aboutsummaryrefslogtreecommitdiffstats
path: root/documentation/ref-manual
diff options
context:
space:
mode:
authorScott Rifenbark <srifenbark@gmail.com>2016-07-29 10:13:52 -0700
committerRichard Purdie <richard.purdie@linuxfoundation.org>2016-08-18 23:50:45 +0100
commitdfd845a126ca690e1a7971889fb323196affc30d (patch)
tree9bfb20ee2bda1e095a6b68400aafcc84978447db /documentation/ref-manual
parent70ccc66126552c0b9b606c7010ea6c3e737b2463 (diff)
downloadopenembedded-core-contrib-dfd845a126ca690e1a7971889fb323196affc30d.tar.gz
ref-manual: Updated the PROVIDES variable description.
Added more information about virtual targets to the end of the description. Fixes [YOCTO #10011] (From yocto-docs rev: ce7ae0c6ad4ad3a0c2422b797556563dc48a9a5b) Signed-off-by: Scott Rifenbark <srifenbark@gmail.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Diffstat (limited to 'documentation/ref-manual')
-rw-r--r--documentation/ref-manual/ref-variables.xml28
1 files changed, 28 insertions, 0 deletions
diff --git a/documentation/ref-manual/ref-variables.xml b/documentation/ref-manual/ref-variables.xml
index 1181d64576..4316ea5dc6 100644
--- a/documentation/ref-manual/ref-variables.xml
+++ b/documentation/ref-manual/ref-variables.xml
@@ -9951,6 +9951,34 @@ recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3"
The <filename>PROVIDES</filename> statement results in
the "libav" recipe also being known as "libpostproc".
</para>
+
+ <para>
+ In addition to providing recipes under alternate names,
+ the <filename>PROVIDES</filename> mechanism is also used
+ to implement virtual targets.
+ A virtual target is a name that corresponds to some
+ particular functionality (e.g. a Linux kernel).
+ Recipes that provide the functionality in question list the
+ virtual target in <filename>PROVIDES</filename>.
+ Recipes that depend on the functionality in question can
+ include the virtual target in
+ <link linkend='var-DEPENDS'><filename>DEPENDS</filename></link>
+ to leave the choice of provider open.
+ </para>
+
+ <para>
+ Conventionally, virtual targets have names on the form
+ "virtual/function" (e.g. "virtual/kernel").
+ The slash is simply part of the name and has no
+ syntactical significance.
+ </para>
+
+ <para>
+ The
+ <link linkend='var-PREFERRED_PROVIDER'><filename>PREFERRED_PROVIDER</filename></link>
+ variable is used to select which particular recipe
+ provides a virtual target.
+ </para>
</glossdef>
</glossentry>