Something to note here: SPARC is nowhere near as nice as Intel in terms
of system architecture compatibility.  They define "kernel
architectures" that are essentially completely different machines:
sun4, sun4c, sun4m, and sun4d are the current ones, with sun4e
coming.

These might as well be mips, intel, 68k, powerpc, because to do a port
from one kernel architecture to the next is a basic rewrite of all the
low level stuff: i/o, mmu, etc.

Sun divides up their source tree like so:

Makefile        adb/            req.flg         sun4c/          tags
Makefile.targ   common/         sparc/          sun4d/          tags.list
Makefile.uts    cscope.files    srmmu/          sun4e/
README          cscope.out      sun/            sun4m/
SCCS/           old/            sun4/           sunmmu/

The meanings are:

sparc	generic assembler code that works on all SPARC systems
srmmu	code specific to the sun reference mmu (sun4m & sun4d use this)
sun	device drivers that work on most/all sun platforms (zs, eeprom)
sun4	the original sparc system (4/2xx and 4/4xx)
sun4c	sparcstation 1, 2, IPC, and IPX code (SS1 == IPC, SS2 == IPX)
sun4d	sparc server 1000, and sparcserver 2000
sun4e	next sparc architecture (V9, I believe)
sun4m	4/6xx, sparcstation 10, sparc classic, and LX
sunmmu	the original mmu design (sun4, sun4c)

It's a lot of work to deal with all of this.  I would deal with sun4c
and sun4m only, personally.

FYI.
: 
: Quick question. When the sun4m port makes its way along, do you plan to 
: hook it into the sparc tree via #ifdef, define a new tree a la Sun 
: (sparc4m?), or ...
: 
: What is the preferred technique here. I don't care, was just wondering if 
: anyone had worked something up.
: ron
: 
:  rminnich@super.org      | IBM wants to run ATM at 25 mbits/sec, or 1/2 of OC-1
:  (301)-805-7451 or 7312  | This would give them OC/2 for OS/2 on a PS/2
: 
: 

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