that is priority is rasied. Add a new spllowersoftclock() to provide the
atomic drop-to-softclock semantics that the old splsoftclock() provided,
and update calls accordingly.
This fixes a problem with using the "rnd" pseudo-device from within
interrupt context to extract random data (e.g. from within the softnet
interrupt) where doing so would incorrectly unblock interrupts (causing
all sorts of lossage).
XXX 4 platforms do not have priority-raising capability: newsmips, sparc,
XXX sparc64, and VAX. This platforms still have this bug until their
XXX spl*() functions are fixed.
cpu.h: cpu_adjstack() won't work well in the NetBSD execve - need a
different model, stub enablertclock() for now..
exec.h: a netbsd-type exec.h file (ie. empty)
param.h: add MID_MACHINE
pmap.h: delete kernel_pmap hack - it doesn't work for us, + two proto's
vmparam.h: VM_MIN_ADDRESS = 0!