[PATCH v3 4/6] cmd: bcb: introduce 'ab_dump' command to print BCB block content

It's really helpful to have the ability to dump BCB block for debugging
A/B logic on the board supported this partition schema.

Command 'bcb ab_dump' prints all fields of bootloader_control struct
including slot_metadata for all presented slots.

Output example:
=====
> board# bcb ab_dump ubi 0#misc
> Read 512 bytes from volume misc to 000000000bf07580
> Read 512 bytes from volume misc to 000000000bf42f40
> Bootloader Control:       [misc]
> Active Slot:              _a
> Magic Number:             0x42414342
> Version:                  1
> Number of Slots:          2
> Recovery Tries Remaining: 0
> CRC:                      0x2c8b50bc (Valid)
>
> Slot[0] Metadata:
> 	- Priority:         15
> 	- Tries Remaining:  0
> 	- Successful Boot:  1
> 	- Verity Corrupted: 0
>
> Slot[1] Metadata:
> 	- Priority:         14
> 	- Tries Remaining:  7
> 	- Successful Boot:  0
> 	- Verity Corrupted: 0
====

Signed-off-by: Dmitry Rokosov <[email protected]>
---
 boot/android_ab.c    | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 cmd/bcb.c            | 35 +++++++++++++++++++++++++++
 include/android_ab.h | 10 ++++++++
 3 files changed, 113 insertions(+)

diff --git a/boot/android_ab.c b/boot/android_ab.c
index 0045c8133a8e164f1fdd4c0f9b683de0f13f26e0..c93e51541019d0fe793303c4b3d5286df061906f 100644
--- a/boot/android_ab.c
+++ b/boot/android_ab.c
@@ -372,3 +372,71 @@ int ab_select_slot(struct blk_desc *dev_desc, struct disk_partition *part_info,
 
 	return slot;
 }
+
+int ab_dump_abc(struct blk_desc *dev_desc, struct disk_partition *part_info)
+{
+	struct bootloader_control *abc;
+	u32 crc32_le;
+	int i, ret;
+	struct slot_metadata *slot;
+
+	if (!dev_desc || !part_info) {
+		log_err("ANDROID: Empty device descriptor or partition info\n");
+		return -EINVAL;
+	}
+
+	ret = ab_control_create_from_disk(dev_desc, part_info, &abc, 0);
+	if (ret < 0) {
+		log_err("ANDROID: Cannot create bcb from disk %d\n", ret);
+		return ret;
+	}
+
+	if (abc->magic != BOOT_CTRL_MAGIC) {
+		log_err("ANDROID: Unknown A/B metadata: %.8x\n", abc->magic);
+		ret = -ENODATA;
+		goto error;
+	}
+
+	if (abc->version > BOOT_CTRL_VERSION) {
+		log_err("ANDROID: Unsupported A/B metadata version: %.8x\n",
+			abc->version);
+		ret = -ENODATA;
+		goto error;
+	}
+
+	if (abc->nb_slot > ARRAY_SIZE(abc->slot_info)) {
+		log_err("ANDROID: Wrong number of slots %u, expected %zu\n",
+			abc->nb_slot, ARRAY_SIZE(abc->slot_info));
+		ret = -ENODATA;
+		goto error;
+	}
+
+	printf("Bootloader Control:       [%s]\n", part_info->name);
+	printf("Active Slot:              %s\n", abc->slot_suffix);
+	printf("Magic Number:             0x%x\n", abc->magic);
+	printf("Version:                  %u\n", abc->version);
+	printf("Number of Slots:          %u\n", abc->nb_slot);
+	printf("Recovery Tries Remaining: %u\n", abc->recovery_tries_remaining);
+
+	printf("CRC:                      0x%.8x", abc->crc32_le);
+
+	crc32_le = ab_control_compute_crc(abc);
+	if (abc->crc32_le != crc32_le)
+		printf(" (Invalid, Expected: 0x%.8x)\n", crc32_le);
+	else
+		printf(" (Valid)\n");
+
+	for (i = 0; i < abc->nb_slot; ++i) {
+		slot = &abc->slot_info[i];
+		printf("\nSlot[%d] Metadata:\n", i);
+		printf("\t- Priority:         %u\n", slot->priority);
+		printf("\t- Tries Remaining:  %u\n", slot->tries_remaining);
+		printf("\t- Successful Boot:  %u\n", slot->successful_boot);
+		printf("\t- Verity Corrupted: %u\n", slot->verity_corrupted);
+	}
+
+error:
+	free(abc);
+
+	return ret;
+}
diff --git a/cmd/bcb.c b/cmd/bcb.c
index 970c58e56cba0e1bdff21b7cd099f69151f0c5b8..4fd32186ae654915b5a42c26d755e5727c211c63 100644
--- a/cmd/bcb.c
+++ b/cmd/bcb.c
@@ -25,6 +25,7 @@ enum bcb_cmd {
 	BCB_CMD_FIELD_DUMP,
 	BCB_CMD_STORE,
 	BCB_CMD_AB_SELECT,
+	BCB_CMD_AB_DUMP,
 };
 
 static const char * const fields[] = {
@@ -56,6 +57,8 @@ static int bcb_cmd_get(char *cmd)
 		return BCB_CMD_FIELD_DUMP;
 	if (!strcmp(cmd, "ab_select"))
 		return BCB_CMD_AB_SELECT;
+	if (!strcmp(cmd, "ab_dump"))
+		return BCB_CMD_AB_DUMP;
 	else
 		return -1;
 }
@@ -93,6 +96,10 @@ static int bcb_is_misused(int argc, char *const argv[])
 		if (argc != 4 && argc != 5)
 			goto err;
 		return 0;
+	case BCB_CMD_AB_DUMP:
+		if (argc != 3)
+			goto err;
+		return 0;
 	default:
 		printf("Error: 'bcb %s' not supported\n", argv[0]);
 		return -1;
@@ -460,6 +467,28 @@ static int do_bcb_ab_select(struct cmd_tbl *cmdtp, int flag, int argc,
 	return CMD_RET_SUCCESS;
 }
 
+static int do_bcb_ab_dump(struct cmd_tbl *cmdtp, int flag, int argc,
+			  char *const argv[])
+{
+	int ret;
+	struct blk_desc *dev_desc;
+	struct disk_partition part_info;
+
+	if (part_get_info_by_dev_and_name_or_num(argv[1], argv[2],
+						 &dev_desc, &part_info,
+						 false) < 0) {
+		return CMD_RET_FAILURE;
+	}
+
+	ret = ab_dump_abc(dev_desc, &part_info);
+	if (ret < 0) {
+		printf("Cannot dump ABC data, error %d.\n", ret);
+		return CMD_RET_FAILURE;
+	}
+
+	return CMD_RET_SUCCESS;
+}
+
 static struct cmd_tbl cmd_bcb_sub[] = {
 	U_BOOT_CMD_MKENT(load, CONFIG_SYS_MAXARGS, 1, do_bcb_load, "", ""),
 	U_BOOT_CMD_MKENT(set, CONFIG_SYS_MAXARGS, 1, do_bcb_set, "", ""),
@@ -469,6 +498,8 @@ static struct cmd_tbl cmd_bcb_sub[] = {
 	U_BOOT_CMD_MKENT(store, CONFIG_SYS_MAXARGS, 1, do_bcb_store, "", ""),
 	U_BOOT_CMD_MKENT(ab_select, CONFIG_SYS_MAXARGS, 1,
 			 do_bcb_ab_select, "", ""),
+	U_BOOT_CMD_MKENT(ab_dump, CONFIG_SYS_MAXARGS, 1,
+			 do_bcb_ab_dump, "", ""),
 };
 
 static int do_bcb(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
@@ -523,6 +554,10 @@ U_BOOT_CMD(
 	"    - If '--no-dec' is set, the number of tries remaining will not\n"
 	"      decremented for the selected boot slot\n"
 	"\n"
+	"bcb ab_dump -\n"
+	"    Dump boot_control information from specific partition.\n"
+	"    <interface> <dev[:part|#part_name]>\n"
+	"\n"
 	"Legend:\n"
 	"<interface> - storage device interface (virtio, mmc, etc)\n"
 	"<dev>       - storage device index containing the BCB partition\n"
diff --git a/include/android_ab.h b/include/android_ab.h
index 1e53879a25f145a9d18ac0a6553d8c217123aa6f..838230e06f8cbf7a5d79d9d84d9ebe9f96aca10d 100644
--- a/include/android_ab.h
+++ b/include/android_ab.h
@@ -36,4 +36,14 @@ struct disk_partition;
 int ab_select_slot(struct blk_desc *dev_desc, struct disk_partition *part_info,
                    bool dec_tries);
 
+/**
+ * ab_dump_abc() - Dump ABC information for specific partition.
+ *
+ * @dev_desc: Device description pointer
+ * @part_info: Partition information
+ *
+ * Return: 0 on success, or a negative on error
+ */
+int ab_dump_abc(struct blk_desc *dev_desc, struct disk_partition *part_info);
+
 #endif /* __ANDROID_AB_H */

-- 
2.43.0