Need to save some data at runtime in nrf5340 flash memory instead of external EEPROM

[vinodsdw]

Hello, 

   I want to reserve 1KB of flash memory in nrf5340 to save few configuration and keys, text etc. 

I don't want these configurations to get wiped out afer a DFU.

How can I do this?

[Øivind]

Hi,

Take a look at the non-volative storage sample project at zephyr/samples/subsys/nvs

This sample shows how to setup and use the NVS system to store basic information in flash.

[vinodsdw]

Thanks, I will look into that. Will these get wiped off after a DFU ?

[vinodsdw]

Hello,

  I can see 32KB of default storage partition.

        storage_partition: partition@f8000 {

            label = "storage";

            reg = <0x000f8000 0x00008000>;

        };

But how do I know if this is been used for any system related variables like bluetooth etc ?

And from which ID onwards is safe to use ?

[Øivind]

Hi,

thank you for your patience. DFU does not wipe the storage partition, it only wipes the DFU slot. For example mcuboot_primary and mcuboot_secondary.

With NVS those should not be a problem. You can use nvs_calc_free_space to check the remaining space on a partition(note that this is a time consuming operation). And the NVS system handles organization of data for you, so there is no need to worry about overwriting existing data.

Here is a recent guide a colleague wrote about persistent storage of keys and data:  Persistent storage of keys and data using the nRF Connect SDK