Re: [PATCH 0/4] EFI 1:1 mapping
From: James Bottomley
Date: Mon Jun 03 2013 - 17:19:17 EST
On Mon, 2013-06-03 at 19:11 +0100, Matthew Garrett wrote:
> > > The problem there is that you're saying "In theory". We know that
> > > Windows doesn't behave this way, so we have no legitimate expectation
> > > that it'll work. We know that it doesn't on some Apple hardware.
> > Fine, you say we need to call SetVirtualAddressMap because windows does,
> > I agree, I'm just saying we get additional safety from calling it with
> > the 1:1 map ... I don't see what the problem is.
> No. I'm saying that calling it with the 1:1 map is something very
> different to the behaviour of Windows, and I'm saying that doing so is
> known to cause variable writes on some Apple hardware to stop working.
> If we're aiming for maximum compatibility, we need to call
> SetVirtualAddressMap() with addresses above the canonicalisation hole.
OK, so tell me this problem: it's a new one one me. I think you're
saying if we don't call SetVirtualAddressMap with a mapping above a
certain value, some Apple system breaks somehow? (how?).
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/