Cross Compiling From Linux to Raspberry PI

Pre-requirements

Before you start you need to make sure the following is installed:

apt-get install git rsync cmake libc6-i386 lib32z1 lib32stdc++6

Let’s cross compile a Pie!

Start with making a folder in your home directory called raspberrypi.

Go in to this folder and pull down the ENTIRE tools folder you mentioned above:

git clone https://github.com/raspberrypi/tools.git

You wanted to use the following of the 3 ones, gcc-linaro-arm-linux-gnueabihf-raspbian, if I did not read wrong.

Go into your home directory and add:

export PATH=$PATH:$HOME/raspberrypi/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian/bin

to the end of the file named ~/.bashrc

Now you can either log out and log back in (i.e. restart your terminal session), or run . ~/.bashrc in your terminal to pick up the PATH addition in your current terminal session.

Now, verify that you can access the compiler arm-linux-gnueabihf-gcc -v. You should get something like this:

Using built-in specs. COLLECT_GCC=arm-linux-gnueabihf-gcc COLLECT_LTO_WRAPPER=/home/tudhalyas/raspberrypi/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian/bin/../libexec/gcc/arm-linux-gnueabihf/4.7.2/lto-wrapper Target: arm-linux-gnueabihf Configured with: /cbuild/slaves/oort61/crosstool-ng/builds/arm-linux-gnueabihf-raspbian-linux/.b uild/src/gcc-linaro-4.7-2012.08/configure –build=i686-build_pc-linux-gnu –host=i686-build_pc- linux-gnu –target=arm-linux-gnueabihf –prefix=/cbuild/slaves/oort61/crosstool-ng/builds/arm-l inux-gnueabihf-raspbian-linux/install –with-sysroot=/cbuild/slaves/oort61/crosstool-ng/builds/ arm-linux-gnueabihf-raspbian-linux/install/arm-linux-gnueabihf/libc –enable-languages=c,c++,fo rtran –disable-multilib –with-arch=armv6 –with-tune=arm1176jz-s –with-fpu=vfp –with-float= hard –with-pkgversion=’crosstool-NG linaro-1.13.1+bzr2458 – Linaro GCC 2012.08′ –with-bugurl= https://bugs.launchpad.net/gcc-linaro –enable-__cxa_atexit –enable-libmudflap –enable-libgom p –enable-libssp –with-gmp=/cbuild/slaves/oort61/crosstool-ng/builds/arm-linux-gnueabihf-rasp bian-linux/.build/arm-linux-gnueabihf/build/static –with-mpfr=/cbuild/slaves/oort61/crosstool- ng/builds/arm-linux-gnueabihf-raspbian-linux/.build/arm-linux-gnueabihf/build/static –with-mpc =/cbuild/slaves/oort61/crosstool-ng/builds/arm-linux-gnueabihf-raspbian-linux/.build/arm-linux- gnueabihf/build/static –with-ppl=/cbuild/slaves/oort61/crosstool-ng/builds/arm-linux-gnueabihf -raspbian-linux/.build/arm-linux-gnueabihf/build/static –with-cloog=/cbuild/slaves/oort61/cros stool-ng/builds/arm-linux-gnueabihf-raspbian-linux/.build/arm-linux-gnueabihf/build/static –wi th-libelf=/cbuild/slaves/oort61/crosstool-ng/builds/arm-linux-gnueabihf-raspbian-linux/.build/a rm-linux-gnueabihf/build/static –with-host-libstdcxx=’-L/cbuild/slaves/oort61/crosstool-ng/bui lds/arm-linux-gnueabihf-raspbian-linux/.build/arm-linux-gnueabihf/build/static/lib -lpwl’ –ena ble-threads=posix –disable-libstdcxx-pch –enable-linker-build-id –enable-plugin –enable-gol d –with-local-prefix=/cbuild/slaves/oort61/crosstool-ng/builds/arm-linux-gnueabihf-raspbian-li nux/install/arm-linux-gnueabihf/libc –enable-c99 –enable-long-long Thread model: posix gcc version 4.7.2 20120731 (prerelease) (crosstool-NG linaro-1.13.1+bzr2458 – Linaro GCC 2012.08 )

But hey! I did that and the libs still don’t work!

We’re not done yet! So far, we’ve only done the basics.

In your raspberrypi folder, make a folder called rootfs.

Now you need to copy the entire /liband /usr directory to this newly created folder. I usually bring the rpi image up and copy it via rsync:

rsync -rl –delete-after –safe-links pi@192.168.1.PI:/{lib,usr} $HOME/raspberrypi/rootfs

where 192.168.1.PI is replaced by the IP of your Raspberry Pi.

Now, we need to write a cmake config file. Open ~/home/raspberrypi/pi.cmake in your favorite editor and insert the following:

SET(CMAKE_SYSTEM_NAME Linux) SET(CMAKE_SYSTEM_VERSION 1) SET(CMAKE_C_COMPILER $ENV{HOME}/raspberrypi/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian/bin/arm-linux-gnueabihf-gcc) SET(CMAKE_CXX_COMPILER $ENV{HOME}/raspberrypi/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian/bin/arm-linux-gnueabihf-g++) SET(CMAKE_FIND_ROOT_PATH $ENV{HOME}/raspberrypi/rootfs) SET(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER) SET(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY) SET(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)

Now you should be able to compile your cmake programs simply by adding this extra flag: -D CMAKE_TOOLCHAIN_FILE=$HOME/raspberrypi/pi.cmake.

Using a cmake hello world example:

git clone https://github.com/jameskbride/cmake-hello-world.git cd cmake-hello-world mkdir build cd build cmake -D CMAKE_TOOLCHAIN_FILE=$HOME/raspberrypi/pi.cmake ../ make scp CMakeHelloWorld pi@192.168.1.PI:/home/pi/ ssh pi@192.168.1.PI ./CMakeHelloWorld


I have taken the above from stackoverflow:

https://stackoverflow.com/questions/19162072/how-to-install-the-raspberry-pi-cross-compiler-on-my-linux-host-machine

I did not managed to get the cmake to work as the pkg-config seem to have problems identifying where the libraries are and it was adding my libraries from teh host computer rather than the target ones. But following the same instructions it did worked fine when making my own call to the compiler and adding all the paths and libraries manually to the command.