Flashing SD+App+BL SDK12.2

[brett_anderson]

I am trying to flash all three images together. I have the firmware updating working, but if you flash them together, the bootloader doesn't know that the application is programmed. I found this post POST

There are differences however. I found the nrf_dfu_settings.c file, and found a similar line to what is referenced in the post. In nrf_dfu_types.h, I found defines that are similar, and I edited the line to add "NRF_DFU_BANK_VALID_APP" to the bootloader settings. This did not work however.

Are there other settings I need to change?

[bjorn-spockeli]

Hi Brett,

you are correct that the bootloader does not know that there is a valid application if you flash the bootloader, application and SoftDevice with a programmer.

In order to set the correct bootloader settings you need to generate a bootloader settings hex file using nrfutil.

nrfutil settings generate --family NRF52 --application application.hex --application-version 3 --bootloader-version 2 --bl-settings-version 1 settings.hex

which will generate the settings.hex file and output something like this to your terminal

Bootloader DFU Settings:
* File:                 settings.hex
* Family:               nRF52
* CRC:                  0x2B1E5436
* Settings Version:     0x00000001 (1)
* App Version:          0x00000003 (3)
* Bootloader Version:   0x00000002 (2)
* Bank Layout:          0x00000000
* Current Bank:         0x00000000
* Application Size:     0x00003AF4 (15092 bytes)
* Application CRC:      0xF7A69330
* Bank0 Bank Code:      0x00000001

The generated settings.hex file should be merged with the bootloader hex file using the following mergehex command

mergehex -m settings.hex secure_serial_bootloader.hex -o bootloader_w_settings.hex

The merged hexfile can now be flashed to the nRF52 along with the application and the softdevice. (You can also use mergehex to create a single hex file that contains the bootloader, bootloader settings page, application and softdevice).

Best regards

Bjørn

[bjorn-spockeli]

Hi Brett,

1. This is documented on the pc-nrfutil GitHub page, here is the link, as well as on this page on our Infocenter.

2. I think you can, but its not recommended, see 3.

3. No, you do not need to modify the settings since you're merging in the settings file. Yes, you should remove BANK_VALID_APP.