assert(), __FILE__, Path and other cool GNU gcc Tricks to be aware of

It is always good to have a close look what ends up in a microcontroller FLASH memory. For example using EHEP Eclipse plugin to inspect the binary file:

Source File Name in Binary Image

Source File Name in Binary Image

Obviously it has path and source file information in it. Why is that? And is this really needed?

What about:

  • Privacy: the path or file name might expose information (secret project name?) or might be used for reverse engineering?
  • Size: The strings add up to the final data/FLASH size, so this increases the need for ROM space?

So let’s have a look what is the reason for this and how it could be avoided or at least reduced.

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Hey Google: Find ‘Error from StubMonSemihost: “monitor” command not supported by this target.’

Something what I say quite often is: “Google is your friend”. It means that the answer to many questions can be found with an internet search engine. And I have to admit that I have to ‘google’ my own articles to find solutions for problems I feel I have seen in the past too :-).

But for the one problem below I did not find anything: not on my own blog, and not anywhere else in the internet:

Exception

Exception

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Eclipse Indexer Debug Tips

Eclipse includes a background parser called ‘Indexer’ which is used to assist the developer with various kind of information, for example jumping to a variable declaration or definition. Basically it is a parser running in the background collecting information about the sources and building up that ‘index’ data base.

indexer debug output

indexer debug output

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3D Printed Mounting Bridge for Feller Smart Light Control for Philips Hue

The company Feller sells a wall mountable ‘Smart Light Control’: this provides 4 push buttons compatible with the Philips Hue system (on, off, dimming, etc). Unlike many other remote controls and buttons it is a great design and available in different colors. Feller does have a ‘classic’ wall switch series too, so this one is perfect to replace or augment an existing installation and make it ‘smart’.

Feller Smart Light Control

Feller Smart Light Control

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Eclipse CODAN (Static Code Analysis) for C/C++

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 catched by CODAN

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.

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OpenOCD with MCU-Link

The NXP MCU-Link is a powerful $10 debug probe for ARM Cortex-M devices and works with the NXP LinkServer for debugging. The LinkServer does not an implement a gdb server, so it limits its usage e.g. for scripting or command line debugging. But as MCU-Link is also a CMSIS-DAP compatible debug probe, I can use it with OpenOCD which is open source and implements a GDB server. This article shows how I can use it with the MCU-Link.

Debugging FRDM-KL25Z with MCU-Link

Debugging FRDM-KL25Z with MCU-Link

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Standalone and Command Line Programmer with MCUXpresso

The MCU-Link is a $10 CMSIS-DAP capable debug probe which works out-of-the box with the MCUXpresso Eclipse based IDE. This is great for development, but how can I programming with the push of a button or a script? The answer is no: there is an easy way to use the debug probe outside Eclipse from a shell script, and you can use that MCU-Link probe to do the job. This is especially useful as with the example below where I have to program 60 boards this week-end :-).

Programming Boards with MCU-Link using command line

Batch Programming Boards with MCU-Link

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Configure hidden and internal Shortcuts in Eclipse

A very useful feature in Eclipse is Ctrl+Shift+L which lists all the available shortcuts:

List of Shortcuts

List of Shortcuts

Pressing Ctrl+Shift-L again will open up a dialog where I can configure them. But what if the shortcut or action is not listed there?

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Getting a 96bit Unique ID for each Kinetis Device using 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

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?
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Steps to use FreeRTOS with newlib reentrant Memory Allocation

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)

Running FreeRTOS with reentrant newlib

Running FreeRTOS with reentrant newlib

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