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:

          boot = /dev/hda
          delay = 40
          vga = normal
          root = /dev/hda1
          image = /zImage-1.5.99
                  label = try
          image = /zImage-1.0.9
                  label = 1.0.9
          image = /tamu/vmlinuz
               label = tamu
               root = /dev/hdb2
               vga = ask
          other = /dev/hda3
               label = dos
               table = /dev/hda

     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  wait  four  seconds  (40
     deciseconds) for you to press Shift.  If you don't, then the
     first kernel image mentioned (/zImage-1.5.99, that you prob-
     ably  installed  just  five minutes ago) will be booted.  If
     you do, the boot loader will ask you which  image  to  boot.
     In  case  you  forgot  the possible choices, press [TAB] (or
     [?], if you have a US keyboard), and you will  be  presented
     with a menu.  You now have the choice of booting this brand-
     new kernel, or an old trusted kernel, or a kernel on another
     root  file  system (just in case you did something stupid on
     your usual rootfs), or booting a different operating system.
     There can be up to 16 images mentioned in lilo.conf.

     As can be seen above, a configuration  file  starts  with  a
     number  of  global options (the top 6 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.


     There are many possible keywords. The description  below  is
     almost literally from user.tex (just slightly abbreviated).

          Copy the original boot sector to backup-file (which may
          also   be   a   device,  e.g.   /dev/null)  instead  of

          Sets the name of the device (e.g. a  hard  disk  parti-
          tion) 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

          Tries to merge read requests for adjacent sectors  into
          a  single  read  request. This drastically reduces load
          time and keeps the  map  smaller.  Using  `compact'  is
          especially recommended when booting from 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.

          Specifies the number of tenths of  a  second  the  boot
          loader should wait before booting the first image. This
          is useful on systems that  immediately  boot  from  the
          hard disk after enabling the keyboard.  The boot loader
          doesn't wait if `delay' is omitted or is set to zero.

          Defines non-standard parameters for the specified disk.
          See section "Disk geometry" of user.tex for details.

          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.

          This allows lilo to adjust 3D  addresses  in  partition
          tables.    Each   partition   entry   contains   a   3D
          (sector/head/cylinder) and  a  linear  address  of  the
          first and the last sector of the partition. If a parti-
          tion is not track-aligned and if certain other  operat-
          ing 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 con-
          flicting partition table entries.

          Like `backup', but overwrite an old backup copy  if  it

          tells lilo to ignore corrupt partition tables.

          Install the specified file as the new boot  sector.  If
          `install'  is  omitted,  /boot/boot.b  is  used  as the

          Generate   linear   sector   addresses    instead    of
          sector/head/cylinder  addresses.  Linear  addresses are
          translated at run  time  and  do  not  depend  on  disk
          geometry.  Note  that boot disks may not be portable if
          `linear' is used, because the BIOS service to determine
          the  disk  geometry  does  not work reliably for floppy
          disks. When using `linear' with large disks, /sbin/lilo
          may  generate  references  to  inaccessible disk areas,
          because 3D sector addresses are not known  before  boot

     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.

          Specifies the location of the map  file.  If  `map'  is
          omitted, the file /boot/map is used.

          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. 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.

          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.

          forces entering the boot prompt without  expecting  any
          prior key-presses. Unattended reboots are impossible if
          `prompt' is set and `timeout' isn't.

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

          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 con-
          nected to a modem. The parameter string has the follow-
          ing 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, 4800 and 9600 bps. Default is 2400 bps.

          <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  automati-
          cally raised to 20.

          Example:  serial=0,2400n8  initializes  COM1  with  the
          default parameters.

          sets a timeout (in tenths of  a  second)  for  keyboard
          input. If no key is pressed for the specified time, the
          first image is automatically booted.  Similarly,  pass-
          word input is aborted if the user is idle for too long.
          The default timeout is infinite.

          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

     Additionally, the kernel  configuration  parameters  append,
     ramdisk, read-only, 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


     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 line


     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 latter case (booting another system)  there  are  the
     three options

          This specifies the chain loader that  should  be  used.
          By default /boot/chain.b is used. The chain loader must
          be specified if booting from a device  other  than  the
          first hard or floppy disk.

          This specifies the device that contains  the  partition
          table. The boot loader will not pass partition informa-
          tion 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.

          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. `unsafe' and `table' are mutually incompati-

     In both cases the following options apply.

          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  speci-
          fying an alias.

     lock (See above.)

          Omit the image if it is not available at  map  creation
          time.   This is useful to specify test kernels that are
          not always present.

          Protect the image by a password.

          A password is only required to boot the image if param-
          eters are specified on the command line (e.g. single).


     If the booted image is a Linux kernel,  then  one  may  pass
     command line parameters to this kernel.

          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.

               append = "hd=64,32,202"

          Like `append', but removes all other options (e.g. set-
          ting  of the root device). Because vital options can be
          removed unintentionally  with  `literal',  this  option
          cannot be set in the global options section.

          This specifies the size 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.

          This specifies that the  root  file  system  should  be
          mounted  read-only.  Typically, the system startup pro-
          cedure re-mounts the root file system read-write  later
          (e.g. after fsck'ing it).

          This specifies that the  root  file  system  should  be
          mounted read-write.

          This specifies the device that  should  be  mounted  as
          root.  If  the  special  name current is used, the root
          device is set to the device on which the root file sys-
          tem  is currently mounted. If the root has been changed
          with  -r , the respective device is used. If the  vari-
          able  `root'  is  omitted, the root device setting con-
          tained in the kernel image is used.  (And that  is  set
          at compile time using the ROOT_DEV variable in the ker-
          nel Makefile, and can later be changed with the rdev(8)

          This  specifies  the  VGA  text  mode  that  should  be
          selected  when booting. The following values are recog-
          nized (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  con-
          tained 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)


     lilo(8), rdev(8).
     The lilo distribution comes with very  extensive  documenta-
     tion of which the above is an extract.