Adding Device Nodes to the /dev Directory (if Necessary)
If you are using FreeBSD 5.0, this section does not apply. FreeBSD 5.0 uses the DEVFS filesystem interface to the system's devices and builds the /dev virtual filesystem dynamically at boot time.
Many devices will be missing an entry in /dev when you add them to the kernel configuration; devices in /dev include only those devices that have either been part of the base system or added afterward explicitly. You have to create device nodes for new devices that you add to the kernel—they're not generated automatically.
Fortunately, this is done fairly simply. All you have to do, after you reboot with the new kernel, is go into the /dev directory, and run the MAKEDEV shell script:
# ./MAKEDEV ...