How and where to install the arduino cmake toolchaine ?

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I'm following the tutorial CMake with rosserial_arduino on a raspberryPi

In the tutorial, It's write that the generate_arduino_firmware function is provided by the arduino-cmake toolchain.
I have installed the arduino from source and the ros_lib into the arduino environnement. I worked out fine.
To be able to compile the sketch from the command line, I need the arduino-cmake toolchain.

How and where to install the arduino cmake toolchaine ?

Thks
-- Tontome--