Modem FOTA Questions (Firmware compatibility matrix and firmware file storage)

[droberson]

Hello,

I am evaluating the nRF9161 and nRF9151 and have a few questions.

1. In regard to modem FOTA delta firmware updates, where is the delta file stored in both Serial LTE modem (SLM) and non-SLM cases? Is it stored in the modem core flash, or must it be stored in the application core flash or external flash? I have read conflicting information on the DevZone regarding this.

2. When updating to a new modem major firmware version in non-SLM mode via FOTA, say 1.3.x to 1.4.x, this requires a "full" modem firmware update and requires storing the firmware file in external flash due to its size. If you design a product without an external flash, is it true you are then stuck on whatever major version you program and deploy the modem with since you cannot perform a "full' firmware update? Ie, if you are on 1.3.x you can never go to 1.4.x via FOTA?

3. When the modem is used as a Serial LTE modem (SLM), does the modem only support delta firmware updates, or can you also perform a full modem firmware update? If it doesn't support full modem firmware updates in this mode, then are you stuck on whatever modem major version you deploy your product with?

4. Based on the nRF9160 modem firmware compatibility matrix linked below, newer modem firmware versions are not compatible with older versions of the nRF connect SDK. Is this true?

For example, if you are on modem firmware 1.3.1 and nRF Connect SDK 2.0.0, it doesn't seem like you can jump directly to modem firmware 1.3.6 because it isn't compatible with nRF Connect SDK 2.0.0. It seems like you you can only jump to modem firmware 1.3.2 because 1.3.3 isn’t compatible with nRF Connect SDK 2.0.0. Once you jump to modem firmware 1.3.2, you then update to nRF Connect SDK 2.1.0. This will then let you update to modem firmware 1.3.4 (skipping 1.3.2). Then you can update nRF Connect SDK to 2.2.0, which will then let you update the modem firmware to 1.3.6.

Are these incremental updates really necessary?

https://infocenter.nordicsemi.com/topic/comp_matrix_nrf9160/COMP/nrf9160/nrf9160_modem_fw.html

Edit: I have a bonus question not related to FOTA. Please let me know if I should create a new post for this.

5. Do the Nordic cellular modules support multiple carriers with a single eSIM or SoftSIM? If so, how do you add carrier profiles to each SIM type and switch between profiles? I didn't see any AT commands detailing this.

Thanks,

Derek

[Charlie]

Hi Derek,

droberson said:

Question: For customers who want a simple drop-in Serial LTE modem without having to worry about writing or modifying the application core firmware, does Nordic provide a production ready application core firmware and application core FOTA binaries? Or is the customer responsible for generating FOTA binaries using the Nordic provided sample?

The SLM prebuilt binaries are available in nRF9161 DK - Downloads - nordicsemi.com-> nRF9161 DK application and modem firmware.

droberson said:

Question: Is the SLM application core "sample" Nordic provides mature enough to use in production devices without modification from the customer?

Yes, of course, it is part of SDK solution product in addition to Nordic hardware chips.

droberson said:

Question: Does Nordic provide bug fixes for the SLM application core firmware when appropriate, just like the modem core firmware?

Yes, the SLM as an nRF Connect SDK(NCS) cellular sample is updated (including new features and bug fixes if necessary) with NCS versions. You can follow its changes in every NCS release notes.

This is the content to notify SLM changes in NCS v2.7.0: https://docs.nordicsemi.com/bundle/ncs-2.7.0/page/nrf/releases_and_maturity/releases/release-notes-2.7.0.html#serial_lte_modem

Best regards,

Charlie

[droberson]

Charlie,

Thanks, that helps a lot.

Charlie said:

The SLM prebuilt binaries are available in nRF9161 DK - Downloads - nordicsemi.com-> nRF9161 DK application and modem firmware.

I see that Nordic provides modem delta files from the previous revision to the current such as "mfw_nrf91x1_update_from_2.0.0_to_2.0.1.bin" in the "nrf9161dk_mfw-2.0.1_sdk-2.7.0" MFW package.

Question: In regard to the above, upon request, can Nordic provide modem delta files that cover a range of 'minor' versions?

For example, lets say I am on modem firmware 2.0.0 and I want to jump to 2.0.2 (When and if it is released), can Nordic generate a delta file upon request? Such as "mfw_nrf91x1_update_from_2.0.0_to_2.0.2.bin"?

Thanks,

Derek

[Charlie]

Hi Derek,

It could be done in theory, but hard to satisfy this request because this could not be done standardized with our product release process.

You can explain the reason and talk to our regional sales manger about this request.

Best regards,

Charlie

[droberson]

Hey Charlie,

We have used Telit modems in the past (telit.com) and they provide modem firmware delta files to us to whatever version we need to go to from whatever version we are currently on.

Thus, I was curious if Nordic had a similar process, but that is not the case it seems. So it looks like if you want to jump from 2.0.0 to 2.0.2 from my previous example, you must do one of the following:

1. Delta update from 2.0.0 to 2.0.1, then delta update from 2.0.1 to 2.0.2

2. Full firmware update from 2.0.0 to 2.0.2

Thanks again for your time and support. This concludes my questions about Nordic cellular modules. I feel like I now have a good understanding of their core functionality and FOTA process.

Derek