if some sparc hackers are going to usenix (i know pk is), i'd
like to talk with people who might be able to help me understand
how netbsd/sparc handles register windows and traps.

perhaps at the netbsd bof?

in particular, i'm having a hard time figuring out how the overflow and
underflow handlers keep track of which windows belong to the user.

(i'm trying to port VSTa, a microkernel that runs on a 386, to sparc).

i don't really want to dump the whole register file to the user
stack whenever i take a trap.

-matt