Re: Fwd: [PATCH] Reboot Dreamcast under software control

[Adrian M. <ad...@ne...>]

On Mon, 2007-07-30 at 07:50 +0900, Paul Mundt wrote:
> On Sun, Jul 29, 2007 at 07:25:21PM +0100, Adrian McMenamin wrote:
> > diff --git a/arch/sh/kernel/process.c b/arch/sh/kernel/process.c
> > index 6334a4c..6f5e9e4 100644
> > --- a/arch/sh/kernel/process.c
> > +++ b/arch/sh/kernel/process.c
> > @@ -97,6 +97,11 @@ void cpu_idle(void)
> > 
> >  void machine_restart(char * __unused)
> >  {
> > +
> > +#ifdef CONFIG_SH_DREAMCAST
> > +       /*reboot the Dreamcast under software control*/
> > +       writel(0x00007611, 0xA05F6890);
> > +#endif
> >         /* SR.BL=1 and invoke address error to let CPU reset (manual reset) */
> >         asm volatile("ldc %0, sr\n\t"
> >                      "mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001));
> 
> No, if you want to do this, at least use a function pointer and leave
> this as the default implementation. The dreamcast presumably only needs
> this magic write anyways, rather than the SR.BL trick.
> 
OK, stupid question time: How does the build process know what to link
with - ie how to overload?

If I just put a small .c file in /arch/sh/Dreamcast with appropriate
exported function will the linker automagically link in my function or
will it clash with the other generic or generic-SH4 function?

I've tried to work this out from looking at the code but haven't managed
it so far.