RTEMS lwIP STM32 Repository

This example was used to test all three major lwIP APIs on the NUCLEO-H743ZI with RTEMS

1. RAW API, high performance using callbacks
2. Netcon API, sequential API
3. Socket API, sequential API, less performance but portable API.

The APIs were tested using a simple UDP or TCP echoserver. The default port is 7 and DHCP is enabled by default. The assigned server will be printed so it should be sufficient to plug the flashed NUCLEO board into a router and monitor the serial output.

After cloning this repository with

git clone https://github.com/rmspacefish/rtems-stm32-lwip.git
cd rtems-stm32-lwip

make sure to clone the submodules as well

git submodule init
git submodule update

Prerequisites

See here for a guide to build the RTEMS BSP. Alternatively, you can download pre-compiled BSPs for Windows from here

Configuring the application

The application can be configured by using CMake build options. You can use cmake-gui .. or ccmake .. to display the options in the build folder. Alternatively, the conf_app.h file can be edited in the build folder manually after it was generated by CMake.

Building the application

It is assumed the RTEMS BSP is installed at the RTEMS_PREFIX location. On Windows, it is recommended to install MinGW64 to have a Unix environment and run the following command to install CMake and required tools.

pacman -S mingw-w64-x86_64-cmake mingw-w64-x86_64-toolchain

To connect to the STM32, make sure to install the st-link drivers from here as well.

CMake

Set up the environmental variable RTEMS_PREFIX first

export RTEMS_PREFIX=<RTEMS Prefix Path>

You can also extract this step to a script which is sourceed or add it to the environmental variables permanently by adding the line to the .bashrc file.

Generate the build system with CMake first:

mkdir build-Debug && cd build-Debug
cmake -DCMAKE_BUILD_TYPE="Debug" -DRTEMS_BSP="arm/nucleo-h743zi" -DRTEMS_PREFIX=$RTEMS_PREFIX ..

You can now edit the conf_app.h file inside the build folder to configure the application.

After that, RTEMS lwIP needs to be built and installed. A helper script has been provided to do this.

./install-rtems-lwip.sh

Finally, you can build the application

cd build-Debug
cmake --build . -j

Waf

TODO

Flashing the application

You can flash the application with Drag & Drop or with OpenOCD. An Eclipse project file is provided to get started with OpenOCD. You can install OpenOCD for Windows from here with xpm to have good Eclipse integration.

When using OpenOCD, it is recommended to perform following steps to avoid the auto-probe error:

Add the following lines to the stm32h7x.cfg file located inside the OpenOCD folder inside the scripts/target folder:

$_CHIPNAME.cpu0 configure -event gdb-attach {
    halt
}

$_CHIPNAME.cpu0 configure -event gdb-attach {
    reset init
}

Testing the application

The ip_client contains a simply Python TCP/IP client implementation which can be used to test the software.

Alternatively you can use netcat to test the application

Send and receive UDP packet:

echo "Hello from PC" | nc -w1 -u <ipAddress> <port>

UDP Client:

nc -u <ipAddress> <port>

Using Eclipse

To use the given Eclipse project file, copy it from eclipse into the root. Then you can import the folder as an Eclipse project. Make sure to only import the root project file instead of both when importing the project. Right click on the project folder and go to C/C++ Build → Build Variables. Here you can set RTEMS_PREFIX accordingly to set up the Eclipse indexer.