If you are developing Linux or desktop applications with GNU tools, you very likely are familiar with gcov: the GNU coverage tool. It collects data what parts of the code gets executed and represents that in different formats, great to check what is really used in the application code or what has been covered during multiple test runs.
Coverage Information with gcov
line never executed
GNU coverage is possible for resource constraint embedded systems too: it still needs some extra RAM and code space, but very well spent for gathering metrics and improves the firmware quality. As I wrote in “MCUXpresso IDE V11.3.0 for 2021” things are now easier to use, so here is a short tutorial how to use it.
There are many different aspects of Open Source projects: It is not only about the fact if the sources are available (‘open’). It is about the licensing terms (how permissible is it, what can I do with it), maintenance and continuous development (what has changed between releases), how and where is it delivered (Sourceforge, dedicated distribution, packaging) up to collaboration (how can I contribute or submit issues).
The Eclipse CODAN (Code Analysis) plugin is part of CDT and is a powerful static analysis tool finding all kind of possible bugs and issues. Still to my surprise not many C/C++ developers take advantage of it maybe because they are not aware that it exists?
ups! Programming error detected by CODAN
In this article I show a few tips how to effectively use it, especially with the NXP MCUXpresso SDK.
The NXP Kinetis devices implement a UID (Unique ID) for each device, using the ‘Unique Identification Register) which is part of the SIM (System Integration Module):
SIM Unique ID (NXP K22P144M120SF5RM.pdf Reference Manual)
While this number should be unique, I was wondering last week why students in the labs reported the same UID for multiple robots in the lab. So maybe this number is not so unique as it should be? Continue reading →
Having visibility and insights into a running system is highly valuable or critical: not only for optimizations but as well to verify the system design and behavior. In Getting Started with Microsoft Azure RTOS (aka ThreadX) I showed how to quickly run Azure RTOS. This article is about getting trace out of an ThreadX application and show it in TraceX.
Reentrancy is an attribute of a piece of code and basically means it can re-entered by another execution flow, for example by an interrupt or by another task or thread. This is an important concept and still a lot of code ‘in the wild’ does violate reentrancy. As a result the application crashes immediately in the best case. Worse it crashes randomly or even worse it behaves incorrectly 😦 .
Reentrancy is always a concern if using standard library functions, including printf() or malloc(). FreeRTOS offers a reentrant wrapper to the standard malloc() and free() (Memory Scheme 3)
If you are a regular reader of my articles, you probably know that I’m using FreeRTOS in most of my applications, for obvious reasons. But clearly this is not the only RTOS out there. After Microsoft had acquired Express Logic back in April 2019 things kept quite for a while. To me the crown jewel of Express Logic is the ThreadX RTOS. But recently Microsoft is pushing more and more the ‘Azure Sphere’ and trying to monetize the ‘IoT’ (I apologize for mentioning that overused acronym) application space and providing it now free for devices from selected partners which includes NXP now.
‘Dark’ or ‘Black’ themes are on vogue: some love it, some do not care. The good thing is that we all have a choice. Things are getting improved on the host OS (Windows/Linux) side, but the challenge is still on the application side, but things are getting better. This is true for the Eclipse based IDEs too, with the NXP MCUXpresso IDE V11.2.1 just recently released: it comes with improved Dark Theme support: