ICH_REG_X_CIV
ch->civ = ich_rd(sc, ch->regbase + ICH_REG_X_CIV, 1) % ch->blkcnt;
ociv = ich_rd(sc, ch->regbase + ICH_REG_X_CIV, 1);
nciv = ich_rd(sc, ch->regbase + ICH_REG_X_CIV, 1);