Re: [PATCH -v2 0/4] EFI 1:1 mapping

Matthew Garrett
2013-06-19T16:08:11Z

On Wed, Jun 19, 2013 at 03:04:34PM +0200, Ingo Molnar wrote:
> * Borislav Petkov <bp@alien8.de> wrote:
> > And yet there are the Macs which reportedly cannot stomach this.
>
> Do we know why?

I got lost in a maze of pointer arithmetic. There seems to be an
assumption that nvram writes should be forbidden if in runtime mode but
with pointers still below the phys/virt split, which obviously makes no
sense but hey.

But, as always, the only reliable thing to do here is to behave as much
like Windows as possible. Which means performing the 1:1 mapping but
maintaining the high mapping, and passing the high values via
SetVirtualAddressMap.

--
Matthew Garrett | mjg59@srcf.ucam.org