mknod - build special file
/etc/mknod name [ c ] [ b ] major minor
Mknod makes a special file. The first argument is the name of the
entry. The second is b if the special file is block-type (disks, tape)
or c if it is character-type (other devices). The last two arguments
are numbers specifying the major device type and the minor device (e.g.
unit, drive, or line number).
The assignment of major device numbers is specific to each system.
They have to be dug out of the system source file conf.c.