nrf5340 programming of network core flash

[kpreiss]

Hi,

Is it possible to program the FLASH memory on the network core from the application core WITHOUT having to run a bootloader on the network core?

Best,

Kurt

[Hung Bui]

Hi Kurt,

We have a similar case here that you can have a look : https://devzone.nordicsemi.com/f/nordic-q-a/76734/flash-write-issues-with-nrfx-on-nrf5340

From my understanding it should be possible, as long as the SPU is not configured so that the netcore is secured. 

[kpreiss]

The post you linked to pertains to an application running on the network core writing to the application core flash memory.  We would like to have an application running on the app core write to the network core FLASH memory.

Kurt

[Hung Bui]

Hi Kurt, 
Have you tried to test. I don't think there is a difference. 

[kpreiss]

Maybe I am not stating what we are trying to do clearly enough.  We have created a bootloader running on the application core which communicates with a host PC over USB.  The bootloader was created using CMake and the nrfx libraries. The objective of the bootloader is to store the application binary images for the application and network cores in SPIFLASH memory and to reprogram the application images in both cores. 

We have all pieces working EXCEPT programming of the network core flash.  Can we reprogram the network core flash WITHOUT having a custom bootloader running on the network core?

[Hung Bui]

Hi Kurt, 

I had a look at the product spec again and have to correct myself. In fact it's NOT possible to directly access the network core directly from the application core. Sorry for confusing information earlier. 

You can have a look here and here. Quoted: 

The application core does not have direct access to the network core flash memory. The update image is passed indirectly using RAM. 

What we did to solve this is to store the image on a shared RAM area and then have a B0n  bootloader on the network core to access this shared RAM and swap the application on the network core. 

So I'm afraid that there isn't a solution to do network core update without a bootloader on the netcore even though you store the image on an external flash.