fastboot: handle flash write to GPT partitions

Implement a feature to allow fastboot to write the downloaded image
to the space reserved for the Protective MBR and the Primary GUID
Partition Table.
Additionally, prepare and write the Backup GUID Partition Table.

Signed-off-by: Steve Rae <srae@broadcom.com>
Tested-by: Lukasz Majewski <l.majewski@samsung.com>
[Test HW: Exynos4412 - Trats2]

1 files changed, 93 insertions, 0 deletions

diff --git a/disk/part_efi.c b/disk/part_efi.c
index 2c77f29d454..338010e148e 100644
--- a/disk/part_efi.c
+++ b/disk/part_efi.c
@@ -161,6 +161,8 @@ static void prepare_backup_gpt_header(gpt_header *gpt_h)
 	val = le64_to_cpu(gpt_h->my_lba);
 	gpt_h->my_lba = gpt_h->alternate_lba;
 	gpt_h->alternate_lba = cpu_to_le64(val);
+	gpt_h->partition_entry_lba =
+			cpu_to_le64(le64_to_cpu(gpt_h->last_usable_lba) + 1);
 	gpt_h->header_crc32 = 0;
 
 	calc_crc32 = efi_crc32((const unsigned char *)gpt_h,
@@ -545,6 +547,97 @@ err:
 	free(gpt_h);
 	return ret;
 }
+
+int is_valid_gpt_buf(block_dev_desc_t *dev_desc, void *buf)
+{
+	gpt_header *gpt_h;
+	gpt_entry *gpt_e;
+
+	/* determine start of GPT Header in the buffer */
+	gpt_h = buf + (GPT_PRIMARY_PARTITION_TABLE_LBA *
+		       dev_desc->blksz);
+	if (validate_gpt_header(gpt_h, GPT_PRIMARY_PARTITION_TABLE_LBA,
+				dev_desc->lba))
+		return -1;
+
+	/* determine start of GPT Entries in the buffer */
+	gpt_e = buf + (le64_to_cpu(gpt_h->partition_entry_lba) *
+		       dev_desc->blksz);
+	if (validate_gpt_entries(gpt_h, gpt_e))
+		return -1;
+
+	return 0;
+}
+
+int write_mbr_and_gpt_partitions(block_dev_desc_t *dev_desc, void *buf)
+{
+	gpt_header *gpt_h;
+	gpt_entry *gpt_e;
+	int gpt_e_blk_cnt;
+	lbaint_t lba;
+	int cnt;
+
+	if (is_valid_gpt_buf(dev_desc, buf))
+		return -1;
+
+	/* determine start of GPT Header in the buffer */
+	gpt_h = buf + (GPT_PRIMARY_PARTITION_TABLE_LBA *
+		       dev_desc->blksz);
+
+	/* determine start of GPT Entries in the buffer */
+	gpt_e = buf + (le64_to_cpu(gpt_h->partition_entry_lba) *
+		       dev_desc->blksz);
+	gpt_e_blk_cnt = BLOCK_CNT((le32_to_cpu(gpt_h->num_partition_entries) *
+				   le32_to_cpu(gpt_h->sizeof_partition_entry)),
+				  dev_desc);
+
+	/* write MBR */
+	lba = 0;	/* MBR is always at 0 */
+	cnt = 1;	/* MBR (1 block) */
+	if (dev_desc->block_write(dev_desc->dev, lba, cnt, buf) != cnt) {
+		printf("%s: failed writing '%s' (%d blks at 0x" LBAF ")\n",
+		       __func__, "MBR", cnt, lba);
+		return 1;
+	}
+
+	/* write Primary GPT */
+	lba = GPT_PRIMARY_PARTITION_TABLE_LBA;
+	cnt = 1;	/* GPT Header (1 block) */
+	if (dev_desc->block_write(dev_desc->dev, lba, cnt, gpt_h) != cnt) {
+		printf("%s: failed writing '%s' (%d blks at 0x" LBAF ")\n",
+		       __func__, "Primary GPT Header", cnt, lba);
+		return 1;
+	}
+
+	lba = le64_to_cpu(gpt_h->partition_entry_lba);
+	cnt = gpt_e_blk_cnt;
+	if (dev_desc->block_write(dev_desc->dev, lba, cnt, gpt_e) != cnt) {
+		printf("%s: failed writing '%s' (%d blks at 0x" LBAF ")\n",
+		       __func__, "Primary GPT Entries", cnt, lba);
+		return 1;
+	}
+
+	prepare_backup_gpt_header(gpt_h);
+
+	/* write Backup GPT */
+	lba = le64_to_cpu(gpt_h->partition_entry_lba);
+	cnt = gpt_e_blk_cnt;
+	if (dev_desc->block_write(dev_desc->dev, lba, cnt, gpt_e) != cnt) {
+		printf("%s: failed writing '%s' (%d blks at 0x" LBAF ")\n",
+		       __func__, "Backup GPT Entries", cnt, lba);
+		return 1;
+	}
+
+	lba = le64_to_cpu(gpt_h->my_lba);
+	cnt = 1;	/* GPT Header (1 block) */
+	if (dev_desc->block_write(dev_desc->dev, lba, cnt, gpt_h) != cnt) {
+		printf("%s: failed writing '%s' (%d blks at 0x" LBAF ")\n",
+		       __func__, "Backup GPT Header", cnt, lba);
+		return 1;
+	}
+
+	return 0;
+}
 #endif
 
 /*