Does NRF Connect SDK support GPREGRET on nrf5340DK ?

[zohan]

Hello,

After completing DFU on the nRF5340 DK, the default behavior is to reset the MCU.
However, instead of performing a full reset, we would like to jump directly to the bootloader.

I found that on some nRF devices this can be achieved by using the GPREGRET register, which allows the application to pass information to the bootloader across resets.

My questions are:

1. Does the nRF Connect SDK support using GPREGRET on the nRF5340 DK?

2. If yes, is there an example or recommended way to configure the application so that after DFU, it writes to GPREGRET and then jumps to the bootloader instead of doing a standard reset?

3. Are there any differences in behavior between the nRF5340 and earlier nRF52 devices regarding GPREGRET?

Thanks in advance for your guidance!

[Menon]

Hello,

Does the nRF Connect SDK support using GPREGRET on the nRF5340 DK?

Yes, you can use GPREGRET with the nRF Connect SDK and the nRF5340 DK. See the GPREGRET section under Power Control, and the Retained memory section for the nRF5340 DK. The GPREGRET driver is implemented as a Zephyr retained_mem device.

There isn’t a specific sample showcasing your exact use case, but you can call retained_mem_write() to write a value to GPREGRET and then call reboot(). You can refer to the sample mentioned, though note that it doesn’t enter the bootloader itself.

Kind Regards,

Abhijith