FAQ: PREP / CHRP / ofppc / macppc confusion.

[Jochen Kunz <jkunz%unixag-kl.fh-kl.de@localhost>]

Hi.

Could someone enlighten me in the subtly differences / similarities /
relations of the PREP / CHRP / ofppc / macppc architectures please? 

AFAIK "new" PPC Macs are CHRP and use OpenFirmware as well as "new" IBM
RS/6000 machines. There are older RS/6000 machines that are PREP (and
the very old POWER/MCA) and "old" non CHRP(?) PPC Macs. Some PREP
machines use OpenFirmware, some not. Is OpenFirmware a requirement of
CHRP? What is the relation of PREP and CHRP? Is PREP "simply" an older
version of CHRP? And where does ofppc fit in all this?

Reason for this questions: I will get an IBM RS/6000 7046-B50 next
weekend. It looks like this is a CHRP machine with OpenFirmware and now
I try to find the proper NetBSD port for it. 
http://www.netbsd.org/Ports/prep/ says:
NetBSD/prep is the port of NetBSD to early PReP (PowerPC Reference
Platform) machines. 
No CHRP?
But http://www.de.netbsd.org/Ports/ says:
prep powerpc  PReP (PowerPC Reference Platform) and CHRP machines
So I asume the PREP port is the right place to start?
It doesn't hurt me if it doesn't run out of the box. I already entered
kernel programming mode and writing support for a new model of an
already supported architecture looks like a good lesson to me. 

And where can I get docs about CHRP? The link to the PREP specifications
  ftp://ftp.austin.ibm.com/pub/technology/spec/ on the port-prep
homepage is dead. I googled, but found nothing but dead liks. 
-- 



tschüß,
         Jochen

Homepage: http://www.unixag-kl.fh-kl.de/~jkunz/