nrf54l15 - no partition for fcb when using sysbuild

[MichaelGK]

I am developing a FW for the nrf54l15 which should log sensor data into its internal flash (RRAM) and make it read able later from a Smartphone via BLE.

For this scenario the FCB looks like a perfect match, so i tried to set up a partition for it beside the to application slots and the mcuboot. Adding it to the device tree had no effect. (I found out later that the partition manager is used automaticially when sysbuild is active which ignores the devicetree partitions completely)

So i added CONFIG_FCB=y and hoped that the pm will add an partition for me. but in the build/pm.config nothing changed. when i use CONFIG_NVS=y the pm adds a new partition. but fcb seems not to work. 

Do i miss any configuration? 

And when i am able to get a partition, how can i set the size of it?

os: windows 11

nrf connect sdk: v3.2.1

zephyr os: v4.2.99

[Amanda Hsieh]

Hi, 

Any special reason to use FBC instead of ZMS? 

For nRF54L Series devices, it is recommended to use ZMS. See the Data storage in the nRF Connect SDK. 

It will not automatically generate the partition for CONFIG_FCB as CONFIG_NVS. See the code https://github.com/nrfconnect/sdk-nrf/blob/v3.2.2/include/flash_map_pm.h#L32-L45 

If needed, you can refer to the nvs_storage partition generated for NVS to create the static partition for the custom partition. 

Regards,
Amanda H.  

[MichaelGK]

Hi,

the special reason is that we want to keep the overhead as small as possible because our log entries them self have only 10 to 20 bytes.

we even think of writing our own management to even get rid of the overhead of the fcb. 

So i understand it correctly, if i just want any kind of data partition i need to activate the nvs option? Is there no more better way to do that?

and how can i define the size of this partition?

best regards 

Michael

[Amanda Hsieh]

MichaelGK said:

if i just want any kind of data partition i need to activate the nvs option?

No.

MichaelGK said:

Is there no more better way to do that?

You can use a static partition file (pm_static.yml) to create a custom partition and set the size. 

fcb_storage:
  address: 0x15f000
  end_address: 0x165000
  region: flash_primary
  size: 0x6000