LILO.CONF(5)

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:

    # 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/zImage-1.5.99
         label=try
    image=/boot/zImage-1.0.9
         label=1.0.9
    image=/tamu/vmlinuz
         label=tamu
         initrd=initramdisk.img
         root=/dev/hdb2
         vga=ask
    #
    #  other operating systems:
    other=/dev/hda3
         label=dos
         boot-as=0x80    # must be C:
    other=/dev/hdb1
         label=Win98
         boot-as=0x80    # must be C:
    other=/dev/hdb5
         label=os2
         loader=os2_d
         table=E:   # os2 sees as E:

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 user.tex from the lilo 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, (/boot/zImage-1.5.99) 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 user.tex (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.

    N.B.: This option may not be retained in releases beyond 22.5.1, and 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 to use a bitmap image (*.bmp) file which has had a header written by the lilo -E command. If this command is used, then all of the information specified by the 'bmp-colors', 'bmp-table', and 'bmp-timer' options is stored in a special LILO header within the bitmap file. Without this header, the 'bmp-' option values should be specified in the configuration file; if not, default values are used. Any use of the 'bmp-' options within the configuration file overrides the values stored in the bitmap file header.

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 specifes 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. a hard disk partition) that contains the boot sector. If this keyword is omitted, the boot sector is read from (and possibly written to) the device that is currently mounted as root. A raid installation is initiated by specifying a RAID1 device as the boot device; e.g., "boot=/dev/md0". Note that LILO version 22.0 and later operate differently from earlier versions with respect to the actual location of the boot records.

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 user.tex 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 user.tex 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.

    Most USB devices which are implemented as SCSI disks MUST be marked inaccessible unless they are actually assigned a device code by the BIOS.

    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, since for hard disks the lba32 disk addressing option (LILO 21.2) ignores disk geometry.

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

           disk=/dev/loop0
                bios=0x80
                paritition=/dev/loop1
                     start=2048		# offset from sector 0
                paritition=/dev/loop2
                     start=102400		# offset from sector 0

    (22.5.8) 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), 15 (like SCSI disks -- most common value), or 7 (like one array controller). An example specifictaion would be:

         disk=/dev/userd0
              max-partitions=15

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 floppy disk emulation when booting from an El Torito Bootable CD. This option is used only by the mkrescue utility used with the "--iso" switch.

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 or OS/2) 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 configurtion 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 abscence) 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:

         <text>:<highlight>:<border>:<title>

    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.

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 auxilary 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 parition 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=").

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.

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.

append=<string>
    Appends the options specified to the parameter line passed to the kernel. This is typically used to specify parameters of hardware 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. Append may be used only once per "image=" section. Example:

         append="mem=96M hd=576,64,32 console=ttyS1,9600"

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). 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 kernel image is used. (And that is set at compile time using the ROOT_DEV variable in the kernel Makefile, and can later be changed with the rdev(8) program.)

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. 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, or OS/2 on FAT16 or HPFS. The alternate chain loader, os2_d passes partition and drive information unconditionally, and uses a format suitalble for OS/2 and DOS (see 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.

table=<drive-letter>
    This is a special case for the os2_d chain loader. It specifies the DOS drive letter for the partition that will be booted. This is mandatory when booting OS/2 installed on an extended partition. The drive letter may be specified with or without a trailing colon.

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 confict 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 by 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/OS2 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 by 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 OPTIONS (image= & other=)

In both the image= and other= cases, the following options apply.

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 conisdered 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.

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.

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

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.

SEE ALSO
lilo(8), mkinitrd(8), mknod(1), mkrescue(8), rdev(8).

The lilo distribution comes with extensive TEX documentation of which the above is an extract.