How to install the Raspberry Pi cross compiler on my Linux host machine?
I am attempting to get cross-compiling for Raspberry Pi working on my Ubuntu machine.
During my initial attempts I was using the arm-linux-gnueabi compiler, which is available in the Ubuntu repo. I got this working. I was able to build all my dependencies and use the cross-compiler in my cmake project.
However, I believe I should be using the hf version, so I switched to arm-linux-gnueabihf. Then I realized that this does not work with Raspberry Pi since it is armv6.
After some Googling, I then found the pre-built toolchain from GitHub.
I downloaded the toolchain, but I don't really understand how to "install" it. I extracted the files to my home directory. The directory structure looks like this:
/gcc-linearo-arm-linux-gnueabihf-raspbian
/arm-linux-gnueabihf
/bin
(contains g++, gcc, etc)
/lib
(contains libstdc++ library)
/bin
(contains arm-linux-gnueabihf-g++, arm-linux-gnueabihf-...)
/lib
(gcc lib stuff)
If I change directory to the INNER bin folder I am able to compile a test program from the terminal without any problems.
~/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian/
arm-linux-gnueabihf/bin$ g++ test.cpp -o test
I then tried to compile a test program in the OUTER bin folder, which contains the prefixed versions of the tools.
~/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian/bin$
arm-linux-gnueabihf-g++ test.cpp -o test
However, when I try to use the compiler now (from outside the inner bin directory), it is unable to find the libstdc++ shared library that comes with the toolchain:
arm-linux-gnueabihf-gcc: error while loading shared libraries:
libstdc++.so.6: cannot open shared object file: No such file or directory.
Furthermore, I want to be able to use the compiler without having to navigate to the bin directory. So I tried adding the OUTER bin directory (since I want the prefixed versions) and both lib directories to my PATH:
export PATH=$PATH:~/tools/.../bin
export PATH=$PATH:~/tools/.../lib
export PATH=$PATH:~/tools/.../.../lib
However, this results in the same error. How should I "install" the toolchain so that I can use the toolchain from everywhere, just like I can when I use the cross-compilers from the Ubuntu repo?
Answer
I'm gonna try to write this as a tutorial for you so it becomes easy to follow.
NOTE: This tutorial only works for older raspbian images. For the newer Raspbian based on Debian Buster see the following how-to in this thread: https://stackoverflow.com/a/58559140/869402
Pre-requirements
Before you start you need to make sure the following is installed:
apt-get install git rsync cmake ia32-libs
Let's cross compile a Pie!
Start with making a folder in your home directory called raspberrypi.
Go in to this folder and pull down the ENTIRE tools folder you mentioned above:
git clone git://github.com/raspberrypi/tools.git
You wanted to use the following of the 3 ones, gcc-linaro-arm-linux-gnueabihf-raspbian, if I did not read wrong.
Go into your home directory and add:
export PATH=$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 [email protected]:/{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 [email protected]:/home/pi/
ssh [email protected] ./CMakeHelloWorld