Cross Compiling Python for Embedded Linux

Paul Gibson — Mon, 05 Apr 2010 14:17:14 +0000

This article details how to cross compile Python for the PowerPC platform. It should apply equally to other platforms such as ARM, just plug in the correct cross-compiler. The article supports Python versions, 2.6.1, 2.6.2, 2.6.3, 2.6.4, 2.6.5 and 3.1.1, 3.1.2.

Firstly, download the version of Python that you want to use from http://www.python.org/

Unpack the Python package using tar:

tar -xvzf Python-2.6.5.tgz

This will create a directory called Python-2.6.5. Goto the directory:

cd Python-2.6.5

Then run these commands to build the host components:

./configure

make python Parser/pgen

mv python hostpython

mv Parser/pgen Parser/hostpgen

make distclean

Download the correct patch for your version of Python:

Then apply the patch:

patch -p1 < Python-2.6.5-xcompile.patch

Then run this (where ~/Python-2.6.5/_install/ is your desired installation path)

CC=ppc_6xx-gcc CXX=ppc_6xx-g++ AR=ppc_6xx-ar RANLIB=ppc_6xx-ranlib ./configure --host=ppc-linux --build=i686-pc-linux-gnu --prefix=/python

make HOSTPYTHON=./hostpython HOSTPGEN=./Parser/hostpgen BLDSHARED="ppc-linux-gcc -shared" CROSS_COMPILE=ppc_6xx- CROSS_COMPILE_TARGET=yes

make install HOSTPYTHON=./hostpython BLDSHARED="ppc-linux-gcc -shared" CROSS_COMPILE=ppc_6xx- CROSS_COMPILE_TARGET=yes prefix=~/Python-2.6.5/_install

This will install all your python binaries and libraries in ~/Python-2.6.5/_install.

Copy the entire _install directory to the device, setup the PATH environment variable to include the location of the Python executable and run:

python lib/Python-2.6/test/test___all___.py

…and hopefully all the tests will run correctly.

To speed up the importing of Python modules on the target, it is recommended to zip up the lib directory to make a file called python26.zip. This means that we do not have to copy all the individual Python files to the target, just the one zip file. This technique might also save space, but that depends on your file system. On the host machine:

cd _install/lib/python2.6

zip -r -y python26.zip .

Delete libpythonxxx.a site-packages, lib-dynload, config and anything else you do not require from the python26.zip file.

Copy the _install/bin/python to the /usr/bin directory on the target:

Copy the python26.zip file to the /usr/lib directory on the target:

Create a directory on the target called python2.6 in the /usr/lib directory and copy the following directories to that directory:

./lib/python2.6/config
./lib/python2.6/lib-dynload
./lib/python2.6/site-packages

Your directory structure on the target should be as follows:

/usr/lib # ls

python2.6 python26.zip

/python/lib/python2.6 # ls

config lib-dynload site-packages

Set the PYTHONHOME environment variable to /usr/ and you are ready to run Python on the target.

The above patches are based on Chris Lambacher’s patches for Python 2.5 here:

http://whatschrisdoing.com/blog/2006/10/06/howto-cross-compile-python-25/

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Cross Compiling Python for Embedded Linux