just pulled the latest commits (5-24), updated and compiled for 600D. Replaced 5-18 autoexec.bin with newly compiled bin and camera will not start. LED continually blinks. Removed battery, replaced .bin with original, camera starts up fine.
Did a make clean, re-compiled for 600D, and tried new .bin file in camera ... same thing, LED blinks continually and camera will not turn on.
Went back to 5-18 .bin file ... back in working order.