[SeaBIOS] S3 resume is broken on QEMU

[Gleb Natapov]

On Thu, Jan 19, 2012 at 08:59:50AM +0100, Peter Stuge wrote:
> Gleb Natapov wrote:
> > > If someone can point out a spec to the contrary I'd be happy to change
> > > the default in SeaBIOS.
> > 
> > There is spec and there is real life. Real life should take precedence.
> 
> In real life, SeaBIOS does not need to run the VGA BIOS when I resume
> my ThinkPad with coreboot.
> 
So do not run it on a ThinkPad. BTW are you resuming to X? Can you switch
to a console and suspend/resume there to see if it works?

> Why should QEMU impose an artificial requirement which additionally
> aligns poorly with the common specifications?
> 
There is nothing artificial about the requirement. It exists on real HW.
Here for instance: http://www.nvnews.net/vbulletin/showthread.php?t=130909

> "This is how it always was" is fine to have some temporary legacy
> support, but it's not an excuse to not fix the problem properly,
> in the right place.
> 
> 
> > There is not way OSMP can restore unknown state of a random vga card
> > without special driver for that card.
> 
> It sounds like QEMU just needs a simple KMS driver. Isn't there
> actually one already, which might fit well?
> 
QEMU has no drivers. It has devices.

> 
> > This is why vgabios exists in the first place.
> 
> VGA BIOS exists because 30 years ago it seemed like a good idea
> to abstract graphics hardware, so that the only operating system
> at the time did not have to know hardware details.
> 
> That model completely and utterly fails with every operating system
> today, where indeed there are, must be and should be, device drivers.
> 
And meanwhile, in real life, you cannot resume Linux into console.
This abstract graphics HW surely helped Linux adoption. Without it you
wouldn't be able to run Linux even in a text mode on most HW in late
90s since nobody published HW spec and wrote drivers for Linux.

> > I am also not asking to change SeaBIOS default. Just get us back
> > compile time option to always enable it.
> 
> It seems older QEMU would work fine also without the option given the
> right OS drivers. In case they aren't actually available I guess a
> SeaBIOS compile time option is the only workaround.
> 
> 

--
			Gleb.