The short answer is:
However, that sketch is automatically started at startup by the Linux yocto provided by Intel.
There are some extra ideas for working with several sketches at command line at Re: I dont want to upload arduino sketches, i want to open the sketch file directory and run it from ssh
Please elaborate a little bit more about what you want to do.
Thanks for sending that link, I hadn't seen that thread before, but it seems I want to do the same as the OP there.
I have it working now (using that method), as in I can start and stop sketches, but do you know if there is any way I can continue using the terminal whilst the sketch is running? The only way using this method is to ^C, which of course stops the sketch running.
Also, what are these 'zombie processes' you mentioned?
EDIT: Actually I have worked out how to do it - by running the sketch using
./sketch.elf /dev/ttyGS0 &
thus running the process in the background.
Thanks very much - this will help me a lot in future projects.