P_GMII_1GBIT_M
val = FIELD_GET(P_GMII_1GBIT_M, data8);
data8 &= ~P_GMII_1GBIT_M;
data8 |= FIELD_PREP(P_GMII_1GBIT_M, bitval[P_GMII_1GBIT]);
data8 |= FIELD_PREP(P_GMII_1GBIT_M, bitval[P_GMII_NOT_1GBIT]);