WIP: Tetris Board firmware

Thanks to Victor Lamoine for the amazing CMake skeleton!

⚠️ Compiler

• Do NOT use Kubuntu 18.04 ARM none eabi compiler: arm-none-eabi-gcc (15:6.3.1+svn253039-1build1) 6.3.1 20170620 (it contains a bug with memcpy)
• Instead download and install the latest GNU Embedded Toolchain for Arm

building

• the bin folder of the GNU ARM Toolchain has to be in your PATH
• use CMake for building