wfaulk,
Thanks for the input. I have two com ports, and ethernet. But I really want it to work like the empeg: boot up and go to my application. If I quit my app then drop to a normal shell where I can do all of the normal shell stuff. Then allow me to type "appname" and run my app again.
I realize that this is not quite the normal linux way to do things, but my application is strictly an embedded device run from a battery in a small black box out in the middle of a field. It has no particular secrets on it and does not even have access to the serial or ethernet ports from the outside of the box. In fact the main reason I chose the SBC w/linux was to take advantage of the multi-thread kernel, gcc compiler, and built in support for Compact Flash Cards and a real time clock.
I may eventually convert it to a daemon, but then it will require a network to interract with. Where there is little or no interraction required in normal use, it's still nice to be able to just hook up a serial port and work with it. The second serial port sounds like a great plan, but then I need two serial ports or an A/B switch to interract with my app and the linux command line.
--steve