Re: OpenGL-based framebuffer concepts

From: Helge Hafting
Date: Wed May 24 2006 - 02:43:58 EST


Jon Smirl wrote:
On 5/23/06, Matthew Garrett <mgarrett@xxxxxxxxxxxxxxxxxxxxxx> wrote:
Jon Smirl <jonsmirl@xxxxxxxxx> wrote:

> 1) Running the video ROM at boot to reset cards, emu86

Jon, how many times am I going to have to tell you that this won't work?
The video ROM is not always present on laptop hardware, and even when it
is it may jump into sections of ROM that have vanished since boot.
In the long run, graphics drivers need to know how to program cards from
scratch rather than depending on 80x25 text mod being there for them.

1) I didn't put a lot of detail into the line item but you only need
to use the ROM to reset secondary cards on x86 architectures. Primary
cards are always initialized by the system BIOS so you don't need to
run their ROM on boot. I think the only way to get a secondary card
into a laptop is through a PCMCIA slot and I've only seen one PCMCIA
video card.
I wonder, could this secondary initialization be done by the bootloader?
A standard pc bios don't initialize extra graphichs cards, and making
a custom bios isn't easy. But the boot loader (lilo/grub) runs in a mode
where calling into a bios should be easy.

Or will there be a lot of trickery in mapping the secondary (and
tertiary...) card bioses somewhere in order to run them?

Helge Hafting
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