libavb: fsl: use bootctl to select slot in UNLOCK

if avb verifies fail in UNLOCK, modify fsl_bootctl
to read a/b metadata, select curr slot based on
metadata.

Change-Id: Ic34a687bb4eb1f07bf58338ad7a995f241fdeec0
Signed-off-by: Winter Wang <wente.wang@nxp.com>

3 files changed, 45 insertions, 10 deletions

diff --git a/drivers/usb/gadget/f_fastboot.c b/drivers/usb/gadget/f_fastboot.c
index 586e38a..b1a4dbb 100644
--- a/drivers/usb/gadget/f_fastboot.c
+++ b/drivers/usb/gadget/f_fastboot.c
@@ -1912,16 +1912,23 @@ int do_boota(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) {
 	} else { /* lock_status == FASTBOOT_UNLOCK && verify fail */
 		/* if in unlock state, log the verify state */
 		printf(" verify FAIL, state: UNLOCK\n");
-		printf(" boot 'boot_a' still\n");
 #endif
 		/* if lock/unlock not enabled or verify fail
 		 * in unlock state, will try boot */
 		size_t num_read;
 		hdr = &boothdr;
 
+		char bootimg[8];
+		char *slot = select_slot(&fsl_avb_ops);
+		if (slot == NULL) {
+			printf("boota: no bootable slot\n");
+			goto fail;
+		}
+		sprintf(bootimg, "boot%s", slot);
+		printf(" boot '%s' still\n", bootimg);
 		/* maybe we should use bootctl to select a/b
 		 * but libavb doesn't export a/b select */
-		if (fsl_avb_ops.read_from_partition(&fsl_avb_ops, "boot_a",
+		if (fsl_avb_ops.read_from_partition(&fsl_avb_ops, bootimg,
 					0, sizeof(boothdr), hdr, &num_read) != AVB_IO_RESULT_OK &&
 				num_read != sizeof(boothdr)) {
 			printf("boota: read bootimage head error\n");
@@ -1932,7 +1939,7 @@ int do_boota(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) {
 			goto fail;
 		}
 		image_size = android_image_get_end(hdr) - (ulong)hdr;
-		if (fsl_avb_ops.read_from_partition(&fsl_avb_ops, "boot_a",
+		if (fsl_avb_ops.read_from_partition(&fsl_avb_ops, bootimg,
 					0, image_size, (void *)load_addr, &num_read) != AVB_IO_RESULT_OK &&
 				num_read != image_size) {
 			printf("boota: read boot image error\n");
diff --git a/lib/libavb/fsl/fsl_avb.h b/lib/libavb/fsl/fsl_avb.h
index 743bc7c..180186a 100644
--- a/lib/libavb/fsl/fsl_avb.h
+++ b/lib/libavb/fsl/fsl_avb.h
@@ -167,4 +167,8 @@ int rbkidx_erase(const char * kblb_part);
  * */
 int avbkeyblb_init(uint8_t *plainkey, uint32_t keylen, const char *kblb_part /*"avbkey"*/);
 
+/* read a/b metadata to get curr slot
+ * return slot suffix '_a'/'_b' or NULL */
+char *select_slot(AvbOps *ops);
+
 #endif /* __FSL_AVB_H__ */
diff --git a/lib/libavb/fsl/fsl_bootctl.c b/lib/libavb/fsl/fsl_bootctl.c
index dc55444..23625a1 100644
--- a/lib/libavb/fsl/fsl_bootctl.c
+++ b/lib/libavb/fsl/fsl_bootctl.c
@@ -53,19 +53,19 @@ bool is_slotvar_avb(char *cmd) {
 	return false;
 }
 
-static char *get_curr_slot(AvbABData *ab_data) {
+static int get_curr_slot(AvbABData *ab_data) {
 	if (slot_is_bootable(&ab_data->slots[0]) &&
 		slot_is_bootable(&ab_data->slots[1])) {
 		if (ab_data->slots[1].priority > ab_data->slots[0].priority)
-			return slot_suffix[1];
+			return 1;
 		else
-			return slot_suffix[0];
+			return 0;
 	} else if (slot_is_bootable(&ab_data->slots[0]))
-		return slot_suffix[0];
+		return 0;
 	else if (slot_is_bootable(&ab_data->slots[1]))
-		return slot_suffix[1];
+		return 1;
 	else
-		return "no valid slot";
+		return -1;
 }
 
 int get_slotvar_avb(AvbOps *ops, char *cmd, char *buffer, size_t size) {
@@ -102,7 +102,13 @@ int get_slotvar_avb(AvbOps *ops, char *cmd, char *buffer, size_t size) {
 	}
 
 	if (!strcmp_l1("current-slot", cmd)) {
-		strlcpy(buffer, get_curr_slot(&ab_data), size);
+		int curr = get_curr_slot(&ab_data);
+		if (curr >= 0 && curr < SLOT_NUM)
+			strlcpy(buffer, slot_suffix[curr], size);
+		else {
+			strlcpy(buffer, "no bootable slot", size);
+			return -1;
+		}
 
 	} else if (!strcmp_l1("slot-successful:", cmd)) {
 		str += strlen("slot-successful:");
@@ -150,3 +156,21 @@ int get_slotvar_avb(AvbOps *ops, char *cmd, char *buffer, size_t size) {
 
 	return 0;
 }
+
+char *select_slot(AvbOps *ops) {
+	AvbABData ab_data;
+	int curr;
+
+	assert(ops != NULL);
+
+	/* load ab meta */
+	if (ops->read_ab_metadata == NULL ||
+			ops->read_ab_metadata(ops, &ab_data) != AVB_IO_RESULT_OK) {
+		return NULL;
+	}
+	curr = get_curr_slot(&ab_data);
+	if (curr >= 0 && curr < SLOT_NUM)
+		return slot_suffix[curr];
+	else
+		return NULL;
+}