I had switched back to my Alix machine after my last posting and left the case of my Jetway machine open to be ready for further testing. After almost two weeks without further activity in this thread I've decided to live without a working serial console. Yesterday I switched back to the Jetway box to get more experience about stability based on a long term usage when I suddenly saw new responses.
Next step would be to load a plain FreeBSD install on there and see if you can get the serial console to work. If it doesn't work on a stock FreeBSD install either, you can then file a PR with FreeBSD to see if it can be fixed upstream.
Just to get the above information right: Would it be helpful to install FreeBSD on the Jetway machine or did you more address the D2500CC board? Which version of FreeBDS should be used - I assume 9.0, although pfSense 2.1 is based on 8.3. Or do you even think of 8.1? To minimize testing efforts I would like to leave my current 2.0.1_nanobsd_vga install on a 8GB SSD untouched and test FreeBSD on a regular harddisk. Unfortunately, I currently don't have one left, but could get one organized within some days. I've no experience with stock FreeBSD so far but a quick check of its homepage revealed that installation should not differ that much from a full pfSense install. Could you please explain in more detail what you mean with
… you can then file a PR with FreeBSD to see if it can be fixed upstream
May be it' worth to mention that the serial console works without problems with Linux on this board: Grub2 can be remotely controlled over the serial line, kernel messages are being emitted to it and finally init starts agetty for serial logins.
Peter