Kernel Module Compilation

[Nick Lee <nick.lee@nortechonline.co.uk>]

I'm compiling a kernel module under openembedded, and it inherits from 
module and update-rc.d.  I want to pass a preprocessor directive, 
TESTFLAG, to my module source code.  I've tried setting -DTESTFLAG in 
CFLAGS, KERNEL_CFLAGS and EXTRA_CFLAGS in my recipe and in the Makefile 
for my module.  In none of these cases do I get TESTFLAG defined in my 
module code.  The best I can get is a helpful suggestion to use 
EXTRA_CFLAGS, which doesn't work.

What on earth am I doing wrong?  It doesn't seem like a particularly 
unusual thing to want to do!  I've spent most of a day trawling the 
internet and openembedded archives for a solution to this problem, and 
have found nothing.  Maybe it shows a lack of google skills on my part...

Nick