4.1. Configure the LILO boot loader

LILO is the Linux Boot Loader used on Intel machines. Other boot loaders for Intel machines exist, common alternatives are GRUB and SYSLINUX. Equivalents to LILO exist for other processor architectures, their names are usually some play upon "LILO".

LILO is documented in the lilo(8) and lilo.conf(5) manual pages; the LILO Generic boot loader for Linux … User's Guide found in the file /usr/share/doc/lilo…/doc/User_Guide.ps; and the LILO mini-HOWTO.

The LILO configuration is kept in the file /etc/lilo.conf. The first part of the file applies to all images. The following parts are image descriptions for each kernel.

Set LILO to use the serial port. The syntax of the serial line parameters follows that used by the kernel.

Figure 4-1. Syntax of LILO serial command, in EBNF

serial=<serial_port>[,<speed>[<parity>[<data>]]]

Where the variables are the same as used by the kernel (shown in Figure 2-7) and:

Figure 4-2. LILO serial EBNF variables

<serial_port> ::= 0 | 1| … | 3

Our examples use /dev/ttyS0, which LILO knows as port 0.

Figure 4-3. LILO boot loader sample configuration

serial=0,9600n8
timeout=100
restricted
password=PASSWORD

The parameters restricted and password are used to avoid someone dialing in, booting the machine, and stepping around the Linux access permissions by typing:

Example 4-1. Using kernel parameters to avoid access permissions

LILO: linux init=/sbin/sash

The password should be good, as it can be used to gain root access. The LILO password is stored in plain text in the configuration file, so it should never be the same as any other password. The permissions on the configuration file should be set so that only root can read /etc/lilo.conf.

bash# chmod u=rw,go= /etc/lilo.conf

LILO has an option to display a boot message. This does not work with serial consoles. Remove any lines like:

message=/boot/message

LILO is now configured to use the serial console. The kernels booted from LILO are yet to be configured to use the serial console.