If I'm running embedded with no OS, I'm in a very specific environment. My code is going to be tied to my specific hardware, including almost certainly the specific CPU chip. (In this situation, it's usual to have a "CPU" chip that includes several peripherals on-chip, to reduce parts cost. Code is not portable to a CPU with different peripherals, even if it's from the same family.) So, if I can't reuse the code anyway, do I care that I can't reuse the one line that is the "main" function definition?

If I'm running embedded with no OS, what should happen if the program terminates by exiting main? Where is there to go?