Tutorial: Getting ETM Instruction Trace with NXP Kinetis ARM Cortex-M4F

It seems to me that not many developers use hardware trace? ARM indicates that maybe only <5% of developers are using trace. Too bad! Why are all the ARM Cortex microcontroller vendors putting a powerful hardware (and complicated!) trace engine into their devices, if only few developers are using it? Seems like a waste of silicon and an unnecessary price adder? Well, hardware trace can be a life saver: Because only with hardware trace the most complicated bugs and problems can be solved. And maybe because only the best are using it ;-).

In this article I proudly present my research how to get instruction trace out of the ARM Cortex-M4 microcontroller on a NXP TWR-K64F120M board with a Segger J-Trace for ARM:

J-TRACE tracing NXP TWR-K64F Board

J-TRACE tracing NXP TWR-K64F Board

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Tutorial: Using Single Wire Output SWO with ARM Cortex-M and Eclipse

As a standard procedure, I add some console functionality to my embedded applications. That way I have a command line interface and can inspect and influence the target system. One interesting hardware feature of ARM Cortex-M is Single Wire Output (SWO): it allows to send out data (e.g. strings) over up to 32 different stimulus ports, over a single wire.

swo-pin-on-arm-debug-header

swo-pin-on-arm-debug-header

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FreeRTOS Kernel Awareness with Ozone

In my first post about Segger Ozone (see “First Steps with Ozone and the Segger J-Link Trace Pro“) I missed the fact that it includes support for kernels like FreeRTOS. So here is how to show the FreeRTOS (or any other RTOS) threads with Ozone:

freertos-threads-in-ozone

freertos-threads-in-ozone

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First Steps with Ozone and the Segger J-Link Trace Pro

From time to time I face some problems which are really hard to find. Mostly these kind of bugs are very timing sensitive and depend on interrupt execution order. Maybe a dangling pointer is overwriting memory, code is running wild, or some functions are not reentrant as they should be. For these kind of bugs, good tools are worth their weight in gold. The Percepio FreeRTOS+Trace and the Segger SystemView have helped me many times to narrow down such kind problems in my applications. Another ultimate tools is hardware trace: Now I have a Segger J-Trace Pro for ARM Cortex-M in my arsenal of bug extinguishing weapons on my desk:
Dear bugs, look what I have on my desk. Your hiding time is over! 🙂

tracing-cortex-m4-with-j-trace

tracing-cortex-m4-with-j-trace

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ARM Cortex-M, Interrupts and FreeRTOS: Part 2

In “ARM Cortex-M, Interrupts and FreeRTOS: Part 1”  I started with the ARM Cortex-M interrupt system. Because the ARM implementation cann be very confusing, I confused myself and had to fix and extend the description in Part 1 :-). Thank for all the feedback and comments!

Originally I wanted to cover FreeRTOS in Part 2. Based on the questions and discussions in Part 1 I thought it might be a good idea to provide visual examples.

NXP KV58F ARM Cortex-M7

NXP KV58F ARM Cortex-M7

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Eclipse and GDB: Process Properties, Arguments and GDB Traces

To me this was new, and thanks to Liviu I know now how to inspect the command line passed to the GDB server (see “Semihosting (again!) with NXP Kinetis SDK V2.0“) 🙂

Process Properties

Process Properties

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Semihosting (again!) with NXP Kinetis SDK V2.0

I kind of hoped that after “Why I don’t like printf()” and all my other articles about printf and semihosting, that topic would be 200% handled and I won’t have to deal with any more. Well, I was wrong and underestimated how the Kinetis SDK is interfering with semihosting. And I underestimated how many of my readers are still using semihosting (even as there are other and better alternatives), so I keep getting questions and requests for help. That’s ok, and I hope I can help :-).

So here is yet again another post about how to turn on semihosting with Eclipse, GNU ARM Embedded and the Kinetis SDK v2.0. This time with the FRDM-K64F board:

FRDM-K64F Board with lwIP running

FRDM-K64F Board

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Bricking and Recovering OpenSDA Boards in Windows 8 and 10

Getting a board from a distributor like Farnell/Element14/Mouser (add your own distributor) means that chances are high that the default firmware on it is written years from now because the inventory has not been updated, or because boards are still produced with that original firmware (because of testing?). So what happens if I use board with a firmware developed pre-Windows 8/10 area?

Freshly Unboxed NXP FRDM-KL25Z Board

Freshly Unboxed NXP FRDM-KL25Z Board

It might work, but chances are high that the bootloader and firmware is not ready for the ‘modern age’, and as a result the board might be bricked. If you still have a Windows 7 machine around (I do!), you are lucky. If not, then you need to read this article….

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McuOnEclipse Components: 31-July-2016 Release

Time for a new major update of the McuOnEclipse components, with the fillowing main features and changes:

  • FatFS component updated to R0.12 with patch 3 and exFAT support
  • Extended support for Cortex-M7
  • Extended support for Kinetis SDK V2.0
  • USB component support for Kinetis SDK V1.3
  • Improved FreeRTOS for NXP FreeRTOS TAD plugin
  • Added C++ wrappers to multiple components
  • Many smaller fixes and improvements

    SourceForge

    SourceForge

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