Little FS on external FLASH with nrf9161dk and NCS 2.8.0

RE: Little FS on external FLASH with nrf9161dk and NCS 2.8.0

Neal Riedel — Wed, 26 Feb 2025 17:34:12 GMT

Hi Sigurd,

Sorry for the slow response. I didn't see your post!

I tried this fix and it solved the problem, both for the sample I posted and for our larger application.

Thank you very much for your help!

Neal

RE: Little FS on external FLASH with nrf9161dk and NCS 2.8.0

Sigurd Hellesvik — Tue, 18 Feb 2025 14:48:10 GMT

Try to set CONFIG_PM_OVERRIDE_EXTERNAL_DRIVER_CHECK=y in prj.conf.

RE: Little FS on external FLASH with nrf9161dk and NCS 2.8.0

Neal Riedel — Tue, 11 Feb 2025 17:44:45 GMT

Thanks, Sigurd. Any help you can provide is greatly appreciated!

RE: Little FS on external FLASH with nrf9161dk and NCS 2.8.0

Sigurd Hellesvik — Tue, 11 Feb 2025 14:58:51 GMT

[quote user="Neal Riedel"]Is it possible for you to provide a sample on the nrf9161dk that uses littlefs on the external flash with NCS v2.8.0?[/quote]

I tried and I also get -2.

I will have to dig some more into this

RE: Little FS on external FLASH with nrf9161dk and NCS 2.8.0

Neal Riedel — Mon, 10 Feb 2025 22:33:58 GMT

Hi Sigurd,

Thank you for your quick response. I tried disabling the partition manager as you selected. In addition, I changed main.c to remove the include of pm_config.h and updated the FLASH partition ID definition:

#define FLASH_PARTITION_ID 		DT_N_S_soc_S_peripheral_50000000_S_spi_b000_S_gd25wb256e3ir_1_S_partitions_S_partition_0_PARTITION_ID

I got the FLASH_PARTITION_ID value from inspecting the file build/spi_flash_test/zephyr/include/generated/zephyr/devicetree_generated.h

Unfortunately, the problem still exists. The call to flash_area_open() returns "-2" indicating it cannot find the partition. This is the same failure I had with the PM enabled.

I think the problem is in the file zephyr/subsys/storage/flash_map/flash_map_default.c. This file defines the default FLASH map that Zephyr uses to look for the partition ID:

/* We iterate over all compatible 'fixed-partitions' nodes and
 * use DT_FOREACH_CHILD to iterate over all the partitions for that
 * 'fixed-partitions' node.  This way we build a global partition map
 */
const struct flash_area default_flash_map[] = {
	DT_INST_FOREACH_STATUS_OKAY(FOREACH_PARTITION)
};

For some reason, it does not add the littlefs partition to this list.

I also tried enabling the PM and using dynamic partitioning (i.e. I deleted the pm_static.yml file) as described in the sysbuild course. I used "PM_littlefs_storage_ID" as the partition ID in main.c. The result was that the littlefs file system is placed in on-chip FLASH. This configuration works correctly.

However, if I try to move it to external FLASH by building with

west build -b nrf9161dk -p -- -DCONFIG_PM_PARTITION_REGION_LITTLEFS_EXTERNAL=y

The PM places the littlefs in external FLASH (as indicated by the partitions.yml file), but the sample does not work with the same "-2" error.

Is it possible for you to provide a sample on the nrf9161dk that uses littlefs on the external flash with NCS v2.8.0?

Thanks,

Neal

RE: Little FS on external FLASH with nrf9161dk and NCS 2.8.0

Sigurd Hellesvik — Mon, 10 Feb 2025 12:41:01 GMT

Hi,

With v2.8.0, you get the partition manager enabled by default. See some theory on this under our Sysbuild course.

With the partition manager, DTS partitioning is mostly ignored.

If you do not want nor need the partition manager, you can set SB_CONFIG_PARTITION_MANAGER=n in sysbuild.conf.

Does that work?

Regards,
Sigurd Hellesvik

RE: Little FS on external FLASH with nrf9161dk and NCS 2.8.0

Neal Riedel — Sat, 08 Feb 2025 19:58:13 GMT

devzone.nordicsemi.com/.../spi_5F00_flash_5F00_test_5F00_9161.tgz

This is the source of the modified spi_flash_test application.