Sometimes, an external module uses exported symbols from another
external module. Kbuild needs to have full knowledge on all symbols
to avoid spitting out warnings about undefined symbols.
- Two solutions exist to let kbuild know all symbols of more than
+ Three solutions exist to let kbuild know all symbols of more than
one external module.
The method with a top-level kbuild file is recommended but may be
impractical in certain situations.
containing the sum of all symbols defined and not part of the
kernel.
+ Use make variable KBUILD_EXTRA_SYMBOLS in the Makefile
+ If it is impractical to copy Module.symvers from another
+ module, you can assign a space separated list of files to
+ KBUILD_EXTRA_SYMBOLS in your Makfile. These files will be
+ loaded by modpost during the initialisation of its symbol
+ tables.
+
=== 8. Tips & Tricks
--- 8.1 Testing for CONFIG_FOO_BAR