This is (almost) the bare minimum to get a blinking LED on a STM32F3Discovery board.
Works with the ARM GCC toolchain (arm-none-eabi-gcc (Linaro GCC 4.7-2013.01))
Three Step Guide:
cd blink make build make program
The Makefile is only used as a grouping mechanism for the different commands. It doesn't contain any dependency logic for the build.
Most headers are copied from CMSIS and STM's libs, startup is from xpcc (and sligthly modified).
Additional Resources: