Linux cross-compilation

Table of Contents

• Cross compilation steps
• Cross comilation steps for python wrapper
  • Prerequisites
  • Installation steps

Warning

These instructions are no longer recommended because they involve disabling security measures for the target system. Please try the instructions using CMake.

RF24 library supports cross-compilation. Advantages of cross-compilation:

• development tools don't have to be installed on target machine
• resources of target machine don't have to be sufficient for compilation
• compilation time can be reduced for large projects

Following prerequisites need to be assured:

• ssh passwordless access to target machine Here is a hint
• sudo of a remote user without password Here is a hint
• cross-compilation toolchain for your target machine; for RPi

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

  and cross-compilation tools must be in PATH, for example

  export PATH=$PATH:/your/dir/rpi-tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/bin

Cross compilation steps

1. clone RF24 to a machine for cross-compilation

   git clone https://github.com/nRF24/RF24
   cd RF24

2. configure for cross compilation

   ./configure --remote=pi@target_linux_host

   eventually

   ./configure --remote=pi@target_linux_host --driver=<driver>

3. build

   make

4. (optional) install library to cross-compilation machine into cross-exvironment - important for compilation of examples

   sudo make install

5. upload library to target machine

   make upload

6. (optional) compile examples

   cd examples_linux
   make

7. (optional) upload examples to target machine

   make upload

Cross comilation steps for python wrapper

Prerequisites

• Python setuptools must be installed on both target and cross-compilation machines

  sudo pip install setuptools

  or

  sudo apt-get install python-setuptools

Installation steps

1. Assure having libboost-python-dev library in your cross-compilation environment. Alternatively, you can install it into your target machine and copy /usr and /lib directories to the cross-compilation machine. For example

   mkdir -p rpi_root && rsync -a pi@target_linux_host:/usr :/lib rpi_root
   export CFLAGS="--sysroot=/your/dir/rpi_root -I/your/dir/rpi_root/usr/include/python2.7/"

2. Build the python wrapper

   cd pyRF24
   ./setup.py build --compiler=crossunix

3. Make the egg package

   ./setup.py bdist_egg --plat-name=cross

   dist/RF24-<version>-cross.egg should be created.
4. Upload it to the target machine and install there:

   scp dist/RF24-*-cross.egg pi@target_linux_host:
   ssh pi@target_linux_host 'sudo easy_install RF24-*-cross.egg'