documentation: poky-ref-manual - New backfill variables and section.

Document DISTRO_FEATURES_BACKFILL and MACHINE_FEATURES_BACKFILL. We may
wish to expand upon this in future, but at least this explains what
these variables are for and how to use them.

Also add a link from the DISTRO_FEATURES entry to the section that lists
valid DISTRO_FEATURES items.

(From yocto-docs rev: 018af5c28b44464ae66646780ade910bdcab2bef)

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 53 insertions, 1 deletions

diff --git a/documentation/poky-ref-manual/ref-variables.xml b/documentation/poky-ref-manual/ref-variables.xml
index 2baed3788c..ca89a432fc 100644
--- a/documentation/poky-ref-manual/ref-variables.xml
+++ b/documentation/poky-ref-manual/ref-variables.xml
@@ -483,7 +483,35 @@
 
         <glossentry id='var-DISTRO_FEATURES'><glossterm>DISTRO_FEATURES</glossterm>
             <glossdef>
-                <para>The features of the distribution.</para>
+                <para>The features enabled for the distribution.
+                    For a list of valid features, see the
+                    "<link linkend='ref-features-distro'>Distro</link>"
+                    section.
+                </para>
+            </glossdef>
+        </glossentry>
+
+        <glossentry id='var-DISTRO_FEATURES_BACKFILL'><glossterm>DISTRO_FEATURES_BACKFILL</glossterm>
+            <glossdef>
+                <para>Features to be added to 
+                    <filename><link linkend='var-DISTRO_FEATURES'>DISTRO_FEATURES</link></filename>
+                    if not also present in 
+                    <filename><link linkend='var-DISTRO_FEATURES_BACKFILL_CONSIDERED'>DISTRO_FEATURES_BACKFILL_CONSIDERED</link></filename>.
+                    See the "<link linkend='ref-features-backfill'>Feature Backfilling</link>" section for 
+                    more information.
+                    </para>
+            </glossdef>
+        </glossentry>
+
+        <glossentry id='var-DISTRO_FEATURES_BACKFILL_CONSIDERED'><glossterm>DISTRO_FEATURES_BACKFILL_CONSIDERED</glossterm>
+            <glossdef>
+                <para>Features from
+                    <filename><link linkend='var-DISTRO_FEATURES_BACKFILL'>DISTRO_FEATURES_BACKFILL</link></filename>
+                    that should not be added to
+                    <filename><link linkend='var-DISTRO_FEATURES'>DISTRO_FEATURES</link></filename>.
+                    See the "<link linkend='ref-features-backfill'>Feature Backfilling</link>" section for 
+                    more information.
+                    </para>
             </glossdef>
         </glossentry>
 
@@ -1536,6 +1564,30 @@ recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3"
             </glossdef>
          </glossentry>
 
+        <glossentry id='var-MACHINE_FEATURES_BACKFILL'><glossterm>MACHINE_FEATURES_BACKFILL</glossterm>
+            <glossdef>
+                <para>Features to be added to 
+                    <filename><link linkend='var-MACHINE_FEATURES'>MACHINE_FEATURES</link></filename>
+                    if not also present in 
+                    <filename><link linkend='var-MACHINE_FEATURES_BACKFILL_CONSIDERED'>MACHINE_FEATURES_BACKFILL_CONSIDERED</link></filename>.
+                    See the <link linkend='ref-features-backfill'>Feature backfilling</link> section for 
+                    more information.
+                    </para>
+            </glossdef>
+        </glossentry>
+
+        <glossentry id='var-MACHINE_FEATURES_BACKFILL_CONSIDERED'><glossterm>MACHINE_FEATURES_BACKFILL_CONSIDERED</glossterm>
+            <glossdef>
+                <para>Features from
+                    <filename><link linkend='var-MACHINE_FEATURES_BACKFILL'>MACHINE_FEATURES_BACKFILL</link></filename>
+                    that should not be added to
+                    <filename><link linkend='var-MACHINE_FEATURES'>MACHINE_FEATURES</link></filename>.
+                    See the <link linkend='ref-features-backfill'>Feature backfilling</link> section for 
+                    more information.
+                    </para>
+            </glossdef>
+        </glossentry>
+
         <glossentry id='var-MAINTAINER'><glossterm>MAINTAINER</glossterm>
             <glossdef>
                 <para>The email address of the distribution maintainer.</para>