rh_setvmode
rh_setvmode (gp, rh_default_gfx + 1, MT_GFXONLY);
rh_setvmode (gp, rh_default_mon + 1, MT_TXTONLY);
return(rh_setvmode(gp, *(unsigned *) arg,
int rh_setvmode(struct grf_softc *gp, unsigned int mode, enum mode_type type);