DFU at the Application level

[Kaival]

Hi

I want to move DFU at the application level. Is this possible? I want to move DFU at the application level because of my project requirement. 

1. In my project, I have two controllers one is nRF for BLE functionality, other is STM for other applications.

2. nRF is responsible for transferring the FW image of the STM controller.

3. I can go with any BLE DFU or Serial DFU.

4. So the nRF controller will get the FW image of the STM controller.

5. Using Proprietary protocol nRF will send the firmware of STM to the STM controller. We cannot move our proprietory protocol to the nRF bootloader. Bootloader should not contain and application-level logic.

6. Here is the SW flow which I want. serial nrfutils --> nRF DFU --> Proprietary protocol for FW transfer --> Ack from STM( Proprietary protocol)--> Ack to nRF utils.

I want to hold my acknowledgment to serial nrfutil till I get acknowledgment from STM.

Is it possible or not? 

[Kaival]

Is it using UART as a transport medium? It looks like it is using TFTP as the transport medium. Please correct me if I am wrong.

[Einar Thorsrud]

The IoT bootloader uses TFTP, but I was referring to the example in the thread I linked to, which implements does DFU over UART in the application. They are two completely different examples you can refer to see if something can be of use.