> Last time this line of topic was brought on the port-mac68k list, I
> kind of got the impression from Joson (Thorpe)'s post that
> NetBSD/powerpc ran on PowerPC systems with OpenFirmware support which
> PCI-PowerMacs do have thus it was possible to run NetBSD/powerpc on a
> PCI-PowerMac (not on the NuBus-PowerMacs that are supported by
> MkLinux).

MkLinux now supports some PCI macs, too, and linux-pmac supports only
PCI macs (more fully that mklinux, even).

NetBSD/powerpc won't boot on a PCI powermac (at least the earlier
ones--haven't seen a current one) because the Apple OpenFirmware isn't
quite compliant...  ELF files won't load--the only binary formats that
it supports are AIX's XCOFF (only ZMAGIC--not NMAGIC or OMAGIC (ugh))
and Forth or FCode.  I'm currently struggling with the binutils package
to get the ppc bootblocks into an Apple-OpenFirmware-bootable format.
I've run across a few problems...  (like ld core dumping with a seg
fault if I try to specify --oformat aixcoff-rs6000 and objcopy/objdump
not working).

> I deduced, because device drivers would have to interpret
> OFW ROM each time it does I/O, it would run with some (probably
> significant) performance penalty.

Definitely.  Not so much for the ROM accesses, but for the fact that OPW
drivers are not allowed to run with interrupts enabled--if I understand
things correctly.  I'm hoping that it will be possible to replace a
driver at a a time--using a mixture of OpenFirmware and native drivers
until all of the devices are covered by native drivers.

-allen

-- 
              Allen Briggs - end killing - briggs@macbsd.com