[PATCH] int10: Remove the vm86 and stub backends

[Vignatti Tiago (Nokia-MS/Helsinki)]

On Tue, Jul 27, 2010 at 09:46:59PM +0200, ext Adam Jackson wrote:
> On Tue, 2010-07-27 at 20:23 +0200, Mark Kettenis wrote:
> > 
> > How about fixing those bugs before killing it?
> 
> Some of them are... nontrivial.
> 
> The two big ones I know of are that we don't really emulate unreal mode
> properly, and we don't even attempt to emulate MSRs.  This tends not to
> matter except on IGP-ish machines, since you'll rarely do that kind of
> setup unless you _know_ what kind of processor you're attached to; but
> then, those are the sorts of machines people run vesa on...
> 
> But I mean, unreal mode mostly doesn't work in vm86 either, and MSR
> setup is likely to have been changed by the OS to something the BIOS
> isn't expecting, so if/when it works at all with vm86 it's a bit playing
> with fire.
> 
> I also believe that fixing unreal mode requires a modest amount of
> surgery to the int10 harness itself, which is currently subclassed two
> ways depending on whether you're doing vm86 or x86emu, which makes it
> much harder than it needs to be.  Just to pick one example, go look how
> many _different_ real-to-virtual address translation macros there are.


as I said before, I'm really happy to delete vm86 code - Matthew's arguments
are pretty much aligned with mine. 

But we should guarantee that the myriads of devices X.Org claims to support
also run with x86emu. I'd at least ping the guys in those bug reports I
pointed and ask what's the state, if works with x86emu, etc.


Cheers,

             Tiago