Hi,  I'm one of NetBSD developers who are resposible
for NetBSD/mips.

PostgreSQL requires to use a pair of MIPS instructions
named LL (load linked) and (store conditional).  They were
extended instructions instroduced after the original
MIPS processor R2000/R3000 design, and vest majority of
MIPS processors on market does have LL/SC including your
Cobalt.  So, ProtgreSQL should work for your NetBSD/cobalt.

I guess it would make no porting trouble if s_lock.c had
special statements like asm (".set mips2") inside.  In
that case, PostgreSQL can be compiled flawlessly and runs
smartly with LL/SC-capable processors.  If PostgreSQL was
ran with LL/SC-less processors, R2000/R3000 old timers or
some of half baked moderns (notably, NEC and Toshiba), it
would make unimplemented instruction traps on runtime.

Toru Nishimura/Engineering Lead/ALKYL Technology