> 1) Sun put support for the 20 in SunOS, and it just isn't mentioned anywhere in
   >    the kernel config files.
   
   > 2) The differences in the 20 are either in a level not dealt with by the kernel
   >    or there is some sort of compatibility hardware that makes it work with
   >    SunOS but isn't as fast/cool/better as the native support in Solaris.
   
   I believe you're completely wrong on that point. The sun4m architecture is
   in any case a multiprocessor architecture. I don't really find it surprising,
   that a SunOS 4.1.3 kernel for sun4m does indeed work on all sun4m machines.
   Of course, for real multiprocessor support, Sun has put some additional code
   into their kernel.
   
   And a sun4c kernel does not work on sun4m machines, regardless whether they
   have only one or more processors. So we still have lots of work to do, to
   get sun4m running, even without "real" multiprocessor support.

two of the biggest problems with the sun4m port at this stage
is the total lack of pmap code, and mmu code.  theo deraadt
has done most (all?) of the work for this port so far, but he's
hesitant to contribute after being asked to leave core.  i do
miss his contributions.

.mrg.