MGX_REG_VRAM8
sc->sc_paddr = sbus_bus_addr(bt, sa->sa_reg[MGX_REG_VRAM8].sbr_slot,
sa->sa_reg[MGX_REG_VRAM8].sbr_offset);
if (sbus_bus_map(bt, sa->sa_reg[MGX_REG_VRAM8].sbr_slot,
sa->sa_reg[MGX_REG_VRAM8].sbr_offset,