lilo.conf - configuration file for lilo
This file, by default /etc/lilo.conf
, is read by the boot loader
installer 'lilo' (see lilo(8)
It might look as follows:
# global options:
menu-title=" John's Computer "
### bootable kernel images ###
### other operating systems ###
boot-as=0x80 # must be C:
boot-as=0x80 # must be C:
This configuration file specifies that lilo uses the Master Boot Record on
/dev/hda. (For a discussion of the various ways to use lilo, and the
interaction with other operating systems, see html/user_21-5.html inside the
When booting, the boot loader will issue its boot:
prompt and wait for
you to enter the label of the kernel (and any options) which you wish to boot.
At any time you may hit [Tab] to see a list of kernel/other labels.
Alternately, if the menu
boot loader is installed, a menu of boot
options will be presented for your selection. The title of this menu is
overridden with the menu title specification in this configuration file. If
you enter nothing, then the default kernel image, the first mentioned, (in the
example /boot/vmlinuz-2.6.29-1-i386) will be booted after a timeout of 15
seconds (150 deciseconds). There may be at least 16 images mentioned in
lilo.conf. (The exact number depends upon compilation options.)
As can be seen above, a configuration file starts with a number of global
options (the top 9 lines in the example), followed by descriptions of the
options for the various images. An option in an image description will
override a global option.
Comment lines may appear anywhere, and begin with the "#" character.
There are many possible keywords. The description below is almost literally from
html/user_21-5.html inside the old documentation (just slightly abbreviated).
- Specifies the location where a copy of any modified boot sector will be
saved in a file. 'backup=' may specify this location in one of three ways:
a directory where the default backup file 'boot.NNNN' will be created; a
file pathname template to which the '.NNNN' suffix will be added; or the
full file pathname, which must include the correct '.NNNN' suffix. All
RAID installations should use only the first two alternatives, as multiple
backups may be created. The '.NNNN' suffix is the hexadecimal
representation of the major and minor device numbers of the device or
partition. If this option is not specified, the default name of boot
sector backups is '/boot/boot.NNNN'. If a backup already exists, it will
be preserved, rather than overwritten. C.f., force-backup=
- The option is indicated as yes, no, or unknown. If
not specified, a value of "unknown" is assumed, unless
additional information is available to the boot installer. When
"no" is specified, it indicates that the BIOS is known not to
pass the current boot device code to the boot loader in the DL register.
Its only function at this point is experimental, as certain RAID
installations may benefit from knowing that the BIOS is 100% reliable. Its
use should be considered experimental.
This option may be specified on the command line with the '-Z' switch:
- Specifies use of a 640x480x16 (VGA BIOS) or 640x480x256 (VGA/VESA BIOS)
bitmap file as the background on which a boot menu is displayed. May not
be used if 'message=' is specified. Use of this option will select a
bitmap-capable boot loader, unless overridden with "install="
When a bitmap file is specified as a background screen during the boot
process, the color selection and layout of the text which overlays the
graphic image must be specified in one of two ways.
One way is the use of header information in the bitmap image (*.bmp) file:
From a text file with all the information about 'bmp-colors', 'bmp-table'
and 'bmp-timer' options together with the 'bitmap' option are stored in
the special LILO header of the bitmap image file by the lilo -E
command. Another way works without these special header information: All
the information about 'bmp-colors', 'bmp-table' and 'bmp-timer' options
together with the 'bitmap' option are stored in the configuration file.
Any use of the 'bmp-' options within the configuration file overrides the
options stored in the bitmap file header. If lilo cannot find any of the
'bmp-' options, then default values are used.
- Specifies the decimal values of the colors to be used for the menu display
on a 'bitmap=' background. The list consists of 6 entries, 3 for normal
text followed by 3 for highlighted text. The order of each triple is:
foreground color, background color, shadow color. If background color is
not specified, "transparent" is assumed. If shadow color is not
specified, then "none" is assumed. The list entries are
separated by commas, with no spaces.
- Option applies to all 'image=' and 'other=' sections. (See COMMON OPTIONS,
- Specifies the location and layout of the menu table. <x>,<y>
specify the starting x- and y-position of the upper left corner of the
table in character coordinates: x in [1..80], y in [1..30]. <ncol>
is the number of columns in the menu (1..5); and <nrow> is the
number of rows (entries) in each column. If more than one column is
specified, then <xsep> is the number of character columns between
the leftmost characters in each column: (18..40), and <spill> is the
number of entries in one column which must be filled before entries spill
into the next column. <spill> must be .le. <nrow>. If pixel
addressing is used, instead of character addressing, then any of
<x>, <y>, or <xsep> may be specified with a 'p' suffix
on the decimal value.
- Optional specification of the 'timeout=' countdown timer.
<x>,<y> specifies the character (or pixel) coordinate of the
location of the timer the same as 'bmp-table=' above; and the color triple
specifies the character color attributes the same as 'bmp-colors=' above,
with the exception that the background color must be specified. If
used to override the timer specification in a bitmap file, then the form
'bmp-timer = none' is acceptable. This will disable the timer display
- Sets the name of the device (e.g. hard disk or partition) that contains
the boot sector and where the new boot sector should be written to.
Notice: The boot-device should be the device with the currently mounted
A raid installation is initiated by specifying a RAID1 device as the boot
device; e.g., "boot=/dev/md0".
On newer systems you need an unique ID for the boot device. If the boot
sector should write to a partition you can use its UUID in the same manner
is for the root options.
If your boot device is a hard disk you need a special ID, which is supported
by udev. You find the right ID in the directory /dev/disks/by-id, i.
boot = /dev/disk/by-id/ata-SAMSUNG_SV1604N_S01FJ10X999999
- Defines boot-time changes to partition type numbers (`hiding').
- The above excerpt from a configuration file specifies that all default
change-rules are removed ("reset"), and the change-rules
for three partition types are specified. Without the reset, the
three types specified would have been added to the existing default
change-rules. Normally, the default rules are sufficient. The strings
which define the partition types are used in a change section (see
below), with the suffixes "_normal" or "_hidden"
appended. See section "Partition type change rules" of
html/user_21-5.html inside the old documentation for more details.
- Tries to merge read requests for adjacent sectors into a single read
request. This drastically reduces load time and keeps the map file
smaller. Using `compact' is especially recommended when booting using a
map file on a floppy disk.
- Uses the specified image as the default boot image. If `default' is
omitted, the image appearing first in the configuration file is used. See
also, vmdefault below.
- Specifies the number of tenths of a second the boot loader should wait
before automatically booting a locked command line, a command line
pre-stored by "lilo -R", or the default `image=' or `other='.
When `delay' is non-zero, the boot loader will wait for an interrupt for
the specified interval. If an interrupt is received, or is already
waiting, the boot: prompt will be be issued, and no automatic boot
will take place. The setting of CAPS LOCK or SCROLL LOCK, or any of the
keys ALT, CTRL, or SHIFT, when held down, are taken as interrupts.
This action is modified by specifying `prompt' (see below).
- Defines non-standard parameters for the specified disk. See section
"Disk geometry" of html/user_21-5.html inside the old
documentation for details. For versions of LILO prior to 22.5, the `bios='
parameter is quite useful for specifying how the BIOS has assigned device
codes to your disks. For example,
would say that your SCSI disk is the first BIOS disk (0x80), that your
(primary master) IDE disk is the second BIOS disk (0x81), and that your
second SCSI disk (perhaps a USB device) receives no device code, and is
therefore inaccessible at boot time.
NOTE: Use of the 'bios=' option is largely obsolete beginning with LILO
version 22.5, as the boot loader now identifies disks by 32-bit Volume-ID,
and defers BIOS device code determination until boot time.
Other options include the specification of disk geometry; e.g.,
probably only useful for floppy disks and loopback devices, because for hard
disks the lba32 disk addressing option ignores disk geometry.
Developers who have implemented a disk driver for a new block storage device
will have to indicate to LILO the maximum number of partitions on the
device. This is in addition to making all of the necessary entries for the
device in the "/dev" directory (with 'mknod'). The maximum
number of partitions must be one of 63 (like an IDE disk), 31 (uncommon),
15 (like SCSI disks -- most common value), or 7 (like one array
controller). An example specification would be:
In cases where there is no kernel partition information available, such as
on loopback devices, the 'disk=' specification may include paritition
start information; viz.,
bios=0x80 # use this BIOS code
max-partitions=7 # declare partitionable
start=63 # offset from sector 0
start=102400 # offset from sector 0
- Specifies the name of the disk parameter table. The map installer looks
for /etc/disktab if `disktab' is omitted. The use of disktabs is
- Flag second stage loader to terminate disk emulation when booting from an
El Torito Bootable CD. This option is used by the mkrescue utility
when the "--iso" switch is specified.
- This allows lilo to adjust 3D addresses in partition tables. Each
partition entry contains a 3D (cylinder/head/sector) and a linear address
of the first and the last sector of the partition. If a partition is not
track-aligned and if certain other operating systems (e.g. PC/MS-DOS) are
using the same disk, they may change the 3D address. lilo can store its
boot sector only on partitions where both address types correspond. lilo
re-adjusts incorrect 3D start addresses if `fix-table' is set.
WARNING: This does not guarantee that other operating systems may not
attempt to reset the address later. It is also possible that this change
has other, unexpected side-effects. The correct fix is to re-partition the
drive with a program that does align partitions to tracks. Also, with some
disks (e.g. some large EIDE disks with address translation enabled), under
some circumstances, it may even be unavoidable to have conflicting
partition table entries.
- Operation is identical to backup= above, except an existing backup
file is unconditionally overwritten if it exists.
- Force disk addressing which is compatible with older versions of LILO.
Geometric addressing uses cylinder/head/sector addresses, and is limited
to disk cylinders up to 1023. If inaccessible cylinders are referenced,
diagnostics will be issued at boot-install time, rather than boot-time.
With a newer BIOS, use of 'lba32' is recommended.
- tells lilo to ignore corrupt partition tables.
- Selects the user interface which will be seen at boot time. One of the
following three options may be specified: text, menu, or
bmp. The traditional LILO interface is `text'; but `menu' is now
the default, unless the configuration file contains the `bitmap='
specification. The text interface is strictly a command-line
interface as though the console were a dumb terminal. The menu
interface is a text-based screen of the boot choices, with the option to
enter additional command line parameters. And the bmp interface is
a menu presented against a graphic screen, specified as a 640x480 BitMaP
file of 16 or 256 colors. (See the 'lilo -E' switch for editing options).
(Prior to LILO version 22.3, `install=' specified the user interface as a
file in the `/boot' directory.)
- Normally any initial ramdisk (initrd) loaded with a kernel is loaded as
high in memory as possible, but never above 15Mb. This is due to a BIOS
limitation on older systems. On newer systems, this option enables using
memory above 15Mb (up to a kernel imposed limit, around 768Mb) for passing
the initrd to the kernel. The presence of this option merely indicates
that your system does not have the old BIOS limitation.
This switch (or its absence) is not passed to the kernel, and does not in
any way affect the amount of physical memory which it will use. (See the
kernel documentation for the kernel command line parameter
"mem=" for limiting the memory used by the kernel.)
- Generate 32-bit Logical Block Addresses instead of cylinder/head/sector
addresses. If the BIOS supports packet addressing, then packet calls will
be used to access the disk. This allows booting from any partition on
disks with more than 1024 cylinders. If the BIOS does not support packet
addressing, then 'lba32' addresses are translated to cylinder/head/sector
('geometric'), just as for 'linear'. All floppy disk references are
retained in C:H:S form. Use of 'lba32' is recommended on all post-1998
systems. Beginning with LILO version 22, 'lba32' is the default disk
- Generate 24-bit linear sector addresses instead of cylinder/head/sector
(geometric) addresses. Linear addresses are translated at run time to
geometric addresses, and are limited to cylinders <= 1023. When using
`linear' with large disks, /sbin/lilo may generate references to
inaccessible disk cylinders. 'lba32' avoids many of these pitfalls with
its use of packet addressing, but requires a recent BIOS (post-1998). The
'linear' option is considered obsolete, and its use is strongly
- Enables automatic recording of boot command lines as the defaults for the
following boots. This way, lilo "locks" on a choice until it is
- The per-image password option `mandatory' (see below) applies to all
- Specifies the location of the map file. If `map' is omitted, the file
/boot/map is used.
On machines with a pre-1998 BIOS, the EDD bios extensions which are required
to support "lba32" disk sector addressing may not be present. In
this case, the boot-loader will fall back automatically to
"geometric" addressing; this fall back situation, or the
specific use of "geometric" or "linear" addressing,
will require the map file to be located within the first 1024 cylinders of
the disk drive. This BIOS limitation is not present on post-1998 systems,
most of which support the newer EDD disk BIOS calls.
- Specifies the title line (up to 37 characters) for the boot menu. This
title replaces the default "LILO Boot Menu" title string. If
menu is not installed as the boot loader (see install=
option), then this line has no effect.
- The default color scheme of the boot menu may be overridden on VGA
displays using this option. (The color scheme of MDA displays is fixed.)
The general color-scheme string is of the form:
where each entry is two characters which specify a foreground color and a
background color. Only the first entry is required. The default highlight
is the reverse of the text color; and the default border and title colors
are the text color. Colors are specified using the characters
kbgcrmyw, for blac K, Blue, Green,
Cyan, Red, Magenta, Yellow, and White:
upper case for intense (fg only), lower case for dim. Legal color-scheme
strings would be
menu-scheme=Wm intense white on magenta
menu-scheme=wr:bw:wr:Yr the LILO default
menu-scheme=Yk:kw bright yellow on black
If menu is not installed as the boot loader, then this line has no
- specifies a file containing a message that is displayed before the boot
prompt. No message is displayed while waiting for a shifting key after
printing "LILO ". In the message, the FF character ([Ctrl L])
clears the local screen. This is undesirable when the menu boot
loader is installed. The size of the message file is limited to 65535
bytes. The map file has to be rebuilt if the message file is changed or
moved. 'message=' and 'bitmap=' are mutually exclusive.
- (22.8) Disables pre-loading of the internal device cache. May be needed
for Linux distributions which use non-standard device naming conventions;
e.g., when the first IDE disk is not `/dev/hda'.
- (22.7.2) The named descriptor is taken to be the default boot image if no
IBM-PC keyboard is present. If no serial interface ("serial=")
is in use, then any "prompt" keyword and "timeout"
value are bypassed, and default booting occurs as specified by
"delay=". The keyboard detection codes cannot detect the
presence or absence of a newer USB keyboard.
- Disables the automatic marking of disk volumes which are components of
RAID arrays as inaccessible. This allows the user to edit the
disk= / inaccessible declarations into the configuration
file himself. Without such declarations, duplicate Volume IDs will be
overwritten, leading to confusing situations at boot-time, and possible
failure to boot. The use of this keyword is generally not necessary.
- Disables warnings about possible future dangers.
- The per-image option `optional' (see below) applies to all images.
- The per-image option `password=...' (see below) applies to all images.
This option may prevent unattended booting, if the default image is
`password=' protected at the default level `mandatory', which is a level
higher than `restricted'.
- Automatic booting (see `delay' above) will not take place unless a locked
or pre-stored ("lilo -R") command line is present. Instead, the
boot loader will issue the boot: prompt and wait for user input
before proceeding (see timeout below). Unattended default image
reboots are impossible if `prompt' is set and `timeout' is not, or the
default image is password protected at a higher level than
- This option only has meaning for RAID1 installations. The <option>
may be specified as none, auto, mbr, mbr-only,
or a comma-separated list of devices; e.g.,
"/dev/hda,/dev/hdc6". Starting with LILO version 22.0, the boot
record is normally written to the first sector of the RAID1 partition. On
PARALLEL raid sets, no other boot records are needed. The default action
is auto, meaning, automatically generate auxiliary boot records as
needed on SKEWED raid sets. none means suppress generation of all
auxiliary boot records. mbr-only suppresses generation of a boot
record on the raid device, and forces compatibility with versions of LILO
earlier than version 22.0 by writing boot records to all Master Boot
Records (MBRs) of all disks which have partitions in the raid set.
mbr is like mbr-only except the boot record on the RAID
partition is not suppressed. Use of an explicit list of devices, forces
writing of auxiliary boot records only on those devices enumerated, in
addition to the boot record on the RAID1 device. Since the version 22
RAID1 codes will never automatically write a boot record on the MBR of
device 0x80, if such a boot record is desired, this is one way to have it
written. Use of mbr is the other way to force writing to the MBR of
- The per-image password option `restricted' (see below) applies to all
- enables control from a serial line. The specified serial port is
initialized and the boot loader is accepting input from it and from the
PC's keyboard. Sending a break on the serial line corresponds to pressing
a shift key on the console in order to get the boot loader's attention.
All boot images should be password-protected if the serial access is less
secure than access to the console, e.g. if the line is connected to a
modem. The parameter string has the following syntax:
<port>: the number of the serial port, zero-based. 0 corresponds to
COM1 alias /dev/ttyS0, etc. All four ports can be used (if present).
<bps>: the baud rate of the serial port. The following baud rates are
supported: 110, 150, 300, 600, 1200, 2400(default), 4800, 9600, plus the
extended rates 19200, 38400, and 57600(56000). 115200 is allowed, but may
not work with all COMx port hardware.
<parity>: the parity used on the serial line. The boot loader ignores
input parity and strips the 8th bit. The following (upper or lower case)
characters are used to describe the parity: "n" for no parity,
"e" for even parity and "o" for odd parity.
<bits>: the number of bits in a character. Only 7 and 8 bits are
supported. Default is 8 if parity is "none", 7 if parity is
"even" or "odd".
If `serial' is set, the value of `delay' is automatically raised to 20.
Example: "serial=0,2400n8" initializes COM1 with the default
- This option specifies that boot images or 'other's are to be selected and
launched with a single keystroke. Selection is based upon the first
character of each name, which must be unique. This option should not be
used with the menu or bitmap user interface ("install=").
- Causes the operation of the boot installer and boot loader to bypass the
use of Volume-ID information, and to revert to a mode of operation of
versions of LILO from 22.4 backward. With Volume-ID booting (22.5 and
later), the BIOS codes of disks are determined at boot time, not install
time; hence they may be switched around, either by adding or removing
disk(s) from the hardware configuration, or by using a BIOS menu to select
the boot device.
With the use of this option, BIOS codes of disks MUST be correctly specified
at install time; either guessed correctly by LILO (which often fails on
mixed IDE/SCSI systems), or explicitly specified with 'disk=/dev/XXX
bios=0xYY' statements. The use of this option precludes any activity which
may switch around the BIOS codes assigned to particular disk devices, as
In general, this option should never be used, except as a bug
- This global option suppresses the boot-time real mode collection of BIOS
data on systems which hang on certain BIOS calls. It is equivalent to
using the boot-time switch 'nobd'.
This option defeats the disk volume recognition and BIOS device code
detection features of LILO on systems with more than one disk. Thus the
use of this option will produce a strong cautionary message, which cannot
- sets a timeout (in tenths of a second) for keyboard input at the
boot: prompt. "timeout" only has meaning if
"prompt" is mentioned. If no key is pressed for the specified
time, the default image is automatically booted. The default timeout is
- (22.6) Alters the operation of the "timeout" parameter in a
manner which is useful on noisy serial lines. Each typed (or noise)
character restarts the "timeout" timer and a timeout will always
boot the default descriptor, even if noise characters have appeared on the
- Turns on lots of progress reporting. Higher numbers give more verbose
output. If -v is additionally specified on the lilo command line, the
level is increased accordingly. The maximum verbosity level is 5.
- The named boot image is used as the default boot if booting in
"virtual" mode with a virtual monitor, such as VMware(tm). Thus
a real mode boot and a virtual mode boot can be made to have different
default boot images.
Additionally, the kernel configuration parameters append
can be set in
the global options section. They are used as defaults if they aren't specified
in the configuration sections of the respective kernel images.
A per-image section starts with either a line
to indicate a file or device containing the boot image of a Linux kernel, or a
to indicate an arbitrary system to boot.
In the former case, if an image
line specifies booting from a device,
then one has to indicate the range of sectors to be mapped using
In the third case, 'nsec=1' is assumed.
KERNEL OPTIONS (image=)¶
If the booted image is a Linux kernel, then one may pass command line parameters
to this kernel.
- The kernel parameters of this string are concatenated to the parameter(s)
from an append= option (see below). The string of addappend must be
enclosed within double quotes. Usually, the previous append= will
set parameters common to all kernels by appearing in the global section of
the configuration file and addappend= will be used to add local
parameter(s) to an individual image. The addappend option may be used only
once per "image=" section.
If the string is a very long line, this line can be divided in more lines
using "\" as last character of a line, e.g.
addappend="noapic acpi=off pci=usepirqmask \
pnpbios=off pnpacpi=off noisapnp"
- Appends the options specified to the parameter line passed to the kernel.
This is typically used to specify hardware parameters that can't be
entirely auto-detected or for which probing may be dangerous. Multiple
kernel parameters are separated by a blank space, and the string must be
enclosed in double quotes. A local append= appearing within an image=
section overrides any global append= appearing in the global section of
the configuration file. The append option may be used only once per
"image=" section. To concatenate parameter strings, use
append="mem=96M hd=576,64,32 console=ttyS1,9600"
If the string is a very long line, this line can be divided in more lines
using "\" as last character of a line. See example of addappend
- Specifies the initial ramdisk image to be loaded with the kernel. The
image will contain modules needed at boot time, such as network and scsi
drivers. See man pages for mkinitrd(8).
- Like `append', but removes all other options (e.g. setting of the root
device). 'literal' overrides all 'append' and 'addappend' options. Because
vital options can be removed unintentionally with `literal', this option
cannot be set in the global options section.
- This specifies the size (e.g., "4096k") of the optional RAM
disk. A value of zero indicates that no RAM disk should be created. If
this variable is omitted, the RAM disk size configured into the boot image
- This specifies that the root file system should be mounted read-only. It
may be specified as a global option. Typically, the system startup
procedure re-mounts the root file system read-write later (e.g. after
- This specifies that the root file system should be mounted read-write. It
may be specified as a global option.
- This specifies the device that should be mounted as root. It may be
specified as a global option. If the special name current is used,
the root device is set to the device on which the root file system is
currently mounted. If the root has been changed with -r , the respective
device is used. If the variable `root' is omitted, the root device setting
contained in the running kernel image is used. Warning: This can induce to
an unbootable system!
The root filesystem may also be specified by a LABEL= or UUID=
directive, as in '/etc/fstab'. In this case, the argument to root=
must be enclosed in quotation marks, to avoid a syntax error on the second
equal sign, e.g.:
Note: The command line root= parameter passed to the kernel will be:
'root=LABEL=MyDisk'; i.e., without the quotation marks. If the
root= parameter is passed from the boot time boot: prompt,
no quotes are used. The quotes are only there to satisfy the requirements
of the boot-installer parser, which treats an equal sign as an operator.
The kernel command line parser is very much simpler, and must not see any
quotation marks. Simply stated, only use the quotation marks within
- This specifies the VGA text mode that should be selected when booting. It
may be specified as a global option. The following values are recognized
(case is ignored):
normal: select normal 80x25 text mode.
extended (or ext): select 80x50 text mode.
ask: stop and ask for user input (at boot time).
<number>: use the corresponding text mode (can specify the number in
decimal or in hex with the usual '0x' convention). A list of available
modes can be obtained by booting with vga=ask and pressing [Enter].
If this variable is omitted, the VGA mode setting contained in the kernel
image is used. (And that is set at compile time using the SVGA_MODE
variable in the kernel Makefile, and can later be changed with the rdev(8)
ALTERNATE SYSTEM (other=)¶
Used to load systems other than Linux. The `other = <device>' specifies
the boot sector of an alternate system contained on a device or disk
partition; e.g., DOS on, say, `/dev/hda2', or a floppy on `/dev/fd0'. In the
case of booting another system there are these options:
- This specifies the chain loader that should be used. It may also be
specified as a global option. By default chain is used. This chain
loader passes partition and drive information in the boot sector it loads
only to DOS on FAT12 or FAT16, Windows on FAT16 or FAT32. (see also
- This specifies the device that contains the partition table. The boot
loader will pass default partition information to the booted operating
system if this variable is omitted. (Some operating systems have other
means to determine from which partition they have been booted. E.g.,
MS-DOS usually stores the geometry of the boot disk or partition in its
boot sector.) Note that /sbin/lilo must be re-run if a partition table
mapped referenced with `table' is modified.
- This keyword starts a section which describes how primary partition IDs
are changed, and how primary partitions are activated and deactivated. If
change is omitted, change rules are generated as though the
automatic keyword were specified. The keyword change alone,
without any rules following, will suppress automatic change-rules. For
- specifies that when primary partition /dev/hda2 is booted, automatic
change-rules will be in effect; plus, partition 1, a DOS12 partition, will
be set hidden, and deactivated. In addition, partition 2, will be set
normal, and activated. Activation sets the boot-flag in the partition
table. The automatic keyword may conflict with default change
rules, so the set= lines above may be redundant.
- This option (LILO version 22.5.1) indicates the BIOS device code which
must be assigned to the specified drive in order for the
"other=" operating system to boot. If the chain loader detects
that another BIOS device code is assigned to this disk, then it will
dynamically swap the assigned device code with the specified device code.
This option is easier to specify than "map-drive=" and more
general than "master-boot" in that any device code may be
specified. Unlike "map-drive=", the determination whether to
swap device codes is made at boot time, not install time. This is
advantageous on systems where the BIOS presents a boot menu of devices,
and will map disks to devices in different ways, depending upon the BIOS
This option may be specified as a global option, in which case it applies to
all "other=" sections unless overridden with a specific
"master-boot" option. If one of "boot-as=" or
"master-boot" is specified as a global option, it is better to
specify "master-boot" as the global option, as it will not
interfere with floppy disk BIOS device codes; "boot-as=" is then
used as a local option to override "master-boot" as
- This flag (LILO version 22.5) indicates a DOS/Windows or other system
which will only boot from BIOS device 0x80, the "C:" drive, or
BIOS device 0, the A: drive. When this flag is specified, if this drive is
not assigned device code 0x80 or 0 by the BIOS, then the chain loader will
dynamically swap the device code actually assigned with device code 0x80
or 0 to make this drive appear to be the first hard or floppy drive,
"C:" or "A:".
This flag is easier to use than "map-drive=" (see below), and is
preferred, if simple forcing of device code 0x80 is all that is required.
It is also more general, in that the necessity to swap BIOS device codes
is determined dynamically at boot-time, not at boot install-time, as with
"map-drive=". It is slightly more powerful than
"boot-as=", in that the device code which is assigned, 0 or
0x80, is determined dynamically.
This option may be specified as a global option, in which case it applies to
all "other=" sections unless overridden with a specific
- Maps BIOS calls for the specified drive to the device code specified on
the next line as to=<num>. This mapping is useful for booting
operating systems, such as DOS, from the second hard drive. The following,
swaps the C: and D: drives,
This option is largely rendered obsolete by "boot-as=", introduced
with LILO version 22.5.
- Do not access the boot sector at map creation time. This disables some
sanity checks, including a partition table check. If the boot sector is on
a fixed-format floppy disk device, using UNSAFE avoids the need to put a
readable disk into the drive when running the map installer. If the boot
sector is on a hard drive, the BIOS device code of the drive will have to
be specified explicitly with "disk=/dev/XXXX bios=0x8X
inaccessible" in the configuration file. `unsafe' and `table'
(explicit or implicit) are mutually incompatible.
COMMON DESCRIPTOR OPTIONS (image= & other=)¶
In both the image=
cases, the following options apply.
- No password is required to boot this image. Used to indicate that the
global password does not apply to this `image=' or `other='. See
- The boot loader uses the main file name (without its path) of each image
specification to identify that image. A different name can be used by
setting the variable `label'.
- A second name for the same entry can be used by specifying an alias.
- The bitmap graphic (install=bmp) is retained when control is passed to the
loaded kernel image, or other= bootloader; i.e., the screen is not blanked
to alphanumeric mode before starting the kernel. This feature is
considered EXPERIMENTAL, for those users working with startup splash
- Specifies a string that is stored as the default command line if the
current image is booted. This is useful when experimenting with kernels
which may crash before allowing interaction with the system. If using the
fallback option, the next reboot (e.g. triggered by a manual reset
or by a watchdog timer) will load a different (supposedly stable) kernel.
The command line stored by the fallback mechanism is cleared by removing
or changing the default command line with the -R option, which
should be a part of the boot startup scripts.
- (See above.)
- Omit the image if it is not available at map creation time. It may be
specified as a global option. This is useful to specify test kernels that
are not always present.
- Protect the `image=' or `other=' with a password (or passphrase). It may
be specified as a global option. The interpretation of the `password='
setting is modified by the words `mandatory', `restricted', and `bypass'
The password may be specified in the config-file (less secure) or entered at
the time the boot loader is installed. To request interactive entry of the
password, it should be specified: password="". Passwords
entered interactively are not required to be entered again if the boot
installer is re-run. They are cached, in hashed form, in a companion file
to the config-file, default name: /etc/lilo.conf.crc. If the
config-file is updated, a warning message will be issued telling you to
re-run lilo -p to force re-creation of the password cache
- A password is required to boot this image. This is the default. May be
used on a single `image=' or `other=' to override a different global
- (22.7.2) The specified descriptor is not bootable if the IBM-PC keyboard
is not present. This option is really only useful if the
"serial=" boot terminal is in use. With no keyboard (and no
serial terminal) attached, selecting a boot descriptor other than the
default is impossible. See nokbdefault above.
- A password is only required to boot the image if kernel parameters are
specified on the command line (e.g. 'single'). May be used on a single
`image=' or `other=' to override a different global setting.
- If booting under a virtual monitor such as VMware(tm), the image with this
label will cause a cautionary warning to be issued at boot time, and user
intervention will be required to continue or to abort the boot
- If booting under a virtual monitor, the image with this label will not be
displayed as a boot option. The image is only bootable in real mode. See