Alternative ways to flash modem firmware

[haricane]

Hello Nordic team, 

I am looking for an alternative method to flash the modem firmware to nrf 9160. 

The issue I have with nrf connect's programmer is that it behaves unpredictably. For instance, I routinely get such errors

ERROR Unsupported device. The detected device could not be recognized as neither JLink device nor Nordic USB device.

or 

RROR Core0: Error while reading non-volatile memory: Error: Error occured when read. Errorcode: CouldNotCallFunction (0x9)
Lowlevel error: JLINKARM_DLL_ERROR (ffffff9a)

2021-10-06T21:52:14.834Z ERROR Error when getting device info: Error: Error: Error occured when read. Errorcode: CouldNotCallFunction (0x9)
Lowlevel error: JLINKARM_DLL_ERROR (ffffff9a)

However, I am able to use Segger's Jflash, open up a swd connection to the MCU and flash my application code in 2-3 seconds. 

My questions would be:

1) is there a way to take the contents of the modem firmware zip file, create one hex file and flash it using seggers Jflash?

2) Could you please provide some insight on the various files inside the zip file of the modem firmware. 

3) Can the nrfprog command line tool be used to flash modem firmware?

Thanks, 

Hari 

[Elfving]

Hey Hari!

1) No I don't think so. The process of updating the modem differs a lot from flashing the application code.

2) It mainly includes the image segments (for more info on that, see here) and checksums. (The latest release also includes FOTA test images) I do not know all the details on this however, and could look more into it if you want me to.

3) Yes, with nRF Command Line Tools version 10.13.0 onwards you can use nrfjprog to perform a modem firmware upgrade. 

nrfjprog --program <path-to-fw-zip> -s <serial number> --verify

 You can check the release notes about it for more info. 

Here is also an older python script that can be used to update the modem: nrf-dfu-tool.zip. It might also give you a bit insight into the process of updating it, and what it is that makes it a bit different.

Best regards,

Elfving

[haricane]

Hi Elfving, 

Thanks for the response. 

I think nrfjprog is great for me. I will use that moving forward. 

I dont need more info on the zip file contents. 

I do have one follow up question. Where is the modem firmware stored on nrf9160? Is there a separate flash for modem, or is it stored on the 1 mb application flash? 

Regards, 

Hari 

[Elfving]

Great! Glad to hear it!

haricane said:

Where is the modem firmware stored on nrf9160? Is there a separate flash for modem, or is it stored on the 1 mb application flash? 

Yes, it is separate from the application flash. It is on the LTE modem host processor. 

Best regards,

Elfving