something wrong with the kernel stack.
Add code to check the kernel stack pointer in various important places
and try hard not to go down in flames if its wrong.
specified by the sparc abi. We use numerically higher values for all
internal kernel types.
Remove soft trap types which need to be exposed to userland. They will
move to utrap.h.
- mostly complete kernel pmap support, and tested but currently turned
off userland pmap support
- low level assembly language trap, context switching and support code
- fully implemented atomic.h and supporting cpufunc.h
- some support for kernel debugging with ddb
- various header tweaks and filling out of machine dependent structures