Re: [Qemu-devel] [PATCH 2/3] target-i386/translate.c: mov to/from crN/drN: ignore mod bits

[malc]

On Fri, 27 Jul 2012, Matthew Ogilvie wrote:

> Microport UNIX System V/386 v 2.1 (ca 1987) uses mod R/M bytes for
> the control register mov instructions where the mod bits are 0,
> even though the 80386 spec claims they are "always" 1's.  The fact
> that it ran at all clearly indicates the real chips (at least 386
> and 486) just ignores the bits and assumes they are 1's, rather
> than trigger an illegal instruction if they aren't.
> 

AMD's document is explicit about it:

This instruction is always treated as a register-to-register (MOD = 11)
instruction, regardless of the encoding of the MOD field in the MODR/M
byte.

24594.pdf page 316

So i belive this patch should just be applied, thanks.

[..snip..]

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