MVMEBUS_AM_CAP_BLKD64
MVMEBUS_AM_CAP_BLKD64 | MVMEBUS_AM_CAP_USER,
MVMEBUS_AM_CAP_BLKD64 | MVMEBUS_AM_CAP_SUPER,
if (am & MVMEBUS_AM_CAP_BLKD64)
vr->vr_am |= MVMEBUS_AM_CAP_BLKD64;