[PATCH v3 36/44] boot: Consider non-bootable partitions

[Heinrich Schuchardt]

Am 25. Februar 2025 00:06:25 MEZ schrieb Simon Glass <sjg at chromium.org>:
>The 'bootable' flag in the DOS partition is deprecated so we should not
>rely on it by default. The logic which skips non-bootable partitions can
>miss extlinux.conf files on the root disk.

It is unclear why you assume that this flag is deprecated. A link to the specification change in the commit message would be helpful.

Best regards

Heinrich


>
>Put this logic behind a flag and update the documentation.
>
>Signed-off-by: Simon Glass <sjg at chromium.org>
>---
>
>Changes in v3:
>- Add new patch to consider non-bootable partitions
>
> boot/bootdev-uclass.c            | 4 +++-
> doc/develop/bootstd/overview.rst | 5 +++--
> include/bootflow.h               | 2 ++
> test/boot/bootdev.c              | 1 +
> test/boot/bootflow.c             | 5 +++--
> 5 files changed, 12 insertions(+), 5 deletions(-)
>
>diff --git a/boot/bootdev-uclass.c b/boot/bootdev-uclass.c
>index c39147940b6..9e4c3db2dc1 100644
>--- a/boot/bootdev-uclass.c
>+++ b/boot/bootdev-uclass.c
>@@ -168,8 +168,10 @@ int bootdev_find_in_blk(struct udevice *dev, struct udevice *blk,
> 		 */
> 
> 	/* if there are bootable partitions, scan only those */
>-	} else if (iter->first_bootable >= 0 &&
>+	} else if ((iter->flags & BOOTFLOWIF_ONLY_BOOTABLE) &&
>+		   iter->first_bootable >= 0 &&
> 		   (iter->first_bootable ? !info.bootable : iter->part != 1)) {
>+		log_debug("Skipping non-bootable partition %d\n", iter->part);
> 		return log_msg_ret("boot", -EINVAL);
> 	} else {
> 		ret = fs_set_blk_dev_with_part(desc, bflow->part);
>diff --git a/doc/develop/bootstd/overview.rst b/doc/develop/bootstd/overview.rst
>index c46bd7a5a90..7bca043791b 100644
>--- a/doc/develop/bootstd/overview.rst
>+++ b/doc/develop/bootstd/overview.rst
>@@ -235,8 +235,9 @@ means that `default_get_bootflow()` is used. This simply obtains the
> block device and calls a bootdev helper function to do the rest. The
> implementation of `bootdev_find_in_blk()` checks the partition table, and
> attempts to read a file from a filesystem on the partition number given by the
>-`@iter->part` parameter. If there are any bootable partitions in the table,
>-then only bootable partitions are considered.
>+`@iter->part` parameter. If there are any bootable partitions in the table and
>+the BOOTFLOWIF_ONLY_BOOTABLE flag is set in `@iter->flags`, then only bootable
>+partitions are considered.
> 
> Each bootdev has a priority, which indicates the order in which it is used,
> if `boot_targets` is not used. Faster bootdevs are used first, since they are
>diff --git a/include/bootflow.h b/include/bootflow.h
>index d9045bc3dae..2caeb80b878 100644
>--- a/include/bootflow.h
>+++ b/include/bootflow.h
>@@ -161,6 +161,7 @@ struct bootflow_img {
>  * before using it
>  * @BOOTFLOWIF_ALL: Return bootflows with errors as well
>  * @BOOTFLOWIF_HUNT: Hunt for new bootdevs using the bootdrv hunters
>+ * @BOOTFLOWIF_ONLY_BOOTABLE: Only consider partitions marked 'bootable'
>  *
>  * Internal flags:
>  * @BOOTFLOWIF_SINGLE_DEV: (internal) Just scan one bootdev
>@@ -177,6 +178,7 @@ enum bootflow_iter_flags_t {
> 	BOOTFLOWIF_SHOW			= 1 << 1,
> 	BOOTFLOWIF_ALL			= 1 << 2,
> 	BOOTFLOWIF_HUNT			= 1 << 3,
>+	BOOTFLOWIF_ONLY_BOOTABLE	= BIT(4),
> 
> 	/*
> 	 * flags used internally by standard boot - do not set these when
>diff --git a/test/boot/bootdev.c b/test/boot/bootdev.c
>index 5f07430714e..d5499918249 100644
>--- a/test/boot/bootdev.c
>+++ b/test/boot/bootdev.c
>@@ -509,6 +509,7 @@ static int bootdev_test_bootable(struct unit_test_state *uts)
> 	iter.part = 0;
> 	ut_assertok(uclass_get_device_by_name(UCLASS_BLK, "mmc1.blk", &blk));
> 	iter.dev = blk;
>+	iter.flags = BOOTFLOWIF_ONLY_BOOTABLE;
> 	ut_assertok(device_find_next_child(&iter.dev));
> 	uclass_first_device(UCLASS_BOOTMETH, &bflow.method);
> 
>diff --git a/test/boot/bootflow.c b/test/boot/bootflow.c
>index 49ef4d0c3ab..1447af2eb14 100644
>--- a/test/boot/bootflow.c
>+++ b/test/boot/bootflow.c
>@@ -301,8 +301,9 @@ static int bootflow_iter(struct unit_test_state *uts)
> 
> 	/* The first device is mmc2.bootdev which has no media */
> 	ut_asserteq(-EPROTONOSUPPORT,
>-		    bootflow_scan_first(NULL, NULL, &iter,
>-					BOOTFLOWIF_ALL | BOOTFLOWIF_SKIP_GLOBAL, &bflow));
>+		    bootflow_scan_first(NULL, NULL, &iter, BOOTFLOWIF_ALL |
>+					BOOTFLOWIF_SKIP_GLOBAL |
>+					BOOTFLOWIF_ONLY_BOOTABLE, &bflow));
> 	ut_asserteq(2, iter.num_methods);
> 	ut_asserteq(0, iter.cur_method);
> 	ut_asserteq(0, iter.part);