Sometimes it makes sense to write everything in assembly, even these days. For example if using a tiny microcontroller. Or just if one just don’t need all the productivity of the C/C++ tools. And it is a good educational experience: getting hands-on on the lower levels.Continue reading
Tag Archives: arm gcc
Building a Triumvirate: From Eclipse CDT to CMake, CMD and Visual Studio Code
A Triumvirate is or Triarchy is built by three individuals which lead or rule something. In this article I want to rule a project with Eclipse CDT, Visual Studio Code and with building it from the command line for automated builds.
So what if I have an Eclipse project (say MCUXpresso IDE and SDK), and want to build it on a build server, and and I want to use the same time the project with Eclipse IDE and Visual Studio code?
Key to this is CMake: I’m keeping the Eclipse CDT features, adding CMake with Make and Ninja to the fix, and have it ‘ruled’ by three different ’emperor’: Eclipse, Visual Studio Code and from a shell console:Continue reading
RP2040 with PIO and DMA to address WS2812B LEDs
I love the WS2812B (aka SK6812) addressable LEDs: they are inexpensive and available in different packages. I have used them in different projects, including the MetaClockClock one. I used the NXP Kinetis for these projects, but because they are not available any more, for a new project we had to choose a new microcontroller, with the Raspberry Pi Pico RP2040 as the winner.Continue reading
Using Semihosting the direct Way
Most embedded developers have probably used ‘semihosting’. And yes, it is generally seen as a bad thing. Maybe you have used it, without realizing what it really is and what it does. It is simple to add a
printf() to the code (again: you should not use printf), and with the right standard library, it magically it shows up in a console view:
That looks great, but what is behind this, to make it happen? Actually, it is really amazing technology. And it can be used for better things than just printing text.Continue reading
IDE Custom C/C++ Local Build Environment
On my host machine I have many different development environment installed. From different make, cmake and python versions up to different versions of GNU tool chains. Adding them to the PATH environment variable on Windows is really a bad thing: instead I want to keep my PATH as clean as possible. If I need to set up a different environment with different tools, then I prefer to have a ‘local’ environment.Continue reading
Avoiding Stack Overflows: Application Monitoring the Stack Usage
One of the biggest fears of embedded systems developers are stack overflows. FreeRTOS includes a cool feature to monitor and catch task stack overflows. But what about the MSP (Main Stack Pointer) on ARM, or the interrupt stack? What if not using an RTOS and running a bare-metal application?
There is a simple way monitoring stack usage at runtime, and for this I want to share the routines and what is now available inside the McuArm module.Continue reading
You_Shall_Not_Use_Printf: How to make sure no printf() is used
Every embedded system developer should know by now, that using printf() is not a good thing for smaller systems. Printf() and the like are not only problematic from a code and data size perspective, they are infamous for vulnerability attacks too.
In this article I’ll show you multiple ways how to ban printf() or anything similar you want to avoid.Continue reading
Adding the Picolib C/C++ Standard Library to an existing GNU ARM Embedded Toolchain
It looks like my previous article “Which Embedded GCC Standard Library? newlib, newlib-nano, …” stirred up something: I saw and knew about the Picolib created and maintained by Keith Packard, but never had the time to try it out. With the university grading mostly over, I have put aside a few hours to try it out. And the result is very interesting:Continue reading
Debugging Embedded Targets with pyOCD and Eclipse
If doing embedded development, then the debugging solution is probably the most important single tool in the development chain. Because very debugging probe has its pros and cons, I usually have at least three different debug probes on my desk, simply to get the job done in all aspects.
What is true for the hardware debugging probes, is true for the gdb client and server side. I’m using mostly the P&E, SEGGER and CMSIS-DAP plugins (e.g. NXP LinkServer) and OpenOCD from the Eclipse IDE side. But there are more choices, for example pyOCD.Continue reading
Which Embedded GCC Standard Library? newlib, newlib-nano, …
When developing with C or C++ an application, then you mostly focus on your own code. You don’t want to bother with the details how input/output functions like printf() or scanf(), and you might just use these functions and helpers and that’s it.
The implementation is part of the ‘C Standard Library’ (or C++ Standard Library). In the world of Linux, this is usually the ‘glibc’ or ‘GNU C Library, and one usually link with ‘libc’. That provides the implementation of printf(), or use ‘libm’ if using math functions like sin() or cos().
In the embedded world, things are much more complex, with plethora of choices, for example in the MCUXpresso IDE:Continue reading