Bootloader being written to application address after DFU.

[atharva]

The nrfgprgret register is used from the application(custom) to trigger the system into dfu mode. The nrf 52 enters dfu mode and a zip file containing bootloder.bin/.dat and manifest is successfully transferred. But the bootloader(custom) is being written to the application address. 

1-Where exactly in the dfu process is the address for the destination(BOOTLOADER_START_ADDR ?) set?   

2-The linkers being used are taken from the example of SDK14 bootloader_secure_ble. Is there any change required, for the above use case?

Any direction is appreciated!

WR,

Atharva

[Bjørn Kvaale]

Hi Atharva,

1) It is not possible to change the BOOTLOADER_START_ADDR unfortunately. This address is set in the UICR.NRFFW[0] register location & remains static (see link). The BOOTLOADER_START_ADDR is not changed during the DFU process. It is only defined when the chip is programmed during production.

2) No changes are required.

It might be useful for you to take a look at the dual bank & single bank update processes located here. Also, what changes are you making to your custom bootloader compared with the regular bootloader (i.e. bootloader_secure_ble)?

Kind Regards,

Bjørn Kvaale