Building Vanetza for Cohda MK5 using Cohda SDK

This document describes step-by-step how to build Vanetza using the Cohda SDK. At the end, we have Vanetza libraries and its socktap tool cross-compiled for Cohda MK5 devices.

Cohda SDK

Cohda SDK is provided by Cohda Wireless along with their MK5 units. Since you are reading this build how-to you most likely already possess one of these units. This how-to has been created for the Release 16 of the SDK. The following instructions are expected to be done within the virtual machine (VM) provided by Cohda.

Please make sure that a recent GCC version for the arm-linux-gnueabihf target is installed in this VM. I recommend to deinstall g++-4.8-arm-linux-gnueabihf entirely as this version supports C++11 only poorly. g++-5-arm-linux-gnueabihf is known to work well.

Vanetza build dependencies

Compilation of Vanetza depends on several third-party libraries, e.g. Boost, GeographicLib and Crypto++ as mentioned in Vanetza’s README. Steps to compile those dependencies are described in our cross-compile dependencies document. For the sake of simplicity, we provide the pre-compiled dependencies for Cohda MK5 as compressed archives.

Archive	Content	MD5 checksum
vanetza-deps-20171129.tar.bz2	Boost 1.65.1, GeographicLib 1.49, Crypto++ 5.6.5	`853a2833fde0266674d4a4dbe22fe7ef`
vanetza-deps-20191126.tar.bz2	Boost 1.71.0, GeographicLib 1.50, Crypto++ 8.2.0	`1d8832949673e3935f72aac6c00a132d`

At the moment, these archives are hosted on box.com. We recommend to download the most recent archive in general. Before the next step, extract the archive’s content into /home/duser/vanetza-deps.

Compile Vanetza

We assume you have copy of the Vanetza repository in your home directory at /home/duser/vanetza. Create a build directory and tell CMake to use the cross-compiler installed in the Cohda VM and to look up additional dependencies in vanetza-deps:

mkdir vanetza-build
cd vanetza-build
cmake $HOME/vanetza \
    -DCMAKE_TOOLCHAIN_FILE=$HOME/vanetza/cmake/Toolchain-Cohda-MK5.cmake \
    -DCMAKE_FIND_ROOT_PATH=$HOME/vanetza-deps \
    -DCMAKE_INSTALL_RPATH=\$ORIGIN/../lib \
    -DCMAKE_INSTALL_PREFIX=$HOME/vanetza-dist
make

This builds the Vanetza libraries only. Enable the BUILD_SOCKTAP CMake option if you want to try socktap as well. Additionally, enable the SOCKTAP_WITH_COHDA_LLC CMake option if you want socktap to use 802.11p via Cohda’s LLC network interface on your MK5. Fortunately, socktap’s additional gpsd dependency is already shipped with the Cohda SDK itself. You only need to specify its location by setting GPS_LIBRARY to /home/duser/mk5/stack/v2x-lib/lib/mk5/libgps_static.a and GPS_INCLUDE_DIR to /home/duser/mk5/stack/v2x-lib/include. Please note, that socktap does not make use of Cohda’s socket API currently. We might provide a modified socktap application in the future.

Deployment

make install

Compile and link socktap with correct RPATH, binaries are copied to $HOME/vanetza-dist.

copy runtime dependencies

Copy the shared object files (*.so) from $HOME/vanetza-deps/libs onto the MK5, e.g. to /home/user/vanetza/lib.

copy socktap onto MK5

Copy the files from $HOME/vanetza-dist to /home/user/vanetza on the MK5, i.e. Vanetza libraries and its dependency libraries are located in the same directory. You can execute socktap located at /home/user/vanetza/bin/socktap and it will look up its shared objects in the sibling lib directory. If you have enabled the SOCKTAP_WITH_COHDA_LLC CMake option, make sure to give socktap the name of a Cohda LLC network interface via the command line option --interface/-i (e.g. cw-llc0).