Loadable Module Compilation Options

[Russell King - ARM Linux]

On Wed, Dec 02, 2009 at 04:23:08PM -0000, David Wooff wrote:
> Hello,
> how do I establish what build options I need to compile a driver module
> for my ARM processor?
>  
> I currently have a working kernel (2.6.30) running on an Atmel
> AT91SAM9G20-EK and I'm able to compile a simple application in Eclipse
> simply by pointing the compiler and linker commands to the appropriate
> cross-compiler path with some very basic compiler options.  I can also
> download to the target and run.
>  
> However, when I come to try to build a simple loadable driver module
> (does nothing but print a kernel message), I get all sorts of build
> errors.  I believe I'm missing a lot of options - things like __KERNEL__
> and __LINUX_ARM_ARCH__ etc.  There is a makefile in
> ~/linux-2.6.30/arch/arm but it's geared towards building the kernel (I
> think) and it is extremely hard to pick out exactly what I need.

There is an interface from the kernel makefiles for building external
modules.  See Documentation/kbuild/modules.txt