bootstd: Only scan bootable partitions

At present all partitions are scanned, whether marked bootable or not.
Use only bootable partitions, defaulting to partition 1 if none is
found.

Signed-off-by: Simon Glass <sjg@chromium.org>

boot/bootdev-uclass.c

@@ -163,7 +163,15 @@ int bootdev_find_in_blk(struct udevice *dev, struct udevice *blk,
 	 */
 	iter->max_part = MAX_PART_PER_BOOTDEV;
 
-	if (iter->part) {
+	/* If this is the whole disk, check if we have bootable partitions */
+	if (!iter->part) {
+		iter->first_bootable = part_get_bootable(desc);
+		log_debug("checking bootable=%d\n", iter->first_bootable);
+
+	/* if there are bootable partitions, scan only those */
+	} else if (iter->first_bootable ? !info.bootable : iter->part != 1) {
+		return log_msg_ret("boot", -EINVAL);
+	} else {
 		ret = fs_set_blk_dev_with_part(desc, bflow->part);
 		bflow->state = BOOTFLOWST_PART;
 

include/bootflow.h

@@ -123,6 +123,7 @@ enum bootflow_flags_t {
  * @method: Current bootmeth
  * @max_part: Maximum hardware partition number in @dev, 0 if there is no
  *	partition table
+ * @first_bootable: First bootable partition, or 0 if none
  * @err: Error obtained from checking the last iteration. This is used to skip
  *	forward (e.g. to skip the current partition because it is not valid)
  *	-ESHUTDOWN: try next bootdev
@@ -144,6 +145,7 @@ struct bootflow_iter {
 	int part;
 	struct udevice *method;
 	int max_part;
+	int first_bootable;
 	int err;
 	int num_devs;
 	int cur_dev;

test/boot/bootdev.c

@@ -301,3 +301,40 @@ static int bootdev_test_cmd_hunt(struct unit_test_state *uts)
 }
 BOOTSTD_TEST(bootdev_test_cmd_hunt, UT_TESTF_DM | UT_TESTF_SCAN_FDT |
 	     UT_TESTF_ETH_BOOTDEV);
+
+/* Check that only bootable partitions are processed */
+static int bootdev_test_bootable(struct unit_test_state *uts)
+{
+	struct bootflow_iter iter;
+	struct bootflow bflow;
+	struct udevice *blk;
+
+	memset(&iter, '\0', sizeof(iter));
+	memset(&bflow, '\0', sizeof(bflow));
+	iter.part = 0;
+	ut_assertok(uclass_get_device_by_name(UCLASS_BLK, "mmc1.blk", &blk));
+	iter.dev = blk;
+	ut_assertok(device_find_next_child(&iter.dev));
+	uclass_first_device(UCLASS_BOOTMETH, &bflow.method);
+
+	/*
+	 * initially we don't have any knowledge of which partitions are
+	 * bootable, but mmc1 has two partitions, with the first one being
+	 * bootable
+	 */
+	iter.part = 2;
+	ut_asserteq(-EINVAL, bootdev_find_in_blk(iter.dev, blk, &iter, &bflow));
+	ut_asserteq(0, iter.first_bootable);
+
+	/* scan with part == 0 to get the partition info */
+	iter.part = 0;
+	ut_asserteq(-ENOENT, bootdev_find_in_blk(iter.dev, blk, &iter, &bflow));
+	ut_asserteq(1, iter.first_bootable);
+
+	/* now it will refuse to use non-bootable partitions */
+	iter.part = 2;
+	ut_asserteq(-EINVAL, bootdev_find_in_blk(iter.dev, blk, &iter, &bflow));
+
+	return 0;
+}
+BOOTSTD_TEST(bootdev_test_bootable, UT_TESTF_DM | UT_TESTF_SCAN_FDT);

test/boot/bootflow.c

@@ -316,14 +316,14 @@ static int bootflow_iter(struct unit_test_state *uts)
 	bootflow_free(&bflow);
 
 	/* Then more to partition 2 which exists but is not bootable */
-	ut_asserteq(-EPERM, bootflow_scan_next(&iter, &bflow));
+	ut_asserteq(-EINVAL, bootflow_scan_next(&iter, &bflow));
 	ut_asserteq(2, iter.num_methods);
 	ut_asserteq(0, iter.cur_method);
 	ut_asserteq(2, iter.part);
 	ut_asserteq(0x1e, iter.max_part);
 	ut_asserteq_str("syslinux", iter.method->name);
 	ut_asserteq(0, bflow.err);
-	ut_asserteq(BOOTFLOWST_PART, bflow.state);
+	ut_asserteq(BOOTFLOWST_MEDIA, bflow.state);
 	bootflow_free(&bflow);
 
 	bootflow_iter_uninit(&iter);