MIPS32 support

[Oleksandr Tymoshenko]

     Hello people. For last few weekends I've been tweaking code of latest
freebsd-mips snapshot, provided by Juli, intending to run it on MIPS32
evaluation board I'd got. On the moment I have some low-level stuff
ported: TLB handling, traps handling, interrupt handling. Kernel boots
and runs on a board(well, till a certain moment of course, there is no
PCI bus support yet).  Not many changes to original code, but it took a
while to look through architecture specs. Now, when I know where to go
further with porting, I'd like to put my changes together, clean them
out and keep in sync with main development branch. The latest available
sources are more then one year old. Was there any progress since then? Also
there is a question of keeping mips64/mips32 sources together.  NetBSD
keeps code for both platforms as one meta-architecture "mips" and manage
it with #defines from architectures like "evbmips". It's only mips64
tree in the snapshot so far. So I wander if there is a kind of roadmap
for freebsd-mips project. Thanks!

-- 
gonzo