1 Build environment
  The gcc compiler is used by default (see Makefile).
  libfuse-dev - Filesystem in Userspace (development) must be installed
  at the build system.
  glibc must support pthreads.

2 Target
  The linux kernel at the target system must support FUSE (FUSE_FS=y) and
  libpthread and libfuse must be installed in the root filesystem.

3 Build
   The default target in the Makefile builds the Network Virtual Terminal.
   Output name is: ttynvt.

4 Run
  The application (ttynvt) installs a virtual serial device in the /dev
  directory (by default: /dev/ttyNVT0).
  The major/minor number of the device, the address (name/IP) and the port
  number of the serial server must be specified when the application
  is started (command-line options).

  E.g.
  ./ttynvt -M 199 -m 6 -n ttyNVT0 -p 5020 -s 169.254.1.1

  To get a list of all command-line options:
  ./ttynvt --help

5. Test
   The serial server: ser2net (http://ser2net.sourceforge.net/) might be used
   to test the virtual serial server on the target.
   Install the server (ser2net) and add folling line to the configuration
   file (/etc/ser2net.conf):
   5020:telnet:0:/dev/ttyS0:115200 remctl NONE 1STOPBIT 8DATABITS RTSCTS HANGUP_WHEN_DONE
   At the server, plug-in a loopback connector in the serial port (ttyS0).
   At the target, open the virtual serial port, with a termial program,
   e.g minicom:
   minicom -D /dev/ttyNVT0

6 Diagnostic
  Add the command-line option '-l' to enable logging of diagnostic information.
  Wireshark is also very useful when debugging the interface between the client
  and the server.

Ref: RFC-854  - Telnet Protocol Specification
     RFC-2217 - Telnet Com Port Control Option