Ubuntu Manpage: lilo.conf - configuration file for lilo

NAME

       lilo.conf - configuration file for lilo

DESCRIPTION

       This  file,  by  default  /etc/lilo.conf, is read by the boot loader installer 'lilo' (see
       lilo(8)).

       It might look as follows:

              # /etc/lilo.conf
              #
              #  global options:
              boot=/dev/hda
              prompt
              timeout=150
              lba32
              compact
              vga=normal
              root=/dev/hda1
              read-only
              menu-title=" John's Computer "
              #
              ### bootable kernel images ###
              image=/boot/vmlinuz-2.6.29-1-i386
                   label=try
                   initrd=/boot/initrd.img-2.6.29-1-i386
              image=/boot/vmlinuz-2.4.33-1-i386
                   label=2.4.33
              image=/tamu/vmlinuz
                   label=tamu
                   initrd=/tamu/initrd.img
                   root=/dev/hdb2
                   vga=ask
              #
              ### other operating systems ###
              other=/dev/hda3
                   label=PCDOS
                   boot-as=0x80    # must be C:
              other=/dev/hdb1
                   label=WinXP
                   boot-as=0x80    # must be C:
              other=/dev/hdb5
                   label=oldDOS
                   loader=chain
                   table=/dev/hdb5

       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 old documentation.)

       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.

GLOBAL OPTIONS

There are many possible keywords. The description below is almost literally from
html/user_21-5.html inside the old documentation (just slightly abbreviated).

backup=<backup-file>
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= below.

bios-passes-dl=<option>
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: yes=1, no=0.

bitmap=<bitmap-file>
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=" (see below).

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.

bmp-colors=<fg>,<bg>,<sh>,<hfg>,<hbg>,<hsh>
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.

bmp-retain
Option applies to all 'image=' and 'other=' sections. (See COMMON OPTIONS, below.)

bmp-table=<x>,<y>,<ncol>,<nrow>,<xsep>,<spill>
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.

bmp-timer=<x>,<y>,<fg>,<bg>,<sh>
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
entirely.

boot=<boot-device>
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 root partition.

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. e.:

boot = /dev/disk/by-id/ata-SAMSUNG_SV1604N_S01FJ10X999999

change-rules
Defines boot-time changes to partition type numbers (`hiding').

change-rules
reset
type=DOS12
normal=1
hidden=0x11
type=DOS16_small
normal=4
hidden=0x14
type=DOS16_big
normal=0x06
hidden=0x16

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.

compact
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.

default=<name>
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.

delay=<tsecs>
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).

disk=<device-name>
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,

disk=/dev/sda
bios=0x80
disk=/dev/hda
bios=0x81
disk=/dev/sdb
inaccessible

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.,

disk=/dev/fd0
sectors=18
heads=2
cylinders=80

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:

disk=/dev/userd0
max-partitions=15

In cases where there is no kernel partition information available, such as on
loopback devices, the 'disk=' specification may include paritition start
information; viz.,

disk=/dev/loop0
bios=0x80 # use this BIOS code
max-partitions=7 # declare partitionable
paritition=/dev/loop1
start=63 # offset from sector 0
paritition=/dev/loop2
start=102400 # offset from sector 0

disktab=<disktab-file>
Specifies the name of the disk parameter table. The map installer looks for
/etc/disktab if `disktab' is omitted. The use of disktabs is discouraged.

el-torito-bootable-CD
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.

fix-table
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.

force-backup=<backup-file>
Operation is identical to backup= above, except an existing backup file is
unconditionally overwritten if it exists.

geometric
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.

ignore-table
tells lilo to ignore corrupt partition tables.

install=<user-interface>
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.)

large-memory
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.)

lba32 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 addressing scheme.

linear 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
discouraged.

lock Enables automatic recording of boot command lines as the defaults for the following
boots. This way, lilo "locks" on a choice until it is manually overridden.

mandatory
The per-image password option `mandatory' (see below) applies to all images.

map=<map-file>
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.

menu-title=<title-string>
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.

menu-scheme=<color-scheme>
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 blacK, 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 effect.

message=<message-file>
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.

nodevcache
(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'.

nokbdefault=<name>
(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.

noraid 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.

nowarn Disables warnings about possible future dangers.

optional
The per-image option `optional' (see below) applies to all images.

password=<password>
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'.

prompt 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
`restricted'.

raid-extra-boot=<option>
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 device 0x80.

restricted
The per-image password option `restricted' (see below) applies to all images.

serial=<parameters>
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>[,<bps>[<parity>[<bits>]]]

<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 parameters.

single-key
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=").

static-BIOS-codes
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 noted above.

In general, this option should never be used, except as a bug workaround.

suppress-boot-time-BIOS-data
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 be suppressed.

timeout=<tsecs>
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
infinite.

unattended
(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 input line.

verbose=<number>
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.

vmdefault=<name>
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, ramdisk, read-only, read-write,
root and vga 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.

PER-IMAGE SECTION

       A per-image section starts with either a line

           image=<pathname>

       to indicate a file or device containing the boot image of a Linux kernel, or a line

           other=<device>

       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

           range=<start>-<end>
           range=<start>+<nsec>
           range=<sector>

       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.

addappend=<string>
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"

append=<string>
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 withing 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 "addappend=". Example:

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 option.

initrd=<name>
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).

literal=<string>
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.

ramdisk=<size>
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 is used.

read-only
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 fsck'ing it).

read-write
This specifies that the root file system should be mounted read-write. It may be
specified as a global option.

root=<root-device>
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.:

root="LABEL=MyDisk"
root="UUID=5472fd8e-9089-4256-bcaa-ceab4f01a439"

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 /etc/lilo.conf.

vga=<mode>
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) program.)

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:

loader=<chain-loader>
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 table=<letter> below).

table=<device>
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.

change 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 example,

other=/dev/hda2
label=dos
table=/dev/hda
change
automatic
partition=/dev/hda1
set=DOS12_hidden
deactivate
partition=/dev/hda2
set=DOS16_big_normal
activate

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.

boot-as=<bios>
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 boot
selection.

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 necessary.

master-boot
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 "boot-as=" option.

map-drive=<num>
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,

map-drive=0x80
to=0x81
map-drive=0x81
to=0x80

This option is largely rendered obsolete by "boot-as=", introduced with LILO
version 22.5.

unsafe 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= and other= cases, the following options apply.

bypass No password is required to boot this image. Used to indicate that the global
password does not apply to this `image=' or `other='. See 'password=' below.

label=<name>
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'.

alias=<name>
A second name for the same entry can be used by specifying an alias.

bmp-retain
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 screens.

fallback=<command-line>
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.

lock (See above.)

optional
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.

password=<password>
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' (see below).
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 file.

mandatory
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 setting.

nokbdisable
(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.

restricted
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.

vmwarn 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 process.

vmdisable
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 vmdefault above.