This tutorial is about how to create a lwIP project with FreeRTOS using the Kinetis SDK V1.3.0 with Kinetis Design Studio on the Freescale FRDM-K64F board.
FRDM-K64F Board with lwIP running
Mastering interrupts is critical to make an embedded application reentrant. The challenge with reentrancy is that things might be implemented in a wrong way and the issue might just show up sporadically (see “EnterCritical() and ExitCritical(): Why Things are Failing Badly“). The ARM Cortex interrupt controller is named NVIC (Nested Vectored Interrupt Controller).
ARM Cortex NVIC Registers
How about to use the Freescale FRDM-KL43Z board (see “Unboxing the Freescale FRDM-KL43Z Board“) to play a Tetris game?
FreeRTOS is probably the most popular RTOS used and I love it: it is efficient, has a lot of features, simple and easy to use. But despite its popularity, debugging it with open source tools as with Eclipse and GDB is really not that user-friendly: debugging threads/tasks is a pain compared to commercial solutions. For my university classes this semester I was looking for something easy to use by my students. Finally I managed to use a GDB helper which makes things easier now: I can switch task threads in Eclipse with GDB now 🙂
Switched to Shell Task
Sometimes I need to link an object file (e.g. bootloader.o) to my application, and I do not want to build it, or I do not have the sources to build it. There is a simple way with the GNU ARM Eclipse plugins to link extra object files:
Other Objects for GNU Linker
Many tool chains and linker are able to produce S19 files, such as with the GNU tools it is the ‘objcopy‘ which does this job (see “Binary (and S19) Files for the mbed Bootloader with Eclipse and GNU ARM Eclipse Plugins“). But these tools usually cannot handle the special cases. For example on the Freescale Kinetis K64F my serial bootloader (see “Serial Bootloader for the Freedom Board with Processor Expert“) had a problem with these lines in the S19 file:
Not aligned S19 file entries
Some of my robotics projects take a rather long time do a full build. When I developed applications with Visual C++ on the host, using precompiled headers gave me a big boost in compilation speed. I was looking for the same in similar with GNU and gcc, and as expected: gcc does support precompiled headers too. And indeed, I was able to cut down compilation time by 30% :-). So this post is about how to use gcc with precompiled headers in Eclipse/CDT to give my builds a boost.
using precompiled header
It has been a while since I published my ‘build my own DIY IDE’ (see “DIY Free Toolchain for Kinetis: Part 1 – GNU ARM Build Tools“). I have used that approaches in my classes successfully. Now a new semester is coming up, so time to update the instructions using the latest Eclipse IDE (Mars) and tools (GCC ARM Embedded (launchpad) with GNU ARM Eclipse).
Eclipse Mars Splash Screen
I have published a Sneak Preview how GNU gprof profiling looks for an embedded target ARM Cortex-M in an earlier post:
This tutorial explains how to profile an embedded application (no RTOS needed) on ARM Cortex-M devices with GNU gprof. Additionally I explain the inner workings to generate the data necessary for gprof.
Continue readingThe STMicroelectronics STM32F103 (ARM Cortex-M3) Nucleo boards include the on-board ST-Link v2 circuit which allows to debug the board. This circuit is similar to the OpenSDA circuit found on Freescale boards. Unlike the Freescale OpenSDA, the ST-Link is only the ST-Link: it is not possible to load a P&E Multilink or Segger J-Link or firmware on it. Luckily, the ST-Link has a SWD connector, but this connector is a non-standard one. So how can I debug that board with an Eclipse based environment with GNU ARM Eclipse plugins and a Segger J-Link?
Connected J-Link with Nucleo Board
MCU on Eclipse 