jeffs@netbsd.org (Jeff Smith) writes in a commit message:
> No longer save $at on syscall entry.  v1 does appear to be used as if
> you do not save it and pass it along in rval the system will start
> to fail running user programs.  This finishes the suggestion by cgd to
> not save some registers on syscall entry.

take a look at lib/libc/sys/arch/mips/sys/sbrk.S.  "somebody was let
out without adult supervision" on that one, for a few reasons.

it'd be interesting to see what e.g. an ultrix binary or other
"vendor-os" does for this...


in any case, it sounds like it can't be fixed immediately, but if libc
is fixed to do something sane (i.e. actually respect the calling
conventions as if a syscall was a function call 8-), then maybe it
could be fixed at some point in the future...



chris