32k memory allocation required for data storage in internal flash of nrf52840

[Anupam]

Hi, I am Working on nRF52840 and using nRF52840-DK.

Below is my working environment SDK - nRF5_SDK_16.0.0_98a08e2 ,

IDE - Segger Embedded studio (windows 10 - 64 Bit)

Softdevice - s140_nrf52_7.0.1_softdevice

Base code - ble_app_multirole_lesc_s140_pca10056

also using bootloader of dual bank for OTA

My device is scanning and advertising both simultaneously. Advertisement interval is 1 second Below are my configurations.

i want to reserve 32k memory in internal flash also these allocated address should not be erased during OTA.

end_addr = nrf5_flash_end_addr_get(); I am getting end_addr is 0xf1000.

i am getting above address using above API,will it is a fixed address in nrf52840 or it will vary.

please suggest better way to reserve this memory for data storage.

[Hung Bui]

Hi Anu, 
You can configure NRF_DFU_APP_DATA_AREA_SIZE in the bootloader to match with the number of bytes you preserve for your application data ( It have to be page size aligned.)

[Anupam]

Hi hung,

we will configure this size in boot loader,can you just please tell, how we will get this allocated address starting address

so that we can use it in our application?

can you please tell which API we have to use for getting this address which we have reserve using NRF_DFU_APP_DATA macro.

waiting for prompt response

[Hung Bui]

Hi Anupam, 

The start address (or actually the end address) of the fds module is by default located right before the bootloader. 
Please have a look at this memory layout : https://infocenter.nordicsemi.com/topic/sdk_nrf5_v17.0.0/lib_bootloader.html?cp=7_1_3_5_0_7#lib_bootloader_memory

In fds, the calculation on where to put the end address is in flash_end_addr() function.