Debugging techniques with MQX and KDS?

[dave408]

I'm new to MQX and am running into problems here and there, and I'm sure there will be more!  I was hoping that members of the community can share some of their special debugging techniques with MQX.

I am aware of the Task Aware Debugging (TAD) feature and have added it to KDS 2.0 (I haven't migrated to KDS 3.0 yet).  But other than this, what else is there?  I have read about enabling the Kernel Logging feature, but have only seen that with the older MQX component.  Since PEx now has MQX as an OSA selection, I no longer see Kernel Logging in the parameter list.

I'd also like to see my stack usage over time, but whenever I go to MQX -> Stack usage, it just says "Stack usage information not found!".  I've had cases where my application locks up, and when I increase my stack space, my problem goes away.  I can only assume that this is okay, since I don't use dynamic memory allocation and don't have to worry about memory leaks.  I got lucky this time, because the way the error manifested itself was with a troubling message when I paused execution:

How do I enable Stack Usage information?

Furthermore, what about the case where an application locks up, and it's not a stack space issue?  How do you go about figuring out what happened?  I left my application running overnight, and when I came back to it this morning, it was frozen.  The green D2 LED on my FRDM-K64F was blinking steadily, but this doesn't tell me much because that LED is controlled by the K20 onboard.  I couldn't pause execution, because the debugger had completely lost connection to the board somehow.

And what about catching Hard Fault errors?  I tried to follow BlackNight​'s informative post on mcuoneclipse, but I have enabled Unhandled vectors -> "Own handler for every", and now I can't figure out where those handlers reside.  :smileyhappy:

I'm looking forward to hearing what everyone else does, as well as hopefully getting feedback on how to enable the debugging features that I have mentioned above.  Thank you!

[dave408]

I'm also open to suggestions about how to better handle this sort of request.  It's a little open-ended, and I'm not sure if that prevents people from posting responses.  Is there a better forum mechanism for this sort of thing?  Maybe I should go back to just posting separate questions...

[dave408]

It seems better to ask directed questions, so I am going to end this discussion and focus on specific ones from now on.  :smileyhappy:

[BlackNight · Accepted solution]

About debugging hard faults: You need to install a handler for it:

Debugging Hard Faults on ARM Cortex-M | MCU on Eclipse

A Processor Expert Component to Help with Hard Faults | MCU on Eclipse

Erich

[dave408]

Hi Erich, I did read both of those posts already.  I enabled "Own handler for every" as described, but as I stated in my original post, I cannot find where those handlers end up, so I can't confirm that they exist.  :smileyhappy:  Your post refers to Vectors.c, but I don't have that in the Generated Code section.  I have looked for Fault, Hard_Fault, vect_table, etc etc and don't see that lookup table anywhere.  Can you point me to where it is in KDS 2.0?  Thanks!

[dave408]

We're now up to KDS 3.0 and I had to get fault handlers working.  It turns out that they are weak linked, so all you have to do is define your own functions like this:

void HardFault_Handler(unsigned long *hardfault_args)
{
}
void MemManage_Handler(unsigned long *hardfault_args)
{
}
void BusFault_Handler(unsigned long *hardfault_args)
{
}
void UsageFault_Handler(unsigned long *hardfault_args)
{
}