[PATCH v1 2/4] cmd: ab: introduce 'ab_dump' command to print BCB block content

[Dmitry Rokosov]

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

Output example:
=====
> board# ab_dump ubi 0#misc
> Read 512 bytes from volume misc to 000000000bf51900
> Bootloader Control: 	[misc]
> Active Slot: 		_a
> Magic Number: 		0x42414342
> Version: 		1
> Number of Slots: 	2
> Recovery Tries Remaining: 7
> CRC: 			0x61378F6F (Valid)
>
> Slot[0] Metadata:
> 	- Priority: 		15
> 	- Tries Remaining: 	4
> 	- Successful Boot: 	0
> 	- Verity Corrupted: 	0
>
> Slot[1] Metadata:
> 	- Priority: 		15
> 	- Tries Remaining: 	5
> 	- Successful Boot: 	0
> 	- Verity Corrupted: 	0
====

Signed-off-by: Dmitry Rokosov <ddrokosov at salutedevices.com>
---
 boot/android_ab.c    | 68 ++++++++++++++++++++++++++++++++++++++++++++
 cmd/ab_select.c      | 30 +++++++++++++++++++
 include/android_ab.h |  9 ++++++
 3 files changed, 107 insertions(+)

diff --git a/boot/android_ab.c b/boot/android_ab.c
index 1e5aa81b7503..359cc1a00428 100644
--- a/boot/android_ab.c
+++ b/boot/android_ab.c
@@ -363,3 +363,71 @@ 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: \t[%s]\n", part_info->name);
+	printf("Active Slot: \t\t%s\n", abc->slot_suffix);
+	printf("Magic Number: \t\t0x%X\n", abc->magic);
+	printf("Version: \t\t%u\n", abc->version);
+	printf("Number of Slots: \t%u\n", abc->nb_slot);
+	printf("Recovery Tries Remaining: %u\n", abc->recovery_tries_remaining);
+
+	printf("CRC: \t\t\t0x%.8X", abc->crc32_le);
+
+	crc32_le = ab_control_compute_crc(abc);
+	if (abc->crc32_le != crc32_le)
+		printf(" (Invalid, Expected: \t0x%.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: \t\t%u\n", slot->priority);
+		printf("\t- Tries Remaining: \t%u\n", slot->tries_remaining);
+		printf("\t- Successful Boot: \t%u\n", slot->successful_boot);
+		printf("\t- Verity Corrupted: \t%u\n", slot->verity_corrupted);
+	}
+
+error:
+	free(abc);
+
+	return ret;
+}
diff --git a/cmd/ab_select.c b/cmd/ab_select.c
index 9e2f74573c22..1d34150ceea9 100644
--- a/cmd/ab_select.c
+++ b/cmd/ab_select.c
@@ -51,6 +51,31 @@ static int do_ab_select(struct cmd_tbl *cmdtp, int flag, int argc,
 	return CMD_RET_SUCCESS;
 }
 
+static int do_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 (argc < 3)
+		return CMD_RET_USAGE;
+
+	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;
+}
+
 U_BOOT_CMD(ab_select, 5, 0, do_ab_select,
 	   "Select the slot used to boot from and register the boot attempt.",
 	   "<slot_var_name> <interface> <dev[:part|#part_name]> [--no-dec]\n"
@@ -66,3 +91,8 @@ U_BOOT_CMD(ab_select, 5, 0, do_ab_select,
 	   "    - If '--no-dec' is set, the number of tries remaining will not\n"
 	   "      decremented for the selected boot slot\n"
 );
+
+U_BOOT_CMD(ab_dump, 3, 0, do_ab_dump,
+	   "Dump boot_control information from specific partition.",
+	   "<interface> <dev[:part|#part_name]>\n"
+);
diff --git a/include/android_ab.h b/include/android_ab.h
index 1fee7582b90a..e53bf7eb6a02 100644
--- a/include/android_ab.h
+++ b/include/android_ab.h
@@ -33,4 +33,13 @@ struct disk_partition;
 int ab_select_slot(struct blk_desc *dev_desc, struct disk_partition *part_info,
                    bool dec_tries);
 
+/**
+ * Dump ABC information for specific partition.
+ *
+ * @param[in] dev_desc Device description pointer
+ * @param[in] 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