parse_uint32
error = parse_uint32(&active_partition, 1, 100, optarg);
error = parse_uint32(&nheads, 1, 255, optarg);
error = parse_uint32(&blksz, 512, INT_MAX+1U, optarg);
error = parse_uint32(&secsz, 512, INT_MAX+1U, optarg);
error = parse_uint32(&nsecs, 1, 63, optarg);