[PATCH] x86: do not enable efi boot for sgi uv machine

[Dave Young]

On Fri, May 23, 2014 at 11:54:27AM -0400, Vivek Goyal wrote:
> On Fri, May 23, 2014 at 09:47:08AM -0400, Dave Young wrote:
> > Hi,
> > 
> > Vivek, replying with webmail, sorry for the formatting issue.
> > 
> > Another way is export the mapping scheme in sysfs. So if kernel boot
> > with efi=old_map we can detect it as well. OTOH in future there's probably
> > other quirk system.
> > 
> > So kexec-tools can switch to use old way if kernel use ioremap.
> 
> Exporting type of mapping being used in current kernel and automatically
> deciding that whether to boot with efi or noefi sounds reasonable to me.
> I am assuming that once type of mapping got fixed in first kernel boot
> it can't be changed in subsequent kernel boots?

Right, 2nd kernel will continue to use the original mapping because we can
only call the firmware function once to enter virtual mode. 

Thanks
Dave