documentation/dev-manual/dev-manual-kernel-appendix.xml: added note

There are some issues with the fact that the build process parses
all kernel .bbappend files whether they are used or not during the
build process.  I added an extra build configuration note regarding
editing the .bbappend file.  I noted that you either have to edit
every .bbappend file and comment out the COMPATIBLE_MACHINE statement
or simply remove all the kernel recipe append files except the one
you are interested in.

(From yocto-docs rev: ecece911a1623b9b12bb73bab50891fbdea7afbe)

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

1 files changed, 8 insertions, 2 deletions

diff --git a/documentation/dev-manual/dev-manual-kernel-appendix.xml b/documentation/dev-manual/dev-manual-kernel-appendix.xml
index 59abf9a12e..d4c8bd566a 100644
--- a/documentation/dev-manual/dev-manual-kernel-appendix.xml
+++ b/documentation/dev-manual/dev-manual-kernel-appendix.xml
@@ -408,8 +408,14 @@
            </para>
 
            <note>
-               Due to some issues there is one more change you have to make before attempting your 
-               build.
+               Before attempting to build the modified kernel there is one more set of changes you 
+               need to make in the <filename>meta-kernel-dev</filename> layer.
+               Because all the kernel <filename>.bbappend</filename> files are parsed during the 
+               build process regardless of whether you are using them or not, you should either 
+               comment out the <filename>COMPATIBLE_MACHINE</filename> statements in all 
+               <filename>.bbappend</filename> files, or you should simply remove all the files 
+               except the one your are using for the build (i.e. <filename>linux-yocto_2.6.37.bbappend</filename>
+               in this example).
            </note>            
        </section>