On Wed, 2015-01-07 at 17:54 +0100, Paul Bolle wrote:
> On Wed, 2015-01-07 at 20:12 +0600, Alexander Kuleshov wrote:
> > There is following definition at arch/x86/realmode/rm/Makefile:
> >
> > KBUILD_CFLAGS := $(LINUXINCLUDE) $(REALMODE_CFLAGS) -D_SETUP -D_WAKEUP \
> > -I$(srctree)/arch/x86/boot
> >
> > Is it used now? I'm asking because _WAKEUP definition everywhere
> > undefined in the code.
>
> git grep tells me:
> $ git grep -n "_WAKEUP\b" arch/x86
> arch/x86/boot/video-bios.c:51:#ifndef _WAKEUP
> arch/x86/boot/video-bios.c:66:#ifdef _WAKEUP
> arch/x86/boot/video-mode.c:169:#ifndef _WAKEUP
> arch/x86/boot/video-vesa.c:27:#ifndef _WAKEUP
> arch/x86/boot/video-vesa.c:29:#else /* _WAKEUP */
> arch/x86/boot/video-vesa.c:31:#endif /* _WAKEUP */
> arch/x86/boot/video-vesa.c:160:#ifndef _WAKEUP
> arch/x86/boot/video-vesa.c:272:#endif /* not _WAKEUP */
> arch/x86/boot/video-vga.c:257:#ifndef _WAKEUP
> arch/x86/boot/video-vga.c:269:#ifndef _WAKEUP
>
> And in that Makefile we also see, a few lines up:
> wakeup-objs := [...] video-mode.o
> [...]
> wakeup-objs += video-vga.o
> wakeup-objs += video-vesa.o
> wakeup-objs += video-bios.o
>
> So this Makefile line defines a _WAKEUP macro that is, it seems, used
> for the build of those four object files. (It's bit more complicated
> than that. But I think KBUILD_CFLAGS is explained in Documentation/,
> isn't it?)
Actually, that doesn't fully explain those wakeup-objs. Because you also
need to look at this:
arch/x86/realmode/rm/video-bios.c:1:#include "../../boot/video-bios.c"
arch/x86/realmode/rm/video-mode.c:1:#include "../../boot/video-mode.c"
arch/x86/realmode/rm/video-vesa.c:1:#include "../../boot/video-vesa.c"
arch/x86/realmode/rm/video-vga.c:1:#include "../../boot/video-vga.c"
And that is the _entire_ content of those files. Rather hackish, but it
apparently works.
Paul Bolle
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