Using a named pipe to simulate a serial port on a VMware virtual machine (linux host and client)
- by Dave M
Trying to write a python program to create a simulated data stream and feed it, through a named pipe, to a VMware virtual machine. The host is running Ubuntu 11.10 and VMware player 5.0.0. The Vm is running Ubuntu netbook 10.04. I am able to get the pipe working on the local machine but I am not able to get the pipe to pass data through the virtual serial port to the programs running on the virtual machine.
  #!/usr/bin/python
  import os
  #
  # Create a named pipe that will be used as the serial port on a VMware virtual machine
  SerialPipe = '/tmp/gpsd2NMEA'
  try:
    os.unlink(SerialPipe)
  except:
    pass
  os.mkfifo(SerialPipe)  
  #
  # Open the named pipe
  NMEApipe = os.open(SerialPipe, os.O_RDWR|os.O_NONBLOCK)
  #
  # Write a string to the named pipe
  NMEAtime = "235959"
  os.write(NMEApipe, str( '%s\n' % NMEAtime ))
Test to see if the python program is working on the host machine 
(displays 235959 if data is passing through the pipe)
  $ cat /tmp/gpsd2NMEA
  235959
Serial port as defined in the VMware .vmx file:
  serial0.present = "TRUE"
  serial0.startConnected = "TRUE"
  serial0.fileType = "pipe"
  serial0.fileName = "/tmp/gpsd2NMEA"
  serial0.pipe.endPoint = "client"
  serial0.autodetect = "FALSE"
  serial0.tryNoRxLoss = "TRUE"
  serial0.yieldOnMsrRead = "TRUE"
Test to see if the serial port in the VM is receiving data
  $ cat /dev/ttyS0
  or
  $ minicom -D /dev/ttyS0
  or
  $ stty -F
  /dev/ttyS0 cs8 -parenb -cstopb 115200
  $ echo < /dev/ttyS0
None of these display any data from the python program.