for user copyinout down to 12, and keeping segments 13/14 for
kernel VA.
It would be nice to have more available, but segments lower than
this are reserved for either memory or 1:1 mapped device i/o,
and seg 15 is OpenFirmware ROM. Also, the effort to keep OpenFirmware
available for callbacks limits the use of VA-mapped segments.
Fortunately UMA_MD_SMALL_ALLOC takes away a lot of VM pressure.
Obtained from: NetBSD
- culled long-dead #define's
- segment register defs moved to sr.h
- NPMAPS moved to pmap.h
- KERNBASE moved to vmparam.h
- removed include of <machine/cpu.h> and fixed src files that
relied on this.
Modifying segment register code no longer causes gcc rebuilds :-)
addressing of memory. Makes a substantial improvement for apps that
stress the limited amount of KVM on PPC (e.g. untarring the ports tree).
uma_machdep.c stolen from amd64/ia64.
