Re: [BUG] x86 kenel won't boot under Virtual PC

From: Linus Torvalds
Date: Sun Aug 31 2008 - 14:47:42 EST




On Sun, 31 Aug 2008, David Sanders wrote:
>
> I recently discovered that x86 kernels won't boot under Virtual PC.

What CPU does Virtual PC emulate? As far as Wikipedia is concerned (not
that I'd take it on complete faith) it emulates a 32-bit Intel Pentium II.

And that commit makes the kernel use the "P6 nops" for such hardware.
Maybe Virtual PC doesn't support the newer intel nop things?

Intel docs say that it should be available on any intel CPU that has
CPUID.01H.EAX[11:8] = 0110B or 1111B. That's the "family ID", and Pentium
II should have a family ID of 6 (ie that 0110B case).

So it sounds like a Virtual PC bug, but I dunno. And maybe we should just
use the legcay nops for anything that isn't modern (ie P4+ or Core)?

Linus
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