From: bernd@iamk4515.mathematik.uni-karlsruhe.de (Bernd Wiebelt) Subject: Re: extended extended VT-switching Date: 26 Feb 1993 19:58:15 GMT
I am no kernel nor C-expert, so don't expect this
to be too exact.
If I am correct, linux determines at boot-time which
type of SVGA-card is built in. Then, depending on
what it discoverd, it does an INT x10 (bios is available
at boot-time) and that's it. So far so good.
For extended VT-switching, we could use this information.
However I don't know how much serveral VGA-Chipsets
differ in setting extended text-modes. I will try to get
this information at least for ET4000. But in general,
this should not be too complicated to implement.
Even running programms on different text-vt's is
no problem, since the only thing the programm does
is writing directly to memory (only some characters)
which should not be too big problem for the kernel to handle.
Another thing is graphics. This, I must admit, is
highly comlpicated. But it would be possible to
get at least the IBM-VGA-Modes in the kernel.
One little problem here is putting graphics-vt's in
the background. Simply stopping output would be
easy, but this is really not what is desired.
I think that putting code to handle background-graphic-vt's
in the kernel is not a good idea. Instead the
running graphics-programm (?vgalib?) should do that
In fact, I think that Xfree86-1.2 works that way.
Some more comments on that? Linus?
Ciao Bernd