Sat Jul 11 15:08:52 EDT 2015

Semaphores on Cortex M

I'm currenly using an approach of:
- no RTOS
- main event loop, polling state machines
- ISRs interacting with FIFOs to bridge to main loop

It's tricky to get the FIFOs right.

Currently I rely on atomic read/write, but in some cases it would help
to have real semaphores.  How to implement on Cortex M?