James Hendricks wrote:
>
> > > 1. To jump to 0xC0000+3 you would have to map the ROM in your VGA
> > > card to that memory. It doesn't get mapped automagically like the
> > > PC BIOS does.
> >
> > maybe. We can map that if needed. But this code is probably PIC, so we can
> > copy it to a random place in memory and run it.
>
> It's a lot worse than that... Often the VGA BIOS is on the same chip as
> the normal BIOS, esp. for the server boards and the cheap boards. When we
> reflash it, we toast the video BIOS, too. That solves the VGA BIOS
> do-ability question... However, on many cards I bet the framebuffer is
> almost all you need. The Cirrus just needed a single bit twiddled, and
> the ATI's have a BIOS-less development kit.
>
If the VGA BIOS is "integrated" with System BIOS as you metioned, it is
really screwed. In most of these cases, VGA BIOS and System BIOS are
COMPRESS in some proprietory way in the flash. It is no way you can
simply "mmap" the flash and jump to the the location.
Ollie
