1N/AINFO-DIR-SECTION Kernel
1N/A* GRUB: (grub). The GRand Unified Bootloader
1N/A* grub-install: (grub)Invoking grub-install. Install GRUB on your drive
1N/A* grub-md5-crypt: (grub)Invoking grub-md5-crypt. Encrypt a password
1N/A* grub-terminfo: (grub)Invoking grub-terminfo. Generate a terminfo
1N/A* grub-set-default: (grub)Invoking grub-set-default. Set a default boot
1N/A* mbchk: (grub)Invoking mbchk. Check for the format of a Multiboot kernel
1N/A Copyright (C) 1999,2000,2001,2002,2004 Free Software Foundation, Inc.
1N/A Permission is granted to make and distribute verbatim copies of this
1N/Amanual provided the copyright notice and this permission notice are
1N/Apreserved on all copies.
1N/A Permission is granted to copy and distribute modified versions of
1N/Athis manual under the conditions for verbatim copying, provided also
1N/Athat the entire resulting derived work is distributed under the terms
1N/Aof a permission notice identical to this one.
1N/A Permission is granted to copy and distribute translations of this
1N/Amanual into another language, under the above conditions for modified
1N/AFile:
grub.info, Node: Diskless, Prev: General usage of network support, Up: Network
1N/ABooting from a network
1N/A======================
1N/A It is sometimes very useful to boot from a network, especially when
1N/Ayou use a machine which has no local disk. In this case, you need to
1N/Aobtain a kind of Net Boot ROM, such as a PXE ROM or a free software
1N/Apackage like Etherboot. Such a Boot ROM first boots the machine, sets
1N/Aup the network card installed into the machine, and downloads a second
1N/Astage boot image from the network. Then, the second image will try to
1N/Aboot an operating system actually from the network.
1N/A GRUB provides two second stage images, `nbgrub' and `pxegrub' (*note
1N/AImages::). These images are the same as the normal Stage 2, except that
1N/Athey set up a network automatically, and try to load a configuration
1N/Afile from the network, if specified. The usage is very simple: If the
1N/Amachine has a PXE ROM, use `pxegrub'. If the machine has an NBI loader
1N/Asuch as Etherboot, use `nbgrub'. There is no difference between them
1N/Aexcept their formats. Since the way to load a second stage image you
1N/Awant to use should be described in the manual on your Net Boot ROM,
1N/Aplease refer to the manual, for more information.
1N/A However, there is one thing specific to GRUB. Namely, how to specify
1N/Aa configuration file in a
BOOTP/DHCP server. For now, GRUB uses the tag
1N/A`150', to get the name of a configuration file. The following is an
1N/Aexample with a BOOTP configuration:
1N/A .allhost:hd=/tmp:bf=null:\
1N/A :ds=145.71.35.1 145.71.32.1:\
1N/A foo:ht=1:ha=63655d0334a7:ip=145.71.35.127:\
1N/A Note that you should specify the drive name `(nd)' in the name of
1N/Athe configuration file. This is because you might change the root drive
1N/Abefore downloading the configuration from the TFTP server when the
1N/Apreset menu feature is used (*note Preset Menu::).
1N/A See the manual of your
BOOTP/DHCP server for more information. The
1N/Aexact syntax should differ a little from the example.
1N/AFile:
grub.info, Node: Serial terminal, Next: Preset Menu, Prev: Network, Up: Top
1N/AUsing GRUB via a serial line
1N/A****************************
1N/A This chapter describes how to use the serial terminal support in
1N/Acould be very useful to control the computers through serial
1N/Acommunications. To connect one computer with another via a serial line,
1N/Ayou need to prepare a null-modem (cross) serial cable, and you may need
1N/Ato have multiport serial boards, if your computer doesn't have extra
1N/Aserial ports. In addition, a terminal emulator is also required, such as
1N/Aminicom. Refer to a manual of your operating system, for more
1N/A As for GRUB, the instruction to set up a serial terminal is quite
1N/Asimple. First of all, make sure that you haven't specified the option
1N/A`--disable-serial' to the configure script when you built your GRUB
1N/Aimages. If you get them in binary form, probably they have serial
1N/Aterminal support already.
1N/A Then, initialize your serial terminal after GRUB starts up. Here is
1N/A grub> serial --unit=0 --speed=9600
1N/A grub> terminal serial
1N/A The command `serial' initializes the serial unit 0 with the speed
1N/A9600bps. The serial unit 0 is usually called `COM1', so, if you want to
1N/Ause COM2, you must specify `--unit=1' instead. This command accepts
1N/Amany other options, so please refer to *Note serial::, for more details.
1N/A The command `terminal' (*note terminal::) chooses which type of
1N/Aterminal you want to use. In the case above, the terminal will be a
1N/Aserial terminal, but you can also pass `console' to the command, as
1N/A`terminal serial console'. In this case, a terminal in which you press
1N/Aany key will be selected as a GRUB terminal.
1N/A However, note that GRUB assumes that your terminal emulator is
1N/Acompatible with VT100 by default. This is true for most terminal
1N/Aemulators nowadays, but you should pass the option `--dumb' to the
1N/Acommand if your terminal emulator is not VT100-compatible or implements
1N/Afew VT100 escape sequences. If you specify this option then GRUB
1N/Aprovides you with an alternative menu interface, because the normal
1N/Amenu requires several fancy features of your terminal.
1N/AFile:
grub.info, Node: Preset Menu, Next: Security, Prev: Serial terminal, Up: Top
1N/AEmbedding a configuration file into GRUB
1N/A****************************************
1N/A GRUB supports a "preset menu" which is to be always loaded before
1N/Astarting. The preset menu feature is useful, for example, when your
1N/Acomputer has no console but a serial cable. In this case, it is
1N/Acritical to set up the serial terminal as soon as possible, since you
1N/Acannot see any message until the serial terminal begins to work. So it
1N/Ais good to run the commands `serial' (*note serial::) and `terminal'
1N/A(*note terminal::) before anything else at the start-up time.
1N/A How the preset menu works is slightly complicated:
1N/A 1. GRUB checks if the preset menu feature is used, and loads the
1N/A preset menu, if available. This includes running commands and
1N/A reading boot entries, like an ordinary configuration file.
1N/A 2. GRUB checks if the configuration file is available. Note that this
1N/A check is performed *regardless of the existence of the preset
1N/A menu*. The configuration file is loaded even if the preset menu was
1N/A 3. If the preset menu includes any boot entries, they are cleared when
1N/A the configuration file is loaded. It doesn't matter whether the
1N/A configuration file has any entries or no entry. The boot entries
1N/A in the preset menu are used only when GRUB fails in loading the
1N/A To enable the preset menu feature, you must rebuild GRUB specifying a
1N/Afile to the configure script with the option `--enable-preset-menu'.
1N/AThe file has the same semantics as normal configuration files (*note
1N/A Another point you should take care is that the diskless support
1N/A(*note Diskless::) diverts the preset menu. Diskless images embed a
1N/Apreset menu to execute the command `bootp' (*note bootp::)
1N/Aautomatically, unless you specify your own preset menu to the configure
1N/Ascript. This means that you must put commands to initialize a network in
1N/Athe preset menu yourself, because diskless images don't set it up
1N/Aimplicitly, when you use the preset menu explicitly.
1N/A Therefore, a typical preset menu used with diskless support would be
1N/A # Set up the serial terminal, first of all.
1N/A serial --unit=0 --speed=19200
1N/A terminal --timeout=0 serial
1N/A # Initialize the network.
1N/AFile:
grub.info, Node: Security, Next: Images, Prev: Preset Menu, Up: Top
1N/AProtecting your computer from cracking
1N/A**************************************
1N/A You may be interested in how to prevent ordinary users from doing
1N/Awhatever they like, if you share your computer with other people. So
1N/Athis chapter describes how to improve the security of GRUB.
1N/A One thing which could be a security hole is that the user can do too
1N/Amany things with GRUB, because GRUB allows one to modify its
1N/Aconfiguration and run arbitrary commands at run-time. For example, the
1N/Acommand `cat' (*note cat::). So it is necessary to disable all the
1N/Ainteractive operations.
1N/A Thus, GRUB provides a "password" feature, so that only administrators
1N/Acan start the interactive operations (
i.e. editing menu entries and
1N/Aentering the command-line interface). To use this feature, you need to
1N/Arun the command `password' in your configuration file (*note
1N/Apassword::), like this:
1N/A password --md5 PASSWORD
1N/A If this is specified, GRUB disallows any interactive control, until
1N/Ayou press the key <p> and enter a correct password. The option `--md5'
1N/Atells GRUB that `PASSWORD' is in MD5 format. If it is omitted, GRUB
1N/Aassumes the `PASSWORD' is in clear text.
1N/A You can encrypt your password with the command `md5crypt' (*note
1N/Amd5crypt::). For example, run the grub shell (*note Invoking the grub
1N/Ashell::), and enter your password:
1N/A Password: **********
1N/A Encrypted: $1$U$JK7xFegdxWH6VuppCUSIb.
1N/A Then, cut and paste the encrypted password to your configuration
1N/A Also, you can specify an optional argument to `password'. See this
1N/Aconfiguration file when you enter the valid password.
1N/A Another thing which may be dangerous is that any user can choose any
1N/Amenu entry. Usually, this wouldn't be problematic, but you might want to
1N/Apermit only administrators to run some of your menu entries, such as an
1N/Aentry for booting an insecure OS like DOS.
1N/A GRUB provides the command `lock' (*note lock::). This command always
1N/Afails until you enter the valid password, so you can use it, like this:
1N/A rootnoverify (hd0,1)
1N/A You should insert `lock' right after `title', because any user can
1N/Aexecute commands in an entry until GRUB encounters `lock'.
1N/A You can also use the command `password' instead of `lock'. In this
1N/Acase the boot process will ask for the password and stop if it was
1N/Aentered incorrectly. Since the `password' takes its own PASSWORD
1N/Aargument this is useful if you want different passwords for different
1N/AFile:
grub.info, Node: Images, Next: Filesystem, Prev: Security, Up: Top
1N/A GRUB consists of several images: two essential stages, optional
1N/Astages called "Stage 1.5", one image for bootable CD-ROM, and two
1N/Anetwork boot images. Here is a short overview of them. *Note
1N/AInternals::, for more details.
1N/A This is an essential image used for booting up GRUB. Usually, this
1N/A is embedded in an MBR or the boot sector of a partition. Because a
1N/A PC boot sector is 512 bytes, the size of this image is exactly 512
1N/A All `stage1' must do is to load Stage 2 or Stage 1.5 from a local
1N/A disk. Because of the size restriction, `stage1' encodes the
1N/A location of Stage 2 (or Stage 1.5) in a block list format, so it
1N/A never understand any filesystem structure.
1N/A This is the core image of GRUB. It does everything but booting up
1N/A itself. Usually, this is put in a filesystem, but that is not
1N/A These are called "Stage 1.5", because they serve as a bridge
1N/A between `stage1' and `stage2', that is to say, Stage 1.5 is loaded
1N/A by Stage 1 and Stage 1.5 loads Stage 2. The difference between
1N/A `stage1' and `*_stage1_5' is that the former doesn't understand
1N/A any filesystem while the latter understands one filesystem (
e.g. 1N/A `e2fs_stage1_5' understands ext2fs). So you can move the Stage 2
1N/A image to another location safely, even after GRUB has been
1N/A While Stage 2 cannot generally be embedded in a fixed area as the
1N/A size is so large, Stage 1.5 can be installed into the area right
1N/A after an MBR, or the boot loader area of a ReiserFS or a FFS.
1N/A This is a boot image for CD-ROMs using the "no emulation mode" in
1N/A El Torito specification. This is identical to Stage 2, except that
1N/A this boots up without Stage 1 and sets up a special drive `(cd)'.
1N/A This is a network boot image for the Network Image Proposal used
1N/A by some network boot loaders, such as Etherboot. This is mostly
1N/A the same as Stage 2, but it also sets up a network and loads a
1N/A configuration file from the network.
1N/A This is another network boot image for the Preboot Execution
1N/A Environment used by several Netboot ROMs. This is identical to
1N/A `nbgrub', except for the format.
1N/AFile:
grub.info, Node: Filesystem, Next: Interface, Prev: Images, Up: Top
1N/AFilesystem syntax and semantics
1N/A*******************************
1N/A GRUB uses a special syntax for specifying disk drives which can be
1N/Aaccessed by BIOS. Because of BIOS limitations, GRUB cannot distinguish
1N/Abetween IDE, ESDI, SCSI, or others. You must know yourself which BIOS
1N/Adevice is equivalent to which OS device. Normally, that will be clear if
1N/Ayou see the files in a device or use the command `find' (*note find::).
1N/A* Device syntax:: How to specify devices
1N/A* File name syntax:: How to specify files
1N/A* Block list syntax:: How to specify block lists
1N/AFile:
grub.info, Node: Device syntax, Next: File name syntax, Up: Filesystem
1N/AHow to specify devices
1N/A======================
1N/A The device syntax is like this:
1N/A `(DEVICE[,PART-NUM][,BSD-SUBPART-LETTER])'
1N/A `[]' means the parameter is optional. DEVICE should be either `fd'
1N/Aor `hd' followed by a digit, like `fd0'. But you can also set DEVICE
1N/Ato a hexadecimal or a decimal number which is a BIOS drive number, so
1N/Athe following are equivalent:
1N/A PART-NUM represents the partition number of DEVICE, starting from
1N/Azero for primary partitions and from four for extended partitions, and
1N/ABSD-SUBPART-LETTER represents the BSD disklabel subpartition, such as
1N/A A shortcut for specifying BSD subpartitions is
1N/A`(DEVICE,BSD-SUBPART-LETTER)', in this case, GRUB searches for the
1N/Afirst PC partition containing a BSD disklabel, then finds the
1N/Asubpartition BSD-SUBPART-LETTER. Here is an example:
1N/A The syntax `(hd0)' represents using the entire disk (or the MBR when
1N/Ainstalling GRUB), while the syntax `(hd0,0)' represents using the first
1N/Apartition of the disk (or the boot sector of the partition when
1N/A If you enabled the network support, the special drive, `(nd)', is
1N/Aalso available. Before using the network drive, you must initialize the
1N/Anetwork. *Note Network::, for more information.
1N/A If you boot GRUB from a CD-ROM, `(cd)' is available. *Note Making a
1N/AGRUB bootable CD-ROM::, for details.
1N/AFile:
grub.info, Node: File name syntax, Next: Block list syntax, Prev: Device syntax, Up: Filesystem
1N/A There are two ways to specify files, by "absolute file name" and by
1N/A An absolute file name resembles a Unix absolute file name, using `/'
1N/Afor the directory separator (not `\' as in DOS). One example is
1N/Ain the first partition of the first hard disk. If you omit the device
1N/Aname in an absolute file name, GRUB uses GRUB's "root device"
1N/Aimplicitly. So if you set the root device to, say, `(hd1,0)' by the
1N/AFile:
grub.info, Node: Block list syntax, Prev: File name syntax, Up: Filesystem
1N/AHow to specify block lists
1N/A==========================
1N/A A block list is used for specifying a file that doesn't appear in the
1N/Afilesystem, like a chainloader. The syntax is
1N/A`[OFFSET]+LENGTH[,[OFFSET]+LENGTH]...'. Here is an example:
1N/A `0+100,200+1,300+300'
1N/A This represents that GRUB should read blocks 0 through 99, block 200,
1N/Aand blocks 300 through 599. If you omit an offset, then GRUB assumes
1N/A Like the file name syntax (*note File name syntax::), if a blocklist
1N/Adoes not contain a device name, then GRUB uses GRUB's "root device". So
1N/A`(hd0,1)+1' is the same as `+1' when the root device is `(hd0,1)'.
1N/AFile:
grub.info, Node: Interface, Next: Commands, Prev: Filesystem, Up: Top
1N/AGRUB's user interface
1N/A*********************
1N/A GRUB has both a simple menu interface for choosing preset entries
1N/Afrom a configuration file, and a highly flexible command-line for
1N/Aperforming any desired combination of boot commands.
1N/A GRUB looks for its configuration file as soon as it is loaded. If one
1N/Ais found, then the full menu interface is activated using whatever
1N/Aentries were found in the file. If you choose the "command-line" menu
1N/Aoption, or if the configuration file was not found, then GRUB drops to
1N/Athe command-line interface.
1N/A* Command-line interface:: The flexible command-line interface
1N/A* Menu interface:: The simple menu interface
1N/A* Menu entry editor:: Editing a menu entry
1N/A* Hidden menu interface:: The hidden menu interface
1N/AFile:
grub.info, Node: Command-line interface, Next: Menu interface, Up: Interface
1N/AThe flexible command-line interface
1N/A===================================
1N/A The command-line interface provides a prompt and after it an editable
1N/Atext area much like a command-line in Unix or DOS. Each command is
1N/Aimmediately executed after it is entered(1) (*note Command-line
1N/Ainterface-Footnote-1::). The commands (*note Command-line and menu
1N/Aentry commands::) are a subset of those available in the configuration
1N/Afile, used with exactly the same syntax.
1N/A Cursor movement and editing of the text on the line can be done via a
1N/Asubset of the functions available in the Bash shell:
1N/A Move forward one character.
1N/A Move back one character.
1N/A Move to the start of the line.
1N/A Move the the end of the line.
1N/A Delete the character underneath the cursor.
1N/A Delete the character to the left of the cursor.
1N/A Kill the text from the current cursor position to the end of the
1N/A Kill backward from the cursor to the beginning of the line.
1N/A Yank the killed text back into the buffer at the cursor.
1N/A Move up through the history list.
1N/A Move down through the history list.
1N/A When typing commands interactively, if the cursor is within or before
1N/Athe first word in the command-line, pressing the <TAB> key (or <C-i>)
1N/Awill display a listing of the available commands, and if the cursor is
1N/Aafter the first word, the `<TAB>' will provide a completion listing of
1N/Adisks, partitions, and file names depending on the context. Note that
1N/Ato obtain a list of drives, one must open a parenthesis, as `root ('.
1N/A Note that you cannot use the completion functionality in the TFTP
1N/Afilesystem. This is because TFTP doesn't support file name listing for
1N/AFile:
grub.info, Node: Command-line interface-Footnotes, Up: Command-line interface
1N/A (1) However, this behavior will be changed in the future version, in
1N/Aa user-invisible way.
1N/AFile:
grub.info, Node: Menu interface, Next: Menu entry editor, Prev: Command-line interface, Up: Interface
1N/AThe simple menu interface
1N/A=========================
1N/A The menu interface is quite easy to use. Its commands are both
1N/Areasonably intuitive and described on screen.
1N/A Basically, the menu interface provides a list of "boot entries" to
1N/Athe user to choose from. Use the arrow keys to select the entry of
1N/Achoice, then press <RET> to run it. An optional timeout is available
1N/Ato boot the default entry (the first one if not set), which is aborted
1N/A Commands are available to enter a bare command-line by pressing <c>
1N/A(which operates exactly like the non-config-file version of GRUB, but
1N/Aallows one to return to the menu if desired by pressing <ESC>) or to
1N/Aedit any of the "boot entries" by pressing <e>.
1N/A If you protect the menu interface with a password (*note Security::),
1N/Aall you can do is choose an entry by pressing <RET>, or press <p> to
1N/AFile:
grub.info, Node: Menu entry editor, Next: Hidden menu interface, Prev: Menu interface, Up: Interface
1N/A The menu entry editor looks much like the main menu interface, but
1N/Athe lines in the menu are individual commands in the selected entry
1N/Ainstead of entry names.
1N/A If an <ESC> is pressed in the editor, it aborts all the changes made
1N/Ato the configuration entry and returns to the main menu interface.
1N/A When a particular line is selected, the editor places the user in a
1N/Aspecial version of the GRUB command-line to edit that line. When the
1N/Auser hits <RET>, GRUB replaces the line in question in the boot entry
1N/Awith the changes (unless it was aborted via <ESC>, in which case the
1N/Achanges are thrown away).
1N/A If you want to add a new line to the menu entry, press <o> if adding
1N/Aa line after the current line or press <O> if before the current line.
1N/A To delete a line, hit the key <d>. Although GRUB unfortunately does
1N/Anot support "undo", you can do almost the same thing by just returning
1N/AFile:
grub.info, Node: Hidden menu interface, Prev: Menu entry editor, Up: Interface
1N/AThe hidden menu interface
1N/A=========================
1N/A When your terminal is dumb or you request GRUB to hide the menu
1N/Ainterface explicitly with the command `hiddenmenu' (*note
1N/Ahiddenmenu::), GRUB doesn't show the menu interface (*note Menu
1N/Ainterface::) and automatically boots the default entry, unless
1N/Ainterrupted by pressing <ESC>.
1N/A When you interrupt the timeout and your terminal is dumb, GRUB falls
1N/Aback to the command-line interface (*note Command-line interface::).
1N/AFile:
grub.info, Node: Commands, Next: Troubleshooting, Prev: Interface, Up: Top
1N/AThe list of available commands
1N/A******************************
1N/A In this chapter, we list all commands that are available in GRUB.
1N/A Commands belong to different groups. A few can only be used in the
1N/Aglobal section of the configuration file (or "menu"); most of them can
1N/Abe entered on the command-line and can be used either anywhere in the
1N/Amenu or specifically in the menu entries.
1N/A* Menu-specific commands::
1N/A* Command-line and menu entry commands::
1N/AFile:
grub.info, Node: Menu-specific commands, Next: General commands, Up: Commands
1N/AThe list of commands for the menu only
1N/A======================================
1N/A The semantics used in parsing the configuration file are the
1N/A * The menu-specific commands have to be used before any others.
1N/A * The files _must_ be in plain-text format.
1N/A * `#' at the beginning of a line in a configuration file means it is
1N/A * Options are separated by spaces.
1N/A * All numbers can be either decimal or hexadecimal. A hexadecimal
1N/A number must be preceded by `0x', and is case-insensitive.
1N/A * Extra options or text at the end of the line are ignored unless
1N/A otherwise specified.
1N/A * Unrecognized commands are added to the current entry, except
1N/A before entries start, where they are ignored.
1N/A These commands can only be used in the menu:
1N/A* default:: Set the default entry
1N/A* fallback:: Set the fallback entry
1N/A* hiddenmenu:: Hide the menu interface
1N/A* timeout:: Set the timeout
1N/A* title:: Start a menu entry
1N/AFile:
grub.info, Node: default, Next: fallback, Up: Menu-specific commands
1N/A - Command: default num
1N/A Set the default entry to the entry number NUM. Numbering starts
1N/A from 0, and the entry number 0 is the default if the command is not
1N/A You can specify `saved' instead of a number. In this case, the
1N/A default entry is the entry saved with the command `savedefault'.
1N/A *Note savedefault::, for more information.
1N/AFile:
grub.info, Node: fallback, Next: hiddenmenu, Prev: default, Up: Menu-specific commands
1N/A - Command: fallback num...
1N/A Go into unattended boot mode: if the default boot entry has any
1N/A errors, instead of waiting for the user to do something,
1N/A immediately start over using the NUM entry (same numbering as the
1N/A `default' command (*note default::)). This obviously won't help if
1N/A the machine was rebooted by a kernel that GRUB loaded. You can
1N/A specify multiple fallback entry numbers.
1N/AFile:
grub.info, Node: hiddenmenu, Next: timeout, Prev: fallback, Up: Menu-specific commands
1N/A - Command: hiddenmenu
1N/A Don't display the menu. If the command is used, no menu will be
1N/A displayed on the control terminal, and the default entry will be
1N/A booted after the timeout expired. The user can still request the
1N/A menu to be displayed by pressing <ESC> before the timeout expires.
1N/A See also *Note Hidden menu interface::.
1N/AFile:
grub.info, Node: timeout, Next: title, Prev: hiddenmenu, Up: Menu-specific commands
1N/A - Command: timeout sec
1N/A Set a timeout, in SEC seconds, before automatically booting the
1N/A default entry (normally the first entry defined).
1N/AFile:
grub.info, Node: title, Prev: timeout, Up: Menu-specific commands
1N/A - Command: title name ...
1N/A Start a new boot entry, and set its name to the contents of the
1N/A rest of the line, starting with the first non-space character.
1N/AFile:
grub.info, Node: General commands, Next: Command-line and menu entry commands, Prev: Menu-specific commands, Up: Commands
1N/AThe list of general commands
1N/A============================
1N/A Commands usable anywhere in the menu and in the command-line.
1N/A* bootp:: Initialize a network device via BOOTP
1N/A* color:: Color the menu interface
1N/A* device:: Specify a file as a drive
1N/A* dhcp:: Initialize a network device via DHCP
1N/A* hide:: Hide a partition
1N/A* ifconfig:: Configure a network device manually
1N/A* pager:: Change the state of the internal pager
1N/A* partnew:: Make a primary partition
1N/A* parttype:: Change the type of a partition
1N/A* password:: Set a password for the menu interface
1N/A* rarp:: Initialize a network device via RARP
1N/A* serial:: Set up a serial device
1N/A* setkey:: Configure the key map
1N/A* terminal:: Choose a terminal
1N/A* terminfo:: Define escape sequences for a terminal
1N/A* tftpserver:: Specify a TFTP server
1N/A* unhide:: Unhide a partition
1N/AFile:
grub.info, Node: bootp, Next: color, Up: General commands
1N/A - Command: bootp [`--with-configfile']
1N/A Initialize a network device via the "BOOTP" protocol. This command
1N/A is only available if GRUB is compiled with netboot support. See
1N/A also *Note Network::.
1N/A If you specify `--with-configfile' to this command, GRUB will
1N/A fetch and load a configuration file specified by your BOOTP server
1N/A with the vendor tag `150'.
1N/AFile:
grub.info, Node: color, Next: device, Prev: bootp, Up: General commands
1N/A - Command: color normal [highlight]
1N/A Change the menu colors. The color NORMAL is used for most lines in
1N/A the menu (*note Menu interface::), and the color HIGHLIGHT is used
1N/A to highlight the line where the cursor points. If you omit
1N/A HIGHLIGHT, then the inverted color of NORMAL is used for the
1N/A highlighted line. The format of a color is
1N/A color names. A symbolic color name must be one of these:
1N/A *These below can be specified only for the foreground.*
1N/A But only the first eight names can be used for BACKGROUND. You can
1N/A prefix `blink-' to FOREGROUND if you want a blinking foreground
1N/A This command can be used in the configuration file and on the
1N/A command line, so you may write something like this in your
1N/A # Set default colors.
1N/A # Change the colors.
1N/AFile:
grub.info, Node: device, Next: dhcp, Prev: color, Up: General commands
1N/A - Command: device drive file
1N/A In the grub shell, specify the file FILE as the actual drive for a
1N/A BIOS drive DRIVE. You can use this command to create a disk image,
1N/A and/or to fix the drives guessed by GRUB when GRUB fails to
1N/A determine them correctly, like this:
1N/A grub> device (fd0) /floppy-image
1N/A This command can be used only in the grub shell (*note Invoking
1N/AFile:
grub.info, Node: dhcp, Next: hide, Prev: device, Up: General commands
1N/A - Command: dhcp [--with-configfile]
1N/A Initialize a network device via the "DHCP" protocol. Currently,
1N/A this command is just an alias for `bootp', since the two protocols
1N/A are very similar. This command is only available if GRUB is
1N/A compiled with netboot support. See also *Note Network::.
1N/A If you specify `--with-configfile' to this command, GRUB will
1N/A fetch and load a configuration file specified by your DHCP server
1N/A with the vendor tag `150'.
1N/AFile:
grub.info, Node: hide, Next: ifconfig, Prev: dhcp, Up: General commands
1N/A - Command: hide partition
1N/A Hide the partition PARTITION by setting the "hidden" bit in its
1N/A partition type code. This is useful only when booting DOS or
1N/A Windows and multiple primary FAT partitions exist in one disk. See
1N/AFile:
grub.info, Node: ifconfig, Next: pager, Prev: hide, Up: General commands
1N/A - Command: ifconfig [`--server=server'] [`--gateway=gateway']
1N/A [`--mask=mask'] [`--address=address']
1N/A Configure the IP address, the netmask, the gateway, and the server
1N/A address of a network device manually. The values must be in dotted
1N/A decimal format, like `192.168.11.178'. The order of the options is
1N/A not important. This command shows current network configuration,
1N/A if no option is specified. See also *Note Network::.
1N/AFile:
grub.info, Node: pager, Next: partnew, Prev: ifconfig, Up: General commands
1N/A - Command: pager [flag]
1N/A Toggle or set the state of the internal pager. If FLAG is `on',
1N/A the internal pager is enabled. If FLAG is `off', it is disabled.
1N/A If no argument is given, the state is toggled.
1N/AFile:
grub.info, Node: partnew, Next: parttype, Prev: pager, Up: General commands
1N/A - Command: partnew part type from len
1N/A Create a new primary partition. PART is a partition specification
1N/A in GRUB syntax (*note Naming convention::); TYPE is the partition
1N/A type and must be a number in the range `0-0xff'; FROM is the
1N/A starting address and LEN is the length, both in sector units.
1N/AFile:
grub.info, Node: parttype, Next: password, Prev: partnew, Up: General commands
1N/A - Command: parttype part type
1N/A Change the type of an existing partition. PART is a partition
1N/A specification in GRUB syntax (*note Naming convention::); TYPE is
1N/A the new partition type and must be a number in the range 0-0xff.
1N/AFile:
grub.info, Node: password, Next: rarp, Prev: parttype, Up: General commands
1N/A - Command: password [`--md5'] passwd [new-config-file]
1N/A If used in the first section of a menu file, disable all
1N/A interactive editing control (menu entry editor and command-line)
1N/A and entries protected by the command `lock'. If the password
1N/A PASSWD is entered, it loads the NEW-CONFIG-FILE as a new config
1N/A file and restarts the GRUB Stage 2, if NEW-CONFIG-FILE is
1N/A specified. Otherwise, GRUB will just unlock the privileged
1N/A instructions. You can also use this command in the script
1N/A section, in which case it will ask for the password, before
1N/A continuing. The option `--md5' tells GRUB that PASSWD is
1N/A encrypted with `md5crypt' (*note md5crypt::).
1N/AFile:
grub.info, Node: rarp, Next: serial, Prev: password, Up: General commands
1N/A Initialize a network device via the "RARP" protocol. This command
1N/A is only available if GRUB is compiled with netboot support. See
1N/A also *Note Network::.
1N/AFile:
grub.info, Node: serial, Next: setkey, Prev: rarp, Up: General commands
1N/A - Command: serial [`--unit=unit'] [`--port=port'] [`--speed=speed']
1N/A [`--word=word'] [`--parity=parity'] [`--stop=stop']
1N/A Initialize a serial device. UNIT is a number in the range 0-3
1N/A specifying which serial port to use; default is 0, which
1N/A corresponds to the port often called COM1. PORT is the I/O port
1N/A where the UART is to be found; if specified it takes precedence
1N/A over UNIT. SPEED is the transmission speed; default is 9600. WORD
1N/A and STOP are the number of data bits and stop bits. Data bits must
1N/A be in the range 5-8 and stop bits must be 1 or 2. Default is 8 data
1N/A bits and one stop bit. PARITY is one of `no', `odd', `even' and
1N/A defaults to `no'. The option `--device' can only be used in the
1N/A grub shell and is used to specify the tty device to be used in the
1N/A host operating system (*note Invoking the grub shell::).
1N/A The serial port is not used as a communication channel unless the
1N/A `terminal' command is used (*note terminal::).
1N/A This command is only available if GRUB is compiled with serial
1N/A support. See also *Note Serial terminal::.
1N/AFile:
grub.info, Node: setkey, Next: terminal, Prev: serial, Up: General commands
1N/A - Command: setkey [to_key from_key]
1N/A Change the keyboard map. The key FROM_KEY is mapped to the key
1N/A TO_KEY. If no argument is specified, reset key mappings. Note that
1N/A this command _does not_ exchange the keys. If you want to exchange
1N/A the keys, run this command again with the arguments exchanged,
1N/A grub> setkey capslock control
1N/A grub> setkey control capslock
1N/A A key must be an alphabet letter, a digit, or one of these symbols:
1N/A `escape', `exclam', `at', `numbersign', `dollar', `percent',
1N/A `caret', `ampersand', `asterisk', `parenleft', `parenright',
1N/A `minus', `underscore', `equal', `plus', `backspace', `tab',
1N/A `bracketleft', `braceleft', `bracketright', `braceright', `enter',
1N/A `control', `semicolon', `colon', `quote', `doublequote',
1N/A `backquote', `tilde', `shift', `backslash', `bar', `comma',
1N/A `less', `period', `greater', `slash', `question', `alt', `space',
1N/A `capslock', `FX' (`X' is a digit), and `delete'. This table
1N/A describes to which character each of the symbols corresponds:
1N/AFile:
grub.info, Node: terminal, Next: terminfo, Prev: setkey, Up: General commands
1N/A - Command: terminal [`--dumb'] [`--no-echo'] [`--no-edit']
1N/A [`--timeout=secs'] [`--lines=lines'] [`--silent'] [`console']
1N/A [`serial'] [`hercules']
1N/A Select a terminal for user interaction. The terminal is assumed to
1N/A be VT100-compatible unless `--dumb' is specified. If both
1N/A `console' and `serial' are specified, then GRUB will use the one
1N/A where a key is entered first or the first when the timeout
1N/A expires. If neither are specified, the current setting is
1N/A reported. This command is only available if GRUB is compiled with
1N/A serial support. See also *Note Serial terminal::.
1N/A This may not make sense for most users, but GRUB supports Hercules
1N/A console as well. Hercules console is usable like the ordinary
1N/A console, and the usage is quite similar to that for serial
1N/A terminals: specify `hercules' as the argument.
1N/A The option `--lines' defines the number of lines in your terminal,
1N/A and it is used for the internal pager function. If you don't
1N/A specify this option, the number is assumed as 24.
1N/A The option `--silent' suppresses the message to prompt you to hit
1N/A any key. This might be useful if your system has no terminal
1N/A The option `--no-echo' has GRUB not to echo back input characters.
1N/A This implies the option `--no-edit'.
1N/A The option `--no-edit' disables the BASH-like editing feature.
1N/AFile:
grub.info, Node: terminfo, Next: tftpserver, Prev: terminal, Up: General commands
1N/A - Command: terminfo `--name=name' `--cursor-address=seq'
1N/A [`--clear-screen=seq'] [`--enter-standout-mode=seq']
1N/A [`--exit-standout-mode=seq']
1N/A Define the capabilities of your terminal. Use this command to
1N/A define escape sequences, if it is not vt100-compatible. You may
1N/A use `\e' for <ESC> and `^X' for a control character.
1N/A You can use the utility `grub-terminfo' to generate appropriate
1N/A arguments to this command. *Note Invoking grub-terminfo::.
1N/A If no option is specified, the current settings are printed.
1N/AFile:
grub.info, Node: tftpserver, Next: unhide, Prev: terminfo, Up: General commands
1N/A - Command: tftpserver ipaddr
1N/A *Caution:* This command exists only for backward compatibility.
1N/A Use `ifconfig' (*note ifconfig::) instead.
1N/A server. The argument IPADDR must be in dotted decimal format, like
1N/A `192.168.0.15'. This command is only available if GRUB is compiled
1N/A with netboot support. See also *Note Network::.
1N/AFile:
grub.info, Node: unhide, Prev: tftpserver, Up: General commands
1N/A - Command: unhide partition
1N/A Unhide the partition PARTITION by clearing the "hidden" bit in its
1N/A partition type code. This is useful only when booting DOS or
1N/A Windows and multiple primary partitions exist on one disk. See also
1N/AFile:
grub.info, Node: Command-line and menu entry commands, Prev: General commands, Up: Commands
1N/AThe list of command-line and menu entry commands
1N/A================================================
1N/A These commands are usable in the command-line and in menu entries.
1N/AIf you forget a command, you can run the command `help' (*note help::).
1N/A* blocklist:: Get the block list notation of a file
1N/A* boot:: Start up your operating system
1N/A* cat:: Show the contents of a file
1N/A* chainloader:: Chain-load another boot loader
1N/A* cmp:: Compare two files
1N/A* configfile:: Load a configuration file
1N/A* debug:: Toggle the debug flag
1N/A* displayapm:: Display APM information
1N/A* displaymem:: Display memory configuration
1N/A* embed:: Embed Stage 1.5
1N/A* fstest:: Test a filesystem
1N/A* geometry:: Manipulate the geometry of a drive
1N/A* halt:: Shut down your computer
1N/A* help:: Show help messages
1N/A* impsprobe:: Probe SMP
1N/A* initrd:: Load an initrd
1N/A* install:: Install GRUB
1N/A* ioprobe:: Probe I/O ports used for a drive
1N/A* kernel:: Load a kernel
1N/A* lock:: Lock a menu entry
1N/A* makeactive:: Make a partition active
1N/A* map:: Map a drive to another
1N/A* md5crypt:: Encrypt a password in MD5 format
1N/A* module:: Load a module
1N/A* modulenounzip:: Load a module without decompression
1N/A* pause:: Wait for a key press
1N/A* quit:: Exit from the grub shell
1N/A* reboot:: Reboot your computer
1N/A* read:: Read data from memory
1N/A* root:: Set GRUB's root device
1N/A* rootnoverify:: Set GRUB's root device without mounting
1N/A* savedefault:: Save current entry as the default entry
1N/A* setup:: Set up GRUB's installation automatically
1N/A* testload:: Load a file for testing a filesystem
1N/A* testvbe:: Test VESA BIOS EXTENSION
1N/A* uppermem:: Set the upper memory size
1N/A* vbeprobe:: Probe VESA BIOS EXTENSION
1N/AFile:
grub.info, Node: blocklist, Next: boot, Up: Command-line and menu entry commands
1N/A - Command: blocklist file
1N/A Print the block list notation of the file FILE. *Note Block list
1N/AFile:
grub.info, Node: boot, Next: cat, Prev: blocklist, Up: Command-line and menu entry commands
1N/A Boot the OS or chain-loader which has been loaded. Only necessary
1N/A if running the fully interactive command-line (it is implicit at
1N/A the end of a menu entry).
1N/AFile:
grub.info, Node: cat, Next: chainloader, Prev: boot, Up: Command-line and menu entry commands
1N/A Display the contents of the file FILE. This command may be useful
1N/A to remind you of your OS's root partition:
1N/AFile:
grub.info, Node: chainloader, Next: cmp, Prev: cat, Up: Command-line and menu entry commands
1N/A - Command: chainloader [`--force'] file
1N/A Load FILE as a chain-loader. Like any other file loaded by the
1N/A filesystem code, it can use the blocklist notation to grab the
1N/A first sector of the current partition with `+1'. If you specify the
1N/A option `--force', then load FILE forcibly, whether it has a
1N/A correct signature or not. This is required when you want to load a
1N/A defective boot loader, such as SCO UnixWare 7.1 (*note SCO
1N/AFile:
grub.info, Node: cmp, Next: configfile, Prev: chainloader, Up: Command-line and menu entry commands
1N/A - Command: cmp file1 file2
1N/A Compare the file FILE1 with the file FILE2. If they differ in
1N/A size, print the sizes like this:
1N/A Differ in size: 0x1234 [foo], 0x4321 [bar]
1N/A If the sizes are equal but the bytes at an offset differ, then
1N/A print the bytes like this:
1N/A Differ at the offset 777: 0xbe [foo], 0xef [bar]
1N/A If they are completely identical, nothing will be printed.
1N/AFile:
grub.info, Node: configfile, Next: debug, Prev: cmp, Up: Command-line and menu entry commands
1N/A - Command: configfile file
1N/A Load FILE as a configuration file.
1N/AFile:
grub.info, Node: debug, Next: displayapm, Prev: configfile, Up: Command-line and menu entry commands
1N/A Toggle debug mode (by default it is off). When debug mode is on,
1N/A some extra messages are printed to show disk activity. This global
1N/A debug flag is mainly useful for GRUB developers when testing new
1N/AFile:
grub.info, Node: displayapm, Next: displaymem, Prev: debug, Up: Command-line and menu entry commands
1N/A - Command: displayapm
1N/A Display APM BIOS information.
1N/AFile:
grub.info, Node: displaymem, Next: embed, Prev: displayapm, Up: Command-line and menu entry commands
1N/A - Command: displaymem
1N/A Display what GRUB thinks the system address space map of the
1N/A machine is, including all regions of physical RAM installed. GRUB's
1N/A the available memory in the first megabyte, or "lower memory", and
1N/A a synthesized number from various BIOS interfaces of the memory
1N/A starting at 1MB and going up to the first chipset hole for "upper
1N/A memory" (the standard PC "upper memory" interface is limited to
1N/A reporting a maximum of 64MB).
1N/AFile:
grub.info, Node: embed, Next: find, Prev: displaymem, Up: Command-line and menu entry commands
1N/A - Command: embed stage1_5 device
1N/A Embed the Stage 1.5 STAGE1_5 in the sectors after the MBR if
1N/A DEVICE is a drive, or in the "boot loader" area if DEVICE is a FFS
1N/A partition or a ReiserFS partition.(1) (*note embed-Footnote-1::)
1N/A Print the number of sectors which STAGE1_5 occupies, if successful.
1N/A Usually, you don't need to run this command directly. *Note
1N/A (1) The latter feature has not been implemented yet.
1N/AFile:
grub.info, Node: find, Next: fstest, Prev: embed, Up: Command-line and menu entry commands
1N/A - Command: find filename
1N/A Search for the file name FILENAME in all mountable partitions and
1N/A print the list of the devices which contain the file. The file
1N/A name FILENAME should be an absolute file name like
1N/AFile:
grub.info, Node: fstest, Next: geometry, Prev: find, Up: Command-line and menu entry commands
1N/A Toggle filesystem test mode. Filesystem test mode, when turned
1N/A on, prints out data corresponding to all the device reads and what
1N/A values are being sent to the low-level routines. The format is
1N/A `<PARTITION-OFFSET-SECTOR, BYTE-OFFSET, BYTE-LENGTH>' for
1N/A high-level reads inside a partition, and `[DISK-OFFSET-SECTOR]'
1N/A for low-level sector requests from the disk. Filesystem test mode
1N/A is turned off by any use of the `install' (*note install::) or
1N/A `testload' (*note testload::) commands.
1N/AFile:
grub.info, Node: geometry, Next: halt, Prev: fstest, Up: Command-line and menu entry commands
1N/A - Command: geometry drive [cylinder head sector [total_sector]]
1N/A Print the information for the drive DRIVE. In the grub shell, you
1N/A can set the geometry of the drive arbitrarily. The number of
1N/A cylinders, the number of heads, the number of sectors and the
1N/A number of total sectors are set to CYLINDER, HEAD, SECTOR and
1N/A TOTAL_SECTOR, respectively. If you omit TOTAL_SECTOR, then it will
1N/A be calculated based on the C/H/S values automatically.
1N/AFile:
grub.info, Node: halt, Next: help, Prev: geometry, Up: Command-line and menu entry commands
1N/A - Command: halt `--no-apm'
1N/A The command halts the computer. If the `--no-apm' option is
1N/A specified, no APM BIOS call is performed. Otherwise, the computer
1N/A is shut down using APM.
1N/AFile:
grub.info, Node: help, Next: impsprobe, Prev: halt, Up: Command-line and menu entry commands
1N/A - Command: help `--all' [pattern ...]
1N/A Display helpful information about builtin commands. If you do not
1N/A specify PATTERN, this command shows short descriptions of most of
1N/A available commands. If you specify the option `--all' to this
1N/A command, short descriptions of rarely used commands (such as *Note
1N/A testload::) are displayed as well.
1N/A If you specify any PATTERNS, it displays longer information about
1N/A each of the commands which match those PATTERNS.
1N/AFile:
grub.info, Node: impsprobe, Next: initrd, Prev: help, Up: Command-line and menu entry commands
1N/A - Command: impsprobe
1N/A Probe the Intel Multiprocessor Specification 1.1 or 1.4
1N/A configuration table and boot the various CPUs which are found into
1N/A a tight loop. This command can be used only in the Stage 2, but
1N/A not in the grub shell.
1N/AFile:
grub.info, Node: initrd, Next: install, Prev: impsprobe, Up: Command-line and menu entry commands
1N/A - Command: initrd file ...
1N/A Load an initial ramdisk for a Linux format boot image and set the
1N/A appropriate parameters in the Linux setup area in memory. See also