nRF5340 ESB OTA

Question

Hello, 
 I have tested the smp_svr with hci_rpmsg Bluetooth OTA feature and I have successfully uploaded the firmware which worked with the old device manager Android app. I would like to use 2 nrf5340 with ESB protocol. What would be a good starting point do I use the hci_rpmsg existing code and enable ESB and configure it as such or is it better to use bootloader UART code? I am a bit stuck as the hci_rpmsg sample code is dependent on bluetooth defines and ESB and bluetooth give an error message when both are enabled. So if you could give me some guidance on the right decision and how I should handle the problem. Thank you I am using: 2x NRF5340 DK nRF Connect for desktop v4.1.2 nRF Connect SDK v2.4.0

Sigurd Hellesvik · Accepted Answer

I will continue helping in this case. 
 After thinking a bit about this case I realized that what makes this case different from BLE is that ESB runs only on the network core. 
 So for BLE, DFU works in two steps: First we move the new image to mcuboot_secondary and tag it to swap. Then we reboot and MCUboot will find this and swap it into mcuboot_primary. For the nRF5340, there is another step: We need to move the network core image into mcuboot_secondary1, then it will be swapped into the network core. The reason for this is that the application core can not write to network core flash. 
 In other words, as long as the update goes into the correct place in flash, we do not care about where in flash it goes to. You can send the binary files in any way you want. 
 We have the mcumgr library to make this easier for us in zephyr. However, this assumes that the images are received in the application core, as is done with BLE. 
 So as I see it, you have two choices: Either make a ESB variant of the hci_rpmsg used by BLE, and implement some kind of ESB host in the application core. Then you could simply add ESB as a transport for mcumgr. 
 Alternatively, you can send the data in whatever way you want to the application core, and then write the updates to the correct slots with our DFU target library , which does not care about transport. 
 Did I understand your issue correctly? 
 Bonus: A colleague of mine created this sample a while ago. Maybe it can serve as some inspiration to how you can communicate between cores with ESB?

nRF5340 ESB OTA

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