feat: Preprovisioned Sample

[GabrielNotman]

Overview

This PR makes two changes which I believe would be helpful to others as they cover issues and questions I ran into when testing out the SoftSIM library (at v5.1.0 with SDK v2.9.1).

Additions

1. Add nonsecure_storage/nvs_storage to the static partition list.
   When using the SoftSIM library with custom boards, this can help make it explicitly clear what additional partitions are required.

2. Add a sample which demonstrates how to preserve existing profile data when re-flashing a device.
   This might help in situations where during production first a test / provisioning firmware image is loaded which is later replaced by an application image. (I had a similar question as the one raised in Provisioning SoftSIM (and staying provisioned) in production #92.)

Issues

Instructions for the new sample have been included in README.md in the sample folder. This is inconsistent with the existing samples which lack a README.md.

The new sample will fault if the device is not already provisioned (a warning about this has been added to the instructions). I tried disabling CONFIG_SOFTSIM_AUTO_INIT and then checking the provisioning using nrf_softsim_check_provisioned(). This worked however, if already provisioned there seems to be some issue with calling nrf_softsim_init() explicitly from main, this was resulting in a fault.

[JoriamVS]

Hello @GabrielNotman,

I am the one that created issue #93. I just looked at your sample and would like to thank you for your insights.
What I discovered myself is that if you flash the dfu_application.zip after the original merged.hex was flashed the SIM profile also stays intact. At least this works for me using the thingy91:x. Might be slightly faster than changing the build configuration as you do in your sample, your sample did help me understand why my discovery works and I think the repository would benefit from having your sample added.

Now for a more detailed overview of my discovery

dfu_application.zip:

• Directly to thingy
• Does not overwrite (or contain) SIM profile. (In my experience so far, could be a coincidence)
• Use this if you want SIM profile untouched
• nrfutil device program --firmware dfu_application.zip --serial-number $serial_number --traits mcuboot --x-family nrf91 --core Application

merged.hex:

• Via nrf9151dk
• Does (over)write SIM profile.
• Use this if you want to change SIM profile.
• nrfutil device program --firmware merged.hex --traits jlink

I hope this helps you or another person that stumbles upon this. Also if someone from Onomondo sees this I would love it if they could confirm/correct my theory.