[Lguest] lguest: unhandled trap
H. Peter Anvin
hpa at zytor.com
Tue Oct 21 06:01:25 EST 2008
Ian Campbell wrote:
>
> Wasn't there some concern about BIOSes which don't correctly reserve
> their DMI tables? Or don't even have e820 maps? H. Peter once said:
>
>> It's pretty standard for 0xf0000...0x100000 to be marked RESERVED in
>> E820 on real hardware (including the system I'm typing on right now.)
>> It is so marked to indicate that hardware cannot be mapped into that
>> space. However, you can't rely on this fact -- heck, you can't rely on
>> E820 even existing on a real machine. I have specimens of real-life
>> machines that go both ways.
>
Not only that, but the ACPI spec states explicitly that the ISA magic
areas should be handled without relying on E820.
-hpa
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