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. 

[Jeffrey Haynes]

Thanks Hung,

We are using the bootloader and the softdevice. I would simply like to swap to the new application firmware (and possibly a new softdevice although that’s less important). 

[Hung Bui]

By "swap" you meant actually swap the new image in flash to replace the old image ?  in your original question you mentioned about "to point to that new firmware and reboot" which is different. 

If you plan to do flash swapping, you can have a look at our  image_copy() function in nrf_bootloader_fw_activation.c to see how we do it with the flash. 

If you plan to simply boot to the new image, you can have a look at this discussion. 

[Jeffrey Haynes]

Ok, that is helpful but maybe I should backup and give more context. We are running a USB CDC serial protocol to our device already, which is used to send configuration and such. I would like to use that same protocol to update the application firmware. 

Should I attempt to form a custom DFU transport and generate the appropriate packets or should I follow the bootloader activation model and simply copy the data into the correct location?

Thanks

[Hung Bui]

Hi Jeff,  could you answer the previous question ? Do you plan to do flash swapping or you want to simply change where you start your application after the softdevice/MBR ?

[Jeffrey Haynes]

I think changing where I start would be better so I’m not overwriting the app until I know it’s in a good state but I can do either. 

[Jeffrey Haynes]

Ok, in going through this it looks like I can probably use the copy image stuff from nrf_bootloader_fw_activation.c. But it also looks like maybe what I really want is to copy from our fds-backed storage into bank1 and then activate, correct?

[Jeffrey Haynes]

Unfortunately it looks like fds storage system and the dfu flash system can’t coexist because of colliding global m_fs defines. One of these days Nordic is going to discover c++ and the beauty of correct scope management :)

[Jeffrey Haynes]

I’m trying to make this work manually but I’m somewhat stuck. I’m calling nrf_dfu_cache_prepare but the assert on line 207 is hit as my cache_address and bootloader_start_addr are both 0x26000.