Linux Intro Wiki | Main / InstallingLinuxIntoAVirtualMachineUsingASerialConnection

Introduction

Based on user experience, this guide will describe the steps to installing Debian 6.0.4 into a virtual machine, in the hope that it can help new users get started with Linux. The install was done on a Windows XP Home machine, but the steps should be similar on other Windows versions. The Linux Terms Defined to Get You Started section has some background to help with understanding the concepts of virtual machines and serial ports. The Linux machine will run inside a virtual machine, and be accessed through a virtual serial port with a terminal emulator program running on the host machine.

The Virtual Machine

Although a virtual machine may not be desirable for regular everyday use since it will perform slower than a dedicated machine, using it to try Linux has some advantages. It does not make any changes to the partitions of the host machine's hard disk. If the machine is not working as expected and you want to begin again, all that is needed is to remove the virtual machine and recreate it.

Without screen reading software installed, it is not possible for someone who is blind to easily read what is on the computer screen. Though sometimes more successful than others, optical character recognition (OCR) can help to get information from a virtual machine. Recent versions of JAWS for Windows and NVDA have the ability to do OCR. Though not perfect just as with printed material, this method can help to access text that is otherwise inaccessible. Using OCR on the virtual machine window can read the text that is on the screen of the virtual machine. This may help you to read a welcome or error message, for instance. It is not useful for cursor navigation, however, because it is generally not possible to tell from the screen text where the cursor is located.

The following steps can be used with NVDA to do OCR on the virtual machine area, provided that the OCR plug-in has been loaded.

Focus on the virtual machine window.
Press modifier+num pad 4 to move to the system menu bar object.
Press modifier + num pad 6 twice to move past the tool bar to the "m unknown" object.
Press modifier + r to do OCR. Review cursor commands can then be used to read the recognized text, such as modifier plus num pad plus to read all of the text starting from the review cursor location.

Getting the Parts

This section contains a description of the different programs and files that were used to get the system working. The documentation for each program should be referred to for detailed setup instructions. Notes on specific settings or procedures useful for this task will be given where applicable. Websites where each program can be downloaded will be provided. Some of the programs are also available on www.cucat.org, though newer versions may be available from the program sspecific websites.

VMWare Player

Website: http://www.vmware.com/
VMWare Player is also available from the vmstuff area of the Linux Admin Student Resources. This guide is based on Version 3.1.4, but other versions should also work. If the user interface is changed in future versions, the required steps may not work exactly as described.

The ISO Image

an ISO file can be used to create a CD, and contains all files and folders that are on the disk. It can also contain boot information used when a computer boots from the disk. An ISO file can be written to a CD using CD writing software. A virtual machine can be configured to use an ISO file for the content of the virtual machine's optical drive. Pointing the virtual machine's optical drive at an ISO file eliminates the need of writing the ISO file to a physical media.

There are several CDs that can be used to start the Debian installation, with larger CDs containing more of the Debian system. For this guide, the largest netinst version was used. This contains the base system, and other software is downloaded over the internet as needed during the install. The Debian website has information on the various options for downloading Debian, an installation guide, FAQ and other documentation. Save the ISO file to a location on the computer. The ISO file will be used in the Creating the Virtual Machine section later in this guide.

7-zip

Website: http://www.7-zip.org/
The 32-bit version is also available from the extras section of the Student Resources section of www.cucat.org. There are different versions for 32-bit and 64-bit operating systems.

Though not necessary, you may wish to explore the files and folders in the ISO file. One utility which can do this is 7-zip. An easy method is to focus on the .iso file in a folder window, and choose 7-zip > Open Archive from the context menu. This opens 7-zip and allows you to explore the contents of the ISO file. A text editor can be set up in the options. This allows you to open the selected file in it by pressing f4.

com0com

Website: http://com0com.sourceforge.net/
Also available from the utils section of the Linux Admin Student Resources.

This utility creates a virtual serial port pair that is used to connect from a terminal emulator program on the host to the serial port of the virtual machine. One side of the pair is used by the terminal emulator on the host, and the other side is used by the virtual machine. When installed, the serial ports are named CNCA0 and CNCB0. However, these ports are not listed byTeraTerm and VMWare Player. Renaming these ports to COM<number>, such as COM5 instead of CNCA0 and COM6 instead of CNCB0 will cause them to appear inTeraTerm and VMWare Player. See the readme for instructions on renaming the ports. In this guide, COM5 will be used for the TeraTerm end of the connection, and COM6 will be used for the virtual machine end.

TeraTerm

Website: http://en.sourceforge.jp/projects/ttssh2/
Also available from the Extras/Teraterm pro section of the Student Resources on www.cucat.org. Note that there is a JAWS script available from cucat.org that will cause text sent to the terminal to be read automatically. NVDA also works well withTeraTerm.

TeraTerm is a terminal emulator program that can be used to connect to other machines over a network or by using a serial port. For now, the best source of information for installingTeraTerm is in the CAVI Linux virtual machine audio quickstart. There is also some additional setup information in the TeraTerm survival guide document in the General Instructions/networking section of the Student Resources on www.cucat.org.

Testing the Virtual Serial Port

To test the virtual serial port, you can open twoTeraTerm windows. Connect to COM5 in the first and COM6 in the second. Text that is typed in one window should appear in the other. Close bothTeraTerm windows when finished.

Creating the Virtual Machine

Use the New Virtual Machine Wizard in VMWare Player to create a new virtual machine. Following are some choices that were used during the install. As this was a new user experience, it is possible that the choices used may not have been the absolute best, but they did result in a working machine. For choices not mentioned in this section, the default settings can be used, or changed if desired.

To open the New Virtual Machine Wizard, choose the "Create a New Virtual Machine..." option from the file menu or press ctrl+n.

Install from: I will install the operating system later. Press next.
Guest operating system: Linux.
Version: Other Linux 2.6 kernel. Press Next.
Name and location: set as desired. Press Next.
Maximum Disk Size: set as desired. Refer to Debian Installation Guide for requirements. Press Next.
The next screen is a summary of the machine configuration. Press the "Customize Hardware..." button.
- Memory can be adjusted as desired.
- New CD/DVD (IDE)
  - Ensure Connect at power on is checked, which should be the default.
  - Connection: Use ISO image file. The browse button can be used to browse to the ISO file that was previously downloaded.
- Printer: if not removed, it uses the first serial port on the machine. An added serial port will use the second serial port on the virtual machine. If removed before the serial port is added (in the next step), the added serial port will use the first serial port on the machine.
- add a serial port. Press the Add... button.
  - Choose serial port from the list. Press Next.
  - Serial Port: Use physical serial port on the host. Press Next.
  - Physical serial port: COM6. Press Finish.
- Press OK. You are returned to the summary screen.
Press Finish. The machine is created.

Starting the Install

Before starting the machine, openTeraTerm and connect to the COM5 serial port. For best results, theTeraTerm window should be open before the virtual machine attempts to use the serial port.

The next step is to play the machine. Since there is no operating system on the hard disk, the machine will boot from the CD drive. The CD drive of the virtual machine points to the downloaded ISO file, which will cause the machine to use the contents of that file as the media in the CD drive. Once the machine is started, the window title should begin with the name of the machine.

At this point, it is necessary to interact with the machine. When focus is in the virtual machine window, press ctrl+g to send input to the virtual machine. Press the escape key once. This causes a boot prompt to appear.

If the printer was removed when setting up the virtual machine, type the following line:
install console=ttyS0,9600n8

This directs the machine to use the first serial port for input and output. Otherwise, replace ttyS0 with ttyS1, which causes the second serial port to be used. Recall that if the printer is installed, it uses the first serial port, making it unavailable to use with a terminal, so the second serial port of the virtual machine is used for communication with the host in this case. Other boot parameters can also be given at the boot prompt.

Press ctrl+alt to direct input back to the host machine.

TheTeraTerm window should now contain the first screen of the installer output. Refer to the Debian installation guide for instructions on the install.

Once the install has finished, the virtual machine will reboot, and output will continue to be displayed inTeraTerm. You can now log in and use the system. If desired, the CD drive can be set to point to a physical drive or disconnected through the virtual machine settings.

Running the Machine

When you wish to use the virtual machine, it is important to startTeraTerm and connect to COM5 before playing the machine. Once the machine is shut down, theTeraTerm connection can be disconnected and the window can be closed.