I'm wondering about a few virtual memory realated things.  After reading
the Hitachi SH4 hardware manual I was wondering how NetBSD handles the
virtual memory stuff.  Which features of the hardware does NetBSD use...

1.) is the address space identifier used?
2.) at a per process level dose the user space have full control over
the lower half of the 32 bit address space?  Does it start at the
beginning?
3.) What is going on with the different PX areas... specifically the
high memory area ones.
4.) I've read all the comments in the pmap.h/pte.h/etc files and it
looks like the sh3/4 pmap is derived from the i386 one but I'm wondering
if it keeps the same structure - if it maintains the kernel virtual
address space and the page table space in the same way.
5.) also could I get just short description of one of the race-conditons
in the vm code so I might use it as a starting place to examine the
code.

All in all I'm wondering exactly how the kernel sees the memory and what
hardware functions are used.

Thanks
Tyrel