This example demonstrates how to build a bare-metal application using
different ARM toolchains. It is designed for the stm32f4discovery
evaluation kit (based on stm32f407vg MCU) and simply flashes the blue
LED on the board.

The following toolchains are supported:

  * GNU Arm Embedded Toolchain
  * IAR Embedded Workbench
  * KEIL Microcontroller Development Kit