LILO.CONF(5)                                         LILO.CONF(5)

       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-2.5.99
                      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  Mas-
       ter Boot Record on /dev/hda. (For a discussion of the var-
       ious ways to use lilo,  and  the  interaction  with  other
       operating  systems,  see user.tex from the lilo documenta-

       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
       probably  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 brandnew kernel, or an old trusted kernel, or a  ker-
       nel  on  another  root  file  system (just in case you did
       something stupid on your usual rootfs), or booting a  dif-
       ferent  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 abbrevi-

              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  par-
              tition) that contains the boot sector. If this key-
              word is omitted, the boot sector is read from  (and
              possibly  written  to) the device that is currently
              mounted as root.

              Defines boot-time changes to partition type numbers
              (`hiding').   See  section  "Partition  type change
              rules" of user.tex for details.

              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.   Especially useful is the `bios=' parame-
              ter.  The BIOS numbers your disks 0x80, 0x81,  etc.
              and  it  is  impossible  to decide which Linux disk
              corresponds to which BIOS disk (since this  depends
              on  the BIOS setup, and on the type of BIOS), so if
              you have an unusual setup you  need  to  state  the
              correspondence  between Linux disks and BIOS disks.
              For example,


              would say that your SCSI disk  is  the  first  BIOS
              disk,  and  your  (primary  master) IDE disk is the
              second BIOS disk.

              Specifies the name of  the  disk  parameter  table.
              The  map installer looks for /etc/disktab if `disk-
              tab' is omitted. The use of  disktabs  is  discour-

              This  allows  lilo to adjust 3D addresses in parti-
              tion 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
              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 operat-
              ing 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 transla-
              tion enabled), under  some  circumstances,  it  may
              even  be  unavoidable to have conflicting partition
              table entries.

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

              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 default.

       linear Generate  linear  sector  addresses instead of sec-
              tor/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  inac-
              cessible  disk  areas,  because 3D sector addresses
              are not known before boot time.

       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 over-

              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  dis-
              played  before  the boot prompt. No message is dis-
              played 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.

       nowarn 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.

       prompt 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  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  fol-
              lowing  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 auto-
              matically 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,
              password 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 5.

       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.

       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 sec-
       tors 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  parti-
              tion  table.   The boot loader will not pass parti-
              tion 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.

       unsafe Do not access the boot sector at map creation time.
              This disables some sanity checks, including a  par-
              tition  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 incompatible.

       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 set-
              ting the variable `label'.

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

       lock   (See above.)

              Omit  the  image if it is not available at map cre-
              ation 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
              parameters are specified on the command line  (e.g.

       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. Example:

                   append = "hd=64,32,202"

              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.

              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
              procedure 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 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.)

              This specifies the VGA text  mode  that  should  be
              selected  when  booting.  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.)

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

                           28 July 1995                         1