[U-Boot] [PATCH v1] fastboot: handle flash write to GPT partition

[Steve Rae]

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.

Signed-off-by: Steve Rae <srae at broadcom.com>
---

 README          |  7 +++++++
 common/fb_mmc.c | 19 ++++++++++++++++---
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/README b/README
index 66770b6..3b6ef7f 100644
--- a/README
+++ b/README
@@ -1769,6 +1769,13 @@ The following options need to be configured:
 		regarding the non-volatile storage device. Define this to
 		the eMMC device that fastboot should use to store the image.
 
+		CONFIG_FASTBOOT_GPT_NAME
+		The fastboot "flash" command supports writing the downloaded
+		image to the Protective MBR and the Primary GUID Partition
+		Table. This occurs when the specified "partition name" on the
+		"fastboot flash" command line matches this value.
+		Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
+
 - Journaling Flash filesystem support:
 		CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
 		CONFIG_JFFS2_NAND_DEV
diff --git a/common/fb_mmc.c b/common/fb_mmc.c
index fb06d8a..89fbf23 100644
--- a/common/fb_mmc.c
+++ b/common/fb_mmc.c
@@ -4,12 +4,17 @@
  * SPDX-License-Identifier:	GPL-2.0+
  */
 
+#include <config.h>
 #include <common.h>
 #include <fb_mmc.h>
 #include <part.h>
 #include <aboot.h>
 #include <sparse_format.h>
 
+#ifndef CONFIG_FASTBOOT_GPT_NAME
+#define CONFIG_FASTBOOT_GPT_NAME GPT_ENTRY_NAME
+#endif
+
 /* The 64 defined bytes plus the '\0' */
 #define RESPONSE_LEN	(64 + 1)
 
@@ -62,9 +67,9 @@ static void write_raw_image(block_dev_desc_t *dev_desc, disk_partition_t *info,
 void fb_mmc_flash_write(const char *cmd, void *download_buffer,
 			unsigned int download_bytes, char *response)
 {
-	int ret;
 	block_dev_desc_t *dev_desc;
 	disk_partition_t info;
+	lbaint_t blksz;
 
 	/* initialize the response buffer */
 	response_str = response;
@@ -76,8 +81,16 @@ void fb_mmc_flash_write(const char *cmd, void *download_buffer,
 		return;
 	}
 
-	ret = get_partition_info_efi_by_name(dev_desc, cmd, &info);
-	if (ret) {
+	if (strcmp(cmd, CONFIG_FASTBOOT_GPT_NAME) == 0) {
+		printf("%s: updating GUID Partition Table (including MBR)\n",
+		       __func__);
+		/* start at Protective MBR */
+		info.start = (GPT_PRIMARY_PARTITION_TABLE_LBA - 1);
+		blksz = dev_desc->blksz;
+		info.blksz = blksz;
+		/* assume that the Partition Entry Array starts in LBA 2 */
+		info.size = (2 + (GPT_ENTRY_NUMBERS * GPT_ENTRY_SIZE) / blksz);
+	} else if (get_partition_info_efi_by_name(dev_desc, cmd, &info)) {
 		error("cannot find partition: '%s'\n", cmd);
 		fastboot_fail("cannot find partition");
 		return;
-- 
1.8.5