On Sat, 6 Jan 1996, Allen Briggs wrote:

> As far as I know, there are efforts in all three free BSD camps
> (FreeBSD, OpenBSD, NetBSD).

Plus there's supposedly Power Mac Linux in progress, althoguh I don't 
know how much info they've been able to squeeze out of Apple.  (Maybe 
another list I should subscribe to on top of my other 4)

> No one else is targetting
> Apple PowerPC-based hardware (as far as I know) because of the
> lack of documentation.

Hmmm.  I'm sure the PREP compliance stuff is out there.  After all, there 
are two or three companies already building clones.  I've got a reference 
manual on my shelf for the PPC 601/603/604/620 procesor.  It includes an 
entire section on OS development for the PPC.  What other information do 
you need?  Is it just stuff about Apple's implementation?  Talk to the 
clone manufacturers.  They'd be a lot more likely to help.  :-)

Anybody put together a cross-compiler for PPC yet?  I was just thinking 
if someone got an AIX copy of gcc (to get the right instruction set) and 
patched it with the standard netbsd/mac68k includes with (possibly) some 
tweaks to the big endian/litle endian stuff, could we at least get a 
kernel that would work as a serial terminal in native mode?  At least 
with the nubus PowerMacs, the internal architecture is nauseatingly 
similar to the Quadras, but with a few changes in the memory management 
and the display and its interface with the memory.

The real drag appears to be in the fact that the PPC uses its own 
internal PMMU.  It's another 040 problem.  How much of that memory 
management code is actually changed from one platform to another?  
How much of that change is done by the compiler?

Any thoughts?

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