You'll need to install an ARM toolchain, for instance from [gcc ARM embedded](https://launchpad.net/gcc-arm-embedded) website, or using your favourite package manager. After installing, you should be able to run `arm-none-eabi-gcc -v` in the command prompt and get sensible output. This toolchain is used instead of `avr-gcc`, which is only for AVR chips. Naturally you'll also need the usual development tools (e.g. `make`), just as in the AVR setting.
You'll need to install an ARM toolchain, for instance from [gcc ARM embedded](https://launchpad.net/gcc-arm-embedded) website, or using your favourite package manager. After installing, you should be able to run `arm-none-eabi-gcc -v` in the command prompt and get sensible output. This toolchain is used instead of `avr-gcc`, which is only for AVR chips. Naturally you'll also need the usual development tools (e.g. `make`), just as in the AVR setting.