Re: suspend to ram problem

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Thursday, 7 of February 2008, matthieu castet wrote:
> Hi,
> 
> 
> Pavel Machek wrote:
> > Hi!
> > So I assume it is some kind of desktop?
> Yes.
> 
> >>
> >> ...if someone calls start as 0x1234:0, we are okay. But if some broken
> >> bios calls us as 0x1:0x234, we've got a problem.
> >
> > Well, in that case the signature/end_signature tests below would 
>  >trigger, no?
> 
> Yes, and for example the beep flag won't work.
> 
> >
> > Not sure what is going on... but if you remove all the stack
> > references, does it go up to 32-bit mode?
> Yes, but I end up with a kernel panic after console resume and some 
> resume stuff.
> 
>  > Looks like ss goes bonkers or the 32-bit opcodes are invalid in real 
> mode.
>  > Matthieu, can you try "pushw %ax; popw %ax;", please?
> I still crash.
> I also try to set ss to 0, and hardcode the stack (knowing we are loaded 
> at 0x1000). And it crash.
> 
> 
> I wonder if there a way to check that we are realy in real mode ?

Yes.  In real mode bit 0 of the cr0 register should be 0.

Thanks,
Rafael