My main point with that statement is that it seems all their firewall devices are just x86 PC hardware so this is just the tip of the iceberg, you can get any other of their appliances and it will most likely be a x86 PC with a BIOS that is booting from a DOM. Just check the firmware upgrade procedure for the appliance and if it tells you to make a flash drive and boot from it to install it over serial console, it's most likely similar to this device and you can just boot whatever you want