Sometimes it is handy to know in the running application the start address, end address and the size of a linked section, e.g. to know the boundaries of RAM or FLASH areas. This means that from the application code I can get access to knowledge of the GNU linker:
The tools and IDE market is constantly changing. Not only there is every year at least one new major Eclipse IDE release, the commercial tool chain and IDE vendors are constantly changing the environment too. For any ARM Cortex-M development, the combination of Eclipse with the GNU tool chain provided by ARM Inc. is the golden standard. But this does not mean that things can be easily moved from one IDE package to another.
While moving between Eclipse versions and GNU versions is usually not a big deal at all, moving between the Eclipse build tool integration is usually not simple. While the GNU MCU Eclipse plugins are widely used (see Breathing with Oxygen: DIY ARM Cortex-M C/C++ IDE and Toolchain with Eclipse Oxygen), the Eclipse based IDEs from the silicon vendors or commercial Eclipse toolchain vendors are using their own GNU toolchain integration. Which means the project files are not compatible :-(.
Eclipse is probably the most used and de-facto standard IDE for any development for ARM Cortex or any other devices. It is very easy these days to construct an unlimited and unrestricted IDE (see “Breathing with Oxygen: DIY ARM Cortex-M C/C++ IDE and Toolchain with Eclipse Oxygen“). Up to the point that I can pack it into a .zip file and pass it around e.g. in a class room environment, so no installer at all is needed with the exception of the debug probe USB drivers. As Eclipse is using a Java Virtual Machine (VM), it is a good idea to bundle the VM with the IDE, and this article is about how to do this.
Last month (June 2017), the latest version of Eclipse “Oxygen” has been released, and I have successfully used it in several embedded projects. Time to write a tutorial how to use it to build a custom Do-It-Yourself IDE for ARM Cortex-M development: simple, easy, unlimited and free of charge. While the DIY approach takes a few minutes more to install, it has the advantage that I have full control and I actually know what I have.
By default, the GNU Linker expects a very special naming scheme for the libraries: the library name has to be surrounded by “lib” and the “.a” extension:
But what if the library I want to use does not conform to that naming standard?
The benefit of an IDE like Eclipse is: it makes working with projects very easy, as generates make files and it takes and automatically manages the make file(s). But sometimes this might not be what I want because I need greater flexibility and control, or I want to use the same make files for my continues integration and automated testing system. In that case a hand crafted make file is the way to go.
One thing does not exclude the other: This article explains how to use make files with Eclipse with similar comfort as the managed build system in Eclipse, but with the unlimited power of make files:
NXP has released an updated of their Eclipse based IDE for ARM Cortex-M (Kinetis and LPC) microcontroller: the version v10.0.2 build 411:
If you are like me – someone who always wants to know what the compiler generates for a piece of source code – then have a look at the Compiler Explorer: A web-based compiler code comparison tool:
Thanks to Matt Godbolt, I can select different compilers and compare their output for a given source code. Very useful to see the impact of a compiler optimization or to compare different GCC compiler versions.
Happy Comparing 🙂
Some silicon vendors provide their Eclipse example and SDK projects using linked files and folders. For example a bootloader demo application is provided in the context of an SDK or library. That’s fine until the time I want to transform such an example into a real project or if I want to have it without the hundreds of files for all the other devices I don’t need or use. I cannot take the project and put it into a version control system as the linked files won’t be in my VCS. I cannot move the project to another place as the links are pointing to many places. What I need is a ‘standalone’ project: a project which has all the needed files in it and is self-containing.
I believe in ‘life-long-learning’. With this I continue to learn and discover new things every day. I’m writing tutorials to give something back to the community from which I have learned so much.
On top of this, I receive emails on a nearly daily basis, asking for help. Many articles have the origin in such requests or questions. I prefer questions or comments in a public forum, because that way I feel all others can benefit from it. Last week Alessandro contacted me with this:
I hope this find you well! I’m starting to using ARM processors, but I find them quite complicated on the configuration side. I started in the past with PIC micro (PIC16) with asm, and I found them quite straightforward to be configured (clock, IO, peripherals, …). Then I moved myself on C language, and on PIC18 without any big issues.
Now I would really like join the ARM community, I see that these processors are what I’ve always looking for, on energy, calc power, peripherals, and FINALLY on IDE (editor, toolchain and utilities)… AMAZING!!!”
The topic is about how to start learning developing for ARM. Alessandro agreed to make this public, so I thought this might be a good topic for an article?
In the area of IoT (Internet of Things), one obvious need is to have a way to send and receive data with an internet protocol. MQTT (or Message Queue Telemetry Transport) is exactly like that: a light-weight Machine-to-Machine communication protocol. With the MQTT protocol a microcontroller (or ‘client’) can send data and/or subscribe to data. For example to the Adafruit.IO:
In “MCUXpresso IDE: Importing Kinetis Design Studio Projects” I explained how Kinetis Design Studio projects can be imported and used inside the MCUXpresso IDE. Processor Expert projects can be used, but no new components added, modified or new Processor Expert projects created. To fully use Processor Expert, two plugins need to installed, and this is what this article is about.
Many of my currently active projects are using Kinetis Design Studio (KDS) V3.2.0 from NXP (I have published many of my projects on GitHub). Now with the advent of the MCUXpresso IDE (see “MCUXpresso IDE: Unified Eclipse IDE for NXPs ARM Cortex-M Microcontrollers“), I have migrated several projects from KDS to MCUXpresso. This post is about how to easily get KDS projects ported and running in MCUXpresso IDE.
This year I managed to attend the Embedded World in Nürnberg/Germany after missing the 2016 show. And 2017 has been a blast! With more than 1000 exhibitors and >30’000 visitors it was huge! There were too many exciting things, so I just pick a few: NXP demonstrated the new MCUXpresso Software and Tools with a new Eclipse Neon based IDE, lots of IoT and Hexiwear, the tiny LPC800-DIP board, and I have met Alan Hawse in person!
The concept of Linux (Open Source, broad developer base and broad usage) is a success story. While there is a lot of diversity (and freedom) in the Linux world, Linux is Linux and again Linux :-). And the world has (mostly) standardized on Linux and its variants on the high embedded system side.
On the other side, the ‘middle and lower end’ Embedded world is fragmented and in many aspects proprietary. So it was no surprise to me when the Linux Foundation announced the ‘Zephyr’ project back in February 2016:
“The Linux Foundation Announces Project to Build Real-Time Operating System for Internet of Things Devices. Open source Zephyr™ Project aims to deliver an RTOS; opens call for developers to help advance project for the smallest footprint IoT devices.“
Ζεφυρος (Zephyros) is the Greek good of spring and the west wind. Obviously this inspired the logo for the Zephyr project:
One of the biggest road blocks (beside of closed source) using the BLE (Bluetooth Low Energy) stack from NXP is that it requires expensive tools to compile and build the stack. The good news is that I have now the NXP BLE stack for the Mikroelektronika Hexiwear ported to Eclipse and GNU gcc build tools for ARM 🙂
The Hexiwear device is a great and versatile device with two microcontrollers on it. Developing firmware on a Hexiwear means changing what was originally on it. And sometimes it happens that I’m not sure if the changes are for good. Or that I accidentally destroyed the firmware on the NXP Kinetis KW40 BLE microcontroller :-(. So I had to find a way to restore the original firmware, and this is what this post is about.
Command line tools to build applications are great. But productivity goes up if I can use the standard Eclipse environment with GNU tools. This tutorial is about how to use standard and free GNU and Eclipse tools to build my FreeRTOS application for the ARM Cortex-M4 on i.MX7 🙂 :
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! 🙂
Smartwatches are around for a while now. To me it is still questionable how useful the ‘big’ ones for iOS and Android are. But there are definitely the crowd funded smartwatch projects which caught my attention. Maybe it is about the ‘do-anything’ with connectivity? One of these gadgets is Hexiwear: a hackable open source device
While it *could* be a kind of smartwatch, the value of this thing is more that it includes a plethora of sensors with two microcontroller, and I can use Eclipse with GNU tools to build my firmware :-).
Alert: Hackster.io is giving away 100 Hexiwears, but you need to hurry up (submission until July 15th 2016)!