SDUNIT
unit = SDUNIT(dev);
unit = SDUNIT(dev);
unit = SDUNIT(dev);
unit = SDUNIT(dev);
unit = SDUNIT(dev);
struct sd_softc *sd = device_lookup_private(&sd_cd, SDUNIT(bp->b_dev));
struct sd_softc *sd = device_lookup_private(&sd_cd, SDUNIT(bp->b_dev));
#define SDLABELDEV(dev) (MAKESDDEV(major(dev), SDUNIT(dev), RAW_PART))
struct sd_softc *sd = device_lookup_private(&sd_cd, SDUNIT(dev));