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

From: Borislav Petkov
Date: Tue Jun 04 2013 - 04:16:10 EST


On Mon, Jun 03, 2013 at 03:54:12PM +0100, Matt Fleming wrote:
> On Mon, 03 Jun, at 03:32:52PM, Matthew Garrett wrote:
> > We can only pass one set of addresses to SetVirtualAddressMap(), but it
> > doesn't seem like there's any intrinsic reason we can't the runtime
> > regions mapped to multiple virtual addresses.
>
> Indeed. That's the approach I took with my 1:1 series from last year. If
> Windows is mapping things at higher addresses like you said, then
> they're probably doing the same.

Right, the way I've done it now is to do the virtual mapping
unconditionally, then do the 1:1 mapping and call SetVirtualAddressMap
(f*cking camelcase is so nasty to type - that's why they need whole IDEs
to program :-)) with that map, if "efi=1:1_map" has been passed on the
cmd line.

After the call, we use *only* the 1:1 map but the virtual mapping is
still there.

The initial approach to addressing the b0rked Macs would then be to
never use the 1:1 map on them.

--
Regards/Gruss,
Boris.

Sent from a fat crate under my desk. Formatting is fine.
--
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/