Removing the storage partition

[Narendra]

Hi. 

We are using nRF Connect SDK v3.2.1 and nRF52832 MCU.

Our current internal flash memory mapping is like below,

mcuboot + mcuboot_primary (application) + mcuboot_secondary + user_storage + nvs_storage + setting_storage

We are facing sort of memory for our application firmware. So, we like to expand the application memory area by removing setting_storage. And combined the nvs_storage and user_storage.

In above, nvs_storage and setting_storage are not utilized. We are using only user_storage to store our device configuration. 

To exand the memory we would like to keep only nvs_storage and like to use that for our device configuration storage. So, new flash mapping will be like below,

mcuboot + mcuboot_primary (application) + mcuboot_secondary + nvs_storage (config data)

What will be the downside of removing setting_storage? Will it create any issue?

Please note, our device is working as BLE peripheral. It advertise and connects with central and remain connected. Device is not using pairing and bonding as of now. We may use pairing in future but no bonding (keys will not be stored).

Thanks,

Narendra

[AHaug]

Hi Narendra,

What will be the downside of removing setting_storage? Will it create any issue?

The settings_storage partition is automatically included when you add BLE to the project because this is where Bluetooth settings and persistant data such as bonding information is stored. The partition is by default 4kB or 8kB if I remember correct and can be reduced if you don't need to store large amount of BLE settings/bonding information. You use roughly about 80 bytes per bonding, plus at least one flash page for garbage collection. 

Bluetooth settings can be stored in a different partition than the default settings_storage, but only if you reconfigure where the Zephyr settings subsystem stores its data.

Kind regards,
Andreas

[Narendra]

Hi Andreas,

Please note we are using pm_static.yml file for flash mapping and have set the CONFIG_SETTINGS=n 

We have removed settings_storage partition from pm_static.yml file. And firmware build without error. 

Thanks,

Narendra

[AHaug]

Noted, make sure that you properly evaluate that you will not need bonding/persistant BLE settings data and/or that you include it in a different storage partition since this will not be possible to add through DFU at a later point in time.

Kind regards,
Andreas