[PATCH] additional external module symbol dependecy handling options

[Nicholas Mc Guire <der.herr@hofr.at>]

additional external module symbol dependecy handling options

The use of KBUILD_EXTRA_SYMBOLS is clarified by an example and
the additional option of using  KBUILD_EXTMOD is added as
equivalent alternative.

This patch is against linux 3.18.0-rc6

Signed-off-by: Nicholas Mc Guire <der.herr@hofr.at>
---
 Documentation/kbuild/modules.txt |   12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/Documentation/kbuild/modules.txt b/Documentation/kbuild/modules.txt
index 3fb39e0..450af1f 100644
--- a/Documentation/kbuild/modules.txt
+++ b/Documentation/kbuild/modules.txt
@@ -517,6 +517,18 @@ build.
 		These files will be loaded by modpost during the
 		initialization of its symbol tables.
 
+		Example:
+			$ make KBUILD_EXTRA_SYMBOLS=/PATH/TO/bar/Module.symvers \
+			  -C $KDIR M=$PWD modules
+
+	Use "make" variable KBUILD_EXTMOD
+		Alternatively to passing the Module.symvers files explicitly
+		one can also pass the directory containing the external module
+		that will satisfy the dependecies with KBUILD_EXTMOD and
+		Kbuild will pick up the Module.symvers found there.
+
+		Example:
+			$ make -C $KDIR M=$PWD KBUILD_EXTMOD=/PATH/TO/bar/ modules
 
 === 7. Tips & Tricks
 
-- 
1.7.10.4