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

From: Matthew Garrett
Date: Mon Jun 03 2013 - 12:24:51 EST


On Mon, Jun 03, 2013 at 09:18:06AM -0700, James Bottomley wrote:

> I don't entirely buy that. All EFI programs run with the physical
> address map, therefore every API an EFI program uses is also tested, at
> boot time only, obviously.

That seems optimistic. Windows never calls QueryVariableInfo() during
boot services, so what makes you think doing so has ever been tested?

> However, the ExitBootServices() code seems to be much simpler, so I
> don't think it will cause too many bugs. The UEFI test suites also
> seem to try UEFI calls before and after ExitBootServices(), so I think
> relying on a 1:1 mapping looks safer to me.

I have no expectation that the majority of system vendors run the test
suite, but I have every expectation that every system vendor runs
Windows. We should behave as close to the tested mechanism as possible,
ie do what Windows does - and that includes calling
SetVirtualAddressMap().

--
Matthew Garrett | mjg59@xxxxxxxxxxxxx
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