On the fatal problem of NRF52832 NRF LOG software

[bevis]

Hi Experts: 

      I'm using SDK15.0, softdevice_v6 to Development NRF52832, which is developing a  non_security bootloader. The bootloader adapted from the example program can run normally in 0x72000, and can also normally boot successfully into the main program address 0x26000 (LED is blinking),J-Link RTT Viewer can output LOG of the bootloader. After the boot is successful, the LOG of the application is unable to output, while the application is running now (LED is blinking). 

      It makes me very puzzled. Bootloader and application project use the same set of NRF LOG RTT configuration parameters. 

      This similar phenomenon has also appeared in SDK14.0-14.2, but it is difficult for bootloader to export LOG, and the application can output LOG perfectly.

I also tried to use NRF_LOG_FLUSH (), and the result was invalid. Thankyou verymuch!

[Hung Bui]

Hi Bevis, 

 

It's a known issue that RTT logging in bootloader and in application may not work together. You can have a look at this case and this case. 

 

I don't understand the 2nd question you have ? If you don't want to protect your MBR and bootloader you can comment out the code, but you risk the chance that your application (or harmful application)  may mess up with the MBR/bootloader and brick the device. 

[bevis]

at last I found the reason, Many times the programming chips on the power up state may cause the application to fail to output RTT.RTT output can be restored by power cut reset chip,This is a phenomenon that has not been found in SDK14.0-14.2