Write to Non-Volatile Memory of rf52832 with nrf Connect SDK

RE: Write to Non-Volatile Memory of rf52832 with nrf Connect SDK

Håkon Alseth — Mon, 05 Jun 2023 10:34:23 GMT

Hi,

[quote user="nefen"]BLE writes configuration settings on flash memory and I do not know if other APIs are also using flash memory.[/quote]

the BT subsys uses the settings (CONFIG_BT_SETTINGS) subsys for storing data:

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/2.4.0/zephyr/services/settings/index.html

Which by default stores data in the "storage" partition.

Are you planning on using a multi-image build (ie. with mcuboot)?

If so, then the partition manager will be invoked for handling of the internal flash partition layout. If you use a single-image build, the partition layout is given in the device-tree.

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/2.4.0/nrf/scripts/partition_manager/partition_manager.html

If you wanted to reserve a specific area, you can (if using multi-image build, ie. PartitionManager) create a pm_static.yml file in the root of your application folder, containing something like this:

my_area:
  address: 0x7e000
  end_address: 0x80000
  region: flash_primary
  size: 0x2000

This reserves two pages from address offset 0x7e000 to 0x80000 (512k)

Kind regards,

Håkon

RE: Write to Non-Volatile Memory of rf52832 with nrf Connect SDK

nefen — Sat, 03 Jun 2023 11:47:04 GMT

I had closed that thread, but I have a related question.

BLE writes configuration settings on flash memory and I do not know if other APIs are also using flash memory.

How can I identify the unused sectors that I might use to store non volatile data?

Is there any formal mechanism to allocate space in flash memory for my application?

RE: Write to Non-Volatile Memory of rf52832 with nrf Connect SDK

Håkon Alseth — Wed, 24 May 2023 09:10:58 GMT

Hi,

Thanks for providing a test-snippet.

To allow flash write when using MPU, you need to enable this using a kconfig:

CONFIG_MPU_ALLOW_FLASH_WRITE=y

Did a smoke-test with your code, and added the above to prj.conf:

*** Booting Zephyr OS build v3.3.99-ncs1-rc1 ***
[00:00:00.356,872] <inf> hello_nvmc: Hello World! nrf52840dk_nrf52840
[00:00:00.356,903] <inf> hello_nvmc: Erasing page...
[00:00:00.441,070] <inf> hello_nvmc: Page succesfully erased.
[00:00:00.441,101] <inf> hello_nvmc: Setting write mode
[00:00:00.441,101] <inf> hello_nvmc: Wait for Ready
[00:00:00.441,131] <inf> hello_nvmc: Writing value 12562 to address 520192.
[00:00:00.441,192] <inf> hello_nvmc: Write finished
[00:00:00.441,192] <inf> hello_nvmc: Write succeeded, by by writing value:12562

Kind regards,

Håkon