[PATCH] environment: prefer non-removable over removable devices for autoprobe

Ahmad Fatoum a.fatoum at pengutronix.de
Thu Nov 27 04:41:34 PST 2025


From: Ahmad Fatoum <a.fatoum at barebox.org>

On systems with only 1-2 MiB of boot flash, it can be sensible to locate
the barebox environment outside of the boot medium.

In that case, it's sensible to give preference to non-removable devices,
so e.g. an eMMC is used instead of the SD-Card when booting from
neither, so adapt the scoring accordingly.

This could be further refined to make use of the eMMC non_removable
attribute, but this is already arguably an improvement.

Signed-off-by: Ahmad Fatoum <a.fatoum at barebox.org>
---
 common/environment.c |  8 ++++++--
 include/block.h      | 11 +++++++++++
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/common/environment.c b/common/environment.c
index 62b8120cbd7d..d7f5f51cfc6d 100644
--- a/common/environment.c
+++ b/common/environment.c
@@ -104,10 +104,14 @@ static struct cdev *default_environment_path_search(void)
 		if (IS_ERR(part))
 			continue;
 
-		score++;
+		/* Prefer eMMC over SD if neither is the boot medium */
+		if (blockdevice_is_removable(blk))
+			score += 1;
+		else
+			score += 2;
 
 		if (boot_node && boot_node == blk->cdev.device_node)
-			score++;
+			score += 4;
 
 		if (score > max_score) {
 			max_score = score;
diff --git a/include/block.h b/include/block.h
index fc7a0a32fb2d..84c247cee3a3 100644
--- a/include/block.h
+++ b/include/block.h
@@ -82,6 +82,17 @@ static inline int block_flush(struct block_device *blk)
 	return cdev_flush(&blk->cdev);
 }
 
+static inline bool blockdevice_is_removable(struct block_device *blk)
+{
+	switch (blk->type) {
+	case BLK_TYPE_USB:
+	case BLK_TYPE_SD:
+		return true;
+	default:
+		return false;
+	}
+}
+
 #ifdef CONFIG_BLOCK
 unsigned file_list_add_blockdevs(struct file_list *files);
 char *cdev_get_linux_rootarg(const struct cdev *partcdev);
-- 
2.47.3




More information about the barebox mailing list