Unable to access mx25r64 partition using partition manager on sdk 2.9.0

RE: Unable to access mx25r64 partition using partition manager on sdk 2.9.0

HuuNghia — Fri, 30 May 2025 04:35:29 GMT

I have the same problem when build and run littlefs sample code on nrf52840dk.
================= prj.conf =================
CONFIG_FLASH=y

CONFIG_FLASH_MAP=y

CONFIG_FILE_SYSTEM=y

CONFIG_FILE_SYSTEM_LITTLEFS=y

CONFIG_PM_PARTITION_REGION_LITTLEFS_EXTERNAL=y

==================================================

================ app,overlay ====================
chosen {

nordic,pm-ext-flash = &mx25r64;

};

==============================================

============== partition report ===================
external_flash (0x800000 - 8192kB):
+-------------------------------------------+
| 0x0: littlefs_storage (0x7f0000 - 8128kB) |
| 0x7f0000: external_flash (0x10000 - 64kB) |
+-------------------------------------------+

flash_primary (0x100000 - 1024kB):
+------------------------------+
| 0x0: app (0x100000 - 1024kB) |
+------------------------------+

sram_primary (0x40000 - 256kB):
+--------------------------------------------+
| 0x20000000: sram_primary (0x40000 - 256kB) |
+--------------------------------------------+
==========================================

*** Booting nRF Connect SDK v3.0.0-3bfc46578e42 ***
*** Using Zephyr OS v4.0.99-3e0ce7636fa6 ***
Sample program to r/w files on littlefs
E: FAIL: unable to find flash area 1: -2

RE: Unable to access mx25r64 partition using partition manager on sdk 2.9.0

Mutheu — Tue, 06 May 2025 12:45:32 GMT

In my case I had not created partitions in the overlay file that is why it was not working. I have followed the overlay example on 3583.littlfs_qspi_ext.zip and I managed to read the partitions in main.c file.
I had assumed that I only need partitions in pm_static.yml file but my assumptions were wrong.

RE: Unable to access mx25r64 partition using partition manager on sdk 2.9.0

AHaug — Tue, 29 Apr 2025 12:32:38 GMT

Hi,

There were one more thing missing:

https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/scripts/partition_manager/partition_manager.html says that to use CONFIG_PM_PARTITION_REGION_LITTLEFS_EXTERNAL you must add a chosen entry for nordic,pm-ext-flash in your devicetree.

Here's a sample that showcases you this can be done as well as how I've configured the pm_static.yml. Alternatively to the pm_static.yml in the zip, you can also do the following if you wish to have the application and external flash statically configured:

app:
  address: 0x0
  end_address: 0x100000
  region: flash_primary
  size: 0x100000
external_flash:
  address: 0x20000
  end_address: 0x800000
  region: external_flash
  size: 0x7e0000
littlefs_storage:
  address: 0x0
  device: DT_CHOSEN(nordic_pm_ext_flash)
  end_address: 0x20000
  placement:
    before:
    - tfm_storage
    - end
  region: external_flash
  size: 0x20000

You can try this sample with your own pm_static.yml as well to compare.

Resulting partition map:

devzone.nordicsemi.com/.../3583.littlefs_5F00_qspi_5F00_ext.zip

Let me know if this works for you or if you're able to apply the changes I've made to the LittleFS sample to your own application

Kind regards,
Andreas

RE: Unable to access mx25r64 partition using partition manager on sdk 2.9.0

Mutheu — Fri, 25 Apr 2025 14:55:07 GMT

I removed the external flash partition in the pm_static.yml file and retained only the littlefs_storage partition but I still get Storage device is NULL

RE: Unable to access mx25r64 partition using partition manager on sdk 2.9.0

AHaug — Fri, 25 Apr 2025 12:50:36 GMT

Hello,

As far as I can see you don't need the following in your static partitioning to set up the external flash

external_flash:
  address: 0x00000000
  end_address: 0x007F0000
  region: external_flash
  size: 0x007F0000

Your overlay file where you set the chosen external flash and in the board files handles this. CONFIG_PM_PARTITION_REGION_LITTLEFS_EXTERNAL sets up the littlefs partition on the external partition and you specify that it should be a static size by setting it up in your pm_static.yml

littlefs_storage:
  address: 0x00000000
  device: mx25r64
  region: external_flash
  size: 0x007F0000

Let me know if this works out for you,

Kind regards,
Andreas