logging "deferred" crashes but "in place" works

RE: logging "deferred" crashes but "in place" works

webbcam — Tue, 31 Dec 2019 07:32:25 GMT

That makes sense now. Thank you for your help!

RE: logging "deferred" crashes but "in place" works

Vidar Berg — Mon, 30 Dec 2019 09:11:24 GMT

Hi,

Thanks for the additional info. So the problem is that the MBR needs this section of RAM to be able to forward interrupts to the Softdevice, application, and bootloader. The interrupt forwarding doesn't have to work with the original example as it does not have any interrupts sources. But the NRF_LOG_DEFERRED config option makes the UART backend operate in asynchronous mode (i.e., interrupt mode) and thus making the app rely on receiving interrupts from the MBR.

RE: logging "deferred" crashes but "in place" works

webbcam — Sat, 28 Dec 2019 21:19:02 GMT

Hi,

Thanks for your reply. I found a fix for this but I don't really understand it. I found a solution here for another problem I was debugging, by modifying the linker script blinky_gcc_nrf52.ld to change the RAM ORIGIN address from 0x20000000 to 0x20000010. Once doing this the deferred logging works as expected. My MEMORY section of linker script looks like this now:

MEMORY
{
  FLASH (rx) : ORIGIN = 0x26000, LENGTH = 0xce000
  RAM (rwx) :  ORIGIN = 0x20000010, LENGTH = 0x3FFF0
}

For more context I am using this board: https://www.adafruit.com/product/4062 which specifies this memory map.

I'm not understanding where the MBR comes into play here and how making this change in the linker script fixed my problem. Could you please provide some insight in this?

Thank you!

btw the exact example I'm using is the pca10056/armgcc blinky example from the 16.0 nRF52 SDK and added the logging module to enable logging over UART. I'm just using a text editor and the 'arm-non-eabi-gcc' command line compiler.

RE: logging "deferred" crashes but "in place" works

Vidar Berg — Fri, 27 Dec 2019 09:12:35 GMT

Hi,

I don't see anything in the code you wrote. The main thing when using deferred logging is to remember to call NRF_LOG_PROCESS() or NRF_LOG_FLUSH() to process the log buffers which you have already done. Are you using Segger embedded studio? In that case, do you use the default flash_placement.xml configuration and is the INITIALIZE_USER_SECTIONS flag still defined in your project settings.

Blinky example from SDK 16 with logging over RTT:

devzone.nordicsemi.com/.../blinky_5F00_logging.zip