RE: Need help with custom DFU bootloader; Transferring back to main app

brooksp — Fri, 19 Jun 2020 13:28:39 GMT

Wow, that did it! Thank you so much for the information and the link, Vidar!

RE: Need help with custom DFU bootloader; Transferring back to main app

Vidar Berg — Fri, 19 Jun 2020 09:29:40 GMT

Hello,

Thanks for uploading the full project. I'm pretty sure you're encountering the bug Bjørn is describing in this answer: https://devzone.nordicsemi.com/f/nordic-q-a/58618/dfu-upgraded-app-wont-boot/239171#239171. I did not spot any other obvious problems with your implementation.

As mentioned in the other thread, the issue can be worked enabling code optimization. This is something you can do for source files individually, which means you can still keep optimization off for your other source files and make debugging of your project easier.

It's nrf_bootloader_app_start_final.c that must be compiled with optimization:

The reason this has not been caught during release testing is mainly that we only test the bootloader with optimization enabled, but it has been reported before, and we will have it fixed in our upcoming SDK release.

You can also fix the bug by replacing the problematic assembly in jump_to_addr() with this:

void jump_to_addr(uint32_t new_msp, uint32_t addr)
{
    __set_MSP(new_msp);
    ((void (*)(void))addr)();
}