In SDK 1.9.1 littlefs can not be assigned to external flash region

Hi there,

Could you do a pull request to the NCS repository? The appropriate person will then evaluate the issue and fix.

Thank you!

best regards

Jared  

I'll work on a PR this weekend.

Great, I'll close this case then.

Have you had an opportunity to work on this yet? I am facing the same issue and very interested in this change. I would be happy to work up a (or help with your) PR if you don't have time.

Have you had an opportunity to work on this yet? I am facing the same issue and very interested in this change. I would be happy to work up a (or help with your) PR if you don't have time.

I have a solution that seemed to work, but had more important items and I was also waiting for a fix for 32bit SFlash addressing from upstream.  I'll post it here shortly if you want to take a look and try it.  But I have not had much time to work on a more generic fix that is required to get it working in the official SDK.

Here was the key change in the SDK, it seems by default there was no way to get the littlefs to goto external memory in the partition manager, but it should be selectable in a PR.

There were a number of other changes that were needed as well to get it full configured.

diff --git a/subsys/partition_manager/pm.yml.file_system b/subsys/partition_manager/pm.yml.file_system
index 2b9907380..73008bbde 100644
--- a/subsys/partition_manager/pm.yml.file_system
+++ b/subsys/partition_manager/pm.yml.file_system
@@ -2,6 +2,7 @@
 
 #ifdef CONFIG_FILE_SYSTEM_LITTLEFS
 littlefs_storage:
+  region: external_flash
   placement: {before: [end]}
   size: CONFIG_PM_PARTITION_SIZE_LITTLEFS
 #endif

This looks great. Thanks for posting it. I took things a little farther to try to implement the configurability you mentioned. Here is what I have so far.:

diff --git a/subsys/partition_manager/Kconfig b/subsys/partition_manager/Kconfig
index b4fb5050c..721011146 100644
--- a/subsys/partition_manager/Kconfig
+++ b/subsys/partition_manager/Kconfig
@@ -118,6 +118,18 @@ config PM_EXTERNAL_FLASH_MCUBOOT_SECONDARY
 	  of the internal flash. This option should only be enabled by the user
 	  in the parent image.
 
+config PM_EXTERNAL_FLASH_LITTLEFS
+	bool "Place the LittleFS partition in external flash"
+	depends on FILE_SYSTEM_LITTLEFS
+	# Only depend on the chosen for the parent image. The value of this
+	# option is propagated to the MCUboot child image automatically.
+	depends on $(dt_chosen_enabled,$(DT_CHOSEN_EXT_FLASH))
+	default n
+	help
+	  Place the partition for LittleFS in the external flash instead
+	  of the internal flash. This option should only be enabled by the user
+	  in the parent image.
+
 config PM_IMAGE_NOT_BUILT_FROM_SOURCE
 	bool
 	help
diff --git a/subsys/partition_manager/pm.yml.file_system b/subsys/partition_manager/pm.yml.file_system
index 7c5462a87..3ff79a7bd 100644
--- a/subsys/partition_manager/pm.yml.file_system
+++ b/subsys/partition_manager/pm.yml.file_system
@@ -2,6 +2,9 @@
 
 #ifdef CONFIG_FILE_SYSTEM_LITTLEFS
 littlefs_storage:
+#if defined(CONFIG_PM_EXTERNAL_FLASH_LITTLEFS)
+  region: external_flash
+#endif
   placement: {before: [tfm_storage, end]}
   size: CONFIG_PM_PARTITION_SIZE_LITTLEFS
 #endif

I will submit this as the starting point for a PR later today

Looks good, what is the link for the PR? Thanks

Unfortunately, I got a little ahead of myself. Since I'm doing this "on company time" I am not able to sign the Contributor License Agreement so I will not be able to push the change through the PR process. Hopefully you, or someone from Nordic can take the patch above through the process.