Re: [Linux-fbdev-devel] vga256fb

[James S. <jsi...@tr...>]

> No I can't use the no-page trick to remap the videoram pages and change
> the hardware state, unfortunatelly: it seems not possible.
> I used it just to mmap the vmalloc()ed "virtual"-fb memory to userspace. There
> is a different kernel timer that updates the video memory and
> switches the registers to write to the proper video plane.

Yuck! You can use the no-page trick to handle banked video cards. Its been
done before. Noramlly VGA uses A000 to AFFFF. Once you go beyond that
(B000) you can stop this is in a page fault handler and then program the
register to switch to a new bank. Note you have to keep a eye on what the
current bank is at all times (think SMP). You also have to flush the page
tables so you can keep page faulting :-(