On Wed, 2002-09-11 at 15:55, Antony Stone wrote:
On Wednesday 11 September 2002 7:22 am, Steve M. Gehlbach wrote:
Maybe someone knows if alphanumeric mode setup is via the standard VGA register set on most modern VGA cards.
I am afraid your are wrong. For modern VGA cards, there is actually no alphanumeric mode. These alphanumeric mode were simulated by BIOS or drivers. The worst thing, if you have no documents about these extended registers, you have no way to drive the clock gen for Dot clock, Hsync, Vsync.
Are you saying that it is not possible to use a text console with Linux (vgacon.c) with modern VGA cards (BIOS mode 3)? Only framebuffer? Or are you saying that without extra information (ie, the BIOS or the manuals) you can't init it into mode 3?
Excuse the second posting to this thread so soon after my last, but I've found a far more succinct way of expressing my point:
If I go out and buy the latest whizz-bang graphics card, just released onto the market, and plug it into my three year old PC, whose designers knew nothing abut today's graphics cards, I expect to see a text console screen when I turn it on.
This means one of two things. Either:
- there's a standard way for the motherboard Bios to initialise _any_
graphics card, so it can initialise a new one it's never heard of before (and presumably LinuxBios could do the same), or:
Yes.
- there's a standard init call to the bios chip on the graphics card, which
knows how to set up that particular model, which again LinuxBios could perform in exactly the same way when it starts up ?
Yes.
Is there a flaw somewhere in my reasoning ?
The flaw is the these standard are "Legacy BIOS standard". You have to provide various legacy BIOS functions since these VGA BIOS/init stuff will call back to system BIOS. LinuxBIOS just doest not or incompletely support these functions.
Ollie