Tutorial: GNU gcov Coverage with the NXP i.MX RT1064

This tutorial shows how to use and collect coverage data using the GNU gcov tool. As board and hardaware I’m using the NXP i.MX RT1064 EVK:

MIMXRT1064-EVK running ThreadX
MIMXRT1064-EVK

While this tutorial uses this specific board, things are pretty generic and should be applicable for any other board or MCU.

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Visual Studio Code for C/C++ with ARM Cortex-M: Part 8 – xPack C/C++ Managed Build Tools

This is a new article in my series about using Microsoft Visual Studio Code: After installation, project setup, building, debugging, setting up a kit, IntelliSense and FreeRTOS. This one is about setting up and using the xPack Extension to build cross-platform-multi-tool project with a project manager.

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MCUXpresso IDE 11.4.0

University exam grading are all done now and results are in the system, and it is already time to prepare for the fall semester. I always try to use the latest and greatest tools in my courses, and the NXP MCUXpresso IDE 11.4.0 just came out. So time to have a look and explore the changes and features.

Debugging with NXP MCUXpresso IDE 11.4.0
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Standalone SWO

SWO (Single Wire Output) in ARM cores is probably one of the most under-used features. Which is surprising, because SWO can be very useful. In a nut shell: SWO is a single wire output pin/signal channel which can provide lots of different data, like PC sampling for coverage information, interrupt tracing data or ‘uart-like’ text packets.

SWO output from application
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Round MetaClockClock

It has been a while since my last MetaClockClock, and with the continued shortage of electronics on the market I had no chance to order new parts. But I still had some remaining parts, and with the modular design of the ’round’ clocks I was able to build up another one, but this time with even less than the usual minimum of 24 clocks:

So if you are up to build a MetaClockClock with less clocks, this might be the way for you.

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Position-Independent Code with GCC for ARM Cortex-M

Welcome to ‘Alice in Wonderland‘! For a university research project using an ARM Cortex-M33 we are evaluating position-independent code as way to load applications or part of it with a bootloader. It sounds simple: just add -fPIC to the compiler settings and you are done.

Unfortunately, it is not that simple. That option opened up a ‘rabbit hole’ with lots of wonderful, powerful and strange things. Something you might not have been aware of what could be possible with the tools you have at hand today. Leading to the central question: how is position-independent code going to work with an embedded application on an ARM Cortex-M?

Let’s find out! Let’s start a journey through the wonderland…

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Visual Studio Code for C/C++ with ARM Cortex-M: Part 7 – FreeRTOS

This is a new article in my series about using Microsoft Visual Studio Code: After installation, project setup, building, debugging, setting up a kit and IntelliSense. This one is about setting up and using FreeRTOS:

Microsoft Visual Studio Code with Debugging FreeRTOS application on ARM Cortex-M
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Finding Memory Bugs with Google Address Sanitizer (ASAN) on Microcontrollers

Dangling pointers and memory corruption problems are nasty issues for any developer, and usually hard to find and locate in the code. Luckily Google has developed an open source tool to solve such issues: the Address Sanitizer (ASAN). The tool is available for x86 and other desktop style architectures, including Android and Linux. This article describes how ASAN can be used for an embedded target, e.g. ARM Cortex-M4 or similar.

Catching memory errors on ARM Cortex-M4F with ASAN
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Placing Code in Sections with managed GNU Linker Scripts

Managed linker scripts are great on one side: the simplify the otherwise complex GNU linker script handling. On the other side it requires knowledge how to tweak them in case ‘non-standard’ behavior is needed.

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