efi_block_read
status = efi_block_read(bdev,
status = efi_block_read(bdev,
status = efi_block_read(bdev, 0, &mbr, sizeof(mbr));
status = efi_block_read(bdev, (EFI_LBA)GPT_HDR_BLKNO * bdev->bio->Media->BlockSize, &hdr,
status = efi_block_read(bdev,
status = efi_block_read(bpart->bdev, off, buf, size);