Re: Linux 2.6 KBUILD Help Required.

[Sam Ravnborg <sam@ravnborg.org>]

On Thu, Jan 03, 2008 at 01:45:32PM +0530, murtuja bharmal wrote:
> Hello,
> 
>           I have a one question.
>           If I have to add  additional external flag on my external kernel module source during compilation with KBUILD.
>           lest say I have one kernel module file hello.c
>           and I want to add one flag -D testdebug.
>          
>         suppose this is my makefile.
> 
> obj-m += hello.o
> all:
>  make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
> clean:
>  make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean
> 
> where I can add this flag.

>From Documentation/kbuild/makefile.txt:
--- 3.7 Compilation flags

    ccflags-y, asflags-y and ldflags-y
        The three flags listed above applies only to the kbuild makefile
        where they are assigned. They are used for all the normal
        cc, as and ld invocation happenign during a recursive build.
        Note: Flags with the same behaviour were previously named:
        EXTRA_CFLAGS, EXTRA_AFLAGS and EXTRA_LDFLAGS.
        They are yet supported but their use are deprecated.

        ccflags-y specifies options for compiling C files with $(CC).

        Example:
                # drivers/sound/emu10k1/Makefile
                ccflags-y += -I$(obj)
                ccflags-$(DEBUG) += -DEMU10K1_DEBUG


	Sam