Littlefs file system on external SPI flash memory with non-secure build

Question

In my project, I am planning to use LTE modem and an external flash memory with a file system. I have problems to run code for the non-secure build type. A similar problem occurs when trying to use the shell/fs example (developer.nordicsemi.com/.../README.html) on the nrf9160dk_nrf9160_ns target. Building for the secure nrf9160dk_nrf9160 target works well.

Here is my "prj.conf":

CONFIG_FLASH=y CONFIG_LOG=y #CONFIG_FS_LOG_LEVEL_DBG=y CONFIG_HEAP_MEM_POOL_SIZE=16384 CONFIG_SHELL=y CONFIG_SHELL_LOG_LEVEL_INF=y CONFIG_FILE_SYSTEM=y CONFIG_FILE_SYSTEM_SHELL=y CONFIG_FILE_SYSTEM_LITTLEFS=y CONFIG_FLASH_MAP=y CONFIG_FLASH_PAGE_LAYOUT=y CONFIG_SPI=y CONFIG_SPI_NOR=y CONFIG_SPI_NOR_FLASH_LAYOUT_PAGE_SIZE=4096

and here is my "app.overlay":

/delete-node/ &storage_partition; &mx25r64 { // spi-max-frequency = <1000000>; partitions { compatible = "fixed-partitions"; #address-cells = <1>; #size-cells = <1>; storage_partition: partition@0 { label = "storage"; reg = <0x00000000 0x00800000>; }; }; };

For nrf9160dk_nrf9160 target there is usual shell:

uart:~$ *** Booting Zephyr OS build v3.0.99-ncs1 ***

uart:~$ fs mount littlefs /lfs
[00:00:24.930,999] <inf> littlefs: LittleFS version 2.4, disk version 2.0
[00:00:24.932,769] <inf> littlefs: FS at MX25R64:0x0 is 2048 0x1000-byte blocks with 512 cycle
[00:00:24.932,800] <inf> littlefs: sizes: rd 16 ; pr 16 ; ca 64 ; la 32
[00:00:24.935,363] <inf> littlefs: /lfs mounted
uart:~$ fs cd /lfs
uart:~$ fs ls
file.bin
uart:~$ fs read file.bin
File size: 9
00000000 11 22 33 44 55 BA DC 0F FE ."3DU....
uart:~$ fs statvfs /lfs
bsize 16, frsize 4096, blocks 2048, bfree 2046
uart:~$

But for nrf9160dk_nrf9160_ns target nothing happens. I can run with the debugger and see that everything stops somewhere here:

My question is: what additional settings are required for the example to work in non-secure mode?

ANDRIJ GRABCZAK · Accepted Answer

I finally managed to run the example with an external SPI flash memory. Thank you for your support. But I have to describe the difficulties and present the files for those who need to repeat the example. First, the git checkout to the main branch completely destroyed my build system (I work on Windows 10 and Visual Studio Code). So I just fixed manually files in /ncs/v2.0.2/nrf/subsys/partition_manager/... Secondly, it was not possible to build the example for TF-M. Only for SPM non-secure build and secure build. Here is my prj.conf: CONFIG_LOG=y CONFIG_HEAP_MEM_POOL_SIZE=16384 CONFIG_SHELL=y CONFIG_SHELL_LOG_LEVEL_INF=y CONFIG_FILE_SYSTEM=y CONFIG_FILE_SYSTEM_SHELL=y CONFIG_FILE_SYSTEM_LITTLEFS=y CONFIG_FLASH=y CONFIG_FLASH_MAP=y CONFIG_FLASH_PAGE_LAYOUT=y CONFIG_SPI=y CONFIG_SPI_NOR=y CONFIG_SPI_NOR_FLASH_LAYOUT_PAGE_SIZE=4096 CONFIG_SPI_NRFX_RAM_BUFFER_SIZE=32 # only works with SPM CONFIG_BUILD_WITH_TFM=n # need sdk-nrf fix: # https://github.com/nrfconnect/sdk-nrf/commit/f9434e393c1feb10a18af838ec43ac8b0248821a CONFIG_PM_PARTITION_REGION_LITTLEFS_EXTERNAL=y CONFIG_PM_PARTITION_SIZE_LITTLEFS=0x800000 Here is my app.overlay: /delete-node/ &storage_partition; / { chosen { nordic,pm-ext-flash = &mx25r64; }; }; &mx25r64 { partitions { compatible = "fixed-partitions"; #address-cells = <1>; #size-cells = <1>; storage_partition: partition@0 { label = "storage"; reg = <0x00000000 0x00800000>; }; }; };