Re: [PATCH] Use correct x86 reboot vector

[ebiederm@xmission.com (Eric W. Biederman)]

Alan Cox <alan@lxorguk.ukuu.org.uk> writes:

> On Sad, 2003-05-10 at 04:35, CaT wrote:
> > On Sat, May 10, 2003 at 04:56:34AM +0200, Andi Kleen wrote:
> > > Extensive discussion by various experts on the discuss@x86-64.org
> > > mailing list concluded that the correct vector to restart an 286+ 
> > > CPU is f000:fff0, not ffff:0000. Both seem to work on current systems, 
> > > but the first is correct.
> > 
> > Could this bug, by any chance, cause a system to shutdown instead of
> > rebooting? This is what happens to me at the moment but not each and
> > every time.
> 
> Unlikely. But try it and see 8)
> 
> At least some SMP boxes freak if you do a poweroff request on CPU != 0

As per the MP spec.  The system should reboot on the bootstrap cpu.
smp_processor_id() == 0 on x86.  apicid??

I have a patch for this as part my kexec stuff as the kernel freaks
when it doesn't start up on the bootstrap cpu as well.  I am busily
cleaning it up so it works in interrupt context as well.

Alan if you want it holler and I can send it to you as well.

Eric