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C.2. Configure the BIOS to use the serial port

Many servers allow the BIOS to be configured from the serial port, especially on systems designed for rack mounting. At the moment few machines designed to be used as desktop systems allow the BIOS to be accessed from the serial port.

Refer to your vendor's documentation to set the BIOS to use the serial port. Some vendors call this feature "console redirection". Unfortunately, the meaning of this term varies by vendor. Some vendors use it to mean the redirection of the VGA output and keyboard to a remote PC using a proprietary serial protocol. This feature can only be used in conjunction with the Linux serial console if the BIOS can be instructed to disable the serial redirection after booting.

As an example of the confusion, Dell uses "console redirection" when describing the Dell 2400 and the Dell 2450. The Dell 2450 BIOS can be configured from the serial port. The Dell 2400's "console redirection" is additional hardware that remotely replicates the computer's VGA monitor and keyboard.

An example of a BIOS configuration is given in Figure C-1.

Figure C-1. Configuring BIOS to use serial link

BIOS setup console redirection

Enter BIOS setup during boot when
  Keyboard:     [Ctrl+Alt+Esc pressed]
  Serial port:  ["HAL" is typed]

Serial port
  Port:         [COM1]
  Speed         [9600] bps
  Data:         [8] bits
  Parity:       [None]
  Stop:         [1] bits
  Handshaking:  [Full CTS/RTS handshaking]
  Terminal:     [Dumb]

Many BIOSs will enter their configuration dialogs if a particular terminal key is pressed during the BIOS boot. This can be a problem if the modem link is noisy.

For normal operation, set the boot order to attempt to boot from the hard disk first.

Figure C-2. Configuring BIOS to boot from hard disk

BIOS setup boot order

First:  [Hard disk]
Second: [CD-ROM]
Third:  [Floppy disk]