James Hendricks wrote:
>
> > And the Texas Instruments TVP4020 [Permedia 2]
> Cool!
>
> > Do you know where I'd need to start to get an ATI Rage XL chip working?
> > It is the onboard video controller for the Dual-Athlon board, and I would
> > like to get it working.
>
> The first step is getting a working devfb; there is a devfb for Rage128,
> but I don't know if it works for the Rage XL as well. Jeff Garzik is the
> master in this realm (do you know his email?). As I recall, it looked
> easy enough to write a generic fb that was slow from fbgen.c, but I never
> tried it. Hopefully the ATI FB driver will work.
>
> The next step is getting the big, thick, programmer's reference manual to
> figure out how to init the card. Garzik had the GD5480 manual lying
> around when I asked him -- he may have the Rage manual as well.
> Otherwise, it looks as though ati.com has an OK developer's program for
> manuals and such. I signed up so hopefully I'll be able to fetch docs
> soon.
>
> The final step is initialization. If the docs don't say enough, I may be
> able to reverse engi..., er, I mean, "interpret" the current BIOS to see
> how this is done. It should be easy; I'll just step up to the video BIOS
> init and step through the instructions until my flatpanel receives a sync
> signal. The previous instruction would then be "power-on". Because it
> probably uses SRAM, RAM init is trivial (do bigger 64MB cards use DRAM?).
> If you want me to do this, tell me an otherwise working LinuxBIOS platform
> with the ATI Rage XL that Ron has lying around.
>
>From my exprience writing SiSFB Lite, you need to know 2 things before
you can have a fbdev without VGA BIOS.
1. Chip Init including DRAM Timming/Sizing:
VGA chips are as hard or harder to init than system chips.
There are many traps/undocumented/legacy stuff waiting for you.
DRAM Timming/Sizing are as complex as system memory for
recent VGA cards (which support 8-64MB SDR/DDR, with no SPD
for rescue).
2. Mode setting.
Some card support legacy VGA register 0x3x4, 0x3x5 for vidoe
mode setting. Some other chips use totally different registers
on PCI IO space. Some mixed both :-(.
Anyway, good luck for any brave man trying on this.
Ollie
