static int find_partition(BlockDriverState *bs, int partition, off_t *offset, off_t *size) { struct partition_record mbr[4]; uint8_t data[512]; int i; int ext_partnum = 4; int ret; if ((ret = bdrv_read(bs, 0, data, 1)) < 0) { errno = -ret; err(EXIT_FAILURE, "error while reading"); } if (data[510] != 0x55 || data[511] != 0xaa) { errno = -EINVAL; return -1; } for (i = 0; i < 4; i++) { read_partition(&data[446 + 16 * i], &mbr[i]); if (!mbr[i].nb_sectors_abs) continue; if (mbr[i].system == 0xF || mbr[i].system == 0x5) { struct partition_record ext[4]; uint8_t data1[512]; int j; if ((ret = bdrv_read(bs, mbr[i].start_sector_abs, data1, 1)) < 0) { errno = -ret; err(EXIT_FAILURE, "error while reading"); } for (j = 0; j < 4; j++) { read_partition(&data1[446 + 16 * j], &ext[j]); if (!ext[j].nb_sectors_abs) continue; if ((ext_partnum + j + 1) == partition) { *offset = (uint64_t)ext[j].start_sector_abs << 9; *size = (uint64_t)ext[j].nb_sectors_abs << 9; return 0; } } ext_partnum += 4; } else if ((i + 1) == partition) { *offset = (uint64_t)mbr[i].start_sector_abs << 9; *size = (uint64_t)mbr[i].nb_sectors_abs << 9; return 0; } } errno = -ENOENT; return -1; }