Subject: Re: Adding video mode info to struct wsscreen_descr
To: None <itojun@iijlab.net>
From: Bang Jun-Young <junyoung@mogua.com>
List: tech-kern
Date: 07/10/2002 20:45:02
On Wed, Jul 10, 2002 at 07:55:18PM +0900, itojun@iijlab.net wrote:
> >AFAIK, most graphics cards manufactured so far need such timing
> >information for mode switch. It's not chip dependant. If it were,
> >for what does XFree86 provide common mode lines in XF86Config file? 
> 
> 	i'm no expert in various VGA cards these days, but isn't it better
> 	to let BIOS handle it?  i.e. call VGA BIOS for initialization and
> 	let it initialize the parameter, instead of cooking up parameters.
> 	kvm86.c looks promising for this...(assuming VGA BIOS gives you
> 	enough functionality)

It would make sense with i386, but not with others. There's no
known/easy/MI method to set screen to 1280x1024 at 75 Hz on sparc64,
for example. Even on i386, VESA BIOS provides limited number of video
modes, so display drivers have to know how to do mode switching. 

Jun-Young

-- 
Bang Jun-Young <junyoung@mogua.com>