I've been trying to narrow down what's causing Apple's new PowerBook model to 
hang early during boot.  I've found the line of code it's choking on, but I'm 
really stumped as to what could be going wrong, so I figured I'd ask here for 
any thoughts or suggestions.

	Booting kernels I built or the one Tsubai posted a few days ago, I get the 
initial message "console keyboard type: ADB", and a message from DDB about the 
symbol table if applicable (either preserving the symbol table, or saying that 
it's at a bad start address if I don't boot via ofwboot.elf).  But it then 
hangs, never printing out the NetBSD copyright message.

	Poking around I found that it's failing in initppc(), in pmap_bootstrap().  
Specifically, the machine hangs when doing the "mtsrin %0,%1" on line 501 in 
/sys/arch/powerpc/powerpc/pmap.c.  It fails on the 11th iteration of the loop 
(when i=10).  If I skip 10 but do the other 15 SRs it doesn't hang until the 
mtsr below the loop, and if I disable that too it hangs somewhere in the 
tlbia() call right below that.  I figure by this point I've already screwed up 
way too much to have any hope that it would finish booting..  =)

	I don't know why this line should fail, considering that it seems to work on 
every other machine.  I guess it's likely a sign of something else being 
wrong, but I really don't know enough about the macppc internals to have any 
idea where to look next.

	The machine itself should look much like an iBook or iMac DV, it's uni-north 
based, with a PPC750 (this one is 500MHz).  Seems like it should be hardware 
we're capable of booting on...

	Anybody have any ideas?  Should I raise this one to the more general 
port-powerpc list since it's actually in the arch/powerpc tree?  I'm not right 
now since it seems to be specific to this macppc model.

	Thank you in advance.
                                                Will