Cross compiling for the Raspberry Pi

You can cross compile the project for a raspberry pi on a Linux system.

Make sure you have all the dependencies installed as outlined in the Getting started page.

Downloading raspberry pi tools

To cross compile you will need a local copy of the raspberry pi tools repository. Run the following command:

git clone --depth 1 https://github.com/raspberrypi/tools.git

The cloned repository will be around 1gb so the command will take some time to finish.

Cross compiling boost

Once you've cloned the raspberry pi tools, you will now need to compile boost's filesystem library for arm.

There is a helper script, /build-boost-arm.sh that will automate this process. The script will download boost to a boost_1_70_0 directory and compile it for arm in that same directory. To use it you will need to set the RPI_TOOLS environment variable to the path of the raspberry pi tools repository you cloned above.

Example of running the script:

# cd out of the repository
cd ..

# set the RPI_TOOLS environment variable
export RPI_TOOLS=/path/to/raspberry/pi/tools

# run the script, it will create a boost_1_70_0 directory
./feat-cross-compilation/build-boost-arm.sh

Cross compiling libi2c

To cross compile you will need to set two environment variables:

• RPI_TOOLS which points to the path of the raspberry pi tools repository you cloned above

Run build-libi2c.sh

The libi2c library should be install in the i2c-tools-4.3/ folder

Cross compiling

To cross compile you will need to set two environment variables:

• RPI_TOOLS which points to the path of the raspberry pi tools repository you cloned above
• BOOST_DIRECTORY which points to the cross compiled boost directory you created above
• LIBI2C_DIRECTORY which points to the cross compiled libi2c directory you created above

Finally, run the /build-arm.sh script:

# set the required environment variables
export RPI_TOOLS=/path/to/raspberry/pi/tools
export BOOST_DIRECTORY=/path/to/boost_1_70_0
export LIBI2C_DIRECTORY=/path/to/libi2c


# build the project
./build-arm.sh

Your final arm executable will be at /build-arm/MainLoop.

If you don't want to set the environment variables above every time you can append the following to your .bashrc file:

export RPI_TOOLS=/path/to/raspberry/pi/tools
export BOOST_DIRECTORY=/path/to/boost_1_70_0
export LIBI2C_DIRECTORY=/path/to/libi2c