On Mon, 14 Jan 2002, Martijn van Buul wrote:

> Todd Vierling wrote:
> > My point was that the low-level interface to non-OFW PowerMacs is so
> > different from that of OFW machines that keeping them in the same port won't
> > be a particularly easy task.
> 
> Well, I may sound stupid, but how does Linuxppc cope with that?

Fake device tree stored in RAM regardless of how you boot.  If you were to
boot raw from OF, the device tree would be copied before OF is quiesced,
but I'm not sure if that booting mode is even still supported on macs.
Anyway, the routines all read from the tree in RAM instead of making OF
calls.


> The point of many non-OF powermacs is that while they *seem* to be quite
> close to a NUBUS mac, they differentiate enough to make it a difficult
> task. I once tried to comprehend a Performa 5200 (603, Quadra 630 based),
> but failed miserably because of Apple not wanting to share information about
> their glue logic.

The 5200 was a hideous beast.  Take it from the poor sap who made MkLinux
run on it.  BTW, it's the same as the PPC upgrade card.  You pretty much
treat it as a transparent bridge and treat the machine as being a Q630
that happens to have a PPC procesor, and it "just works".  Really gross.


> > Heck, MacOS X dropped support for the NuBus machines, too.  Wonder if Apple
> > knows something odd about these machines that we don't.  8-)
> 
> Having run MacOS X for a brief period on my Beige G3/233, I can say that
> it wouldn't be workable anyway. 

Yeah.  Would be fun, though, for the truly massochistic.


David

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