Hi I managed to run micropython on the STM32F4DISCOVERY board easily, here are some notes:

• rtc_init has to be commented (for some reason haven't look at it probably I/O is used for something else)
• sw_init has to be commented otherwise debugger won't work, (there's a related hardware issue see workaround) on the discovery, the user switch is connected to PA0 which is okay to use (won't conflict with debugger) but it's used in the servo module.
• discovery has 4 user leds too (red, green, blue and orange) but those are pulled low, not high, and use PP in I/O..

Any thoughts on how to proceed now ? the comments in #19 seems to be in favor of using #ifdef's for portability ? I have started doing something like that, with a TARGET definition, but I just want to make sure that this okay, at least for now ?