How to know if an OTA update just happened?

[mmnano]

Hello,

I am currently developing using Zephyr/NCS an application that supports FOTA/DFU.

The device needs to be tapped to be woken up and start advertising. So, when a FOTA process happens, the verification phase at the end cannot be performed without tapping the device. I would like for the update process to not require this tapping step. However, I do not know how to proceed with that.

So, based on the SMP_SVR sample in zephyr, how would you check if the reset that just happened is due to an OTA update ? Maybe I can store something in non-volatile storage or is there a function that can check that somewhere already ?

Thank you very much for any help you can give me.

[Sigurd]

Hi,

Maybe I can store something in non-volatile storage or is there a function that can check that somewhere already ?

 You can use the fw_info module, and the fw_info_find() function.

developer.nordicsemi.com/.../fw_info.html

[mmnano]

Hi,

Thank you very much, this is what I was looking for.

How would you implement this using this function ?

[Sigurd]

mmnano said:

How would you implement this using this function ?

 I would have used it together with the general purpose retention register .It's e.g. used to store reset type: https://github.com/nrfconnect/sdk-zephyr/blob/01a38e7fa55913350c647df1f51715fea5d80daa/soc/arm/nordic_nrf/nrf52/soc.c#L52

E.g use nrf_power_gpregret2_set(), and set some value from what fw_info_find() returns, before you start the DFU. Then on reboot, check what fw_info_find() returns and compare with what nrf_power_gpregret2_get() returns. Could perhaps use this without fw_info_find() also. Just set the gpregret register to some magic value before the DFU reboots the app. On reboot, read the register, and check if the magic value is present or not. After the check, remember to set the register back to 0.