Secure DFU: Bootloader Settings

RE: Secure DFU: Bootloader Settings

RVM — Thu, 21 Jan 2021 16:55:20 GMT

Thanks Vidar

That makes perfect sense.

Cheers

RMV

RE: Secure DFU: Bootloader Settings

Vidar Berg — Thu, 21 Jan 2021 07:23:28 GMT

Hi,

Your understanding is correct, the MBR is included in the Softdevice binary (0x0 - 0x1000), and it's never rewritten during DFU. OP had an application that didn't use the Softdevice, and therefore had to program our standalone MBR binary to support DFU.

Cheers

Vidar

RE: Secure DFU: Bootloader Settings

RVM — Wed, 20 Jan 2021 19:38:57 GMT

I do not understand why the proposed solution 'fixes the original problem'.

My understanding is that if I program a softdevice to the board, it should ALSO program the MBR at address 0x0.
And it is also my understanding that one does NOT need to rewrite this MBR to support a secure bootloader/DFU module placed at another location in the flash memory map.

Cheers

RMV

RE: Secure DFU: Bootloader Settings

tejaChintalapati — Tue, 10 Nov 2020 10:40:38 GMT

Thanks Vidar. Indeed, this is the problem.

Here's how I fixed the problem:

Merging MBR, BL Settings and BL Hex files

mergehex -m mbr_nrf52_2.4.1_mbr.hex bootloader_settings.hex secure_bootloader_uart_mbr_pca10056.hex -o bl_mbr_blSettings.hex

Merging the App with BL

mergehex -m bl_mbr_blSettings.hex Firmware_PD52840V1R1.hex -o combinedHex.hex

After flashing the combinedHex.hex, nRF is booting up as expected. Thanks for the help. I appreciate the help.

RE: Secure DFU: Bootloader Settings

Vidar Berg — Tue, 10 Nov 2020 07:32:26 GMT

Hi,

The combinedHex.hex did not include the MBR section. Here's how I checked it with nrfjprog:

$ nrfjprog --program combinedHex.hex --chiperase -r
Parsing hex file.
Erasing user available code and UICR flash areas.
Applying system reset.
Checking that the area to write is not protected.
Programming device.
Applying system reset.
Run.

$ nrfjprog --memrd 0
0x00000000: FFFFFFFF |....| /* Flash at address 0x0 is erased */

The MBR hex file can be found in <sdk_root>\components\softdevice\mbr\hex\

RE: Secure DFU: Bootloader Settings

tejaChintalapati — Mon, 09 Nov 2020 15:43:05 GMT

Thanks Vidar.

I believe the merged hex contains MBR at the address 0x000000 as shown in the hex files shown. Can you please have a look and see if the hex files are merged correctly?devzone.nordicsemi.com/.../nRF52840_5F00_Combined_5F00_Hex.rar

RE: Secure DFU: Bootloader Settings

Vidar Berg — Fri, 06 Nov 2020 12:40:20 GMT

Hi,

Looks like you are doing everything correctly, but I can't tell if the merged hex includes the MBR at the beginning of flash or not, does it (Memory layout)?