[PATCH v1 4/4] common: android_ab: fix slot suffix for abc block

[Dmitry Rokosov]

To align with the official Android BCB (Boot Control Block)
specifications, it's important to note that the slot_suffix should start
with an underscore symbol.

For a comprehensive understanding of the expected slot_suffix format in
userspace, please refer to the provided reference [1].

Links:
[1] - https://source.android.com/docs/core/architecture/bootloader/updating#slots

Signed-off-by: Dmitry Rokosov <ddrokosov at salutedevices.com>
---
 boot/android_ab.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/boot/android_ab.c b/boot/android_ab.c
index 359cc1a00428..45c154b10f1a 100644
--- a/boot/android_ab.c
+++ b/boot/android_ab.c
@@ -53,7 +53,7 @@ static int ab_control_default(struct bootloader_control *abc)
 	if (!abc)
 		return -EFAULT;
 
-	memcpy(abc->slot_suffix, "a\0\0\0", 4);
+	memcpy(abc->slot_suffix, "_a\0\0", 4);
 	abc->magic = BOOT_CTRL_MAGIC;
 	abc->version = BOOT_CTRL_VERSION;
 	abc->nb_slot = NUM_SLOTS;
@@ -319,7 +319,8 @@ int ab_select_slot(struct blk_desc *dev_desc, struct disk_partition *part_info,
 		 * or the device tree.
 		 */
 		memset(slot_suffix, 0, sizeof(slot_suffix));
-		slot_suffix[0] = BOOT_SLOT_NAME(slot);
+		slot_suffix[0] = '_';
+		slot_suffix[1] = BOOT_SLOT_NAME(slot);
 		if (memcmp(abc->slot_suffix, slot_suffix,
 			   sizeof(slot_suffix))) {
 			memcpy(abc->slot_suffix, slot_suffix,
-- 
2.43.0