mirrors/poky
1
0
Fork 0
mirror of https://git.yoctoproject.org/poky synced 2026-04-07 23:02:22 +02:00
Code Issues Packages Projects Releases Wiki Activity

bitbake: user-manual-metadata.xml: Re-write of "Variants - Class Extension Mechanism" section.

Browse Source 
Some general rewrites here.

(Bitbake rev: 7149ab6f6e936c19d681f05aa64b123c10f2f3da)

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
This commit is contained in:
Scott Rifenbark
2014-02-10 12:31:56 -06:00
committed by Richard Purdie
parent 3940d59e64
commit bfafc2fc3c
1 changed files with 40 additions and 29 deletions
Download Patch File Download Diff File Expand all files Collapse all files

69
bitbake/doc/user-manual/user-manual-metadata.xml
View File

@@ -1451,40 +1451,51 @@
<title>Variants - Class Extension Mechanism</title>
<para>
Two BitBake features exist to facilitate the creation of
multiple buildable incarnations from a single recipe file.
</para>
<para>
The first is <filename>BBCLASSEXTEND</filename>.
This variable is a space separated list of classes used to "extend" the
recipe for each variant.
Here is an example that results in a second incarnation of the current
recipe being available.
This second incarnation will have the "native" class inherited.
<literallayout class='monospaced'>
BitBake supports two features that facilitate creating
from a single recipe file multiple incarnations of that
recipe file where all incarnations are buildable.
These features are enabled through the
<link linkend='var-BBCLASSEXTEND'><filename>BBCLASSEXTEND</filename></link>
and
<link linkend='var-BBVERSIONS'><filename>BBVERSIONS</filename></link>
variables:
<itemizedlist>
<listitem><para><emphasis><filename>BBCLASSEXTEND</filename>:</emphasis>
This variable is a space separated list of classes used to "extend" the
recipe for each variant.
Here is an example that results in a second incarnation of the current
recipe being available.
This second incarnation will have the "native" class inherited.
<literallayout class='monospaced'>
BBCLASSEXTEND = "native"
</literallayout>
The second feature is <filename>BBVERSIONS</filename>.
This variable allows a single recipe to build multiple versions of a
project from a single recipe file, and allows you to specify
conditional metadata (using the <filename>OVERRIDES</filename>
mechanism) for a single version, or an optionally named range of versions:
<literallayout class='monospaced'>
</literallayout></para></listitem>
<listitem><para><emphasis><filename>BBVERSIONS</filename>:</emphasis>
This variable allows a single recipe to build multiple versions of a
project from a single recipe file.
You can also specify conditional metadata
(using the
<link linkend='var-OVERRIDES'><filename>OVERRIDES</filename></link>
mechanism) for a single version, or an optionally named range of versions.
Here is an example:
<literallayout class='monospaced'>
BBVERSIONS = "1.0 2.0 git"
SRC_URI_git = "git://someurl/somepath.git"
</literallayout>
<literallayout class='monospaced'>
BBVERSIONS = "1.0.[0-6]:1.0.0+ \ 1.0.[7-9]:1.0.7+"
SRC_URI_append_1.0.7+ = "file://some_patch_which_the_new_versions_need.patch;patch=1"
</literallayout>
The name of the range will default to the original version of the
recipe, so given OE, a recipe file of <filename>foo_1.0.0+.bb</filename>
will default the name of its versions to <filename>1.0.0+</filename>.
This is useful, as the range name is not only placed into overrides;
it's also made available for the metadata to use in the form of the
<filename>BPV</filename> variable, for use in
<filename>file://</filename> search paths (<filename>FILESPATH</filename>).
</literallayout>
The name of the range defaults to the original version of the
recipe.
For example, in OpenEmbedded, the recipe file
<filename>foo_1.0.0+.bb</filename> creates a default name range
of <filename>1.0.0+</filename>.
This is useful because the range name is not only placed
into overrides, but it is also made available for the metadata to use
in the variable that defines the base recipe versions for use in
<filename>file://</filename> search paths
(<link linkend='var-FILESPATH'><filename>FILESPATH</filename></link>).
</para></listitem>
</itemizedlist>
</para>
</section>