#Various Toolchains and Tools for Embedded Development
Get Homebrew and check the dependencies.
Then add this repo by
brew tap thomaseichinger/embedded
brew install arm-2008q3-binutils
brew install arm-2008q3-gcc
brew install arm-none-eabi-binutils
brew install arm-none-eabi-linaro-gcc
brew install arm-none-eabi-linaro-gdb
brew install avr-binutils
brew install avr-gcc