> The R4000 models, usually known as MIPS Magnums or Magnum 4000, will
> work in either endian mode.

It's interesting to know that R3000 Magnum document refers briefly
that the machine is designed bi-endian.  By writing a specific value
to special hardware address, R3000 Magnum can boot in little-endian
mode next time (Oh, well...)

Device registers in R3000 Magnum are populated in 4B stroke, it's
technically possible to make NetBSD/mipsco endian-neutral (le/be
kernel from a single set of source code) as long as device drivers
avoid 16bit/8bit access carefully. 

However, NetBSD/mipsco will take big-endian path because its primary
goal is to embrace pre-R4000 products by MIPS Computer Systems.

Tohru Nishimura