How to set bootloader run first in my application?

RE: How to set bootloader run first in my application?

Hung Bui — Fri, 05 May 2017 12:38:06 GMT

I know it doesn't come to your bootloader, but you need to check if the value is still there when you restart.

Note that the way it works is : MBR run first at reset handle address 0x00004. Then it check if there is anything at NRF_UICR->NRFFW[0] , if it's 0xFFFFFFF it will then forward to the softdevice, the softdevice then forward to normal application. If there is something in NRF_UICR->NRFFW[0] then the MBR will forward interrupt and PC to that address.

What if you simply test to flash your application, softdevice, and then use nrfjprog and write to nRF_UICR->NRFFW[0] address 0x78000. If everything works as it should it should brick the code and your application shouldn't run after a reset after that.

What do you do in your bootloader ?

RE: How to set bootloader run first in my application?

sheep — Fri, 05 May 2017 09:15:06 GMT

I use my own boot loader ,device is nrf52832 and S132,so when power on，it come to the app，I set the NRF_UICR->NRFFW[0] and then read back to check in the app program。When I power off and on,I wish it run boot loader first,but it doesn't come to my own boot loader.

RE: How to set bootloader run first in my application?

Hung Bui — Fri, 05 May 2017 08:53:41 GMT

Hi Sheep,

Do you use our bootloader or your own bootloader? If you use our bootloader, the UICR is already written when flashing the bootloader (using attribute keyword) check nrf_bootloader_info.c . Could you try to test with the DFU bootloader included in the SDK ?

I assume you used and flashed S132, do you have the version you use ? Have you made sure to disable the softdevice before you do NRF_NVMC activity ? it's blocked when the softdevice is active.

When you reset and come back to the application could check and read UICR at offset 0x14, do you see anything ?