link" href="ref-variables-glos.html#var-PACKAGES" title="PACKAGES">PACKAGES</a></code>
before <code class="filename">${PN}</code> so that the packages can pick
up files that would normally be included in the default package.</p></dd>
<dt>
<a name="var-PACKAGE_CLASSES"></a>PACKAGE_CLASSES</dt>
<dd>
<p>This variable, which is set in the <code class="filename">local.conf</code> configuration
file found in the <code class="filename">conf</code> folder of the
<a class="link" href="../dev-manual/source-directory.html" target="_self">Source Directory</a>,
specifies the package manager to use when packaging data.
You can provide one or more arguments for the variable with the first
argument being the package manager used to create images:
</p>
<pre class="literallayout">
PACKAGE_CLASSES ?= "package_rpm package_deb package_ipk"
</pre>
<p>
For information on build performance effects as a result of the
package manager use, see
<a class="link" href="ref-classes-package.html" title="7.13. Packaging - package*.bbclass">Packaging - <code class="filename">package*.bbclass</code></a>
in this manual.
</p>
</dd>
<dt>
<a name="var-PACKAGE_EXTRA_ARCHS"></a>PACKAGE_EXTRA_ARCHS</dt>
<dd><p>Specifies the list of architectures compatible with the device CPU.
This variable is useful when you build for several different devices that use
miscellaneous processors such as XScale and ARM926-EJS).</p></dd>
<dt>
<a name="var-PACKAGECONFIG"></a>PACKAGECONFIG</dt>
<dd>
<p>
This variable provides a means of enabling or disabling
features of a recipe on a per-recipe basis.
The <code class="filename">PACKAGECONFIG</code>
variable itself specifies a space-separated list of the
features to enable.
The features themselves are specified as flags on the
<code class="filename">PACKAGECONFIG</code> variable.
You can provide up to four arguments, which are separated by
commas, to determine the behavior of each feature
when it is enabled or disabled.
You can omit any argument you like but must retain the
separating commas.
The arguments specify the following:
</p>
<div class="orderedlist"><ol class="orderedlist" type="1">
<li class="listitem"><p>Extra arguments
that should be added to the configure script argument list
(<a class="link" href="ref-variables-glos.html#var-EXTRA_OECONF" title="EXTRA_OECONF"><code class="filename">EXTRA_OECONF</code></a>)
if the feature is enabled.</p></li>
<li class="listitem"><p>Extra arguments
that should be added to <code class="filename">EXTRA_OECONF</code>
if the feature is disabled.
</p></li>
<li class="listitem"><p>Additional build dependencies
(<a class="link" href="ref-variables-glos.html#var-DEPENDS" title="DEPENDS"><code class="filename">DEPENDS</code></a>)
that should be added if the feature is enabled.
</p></li>
<li class="listitem"><p>Additional runtime dependencies
(<a class="link" href="ref-variables-glos.html#var-RDEPENDS" title="RDEPENDS"><code class="filename">RDEPENDS</code></a>)
that should be added if the feature is enabled.
</p></li>
</ol></div>
<p>
</p>
<p>
Consider the following example taken from the
<code class="filename">librsvg</code> recipe.
In this example the feature is <code class="filename">croco</code>, which
has three arguments that determine the feature's behavior.
</p>
<pre class="literallayout">
PACKAGECONFIG ??= "croco"
PACKAGECONFIG[croco] = "--with-croco,--without-croco,libcroco"
</pre>
<p>
The <code class="filename">--with-croco</code> and
<code class="filename">libcroco</code> arguments apply only if
the feature is enabled.
In this case, <code class="filename">--with-croco</code> is
added to the configure script argument list and
<code class="filename">libcroco</code> is added to
<code class="filename"><a class="link" href="ref-variables-glos.html#var-DEPENDS" title="DEPENDS">DEPENDS</a></code>.
On the other hand, if the feature is disabled say through
a <code class="filename">.bbappend</code> file in another layer, then
the second argument <code class="filename">--without-croco</code> is
added to the configure script rather than
<code class="filename">--with-croco</code>.
</p>
</dd>
<dt>
<a name="var-PACKAGES"></a>PACKAGES</dt>
<dd>
<p>The list of packages to be created from the recipe.
The default value is the following:
</p>
<pre class="literallayout">
${PN}-dbg ${PN}-staticdev ${PN}-dev ${PN}-doc ${PN}-locale ${PACKAGE_BEFORE_PN} ${PN}
</pre>
</dd>
<dt>
<a name="var-PACKAGES_DYNAMIC"></a>PACKAGES_DYNAMIC</dt>
<dd>
<p>
A promise that your recipe satisfies runtime dependencies
for optional modules that are found in other recipes.
<code class="filename">PACKAGES_DYNAMIC</code>
does not actually satisfy the dependencies, it only states that
they should be satisfied.
For example, if a hard, runtime dependency
(<code class="filename">RDEPENDS</code>) of another package is satisfied
at build time through the <code class="filename">PACKAGES_DYNAMIC</code>
variable, but a package with the module name is never actually
produced, then the other package will be broken.
Thus, if you attempt to include that package in an image,
you will get a dependency failure from the packaging system
during <code class="filename">do_rootfs</code>.
Typically, if there is a chance that such a situation can
occur and the package that is not created is valid
without the dependency being satisfied, then you should use
<code class="filename">RRECOMMENDS</code> (a soft runtime dependency)
instead of <code class="filename">RDEPENDS</code>.
</p>
<p>
For an example of how to use the <code class="filename">PACKAGES_DYNAMIC</code>
variable when you are splitting packages, see the
"<a class="link" href="../dev-manual/handling-optional-module-packaging.html" target="_self">Handling Optional Module Packaging</a>" section
in the Yocto Project Development Manual.
</p>
</dd>
<dt>
<a name="var-PARALLEL_MAKE"></a>PARALLEL_MAKE</dt>
<dd><p>Specifies extra options that are passed to the <code class="filename">make</code> command during the
compile tasks.
This variable is usually in the form <code class="filename">-j 4</code>, where the number
represents the maximum number of parallel threads make can run.
If you development host supports multiple cores a good rule of thumb is to set
this variable to twice the number of cores on the host.</p></dd>
<dt>
<a name="var-PF"></a>PF</dt>
<dd>
<p>Specifies the recipe or package name and includes all version and revision
numbers (i.e. <code class="filename">eglibc-2.13-r20+svnr15508/</code> and
<code class="filename">bash-4.2-r1/</code>).
This variable is comprised of the following:
</p>
<pre class="literallayout">
${PN}-${EXTENDPE}${PV}-${PR}
</pre>
</dd>
<dt>
<a name="var-PN"></a>PN</dt>
<dd>
<p>This variable can have two separate functions depending on the context: a recipe
name or a resulting package name.</p>
<p><code class="filename">PN</code> refers to a recipe name in the context of a file used
by the OpenEmbedded build system as input to create a package.
The name is normally extracted from the recipe file name.
For example, if the recipe is named
<code class="filename">expat_2.0.1.bb</code>, then the default value of <code class="filename">PN</code>
will be "expat".</p>
<p>
The variable refers to a package name in the context of a file created or produced by the
OpenEmbedded build system.</p>
<p>If applicable, the <code class="filename">PN</code> variable also contains any special
suffix or prefix.
For example, using <code class="filename">bash</code> to build packages for the native
machine, <code class="filename">PN</code> is <code class="filename">bash-native</code>.
Using <code class="filename">bash</code> to build packages for the target and for Multilib,
<code class="filename">PN</code> would be <code class="filename">bash</code> and
<code class="filename">lib64-bash</code>, respectively.
</p>
</dd>
<dt>
<a name="var-PR"></a>PR</dt>
<dd><p>The revision of the recipe.
The default value for this variable is "r0".
</p></dd>
<dt>
<a name="var-PRINC"></a>PRINC</dt>
<dd>
<p>Causes the <code class="filename">PR</code> variable of
<code class="filename">.bbappend</code> files to dynamically increment.
This increment minimizes the impact of layer ordering.</p>
<p>In order to ensure multiple <code class="filename">.bbappend</code> files can co-exist,
<code class="filename">PRINC</code> should be self referencing.
This variable defaults to 0.</p>
<p>Following is an example that increments <code class="filename">PR</code> by two:
</p>
<pre class="literallayout">
PRINC := "${@int(PRINC) + 2}"
</pre>
<p>
It is adviseable not to use strings such as ".= '.1'" with the variable because
this usage is very sensitive to layer ordering.
Explicit assignments should be avoided as they cannot adequately represent multiple
<code class="filename">.bbappend</code> files.</p>
</dd>
<dt>
<a name="var-PV"></a>PV</dt>
<dd><p>The version of the recipe.
The version is normally extracted from the recipe filename.
For example, if the recipe is named
<code class="filename">expat_2.0.1.bb</code>, then the default value of <code class="filename">PV</code>
will be "2.0.1".
<code class="filename">PV</code> is generally not overridden within
a recipe unless it is building an unstable (i.e. development) version from a source code repository
(e.g. Git or Subversion).
</p></dd>
<dt>
<a name="var-PE"></a>PE</dt>
<dd><p>
the epoch of the recipe.
The default value is "0".
The field is used to make upgrades possible when the versioning scheme changes in
some backwards incompatible way.
</p></dd>
<dt>
<a name="var-PREFERRED_PROVIDER"></a>PREFERRED_PROVIDER</dt>
<dd>
<p>
If multiple recipes provide an item, this variable
determines which recipe should be given preference.
The variable must always be suffixed with the name of the
provided item, and should be set to the
<code class="filename">PN</code> of the recipe
to which you want to give precedence.
Here is an example:
</p>
<pre class="literallayout">
PREFERRED_PROVIDER_virtual/xserver = "xserver-xf86"
</pre>
<p>
</p>
</dd>
<dt>
<a name="var-PREFERRED_VERSION"></a>PREFERRED_VERSION</dt>
<dd>
<p>
If there are multiple versions of recipes available, this
variable determines which recipe should be given preference.
The variable must always be suffixed with the <code class="filename">PN</code>
for which to select, and should be set to the
<code class="filename">PV</code> to which you want to give precedence.
You can use the "<code class="filename">%</code>" character as a wildcard
to match any number of characters, which can be useful when
specifying versions that contain long revision number that could
potentially change.
Here are two examples:
</p>
<pre class="literallayout">
PREFERRED_VERSION_python = "2.6.6"
PREFERRED_VERSION_linux-yocto = "3.0+git%"
</pre>
<p>
</p>
</dd>
</dl>
</div>
<div class="glossdiv" title="R">
<h3 class="title">R</h3>
<dl>
<dt>
<a name="var-RCONFLICTS"></a>RCONFLICTS</dt>
<dd>
<p>The list of packages that conflict with a package.
Note that the package will not be installed if the conflicting packages are not
first removed.</p>
<p>
Like all package-controlling variables, you must always use them in
conjunction with a package name override.
Here is an example:
</p>
<pre class="literallayout">
RCONFLICTS_${PN} = "another-conflicting-package-name"
</pre>
<p>
</p>
</dd>
<dt>
<a name="var-RDEPENDS"></a>RDEPENDS</dt>
<dd>
<p>
Lists a package's run-time dependencies (i.e. other packages)
that must be installed for the package to be built.
In other words, in order for the package to be built and
run correctly, it depends on the listed packages.
If a package in this list cannot be found, it is probable
that a dependency error would occur before the build.
</p>
<p>
The names of the variables you list with
<code class="filename">RDEPENDS</code> must be the names of other
packages as listed in the
<a class="link" href="ref-variables-glos.html#var-PACKAGES" title="PACKAGES"><code class="filename">PACKAGES</code></a>
variable.
You should not list recipe names (<code class="filename">PN</code>).
</p>
<p>
Because the <code class="filename">RDEPENDS</code> variable applies
to packages being built, you should
always attach a package name to the variable to specify the
particular run-time package that has the dependency.
For example, suppose you are building a development package
that depends on the <code class="filename">perl</code> package.
In this case, you would use the following
<code class="filename">RDEPENDS</code> statement:
</p>
<pre class="literallayout">
RDEPENDS_${PN}-dev += "perl"
</pre>
<p>
In the example, the package name
(<code class="filename">${PN}-dev</code>) must appear as it would
in the
<code class="filename"><a class="link" href="ref-variables-glos.html#var-PACKAGES" title="PACKAGES">PACKAGES</a></code>
namespace before any renaming of the output package by
classes like <code class="filename">debian.bbclass</code>.
</p>
<p>
In many cases you do not need to explicitly add dependencies
to <code class="filename">RDEPENDS</code> since some automatic
handling occurs:
</p>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem"><p><span class="emphasis"><em><code class="filename">shlibdeps</code></em></span>: If
a run-time package contains a shared library
(<code class="filename">.so</code>), the build
processes the library in order to determine other
libraries to which it is dynamically linked.
The build process adds these libraries to
<code class="filename">RDEPENDS</code> when creating the run-time
package.</p></li>
<li class="listitem"><p><span class="emphasis"><em><code class="filename">pcdeps</code></em></span>: If
the package ships a <code class="filename">pkg-config</code>
information file, the build process uses this file
to add items to the <code class="filename">RDEPENDS</code>
variable to create the run-time packages.
</p></li>
</ul></div>
<p>
</p>
</dd>
<dt>
<a name="var-RRECOMMENDS"></a>RRECOMMENDS</dt>
<dd>
<p>
A list of packages that extend the usability of a package being
built.
The package being built does not depend on this list of packages in
order to successfully build, but needs them for the extended usability.
To specify runtime dependencies for packages, see the
<code class="filename"><a class="link" href="ref-variables-glos.html#var-RDEPENDS" title="RDEPENDS">RDEPENDS</a></code> variable.
</p>
<p>
The OpenEmbedded build process automatically installs the list of packages
as part of the built package.
However, you can remove them later if you want.
If, during the build, a package from the list cannot be found, the build
process continues without an error.
</p>
<p>
Because the <code class="filename">RRECOMMENDS</code> variable applies to packages
being built, you should
always attach an override to the variable to specify the particular package
whose usability is being extended.
For example, suppose you are building a development package that is extended
to support wireless functionality.
In this case, you would use the following:
</p>
<pre class="literallayout">
RRECOMMENDS_${PN}-dev += "&lt;wireless_package_name&gt;"
</pre>
<p>
In the example, the package name (<code class="filename">${PN}-dev</code>) must
appear as it would in the
<code class="filename"><a class="link" href="ref-variables-glos.html#var-PACKAGES" title="PACKAGES">PACKAGES</a></code> namespace before any
renaming of the output package by classes like <code class="filename">debian.bbclass</code>.
</p>
</dd>
<dt>
<a name="var-RREPLACES"></a>RREPLACES</dt>
<dd><p>The list of packages that are replaced with this package.</p></dd>
</dl>
</div>
<div class="glossdiv" title="S">
<h3 class="title">S</h3>
<dl>
<dt>
<a name="var-S"></a>S</dt>
<dd>
<p>
The location in the <a class="link" href="../dev-manual/build-directory.html" target="_self">Build Directory</a>
where unpacked package source code resides.
This location is within the working directory
(<code class="filename"><a class="link" href="ref-variables-glos.html#var-WORKDIR" title="WORKDIR">WORKDIR</a></code>), which
is not static.
The unpacked source location depends on the package name
(<code class="filename"><a class="link" href="ref-variables-glos.html#var-PN" title="PN">PN</a></code>) and
package version (<code class="filename"><a class="link" href="ref-variables-glos.html#var-PV" title="PV">PV</a></code>) as
follows:
</p>
<pre class="literallayout">
${WORKDIR}/${PN}-${PV}
</pre>
<p>
As an example, assume a
<a class="link" href="../dev-manual/source-directory.html" target="_self">Source Directory</a> top-level
folder named <code class="filename">poky</code>
and a default <a class="link" href="../dev-manual/build-directory.html" target="_self">Build Directory</a>
at <code class="filename">poky/build</code>.
In this case, the working directory the build system uses to build
the <code class="filename">db</code> package is the following:
</p>
<pre class="literallayout">
~/poky/build/tmp/work/qemux86-poky-linux/db-5.1.19-r3/db-5.1.19
</pre>
<p>
</p>
</dd>
<dt>
<a name="var-SDKIMAGE_FEATURES"></a>SDKIMAGE_FEATURES</dt>
<dd><p>Equivalent to
<code class="filename"><a class="link" href="ref-variables-glos.html#var-IMAGE_FEATURES" title="IMAGE_FEATURES">IMAGE_FEATURES</a></code>.
However, this variable applies to the SDK generated from an image using
<code class="filename">bitbake -c populate_sdk imagename</code>).
</p></dd>
<dt>
<a name="var-SECTION"></a>SECTION</dt>
<dd><p>The section in which packages should be categorized.
Package management utilities can make use of this variable.</p></dd>
<dt>
<a name="var-SELECTED_OPTIMIZATION"></a>SELECTED_OPTIMIZATION</dt>
<dd><p>
The variable takes the value of
<code class="filename"><a class="link" href="ref-variables-glos.html#var-FULL_OPTIMIZATION" title="FULL_OPTIMIZATION">FULL_OPTIMIZATION</a></code>
unless <code class="filename"><a class="link" href="ref-variables-glos.html#var-DEBUG_BUILD" title="DEBUG_BUILD">DEBUG_BUILD</a></code> = "1".
In this case the value of
<code class="filename"><a class="link" href="ref-variables-glos.html#var-DEBUG_OPTIMIZATION" title="DEBUG_OPTIMIZATION">DEBUG_OPTIMIZATION</a></code> is used.
</p></dd>
<dt>
<a name="var-SERIAL_CONSOLE"></a>SERIAL_CONSOLE</dt>
<dd><p>The speed and device for the serial port used to attach the serial console.
This variable is given to the kernel as the "console"
parameter and after booting occurs <code class="filename">getty</code> is started on that port
so remote login is possible.</p></dd>
<dt>
<a name="var-SITEINFO_ENDIANNESS"></a>SITEINFO_ENDIANNESS</dt>
<dd><p>
Specifies the endian byte order of the target system.
The value should be either "le" for little-endian or "be" for big-endian.
</p></dd>
<dt>
<a name="var-SITEINFO_BITS"></a>SITEINFO_BITS</dt>
<dd><p>
Specifies the number of bits for the target system CPU.
The value should be either "32" or "64".
</p></dd>
<dt>
<a name="var-SPECIAL_PKGSUFFIX"></a>SPECIAL_PKGSUFFIX</dt>
<dd><p>
A list of prefixes for <a class="link" href="ref-variables-glos.html#var-PN" title="PN"><code class="filename">PN</code></a> used by the
OpenEmbedded build system to create variants of recipes or packages.
The list specifies the prefixes to strip off during certain circumstances
such as the generation of the <a class="link" href="ref-variables-glos.html#var-BPN" title="BPN"><code class="filename">BPN</code></a> variable.
</p></dd>
<dt>
<a name="var-SRC_URI"></a>SRC_URI</dt>
<dd>
<p>The list of source files - local or remote.
This variable tells the OpenEmbedded build system which bits to pull
in for the build and how to pull them in.
For example, if the recipe only needs to fetch a tarball from the
internet, the recipe uses a single <code class="filename">SRC_URI</code> entry.
On the other hand, if the recipe needs to fetch a tarball, apply
two patches, and include a custom file, the recipe would include four
instances of the variable.</p>
<p>The following list explains the available URI protocols:
</p>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
<p><span class="emphasis"><em><code class="filename">file://</code> -</em></span> Fetches files, which is usually
a file shipped with the metadata, from the local machine.
The path is relative to the
<a class="link" href="ref-variables-glos.html#var-FILESPATH" title="FILESPATH"><code class="filename">FILESPATH</code></a>
variable.
Thus, the build system searches, in order, from the following directories,
which are assumed to be a subdirectories of the directory in which the
recipe file resides:
</p>
<div class="itemizedlist"><ul class="itemizedlist" type="circle">
<li class="listitem"><p><span class="emphasis"><em><code class="filename">${PN}</code> -</em></span> The recipe name
with any special suffix or prefix, if applicable.
For example, using <code class="filename">bash</code> to build for the native
machine, <code class="filename">PN</code> is <code class="filename">bash-native</code>.
Using <code class="filename">bash</code> to build for the target and for Multilib,
<code class="filename">PN</code> would be <code class="filename">bash</code> and
<code class="filename">lib64-bash</code>, respectively.
</p></li>
<li class="listitem"><p><span class="emphasis"><em><code class="filename">${PF}</code> - </em></span>
<code class="filename">${PN}-${EXTENDPE}${PV}-${PR}</code>.
The recipe name including all version and revision numbers
(i.e. <code class="filename">eglibc-2.13-r20+svnr15508/</code> and
<code class="filename">bash-4.2-r1/</code>).</p></li>
<li class="listitem"><p><span class="emphasis"><em><code class="filename">${P}</code> -</em></span>
<code class="filename">${PN}-${PV}</code>.
The recipe name and version (i.e. <code class="filename">bash-4.2</code>).
</p></li>
<li class="listitem"><p><span class="emphasis"><em><code class="filename">${BPN}</code> -</em></span> The
base recipe name without any special suffix or version numbers.
</p></li>
<li class="listitem"><p><span class="emphasis"><em><code class="filename">${BP}</code> -</em></span>
<code class="filename">${BPN}-${PV}</code>.
The base recipe name and version but without any special
package name suffix.</p></li>
<li class="listitem"><p><span class="emphasis"><em>Files -</em></span> Files beneath the directory in which the recipe
resides.</p></li>
<li class="listitem"><p><span class="emphasis"><em>Directory -</em></span> The directory itself in which the recipe
resides.</p></li>
</ul></div>
</li>
<li class="listitem"><p><span class="emphasis"><em><code class="filename">bzr://</code> -</em></span> Fetches files from a
Bazaar revision control repository.</p></li>
<li class="listitem"><p><span class="emphasis"><em><code class="filename">git://</code> -</em></span> Fetches files from a
Git revision control repository.</p></li>
<li class="listitem"><p><span class="emphasis"><em><code class="filename">osc://</code> -</em></span> Fetches files from
an OSC (OpenSuse Build service) revision control repository.</p></li>
<li class="listitem"><p><span class="emphasis"><em><code class="filename">repo://</code> -</em></span> Fetches files from
a repo (Git) repository.</p></li>
<li class="listitem"><p><span class="emphasis"><em><code class="filename">svk://</code> -</em></span> Fetches files from
an SVK revision control repository.</p></li>
<li class="listitem"><p><span class="emphasis"><em><code class="filename">http://</code> -</em></span> Fetches files from
the Internet using <code class="filename">http</code>.</p></li>
<li class="listitem"><p><span class="emphasis"><em><code class="filename">https://</code> -</em></span> Fetches files
from the Internet using <code class="filename">https</code>.</p></li>
<li class="listitem"><p><span class="emphasis"><em><code class="filename">ftp://</code> -</em></span> Fetches files
from the Internet using <code class="filename">ftp</code>.</p></li>
<li class="listitem"><p><span class="emphasis"><em><code class="filename">cvs://</code> -</em></span> Fetches files from
a CVS revision control repository.</p></li>
<li class="listitem"><p><span class="emphasis"><em><code class="filename">hg://</code> -</em></span> Fetches files from
a Mercurial (<code class="filename">hg</code>) revision control repository.</p></li>
<li class="listitem"><p><span class="emphasis"><em><code class="filename">p4://</code> -</em></span> Fetches files from
a Perforce (<code class="filename">p4</code>) revision control repository.</p></li>
<li class="listitem"><p><span class="emphasis"><em><code class="filename">ssh://</code> -</em></span> Fetches files from
a secure shell.</p></li>
<li class="listitem"><p><span class="emphasis"><em><code class="filename">svn://</code> -</em></span> Fetches files from
a Subversion (<code class="filename">svn</code>) revision control repository.</p></li>
</ul></div>
<p>
</p>
<p>Standard and recipe-specific options for <code class="filename">SRC_URI</code> exist.
Here are standard options:
</p>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem"><p><span class="emphasis"><em><code class="filename">apply</code> -</em></span> Whether to apply
the patch or not.
The default action is to apply the patch.</p></li>
<li class="listitem"><p><span class="emphasis"><em><code class="filename">striplevel</code> -</em></span> Which
striplevel to use when applying the patch.
The default level is 1.</p></li>
</ul></div>
<p>
</p>
<p>Here are options specific to recipes building code from a revision control system:
</p>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem"><p><span class="emphasis"><em><code class="filename">mindate</code> -</em></span> Only applies
the patch if <a class="link" href="ref-variables-glos.html#var-SRCDATE" title="SRCDATE"><code class="filename">SRCDATE</code></a>
is equal to or greater than <code class="filename">mindate</code>.</p></li>
<li class="listitem"><p><span class="emphasis"><em><code class="filename">maxdate</code> -</em></span> Only applies
the patch if <a class="link" href="ref-variables-glos.html#var-SRCDATE" title="SRCDATE"><code class="filename">SRCDATE</code></a>
is not later than <code class="filename">mindate</code>.</p></li>
<li class="listitem"><p><span class="emphasis"><em><code class="filename">minrev</code> -</em></span> Only applies
the patch if <a class="link" href="ref-variables-glos.html#var-SRCREV" title="SRCREV"><code class="filename">SRCREV</code></a>
is equal to or greater than <code class="filename">minrev</code>.</p></li>
<li class="listitem"><p><span class="emphasis"><em><code class="filename">maxrev</code> -</em></span> Only applies
the patch if <a class="link" href="ref-variables-glos.html#var-SRCREV" title="SRCREV"><code class="filename">SRCREV</code></a>
is not later than <code class="filename">maxrev</code>.</p></li>
<li class="listitem"><p><span class="emphasis"><em><code class="filename">rev</code> -</em></span> Only applies the
patch if <a class="link" href="ref-variables-glos.html#var-SRCREV" title="SRCREV"><code class="filename">SRCREV</code></a>
is equal to <code class="filename">rev</code>.</p></li>
<li class="listitem"><p><span class="emphasis"><em><code class="filename">notrev</code> -</em></span> Only applies
the patch if <a class="link" href="ref-variables-glos.html#var-SRCREV" title="SRCREV"><code class="filename">SRCREV</code></a>
is not equal to <code class="filename">rev</code>.</p></li>
</ul></div>
<p>
</p>
<p>Here are some additional options worth mentioning:
</p>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem"><p><span class="emphasis"><em><code class="filename">unpack</code> -</em></span> Controls
whether or not to unpack the file if it is an archive.
The default action is to upack the file.</p></li>
<li class="listitem"><p><span class="emphasis"><em><code class="filename">subdir</code> -</em></span> Places the file
(or extracts its contents) into the specified
subdirectory of <a class="link" href="ref-variables-glos.html#var-WORKDIR" title="WORKDIR"><code class="filename">WORKDIR</code></a>.
This option is useful for unusual tarballs or other archives that
don't have their files already in a subdirectory within the archive.
</p></li>
<li class="listitem"><p><span class="emphasis"><em><code class="filename">name</code> -</em></span> Specifies a
name to be used for association with <code class="filename">SRC_URI</code> checksums
when you have more than one file specified in <code class="filename">SRC_URI</code>.
</p></li>
<li class="listitem"><p><span class="emphasis"><em><code class="filename">downloadfilename</code> -</em></span> Specifies
the filename used when storing the downloaded file.</p></li>
</ul></div>
<p>
</p>
</dd>
<dt>
<a name="var-SRC_URI_OVERRIDES_PACKAGE_ARCH"></a>SRC_URI_OVERRIDES_PACKAGE_ARCH</dt>
<dd>
<p></p>
<p>
By default, the OpenEmbedded build system automatically detects whether
<code class="filename"><a class="link" href="ref-variables-glos.html#var-SRC_URI" title="SRC_URI">SRC_URI</a></code>
contains files that are machine-specific.
If so, the build system automatically changes
<code class="filename"><a class="link" href="ref-variables-glos.html#var-PACKAGE_ARCH" title="PACKAGE_ARCH">PACKAGE_ARCH</a></code>.
Setting this variable to "0" disables this behavior.
</p>
</dd>
<dt>
<a name="var-SRCDATE"></a>SRCDATE</dt>
<dd><p>
The date of the source code used to build the package.
This variable applies only if the source was fetched from a Source Code Manager (SCM).
</p></dd>
<dt>
<a name="var-SRCREV"></a>SRCREV</dt>
<dd><p>
The revision of the source code used to build the package.
This variable applies to Subversion, Git, Mercurial and Bazaar
only.
Note that if you wish to build a fixed revision and you wish
to avoid performing a query on the remote repository every time
BitBake parses your recipe, you should specify a <code class="filename">SRCREV</code> that is a
full revision identifier and not just a tag.
</p></dd>
<dt>
<a name="var-SSTATE_DIR"></a>SSTATE_DIR</dt>
<dd><p>The directory for the shared state.</p></dd>
<dt>
<a name="var-SSTATE_MIRRORS"></a>SSTATE_MIRRORS</dt>
<dd>
<p>
Configures the OpenEmbedded build system to search other
mirror locations for prebuilt cache data objects before
building out the data.
This variable works like fetcher
<code class="filename">MIRRORS</code>/<code class="filename">PREMIRRORS</code>
and points to the cache locations to check for the shared
objects.
</p>
<p>
You can specify a filesystem directory or a remote URL such
as HTTP or FTP.
The locations you specify need to contain the shared state
cache (sstate-cache) results from previous builds.
The sstate-cache you point to can also be from builds on
other machines.
</p>
<p>
If a mirror uses the same structure as
<a class="link" href="ref-variables-glos.html#var-SSTATE_DIR" title="SSTATE_DIR"><code class="filename">SSTATE_DIR</code></a>,
you need to add
"PATH" at the end as shown in the examples below.
The build system substitues the correct path within the
directory structure.
</p>
<pre class="literallayout">
SSTATE_MIRRORS ?= "\
file://.* http://someserver.tld/share/sstate/PATH \n \
file://.* file:///some/local/dir/sstate/PATH"
</pre>
<p>
</p>
</dd>
<dt>
<a name="var-STAGING_KERNEL_DIR"></a>STAGING_KERNEL_DIR</dt>
<dd><p>
The directory with kernel headers that are required to build out-of-tree
modules.
</p></dd>
<dt>
<a name="var-STAMP"></a>STAMP</dt>
<dd>
<p>
Specifies the base path used to create recipe stamp files.
The path to an actual stamp file is constructed by evaluating this
string and then appending additional information.
Currently, the default assignment for <code class="filename">STAMP</code>
as set in the <code class="filename">meta/conf/bitbake.conf</code> file
is:
</p>
<pre class="literallayout">
STAMP = "${TMPDIR}/stamps/${MULTIMACH_TARGET_SYS}/${PN}-${EXTENDPE}${PV}-${PR}"
</pre>
<p>
See <a class="link" href="ref-variables-glos.html#var-TMPDIR" title="TMPDIR"><code class="filename">TMPDIR</code></a>,
<a class="link" href="ref-variables-glos.html#var-MULTIMACH_TARGET_SYS" title="MULTIMACH_TARGET_SYS"><code class="filename">MULTIMACH_TARGET_SYS</code></a>,
<a class="link" href="ref-variables-glos.html#var-PN" title="PN"><code class="filename">PN</code></a>,
<a class="link" href="ref-variables-glos.html#var-EXTENDPE" title="EXTENDPE"><code class="filename">EXTENDPE</code></a>,
<a class="link" href="ref-variables-glos.html#var-PV" title="PV"><code class="filename">PV</code></a>, and
<a class="link" href="ref-variables-glos.html#var-PR" title="PR"><code class="filename">PR</code></a> for related variable
information.
</p>
</dd>
<dt>
<a name="var-SUMMARY"></a>SUMMARY</dt>
<dd><p>The short (72 characters or less) summary of the binary package for packaging
systems such as <code class="filename">opkg</code>, <code class="filename">rpm</code> or
<code class="filename">dpkg</code>.
By default, <code class="filename">SUMMARY</code> is used to define
the <a class="link" href="ref-variables-glos.html#var-DESCRIPTION" title="DESCRIPTION"><code class="filename">DESCRIPTION</code></a>
variable if <code class="filename">DESCRIPTION</code> is not set
in the recipe.
</p></dd>
</dl>
</div>
<div class="glossdiv" title="T">
<h3 class="title">T</h3>
<dl>
<dt>
<a name="var-T"></a>T</dt>
<dd>
<p>This variable points to a directory were Bitbake places temporary
files when building a particular package.
It is typically set as follows:
</p>
<pre class="literallayout">
T = ${WORKDIR}/temp
</pre>
<p>
The <a class="link" href="ref-variables-glos.html#var-WORKDIR" title="WORKDIR"><code class="filename">WORKDIR</code></a>
is the directory into which Bitbake unpacks and builds the package.
The default <code class="filename">bitbake.conf</code> file sets this variable.</p>
<p>The <code class="filename">T</code> variable is not to be confused with
the <a class="link" href="ref-variables-glos.html#var-TMPDIR" title="TMPDIR"><code class="filename">TMPDIR</code></a> variable,
which points to the root of the directory tree where Bitbake
places the output of an entire build.
</p>
</dd>
<dt>
<a name="var-TARGET_ARCH"></a>TARGET_ARCH</dt>
<dd><p>The architecture of the device being built.
While a number of values are possible, the OpenEmbedded build system primarily supports
<code class="filename">arm</code> and <code class="filename">i586</code>.</p></dd>
<dt>
<a name="var-TARGET_CFLAGS"></a>TARGET_CFLAGS</dt>
<dd><p>
Flags passed to the C compiler for the target system.
This variable evaluates to the same as
<code class="filename"><a class="link" href="ref-variables-glos.html#var-CFLAGS" title="CFLAGS">CFLAGS</a></code>.
</p></dd>
<dt>
<a name="var-TARGET_FPU"></a>TARGET_FPU</dt>
<dd><p>Specifies the method for handling FPU code.
For FPU-less targets, which include most ARM CPUs, the variable must be
set to "soft".
If not, the kernel emulation gets used, which results in a performance penalty.</p></dd>
<dt>
<a name="var-TARGET_OS"></a>TARGET_OS</dt>
<dd><p>Specifies the target's operating system.
The variable can be set to "linux" for <code class="filename">eglibc</code>-based systems and
to "linux-uclibc" for <code class="filename">uclibc</code>.
For ARM/EABI targets, there are also "linux-gnueabi" and
"linux-uclibc-gnueabi" values possible.</p></dd>
<dt>
<a name="var-TCLIBC"></a>TCLIBC</dt>
<dd>
<p>
Specifies which variant of the GNU standard C library (<code class="filename">libc</code>)
to use during the build process.
This variable replaces <code class="filename">POKYLIBC</code>, which is no longer
supported.
</p>
<p>
You can select <code class="filename">eglibc</code> or <code class="filename">uclibc</code>.
</p>
<div class="note" title="Note" style="margin-left: 0.5in; margin-right: 0.5in;">
<h3 class="title">Note</h3>
This release of the Yocto Project does not support the
<code class="filename">glibc</code> implementation of <code class="filename">libc</code>.
</div>
<p>
</p>
</dd>
<dt>
<a name="var-TCMODE"></a>TCMODE</dt>
<dd>
<p>
The toolchain selector.
This variable replaces <code class="filename">POKYMODE</code>, which is no longer
supported.
</p>
<p>
The <code class="filename">TCMODE</code> variable selects the external toolchain
built using the OpenEmbedded build system or a few supported combinations of
the upstream GCC or CodeSourcery Labs toolchain.
The variable identifies the <code class="filename">tcmode-*</code> files used in
the <code class="filename">meta/conf/distro/include</code> directory, which is found in the
<a class="link" href="../dev-manual/source-directory.html" target="_self">Source Directory</a>.
</p>
<p>
By default, <code class="filename">TCMODE</code> is set to "default", which
chooses the <code class="filename">tcmode-default.inc</code> file.
The variable is similar to
<a class="link" href="ref-variables-glos.html#var-TCLIBC" title="TCLIBC"><code class="filename">TCLIBC</code></a>, which controls
the variant of the GNU standard C library (<code class="filename">libc</code>)
used during the build process: <code class="filename">eglibc</code> or <code class="filename">uclibc</code>.
</p>
</dd>
<dt>
<a name="var-TMPDIR"></a>TMPDIR</dt>
<dd>
<p>
This variable is the temporary directory the OpenEmbedded build system
uses when it does its work building images.
By default, the <code class="filename">TMPDIR</code> variable is named
<code class="filename">tmp</code> within the
<a class="link" href="../dev-manual/build-directory.html" target="_self">Build Directory</a>.
</p>
<p>
If you want to establish this directory in a location other than the
default, you can uncomment the following statement in the
<code class="filename">conf/local.conf</code> file in the
<a class="link" href="../dev-manual/source-directory.html" target="_self">Source Directory</a>:
</p>
<pre class="literallayout">
#TMPDIR = "${TOPDIR}/tmp"
</pre>
<p>
</p>
</dd>
<dt>
<a name="var-TOPDIR"></a>TOPDIR</dt>
<dd><p>
This variable is the
<a class="link" href="../dev-manual/build-directory.html" target="_self">Build Directory</a>.
BitBake automatically sets this variable.
The OpenEmbedded build system uses the Build Directory when building images.
</p></dd>
</dl>
</div>
<div class="glossdiv" title="W">
<h3 class="title">W</h3>
<dl>
<dt>
<a name="var-WORKDIR"></a>WORKDIR</dt>
<dd>
<p>
The pathname of the working directory in which the OpenEmbedded build system
builds a recipe.
This directory is located within the
<a class="link" href="ref-variables-glos.html#var-TMPDIR" title="TMPDIR"><code class="filename">TMPDIR</code></a> directory structure and changes
as different packages are built.
</p>
<p>
The actual <code class="filename">WORKDIR</code> directory depends on several things:
</p>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">The temporary directory - <a class="link" href="ref-variables-glos.html#var-TMPDIR" title="TMPDIR"><code class="filename">TMPDIR</code></a>
</li>
<li class="listitem">The package architecture - <a class="link" href="ref-variables-glos.html#var-PACKAGE_ARCH" title="PACKAGE_ARCH"><code class="filename">PACKAGE_ARCH</code></a>
</li>
<li class="listitem">The target machine - <a class="link" href="ref-variables-glos.html#var-MACHINE" title="MACHINE"><code class="filename">MACHINE</code></a>
</li>
<li class="listitem">The target operating system - <a class="link" href="ref-variables-glos.html#var-TARGET_OS" title="TARGET_OS"><code class="filename">TARGET_OS</code></a>
</li>
<li class="listitem">The recipe name - <a class="link" href="ref-variables-glos.html#var-PN" title="PN"><code class="filename">PN</code></a>
</li>
<li class="listitem">The recipe version - <a class="link" href="ref-variables-glos.html#var-PV" title="PV"><code class="filename">PV</code></a>
</li>
<li class="listitem">The recipe revision - <a class="link" href="ref-variables-glos.html#var-PR" title="PR"><code class="filename">PR</code></a>
</li>
</ul></div>
<p>
</p>
<p>
For packages that are not dependent on a particular machine,
<code class="filename">WORKDIR</code> is defined as follows:
</p>
<pre class="literallayout">
${TMPDIR}/work/${PACKAGE_ARCH}-poky-${TARGET_OS}/${PN}-${PV}-${PR}
</pre>
<p>
As an example, assume a
<a class="link" href="../dev-manual/source-directory.html" target="_self">Source Directory</a> top-level
folder name <code class="filename">poky</code> and a default
<a class="link" href="../dev-manual/build-directory.html" target="_self">Build Directory</a>
at <code class="filename">poky/build</code>.
In this case, the working directory the build system uses to build
the <code class="filename">v86d</code> package is the following:
</p>
<pre class="literallayout">
~/poky/build/tmp/work/qemux86-poky-linux/v86d-01.9-r0
</pre>
<p>
</p>
<p>
For packages that are dependent on a particular machine, <code class="filename">WORKDIR</code>
is defined slightly different:
</p>
<pre class="literallayout">
${TMPDIR}/work/${MACHINE}-poky-${TARGET_OS}/${PN}-${PV}-${PR}
</pre>
<p>
As an example, again assume a Source Directory top-level folder
named <code class="filename">poky</code> and a default Build Directory
at <code class="filename">poky/build</code>.
In this case, the working directory the build system uses to build
the <code class="filename">acl</code> recipe, which is being built for a
MIPS-based device, is the following:
</p>
<pre class="literallayout">
~/poky/build/tmp/work/mips-poky-linux/acl-2.2.51-r2
</pre>
<p>
</p>
</dd>
</dl>
</div>
</div>
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