Debugging with Monitor Mode on NCS

[Martin Weinberg]

Hi,

while using the SoftDevice with MPSL on NCS/Zephyr (nRF52840), there will be a HardFault triggered without using Monitor Mode when a breakpoint is hit.

I understand, why this is happening and already searched for enabling Monitor Mode with Zephyr/NCS but only found the following old answer which claims that it is not possible to use Monitor Mode with NCS:

https://devzone.nordicsemi.com/f/nordic-q-a/70769/problem-using-monitor-mode-debugging-with-the-nrf-connect-sdk

Now i searched a little bit more and found this post which is not anwered until now so i wanted to ask if there is a guide on how to enable monitor mode while using NCS?

https://devzone.nordicsemi.com/f/nordic-q-a/82300/debugging-with-bt-mpsl/347857#347857

Thank you for your help and with kind regards,

Martin

[haakonsh]

We don't have a guide for that yet, but i'll ask if we can make one. It will probably take a while.

[Martin Weinberg]

Ok, that means it IS possible to use monitor mode with NCS to tame the SoftDevice/MPSL? Great news, thank you for that!

Do you have some hints or older devzone topics with some tips i can use in the meantime?

Mainly, i have a problem with understanding how to connect the assembly-written ISR from segger with the IRQ in the zephyr/NCS config...

[haakonsh]

Martin Weinberg said:

Ok, that means it IS possible to use monitor mode with NCS to tame the SoftDevice/MPSL? Great news, thank you for that!

I don't know yet. I still don't know how the kernel will react to a blocking ISR.

From my limited understanding of the scheduler, a blocking ISR will block all threads regardless of the ISR's or the thread's priority. And if that's the case then we need the MMD ISR to schedule a blocking thread of a given priority, and exit the ISR immediately instead of blocking. 

For the time being I recommend using Segger's SystemView: www.zephyrproject.org/.../