Update firmware from nrf85240 flash

[Jeffrey Haynes]

I am looking to update the NRF52840 firmware from the integrated flash. I am able to get the new firmware file there through other means and I just need to point to that new firmware and reboot. I’ve seen a few answers with partial or vague answers. Can someone give me a concrete (e.g. code would be nice) answer for how to do this?  I’m using SDK 15 and I do NOT want to use other DFU mechanisms (e.g. UART or BLE). I suppose it’s also worth noting that I’m using the sd “file system” to store things on flash. 

[Hung Bui]

Hi Jeff, 

If you don't use the bootloader, how do you plan to replace the image ? An application can't replace itself.  You would need to use an external application, such as a bootloader, or use the MBR to do the task. Please describe what exactly you want/plan to do. 

[Jeffrey Haynes]

I am trying to use the bootloader. I’ve added it to my linker script. I’m not sure what else I need to do. 

Thanks

[Hung Bui]

We have a tutorial here regarding the bootloader. It's made for BLE bootloader, but would be similar to the UART bootloader. If you can describe your requirement and why you don't want to use our current bootloader solution we can try to give you an advice on what we think would be the best. 

[Jeffrey Haynes]

Thank you, I think I originally misunderstood. It is now working!

[Jeffrey Haynes]

Ok, sorry to have to revisit this but I realize I still need to update the firmware from the application.

I am now using the vanilla secure usb bootloader example and that works great. However, I also have the nRF attached to a cellular modem. I would like to receive packages from the modem, store them on the nRF internal flash, and then initiate dfu using GPREGRET. 

How do you recommend I go about this?

Thanks