>had some time to kill and decided to look at the scheduler.  what
>struck me was that they *seem* to have replaced spl*()/slpx() with
>calls to cli()/sti() which are the names of the machine instructions
>for the i386 (linux started there, and presumably the code originally
>contained in-line assembly to do just that) that block all interrupts

The Linix kernel originally had a lot of asm("i386-instruction ...") in
it.  That is why there is a NetBSD/pc532.  I first evaluated Linux
and discovered there was way too many MD constructs in code that should
have been MI.  As I recall, there was a asm() in the getpid() code in
the kernel.  It was very obvious at the time that I would have to
rewrite most of the kernel to get it to run on a ns32k processor and 
that Linus was not interested in trying to remove most of the MD code.
Getting NetBSD up and going was a much easier task.

-- 
Phil Nelson
e-mail: philnelson@home.com  (Work: phil@cs.wwu.edu)
web: members.home.com/philnelson