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| author | Richard Purdie <richard.purdie@linuxfoundation.org> | 2014-01-18 14:30:45 +0000 |
|---|---|---|
| committer | Richard Purdie <richard.purdie@linuxfoundation.org> | 2014-01-27 21:03:22 +0000 |
| commit | d6b8f746d46b22abb277520428e9e6fffafbb96b (patch) | |
| tree | e8fec23e9b115c1eb78d46ff7d6aa47807e49966 /bitbake/doc | |
| parent | 76072eaa8e87f7d2f276b4b5d4778f2c882e5c34 (diff) | |
| download | ast2050-yocto-poky-d6b8f746d46b22abb277520428e9e6fffafbb96b.zip ast2050-yocto-poky-d6b8f746d46b22abb277520428e9e6fffafbb96b.tar.gz | |
bitbake: user-manual-metadata: Add section about layers
(Bitbake rev: 0a99fe01dc273c548f7f83f9a7695c21184e7331)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Diffstat (limited to 'bitbake/doc')
| -rw-r--r-- | bitbake/doc/user-manual/user-manual-metadata.xml | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/bitbake/doc/user-manual/user-manual-metadata.xml b/bitbake/doc/user-manual/user-manual-metadata.xml index 9bdf276..73238fd 100644 --- a/bitbake/doc/user-manual/user-manual-metadata.xml +++ b/bitbake/doc/user-manual/user-manual-metadata.xml @@ -615,6 +615,46 @@ Only variable definitions and include directives are allowed in <filename>.conf</filename> files. </para> + + <section id='layers'> + <title>Layers</title> + + <para> + Layers allow you to isolate different types of + customizations from each other. + You might find it tempting to keep everything in one layer + when working on a single project. + However, the more modular you organize your Metadata, the + easier it is to cope with future changes. + </para> + + <para> + To illustrate how layers are used to keep things modular, + consider machine customizations. + These types of customizations typically reside in a special layer, + rather than a general layer, called a Board Specific Package (BSP) Layer. + Furthermore, the machine customizations should be isolated from + recipes and Metadata that support a new GUI environment, for + example. + This situation gives you a couple of layers: one for the machine + configurations, and one for the GUI environment. + It is important to understand, however, that the BSP layer can still + make machine-specific additions to recipes within + the GUI environment layer without polluting the GUI layer itself + with those machine-specific changes. + You can accomplish this through a recipe that is a BitBake append + (<filename>.bbappend</filename>) file, which is described + later in this section. + </para> + + <para> + There are certain variable specific to layers, including: + <itemizedlist> + <listitem><para><filename>LAYERDEPENDS</filename></para></listitem> + <listitem><para><filename>LAYERVERSION</filename></para></listitem> + </itemizedlist> + </para> + </section> </section> <section id='classes'> |
