Debian Installer with Serial Console Support

Printer-friendly versionPDF version

Serial Console?

Our headless systems don't have VGA output as well as keyboard and mouse connectors. They rely on the serial port for software installation. Unfortunately, the current Debian Linux CD-ROM installers don't seem to support serial console out-of-the box.

Most of our systems also have serial console redirection support in the BIOS. It is a convenient way to check a pfSense firewall in a datacenter with just a serial-USB adapter and hyperterminal.

This knowledge-based paper describes how we made some modifications to the "standard" Debian Lenny CD-ROM installers to allow us to install Linux from a serial console.

CD Customization

We got both of the current Debian CD-ROM installers: Lenny 5.04 to be specific.

  1. Debian Lenny Business Card CD-ROM.
  2. Debian Lenny Full CD Disck 1. I actually used jigdo-lite to grab the CD rather than download it directly.

Following are the modifications we made to the Debian CD-ROM installers:

isolinux/isolinux.cfg

The timeout was changed from zero (waiting forever for a user input) to 50 (5 seconds timeout for a default install method).

# D-I config version 1.0
include menu.cfg
default vesamenu.c32
prompt 0
timeout 50

isolinux/txt.cfg

The default install method was changed from "install" to "installserial". By default, it will boot to the first serial console at the 9600 bps speed with eight bit data and even parity.

default installserial
label installserial

menu label ^Installseria
menu default
kernel /install.386/vmlinuz
append vga=normal console=ttyS0,9600n8 initrd=/install.386/initrd.gz -- quiet

isolinux/adtxt.cfg

The "standard" Debian install method is added as an option under this file.

label expert
menu label ^Expert install
kernel /install.386/vmlinuz
append priority=low vga=normal initrd=/install.386/initrd.gz --include rqtxt.cfg
label auto
menu label ^Automated install
kernel /install.386/vmlinuz
append auto=true priority=critical vga=normal initrd=/install.386/initrd.gz --quiet
label install
menu label ^Install
menu default
kernel /install.386/vmlinuz
append vga=normal initrd=/install.386/initrd.gz -- quiet

How well does it work?

Since we are using the USB external CD/DVD drive for installation of Debian Gnu/Linux, the Full CD has timeout and could not complete the installation. It keeps asking for the CD in the middle of the Base installtion. With an EIDE internal CD-ROM, it installed fine.

Since the Business Card version uses the Internet, we were able to complete the installation in one shot.

Download

The Debian Lenny CD-ROM installers are available for download from the following locations.

  1. Debian Lenny Business Card with Serial Console CD-ROM.
  2. Debian Lenny Full CD with Serial Console Disck 1.
Knowledge Base: