Bootloader not entering APP

RE: Bootloader not entering APP

Hung Bui — Fri, 26 Jan 2018 14:34:18 GMT

I see, my mistake, I thought that it was another issue.

RE: Bootloader not entering APP

schef — Fri, 26 Jan 2018 09:56:52 GMT

Ok i will. I thought that this is relevant because it is something that is connected with the connect workaround.

RE: Bootloader not entering APP

Hung Bui — Thu, 25 Jan 2018 14:49:00 GMT

Please create a new case for this schef. But be aware that Jlink may hang the CPU from normal operation.

RE: Bootloader not entering APP

schef — Thu, 25 Jan 2018 13:28:44 GMT

I have a new issue while connecting to the board. Board works and everything is OK and board is alive until i write JLinkExec -> connect command. At that moment the board crashes.

RE: Bootloader not entering APP

Hung Bui — Wed, 24 Jan 2018 15:51:48 GMT

Would this workaround relevant ? devzone.nordicsemi.com/.../

RE: Bootloader not entering APP

schef — Wed, 24 Jan 2018 06:51:21 GMT

I tried memset(_SEGGER_RTT.acID, 0x00, sizeof(_SEGGER_RTT.acID)); and NRF_LOG_FINAL_FLUSH(); in nrf_bootloader_app_start.c just before nrf_bootloader_app_start_impl(start_addr);. Didn't help.

RE: Bootloader not entering APP

schef — Wed, 24 Jan 2018 06:22:01 GMT

Ok this helped and it will work as a workaround for now. Tnx.

RE: Bootloader not entering APP

Turbo J — Tue, 23 Jan 2018 23:01:55 GMT

One could also try to zero out the _SEGGER_RTT.acID[] array in the bootloader before the application starts.

RE: Bootloader not entering APP

Andy — Tue, 23 Jan 2018 22:59:53 GMT

You can type connect afterwards and it will show the output again, without restarting your board.

RE: Bootloader not entering APP

Turbo J — Tue, 23 Jan 2018 22:54:57 GMT

Is it connected with RTT?

Highly likely.

Segger RTT has a problem when the bootloader switches to the app, because the memory location of the RTT buffers will highly likely change at this point.

If the application does not completely clean its RAM, the "old" bootloader buffer may still exist - and RTT will never use the "real" location. Restarting the RTT client (or JLinkExe in your case) could remedy the situation.

If you are fluent in ARM assembly, you could try to argument the application starup code in order to erase all non-reserved RAM addresses. This should trigger RTT on the PC to scan for the new memory location.

RE: Bootloader not entering APP

schef — Tue, 23 Jan 2018 15:32:45 GMT

I have a feeling that when i start my RTT boards restarts. What i want to achive is when my board gets into app_error_handler that the while(loop) prints the last line every second so when my board crashes i can see afterwards where it happend. Here are my commands: JLinkExe -if SWD -device nrf52 -speed 4000 -autoconnect 1 and telnet localhost 19021.