Re: OpenGL-based framebuffer concepts

[Helge Hafting <helge.hafting@aitel.hist.no>]

Jon Smirl wrote:
> On 5/23/06, Matthew Garrett <mgarrett@chiark.greenend.org.uk> wrote:
>> Jon Smirl <jonsmirl@gmail.com> 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