In addition to the options listed here, the kernel options append, read-only, read-write, root, and vga (described later in Section 4.2.1.3) also can be set as global options.

backup=backup-file

Copy the original boot sector to backup-file instead of to /boot/boot.nnnn, where nnnn is a number that depends on the disk device type.

boot=boot-device

Set the name of the device that contains the boot sector. boot defaults to the device currently mounted as root, such as /dev/hda2. Specifying a device such as /dev/hda (without a number) indicates that LILO should be installed in the master boot record; the alternative is to set it up on a particular partition such as /dev/hda2.

change-rules

Begin a section that redefines partition types at boot time for hiding and unhiding partitions. See the LILO User's Guide, which comes with the LILO distribution, for detailed information on using this option and creating a new rule set.

compact

Merge read requests for adjacent disk sectors to speed up booting. Use of compact is particularly recommended when booting from a floppy disk. Use of compact may conflict with linear.

default=name

Use the image name as the default boot image. If default is omitted, the first image specified in the configuration file is used.

delay=tsecs

Specify, in tenths of a second, how long the boot loader should wait before booting the default image. If serial is set, delay is set to a minimum of 20. The default is not to wait. See Section 4.7 at the end of this chapter for ways to get the boot prompt if no delay is set.

disk=device-name

Define parameters for the disk specified by device-name if LILO can't figure them out. Normally, LILO can determine the disk parameters itself and this option isn't needed. When disk is specified, it is followed by one or more parameter lines, such as:

disk=/dev/sda
  bios=0x80      # First disk is usually 0x80, second is usually 0x81
  sectors=...
  heads=...

Note that this option is not the same as the disk geometry parameters you can specify with the hd boot command-line option. With disk, the information is given to LILO; with hd, it is passed to the kernel. Note also that if either heads or sectors is specified, they must both be specified. The parameters that can be specified with disk are listed briefly here; they are described in detail in the LILO User's Guide.

bios=bios-device-code

The number the BIOS uses to refer to the device. See the previous example.

cylinders=cylinders

The number of cylinders on the disk.

heads=heads

The number of heads on the disk.

inaccessible

Tell LILO that the BIOS can't read the disk; used to prevent the system from becoming unbootable if LILO thinks the BIOS can read it. If this parameter is specified, it must be the only parameter.

partition=partition-device

Start a new section for a partition. The section contains one variable, start=partition-offset, which specifies the zero-based number of the first sector of the partition:

partition=/dev/sda1
  start=2048

sectors=sectors

The number of sectors per track.

disktab=disktab-file

This option has been superseded by the disk= option.

fix-table

If set, allow lilo to adjust 3D addresses (addresses specified as sector/head/cylinder) in partition tables. This is sometimes necessary if a partition isn't track-aligned and another operating system such as MS-DOS is on the same disk. See the lilo.conf manpage for details.

force-backup=backup-file

Like backup, but overwrite an old backup copy if one exists.

ignore-table

Tell lilo to ignore corrupt partition tables.

install=boot-sector

Install the specified file as the new boot sector. If install is omitted, the boot sector defaults to /boot/boot.b.

lba32

Generate 32-bit Logical Block Addresses instead of sector/head/cylinder addresses, allowing booting from any partition on hard disks greater than 8.4 GB (i.e., remove the 1024-cylinder limit). Requires BIOS support for the EDD packet call interface[4] and at least LILO Version 21-4.

[4]If your BIOS is dated after 1998, it should include EDD packet call interface support.

linear

Generate linear sector addresses, which do not depend on disk geometry, instead of 3D (sector/head/cylinder) addresses. If LILO can't determine your disk's geometry itself, you can try using linear; if that doesn't work, then you need to specify the geometry with disk=. Note, however, that linear sometimes doesn't work with floppy disks, and it may conflict with compact.

lock

Tell LILO to record the boot command line and use it as the default for future boots until it is overridden by a new boot command line. lock is useful if there are kernel options that you need to enter on the boot command line every time you boot the system.

map=map-file

Specify the location of the map file. Defaults to /boot/map.

message=message-file

Specify a file containing a message to be displayed before the boot prompt. The message can include a formfeed character (Ctrl-L) to clear the screen. The map file must be rebuilt by rerunning the lilo command if the message file is changed or moved. The maximum length of the file is 65,535 bytes.

nowarn

Disable warning messages.

optional

Specify that any image that is not available when the map is created should be omitted and not offered as an option at the boot prompt. Like the per-image option optional but applies to all images.

password=password

Specify a password that the user is prompted to enter when trying to load an image. The password is not encrypted in the configuration file, so if passwords are used, permissions should be set so that only the superuser is able to read the file. This option is like the per-image version, except that all images are password-protected and they all have the same password.

prompt

Automatically display the boot prompt without waiting for the user to press the Shift, Alt, or Scroll Lock key. Note that setting prompt without also setting timeout prevents unattended reboots.

restricted

Can be used with password to indicate that a password needs to be entered only if the user specifies parameters on the command line. Like the per-image restricted option but applies to all images.

serial=parameters

Allow the boot loader to accept input from a serial line as well as from the keyboard. Sending a break on the serial line corresponds to pressing a Shift key on the console to get the boot loader's attention. All boot images should be password-protected if serial access is insecure (e.g., if the line is connected to a modem). Setting serial automatically raises the value of delay to 20 (i.e., 2 seconds) if it is less than that. The parameter string parameters has the following syntax:

port[,bps[parity[bits]]]

For example, to initialize COM1 with the default parameters:

serial=0,2400n8

The parameters are:

port

The port number of the serial port. The default is 0, which corresponds to COM1 (/dev/ttys0). The value can be one of 0 through 3, for the four possible COM ports.

bps

The baud rate of the serial port. Possible values of bps are 110, 300, 1200, 2400, 4800, 9600, 19200, and 38400. The default is 2400 bps.

parity

The parity used on the serial line. Parity is specified as n or N for no parity, e or E for even parity, and o or O for odd parity. However, the boot loader ignores input parity and strips the 8th bit.

bits

Specify whether a character contains 7 or 8 bits. Default is 8 with no parity and 7 otherwise.

timeout=tsecs

Set a timeout (specified in tenths of a second) for keyboard input. If no key has been pressed after the specified time, the default image is booted automatically. timeout is also used to determine when to stop waiting for password input. The default timeout is infinite.

verbose=level

Turn on verbose output, where higher values of level produce more output. If -v is also specified on the lilo command line, the level is incremented by 1 for each occurrence of -v. The maximum verbosity level is 5.

The following options are specified in the image section for a particular boot image. The image can be a Linux kernel or a non-Linux operating system.

The following kernel options can be specified in /etc/lilo.conf as well as on the boot command line:

append=string

Append the options specified in string to the parameter line passed to the kernel. This typically is used to specify certain hardware parameters. For example, while BIOSes on newer systems can recognize more than 64 MB of memory, BIOSes on older systems are limited to 64 MB. If you are running Linux on such a system, you can use append:

append="mem=128M"

initrd=filename

Specify the file to load into /dev/initrd when booting with a RAM disk. See also the options load_ramdisk (in Section 4.7), and prompt_ramdisk, ramdisk_size, and ramdisk_start in this section.

literal=string

Like append, but replace all other kernel boot options.

noinitrd

Preserve the contents of /dev/initrd so they can be read once after the kernel is booted.

prompt_ramdisk=n

Specify whether the kernel should prompt you to insert the floppy disk that contains the RAM disk image, for use during Linux installation. Values of n are:

0

Don't prompt. Usually used for an installation in which the kernel and the RAM disk image both fit on one floppy.

1

Prompt. This is the default.

ramdisk=size

Obsolete; use only with kernels older than Version 1.3.48. For newer kernels, see the option load_ramdisk in Section 4.7, as well as prompt_ramdisk, ramdisk_size, and ramdisk_start in this section.

ramdisk_size=n

Specify the amount of memory, in kilobytes, to be allocated for the RAM disk. The default is 4096, which allocates 4 megabytes.

ramdisk_start=offset

Used for a Linux installation in which both the kernel and the RAM disk image are on the same floppy. offset indicates the offset on the floppy where the RAM disk image begins; it is specified in kilobytes.

read-only

Specify that the root filesystem should be mounted read-only for filesystem checking (fsck), after which it is typically remounted read/write.

read-write

Specify that the root filesystem should be mounted read/write.

root=root-device

Specify the device that should be mounted as root. If the special name current is used as the value, the root device is set to the device on which the root filesystem currently is mounted. Defaults to the root-device setting contained in the kernel image.

vga=mode

Specify the VGA text mode that should be selected when booting. The mode defaults to the VGA mode setting in the kernel image. The values are case-insensitive. They are:

ask

Prompt the user for the text mode. Pressing Enter in response to the prompt displays a list of the available modes.

extended (or ext)

Select 80x50 text mode.

normal

Select normal 80x25 text mode.

number

Use the text mode that corresponds to number. A list of available modes for your video card can be obtained by booting with vga=ask and pressing Enter.