macOS
All the tools can be install using Homebrew:
$ # GDB
$ brew install armmbed/formulae/arm-none-eabi-gcc
$ # OpenOCD
$ brew install openocd
$ # QEMU
$ brew install qemu
NOTE If OpenOCD crashes you may need to install the latest version using:
$ brew install --HEAD openocd
That's all! Go to the next section.