Re: [PATCH] x86: Construct 32 bit boot time page tables in native format.

H. Peter Anvin
2008-01-24T23:55:52Z

Jeremy Fitzhardinge wrote:
> H. Peter Anvin wrote:
>> While we're mucking around in this area, there is another thing which
>> we should eventually get around to fixing:
>>
>> we need a set of page tables with an identity mapping as well as the
>> kernel mapping, for trampolining (during startup, but also during
>> things like ACPI suspend/resume.) Right now, we let those be the
>> swapper page tables, but that's probably not really a good idea, since
>> it can hide bugs.
>
> So you're suggesting a second system pagetable which has a P=V alias as
> well as the normal kernel mapping, used only when we actually need that
> alias? Sounds simple enough to arrange.
>

I just looked at the ACPI suspend code, and it looks like it hacks its
own identity map at runtime. Pavel, am I reading that code right?

-hpa