Re: [coreboot] [PATCH] Good bye vm86, hello x86 real mode ;-)

[Peter Stuge]

Stefan Reinauer wrote:
> drop most of the crappy vm86 code and replace it with a rewritten
> version that has all assembler in a .S file and all C code in a .c
> file. Also, remove requirement to move around between GDTs.
>
> Signed-off-by: Stefan Reinauer
> +++ util/x86emu/x86_asm.S	(revision 0)

..
> movl	%cr0, %eax
> andl	$0xFFFFFFFE, %eax
> movl	%eax, %cr0
> movl	%cr0, %eax
> orl	$0x0000001, %eax /* PE = 1 */
> movl	%eax, %cr0
> movl	%cr0, %eax
> andl	$~1, %eax
> movl	%eax, %cr0
> movl	%cr0, %eax
> orl	$(1 << 0), %eax
> movl	%eax, %cr0
> movl    %cr0, %eax
> orl	$(1 << 0), %eax
> movl	%eax, %cr0
> movl	%cr0, %eax
> andl	$~(1 << 0), %eax
> movl	%eax, %cr0

It would be neat if these different ways of changing PE could be
streamlined a little.

And could it be good to cli/sti around the PE changes?

If not;

Acked-by: Peter Stuge