>> It seems i must use the 
>> 'Makefile.mips' from 'arc/mips/conf' but I don't
>> know how.
>
> Makefiles for multiple target ports which share the same CPU architecture
> (then toolchain) are re-organized some time ago.  The change made it easier
> to maintain Makefiles in phase and consistency.

One more.  The change was prompted by smart cross compiling
environment.  I have changed my builder machine to $900- shiny Compaq
armed with NetBSD pkg collections and could not be happier.  I got the
environment a single evening. It compiles m68k, mipsel and mipseb
lightening fast as well as i386.  Many NetBSDers prepare other CPU
architectures in such way.

Tohru Nishimura