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Table 3.1./etc/lilo.conf configuration parameters
| Parameter | Description |
| boot=<boot_device> | Tells the kernel the name of the device that contains the boot sector. If boot is omitted, the boot sector is read from the device that is currently mounted as root. |
| linear | Generates linear sector addresses instead of sector/head/cylinder addresses, which can be troublesome, especially when used with the compact option. See LILO's documentation for details. |
| install=<boot_sector> | Installs the specified file as the new boot sector. If install is omitted, /etc/lilo/boot.b is used as the default. |
| message=<message_file> | You can use this to display the file's text and customize the boot prompt, with a maximum message of up to 65,535 bytes. Rerun /sbin/lilo if you change this file. |
| verbose=<level> | Turns on progress reporting. Higher numbers give more verbose output, and the numbers can range from 1 to 5. This also has a -v and -q option; see LILO's documentation for details. |
| backup=<backup_file> | Copies the original boot sector to <backup_file> (which can also be a device, such as /dev/null) instead of to /etc/lilo/boot.<number>. |
| force-backup<backup_file> | Similar to backup, this option will overwrite the current backup copy, but backup is ignored if force-backup is used. |
| prompt | Requires you to type a boot prompt entry. |
| timeout=<tsecs> | Sets a time-out (in tenths of a second) for keyboard input, which is handy if you want to boot right away or wait for longer than the default five seconds. Tip: To make LILO wait indefinitely for your keystrokes, use a value of 0. |
| serial=<parameters> | Allows input from the designated serial line and the PC's keyboard to LILO. A break on the serial line mimics a Shift key press from the console. For security, password-protect all your boot images when using this option. The parameter string has the syntax <port>,<bps><parity> <bits>, as in /dev/ttyS1,8N1. The components <bps>, |
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Table 3.1. continued
| Parameter | Description |
| <parity>, and <bits> can be omitted. If one of these components is omitted, all the following components have to be omitted as well. Additionally, the comma has to be omitted if only the port number is specified. See LILO's documentation for details. | |
| ignore-table | Ignore corrupt partition tables. |
| password=<password> | Use this to password protect your boot images. |
| unsafe | This keyword is placed after a definition for a partition. The keyword tells LILO not to attempt to read the MBR or that disk's partition table entry. You can declare all the partitions in your system as a log of all existing partitions and then place the unsafe keyword entry to prevent LILO from reading it. |
After making your changes to lilo.conf, make sure to run /sbin/lilo. You should also always run /sbin/lilo after installing a new kernel.
The following sample list of options can be passed to LILO at the boot prompt to enable special features of your system or to pass options to the Linux kernel to enable a proper boot. Knowing any needed options for your system is especially handy during the Red Hat Linux installation process because you'll be asked for any special options if you choose to install LILO then.
Although you'll normally type linux or dos at the LILO: prompt, you can also try one or two of the following. For a more up-to-date list of kernel messages or options, read Paul Gortmaker's BootPrompt-HOWTO under the /usr/doc/HOWTO directory.
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LOADLIN.EXE is a program that uses the DOS MBR to boot Linux. This handy program, by Hans Lermen, will also pass along kernel options. LOADLIN.EXE is very helpful when you must boot from DOS in order to properly initialize modems or sound cards to make them work under Linux.
You need to do two things before using LOADLIN.EXE:
For example, to boot Linux, type the following from the DOS command line:
loadlin c:\vmlinuz root=/dev/hda3 ro
Make sure that you insert your root partition in the command line. The ro is for read-only. When you are first booting a Linux partition, it should be mounted as read-only or data loss could occur.
If you have a UMSDOS filesystem, you can type
loadlin c:\vmlinuz root=/dev/hda1 rw
The rw is for read/write. It is safe to start a UMSDOS filesystem this way. Again, make sure that you substitute your own partition in. LOADLIN.EXE accepts a number of options. See its documentation in the LOADLIN.TGZ file under the Dosutils directory on the book's CD-ROM.
LILO can be uninstalled using the lilo -u command, or it can be disabled by making another partition active using fdisk under either Linux or MS-DOS.
If LILO has been installed as the MBR, you can restore the original MBR by booting under MS-DOS and using the commands SYS c: or FDISK /MBR.
This chapter covers the basics of configuring, installing, and using LILO, and introduces you to the LOADLIN.EXE boot utility. Hopefully, you've seen that using LILO can give you additional flexibility in the number of operating systems installed on your PC and that Linux can be used along with these other systems. Don't forget to read LILO's documentation, as you'll not only learn about how operating systems boot from your hard drive, but also how you can customize the Linux boot prompt.
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