ADLO, Framebuffer et al.

[ron minnich]

On Thu, 17 Jul 2003, Stefan Reinauer wrote:

> I noticed that for video initialization I need to keep a copy
> of the video rom in the system rom for execution. This definitely
> makes sense for onboard graphics, but for other devices it would
> be nice to just use the option roms held on expansion cards.
> (Like Video cards, SCSI controllers, network cards, etc)

that works. In other words, for linuxbios vga support, the vga startup 
code will find an option room for a VGA device and use it. That code could 
be extended for arbitrary expansion roms. 

I'm not sure you want to always do that. Some of these expansion roms for 
disk cards want to interact with you on bootup, which is crazy for a 
cluster node (crazy in general, as far as I'm concerned).

I think the ADLO code works the way it does because it was set up on an 
SIS 630 which had built-in graphics.

> Is this just a matter of mapping the roms into address space, or is
> there some higher magic preventing this to happen?

The only real issue is expansion roms that break the rules. Some VGA 
roms (e.g. older Nvidia) con't quite follow the rules, and that is hard to 
fix.

But all the bits are there in linuxbios to support arbitrary expansion 
roms. Let me know if you hit trouble.

ron