Not able to combine OpenThread, MCUBoot and LittleFS

[Jørgen Holmefjord]

Hi,

I'm trying to combine OpenThread, MCUBoot and LittleFS in a sample in nRF Connect SDK v1.5.1, but I'm getting the following error:

C:/ncs/v1.5.0/nrf/include/flash_map_pm.h:29:2: error: #error "Not supported"
   29 | #error "Not supported"

I have checked the file, and it seems to suggest that combining NVS (used by OpenThread/settings module for storing network data) with LittleFS is not supported:

#if (CONFIG_SETTINGS_FCB || CONFIG_SETTINGS_NVS) && CONFIG_FILE_SYSTEM_LITTLEFS
#error "Not supported"
#endif

I can reproduce this issue by adding the following configs to the Zephyr LittleFS sample prj.conf file:

CONFIG_BOOTLOADER_MCUBOOT=y

CONFIG_NET_L2_OPENTHREAD=y
CONFIG_NETWORKING=y

Is there any ways I can successfully combine these modules?

[Jørgen Holmefjord]

Hi,

The error generated in flash_map_pm.h is only generated to guard the definition of the 'storage' symbol defined above, to make sure that the symbol is set and used correctly. 

If you redefine the littlefs_storage variable on line 23 to lfs_storage, like this:

#if (CONFIG_SETTINGS_FCB || CONFIG_SETTINGS_NVS)
#define storage settings_storage
#elif CONFIG_FILE_SYSTEM_LITTLEFS
#define lfs_storage littlefs_storage
#elif CONFIG_NVS
#define storage nvs_storage
#endif

,

Then you can remove the error check:

//#if (CONFIG_SETTINGS_FCB || CONFIG_SETTINGS_NVS) && CONFIG_FILE_SYSTEM_LITTLEFS
//#error "Not supported"
//#endif

You can then replace the 'storage' symbol in the LittleFS application with littlefs_storage symbol:

static struct fs_mount_t lfs_storage_mnt = {
	.type = FS_LITTLEFS,
	.fs_data = &littlefs_storage,
	.storage_dev = (void *)FLASH_AREA_ID(storage),
	.mnt_point = "/lfs",
};

I have attached patches that enables the modules in the sample and resolves the error, one for Zephyr and one for the nRF repository. Both needs to be applied:

littlefs_zephyr.patch

littlefs_nrf.patch

[Axel Schlueter]

I'd like to +1 Farhang's concern, having to patch ncs isn't a great fix. Any chances of getting the necessary changes into the official ncs tree?  

[Jørgen Holmefjord]

Hi, we have internal tickets to look into fixing this in the official nRF Connect SDK releases.