mknod —
make device special file
  
    | mknod | [ -rR] [-Ffmt] [-ggid] [-mmode] [-uuid] name
      [c|b]
      [driver | major]
      minor | 
  
    | mknod | [ -rR] [-Ffmt] [-ggid] [-mmode] [-uuid] name
      [c|b]
      major unit subunit | 
  
    | mknod | [ -rR] [-ggid] [-mmode] [-uuid] name
      [c|b]
      number | 
  
    | mknod | [ -rR] [-ggid] [-mmode] [-uuid] namep | 
The mknod command creates device special files, or
  fifos. Normally the shell script /dev/MAKEDEV is used
  to create special files for commonly known devices; it executes
  mknod with the appropriate arguments and can make all
  the files required for the device.
To make nodes manually, the arguments are:
  - -r
- Replace an existing file if its type is incorrect.
- -R
- Replace an existing file if its type is incorrect. Correct the mode, user
      and group.
- -Ffmt
- Create device nodes that may be used by an operating system which uses
      device numbers packed in a different format than
      NetBSD uses. This is necessary when
      NetBSD is used as an NFS server for netbooted
      computers running other operating systems.
    The following values for the fmt are
        recognized: native, 386bsd,
        4bsd, bsdos,
        freebsd, hpux,
        isc, linux,
        netbsd, osf1, sco,
        solaris, sunos,
        svr3, svr4, and
        ultrix. 
- -ggid
- Specify the group for the device node. The gid
      operand may be a numeric group ID or a group name. If a group name is also
      a numeric group ID, the operand is used as a group name. Precede a numeric
      group ID with a #to stop it being treated as a
      name.
- -mmode
- Specify the mode for the device node. The mode may be absolute or
      symbolic, see chmod(1).
- -uuid
- Specify the user for the device node. The uid
      operand may be a numeric user ID or a user name. If a user name is also a
      numeric user ID, the operand is used as a user name. Precede a numeric
      user ID with a #to stop it being treated as a
      name.
- name
- Device name, for example “sd” for a SCSI disk on an HP300 or
      a “pty” for pseudo-devices.
- b|- c|- p
- Type of device. If the device is a block type device such as a tape or
      disk drive which needs both cooked and raw special files, the type is
      b. All other devices are character type devices,
      such as terminal and pseudo devices, and are typec. Specifyingpcreates
      fifo files.
- driver | major
- The major device number is an integer number which tells the kernel which
      device driver entry point to use. If the device driver is configured into
      the current kernel it may be specified by driver name or major number. To
      find out which major device number to use for a particular device, use
      mknod-l, check the file
      /dev/MAKEDEV to see if the device is known, or
      check the system dependent device configuration file:“/usr/src/sys/arch/<arch>/<arch>/conf.c” (e.g.
        /usr/src/sys/arch/vax/vax/conf.c). 
- minor
- The minor device number tells the kernel which one of several similar
      devices the node corresponds to; for example, it may be a specific serial
      port or pty.
- unit and
    subunit
- The unit and subunit numbers select a subset of a device; for example, the
      unit may specify a particular SCSI disk, and the subunit a partition on
      that disk. (Currently this form of specification is only supported by the
      bsdos format, for compatibility with the
      BSD/OS mknod).
- number
- A single opaque device number. Useful for netbooted computers which
      require device numbers packed in a format that isn't supported by
      -F.
- -l
- List the device drivers configured into the current kernel together with
      their block and character major numbers.
Amknod command appeared in
  Version 4 AT&T UNIX. The
  -F option appeared in NetBSD
  1.4. The -g, -l,
  -m, -r,
  -R, and -u options, and the
  ability to specify a driver by name appeared in NetBSD
  2.0.