$ 0 0 bt(4): Sync with FreeBSD. Main change is making it MPSAFE. Taken-from: FreeBSD [DBH] share/man/man4/bt.4 [DBH] sys/dev/disk/buslogic/bt.c [DBH] sys/dev/disk/buslogic/bt_pci.c [DBH] sys/dev/disk/buslogic/btreg.h