Re: port-macppc/48600: Add support for powermac 7200/PPC 601

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

The following reply was made to PR port-macppc/48600; it has been noted by 
GNATS.

From: Michael <macallan%netbsd.org@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: port-macppc/48600: Add support for powermac 7200/PPC 601
Date: Sun, 16 Feb 2014 21:25:54 -0500

 Thanks!
 
 >  2) Use rtc realtime register instead of timebase register, which 601 
 > doesn't have.  It's possible I may have missed some asm calls to mftb/mttb
 > 
 >  3) alignment exceptions - the 601 will throw alignment exceptions if 
 > operands cross page boundaries.   I updated trap.c to handle that, and  
 > changed memcpy.S to always use byte-copy (not word-copy) when in kernel.  
 > There may be a more optimal way to handle. Also, I'm not that familiar with 
 > other powerpc's, so my handler changes may need tweaking for other cpus
 
 That's strange, port-rs6k and port-prep were supposed to work on 601s. I never 
verified this though.
 
 >   4) use CPUFLAGS+= -mcpu=601.  Also, the kernel apparently has to be  < 4M 
 > to netboot
 
 That seems to be an OF limitation, I've seen it on other macs as well.
 
 >   5) /platinum video - video console is not working. I'm not that familar 
 > with this area, but I'll be glad to test any changes
 
 I'm fairly familiar with this kind of work ;)
 
 have fun
 Michael