VIAGR
bus_space_write_1(sc->sc_iot, sc->sc_ioh, VIAGR, i);
bus_space_write_1(sc->sc_iot, sc->sc_ioh, VIAGR + 1,
{VIAGR,GR20,0xFF,0x00},
{VIAGR,GR21,0xFF,0x00},
{VIAGR,GR22,0xFF,0x00},