Re: PCI graphics cards on Sun hardware

[Michael <macallan%netbsd.org@localhost>]

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Hello,

On Mar 20, 2009, at 3:15 AM, Erik Fair wrote:

> Sun Microsystems originated OpenBoot firmware (IEEE 1275), and all  
> add-in cards (Sbus, PCI, whatever) that need boot time intialization  
> are expected to have FCode onboard that the system will run at POST/ 
> initialization time.
>
> Apple Computer adopted OpenBoot firmware for its PCI-based PowerMac  
> (PowerPC CPUs) computers, and I believe they used it until switching  
> to Intel x86 based machines, ergo, all PCI (and AGP) video cards  
> made for PowerMac computers will have FCode on them to do the  
> initialization of the GPU.

Problem here is that many graphics cards made for Power Macs don't  
contain code to support the OpenFirmware text console. For instance  
Matrox's flash kits for Millennium I and II cards fall into this  
category, I also have an S3-based card made by Formac that doesn't  
work as OF console. On the other hand, 3Dfx's Mac firmware works just  
fine, as did an IMS TT3D I tried years ago and likely most graphics  
cards shipped by Apple itself.
> Alas, there are, shall we say, "implementation differences" (Apple  
> didn't do as complete a job of implementing IEEE 1275 as they should  
> have, particularly in the early machines - see the archives of port-macppc%netbsd.org@localhost 
>  for that tale of woe), but it should, in principle, be possible to  
> use a PCI graphics card intended for a PowerMacintosh in a Sun  
> UltraSPARC with PCI and have "the right thing happen" at POST/ 
> initialization time in the Sun.
>
> Can anyone here speak from operational experience?

I tried a few Sun cards in a power mac - with some of them the FCode  
wasn't recognized, some had their node name changed but failed to  
initialize the hardware and one made the whole thing hang up. The  
other way around wasn't any better. I also tried an IBM GXT800P which  
works fine in a PowerStack II with FirmWorks OF, in both a Sun and a  
Mac - results were the same, the card's node name was changed but the  
card itself failed to initialize.

My suspicion is that at least Apple uses just an FCode wrapper to call  
native PowerPC code in ROM. Also, I did not try any of the above with  
a new world PowerMac, maybe I should.

have fun
Michael

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