Re: [Regression] "x86-64/efi: Use EFI to deal with platformwall clock" prevents my machine from booting

From: Jan Beulich
Date: Tue Aug 07 2012 - 06:50:12 EST


>>> On 07.08.12 at 11:30, Matt Fleming <matt.fleming@xxxxxxxxx> wrote:
> On Tue, 2012-08-07 at 08:14 +0100, Jan Beulich wrote:
>> That's not surprising. The question really is what goes wrong
>> when the call is being made - page fault, some other fault, or
>> silent hang. A page fault would point to an incorrect memory
>> map as the prime candidate for causing the problem. My
>> primary suspect would be #NM, i.e. the implementation using
>> floating point (SSE to be precise) instructions when they're
>> unavailable.
>
> I managed to find a machine to reproduce this on and it looks like the
> ASUS firmware engineers are upto their old tricks of referencing
> physical addresses after we've taken control of the memory map,

Yippie. On such systems we simply can't do any runtime calls.
Should we add a command line option forcing efi_native to false,
thus suppressing all runtime calls? Or would the "noefi" one be
enough already?

Jan

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