documentation/dev-manual/dev-manual-common-tasks.xml: Added external SCM

Added the section "Using an External SCM" to the "Common Tasks"
chapter.  This information was formerly in the YP Reference Manual
in the old development chapter.

(From yocto-docs rev: d34cd9e86cb7a6b27cf6a5b4daf58c445dd86331)

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

1 files changed, 24 insertions, 0 deletions

diff --git a/documentation/dev-manual/dev-manual-common-tasks.xml b/documentation/dev-manual/dev-manual-common-tasks.xml
index 6d274361d8..d24838a54b 100644
--- a/documentation/dev-manual/dev-manual-common-tasks.xml
+++ b/documentation/dev-manual/dev-manual-common-tasks.xml
@@ -1681,6 +1681,30 @@
         </para>
     </section>
 
+    <section id="platdev-appdev-srcrev">
+        <title>Using an External SCM</title>
+
+        <para>
+            If you're working on a recipe that pulls from an external Source Code Manager (SCM), it 
+            is possible to have the OpenEmbedded build system notice new changes added to the 
+            SCM and then build the package that depends on them using the latest version. 
+            This only works for SCMs from which it is possible to get a sensible revision number for changes.
+            Currently, you can do this with Apache Subversion (SVN), Git, and Bazaar (BZR) repositories.
+        </para>
+
+        <para>
+            To enable this behavior, simply add the following to the <filename>local.conf</filename>
+            configuration file found in the 
+            <ulink url='&YOCTO_DOCS_DEV_URL;#build-directory'>build directory</ulink>:
+            <literallayout class='monospaced'>
+     SRCREV_pn-&lt;PN&gt; = "${AUTOREV}"
+            </literallayout>
+            where <filename>PN</filename> 
+            is the name of the package for which you want to enable automatic source 
+            revision updating.
+        </para>
+    </section>
+
     <section id="platdev-gdb-remotedebug">
         <title>Debugging With the GNU Project Debugger (GDB) Remotely</title>