LittleFS config creating un-used partition in flash_primary

[Brett_G]

I am using LittleFS for an external NAND flash by using the KCONFIG option CONFIG_FILE_SYSTEM_LITTLEFS=y and managing the driver implementation manually. This has worked well for me, but I have found that this config option seems to also create an un-used partition on the internal flash_primary shown below:

I assume, since the implementation of littleFS is on external flash, that this is not being used for anything.

I had plans to use some of that flash for an NVS implementation, but having the random partition in the middle of everything complicates it a bit.

Is that partition being used for anything internally? or is there a way to enable use of littleFS without allocating a partition in flash_primary?

Thanks,

- Brett

[Øivind]

Hi,

Could I see the prj.conf of the application? And do you get any errors if you add the following configs?

CONFIG_NVS=y
CONFIG_SETTINGS=y
CONFIG_SETTINGS_NVS=y

If that builds, please check the partition.

[Brett_G]

Here is the relevant section of my prj.conf:

# file system
CONFIG_FLASH=y
CONFIG_FLASH_MAP=y
CONFIG_FLASH_PAGE_LAYOUT=y
CONFIG_FILE_SYSTEM=y
CONFIG_FILE_SYSTEM_LITTLEFS=y
CONFIG_FS_LITTLEFS_BLK_DEV=y
CONFIG_DISK_ACCESS=y
CONFIG_DISK_DRIVER_SDMMC=n
CONFIG_FILE_SYSTEM_MKFS=y

Adding those config options didn't cause any errors and as expected the settings_storage partition showed up along side the littlefs partition:

I don't have any doubts that I'll be able to use nvs along side littlefs, I just don't understand why littlefs, when used on external flash, needs to create a partition on internal flash_primary.

[Øivind]

Ok, you can try one of both of these configs:

CONFIG_PM_PARTITION_REGION_LITTLEFS_EXTERNAL=y
CONFIG_PM_PARTITION_SIZE_LITTLEFS=0

Reducing its size to zero may cause issues with code that uses "storage" or "storage_partition" as defined in flash_map_pm.h instead of "settings_storage" or "nvs_storage", unless you also have a "settings_storage" partition.