GCC 5.2.1 arm-eabi for OS X El Capitan
This is GCC 5.2.1 for arm-eabi from GCC ARM Launchpad, tested on
the Cortex-M3 as found on the Arduino Due and the Cortex-M4 as
found on the STMicroelectronics STM32F4 Discovery and STM32F429I
Discovery boards.