Re: SVGA kernel chipset drivers.

Alan Cox (alan@cymru.net)
Mon, 3 Jun 1996 11:56:28 +0100 (BST)


> is in place, but we don't have the mmap()ing stuff to patch together
> linear framebuffers out of banked video memory working yet. We have a
> skeleton VGA driver that does basic textmodes and fonts pretty nicely, and

When you do this please remember your mmap code in 2.1 may have to work
from the kernel AND user side and you might take page faults on those pages
from things like the network layer. You will also get networking and other
kernel code trying to pin these pages down and forbid them being swapped out
so think hard about the semantics. In the networking case I guess we can
simply flag such pages as "funny backing storage", but there are all the
semantics of mlock() and the like to think hard about at all times.

> textmode-oriented stuff, it usually worked just fine. X and SVGAlib
> won't work, though. Because of this, I usually keep two kernel images
> around that are the same except for the presence of the GGI in one. If I
> ever need to use SVGALib or X, I just boot with the other kernel.

Before GGI can go in you will have to address support for at least X and
enough SVGAlib support to run doom, otherwise people won't use it. That
shouldnt be a big problem, and if they screw up well its their problem not
yours ;)

Alan