Re: [coreboot] [PATCH] Free VGA BIOS for K8M890

[Peter Stuge]

Kevin O'Connor wrote:
> > I used libx86 library to catch all IO. It was quite painful until I
> > realize that the emulator cannot handle properly opcodes like
> >
> > 0x66 0xe8 .. .. 0xff 0xff and also mov al,cs:[ebx] which I get
> > caught in Sebios int 15 routine.
>
> Most of SeaBIOS is compiled with gcc.  gcc generates regular 32bit
> code.  Then a gnu assembler (gas) hack is used to make that 32bit
> code run while the processor is in 16bit mode.
>
> As such, I can't think of any way to stop the 0x66/0x67 prefixes -
> they are inherent to the process.

I think the issue is with VGA BIOSes (any option ROMs, really) and
that the various emulators used by coreboot don't handle the
prefixes.

//Peter