OTA Softdevice 7.0 DFU fails to copy

[Konstantin K]

I'm trying to DFU the softdevice (supplied 7.0 hex file) using bootloader example in SDK 6.0. I wrote my own OSX application to do that by parsing the hex file and sending it as per documentation. The NRF51822 is running 7.0 hex (identical to the one being DFUed).

The data is sent over correctly as indicated by CRC validation as well as flash dump and manual check. However, the softdevice fails to swap from bank 0 (0x16000) to sd location (0x00000). The returned error code from SD_MBR_COPY command is 3 (which I some sort of failure).

Can anyone suggest why this may be happening?

[Wojtek]

I didn't use OTA for SD yet, but my blind shot is: check if enable softdevice protecion is checked in nrfstudio. i think it shouldnt be.

[Konstantin K]

I programmed the softdevice with --dfu flag as stated in the migratio notes (nrfjprog -e --programs <sd.hex> --dfu). In addition, the softdevice memory does get significantly changed and corrupts the original softdevice so something must be getting written.