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diff --git a/docs/grub.info b/docs/grub.info deleted file mode 100644 index fe00c44..0000000 --- a/docs/grub.info +++ /dev/null @@ -1,5228 +0,0 @@ -This is /home/phcoder/grub2/bzr/grub-1.99/docs/grub.info, produced by -makeinfo version 4.13 from -/home/phcoder/grub2/bzr/grub-1.99/docs/grub.texi. - -This manual is for GNU GRUB (version 1.99, 14 May 2011). - - Copyright (C) 1999,2000,2001,2002,2004,2006,2008,2009,2010 Free -Software Foundation, Inc. - - Permission is granted to copy, distribute and/or modify this - document under the terms of the GNU Free Documentation License, - Version 1.2 or any later version published by the Free Software - Foundation; with no Invariant Sections. - -INFO-DIR-SECTION Kernel -START-INFO-DIR-ENTRY -* GRUB: (grub). The GRand Unified Bootloader -* grub-install: (grub)Invoking grub-install. Install GRUB on your drive -* grub-mkconfig: (grub)Invoking grub-mkconfig. Generate GRUB configuration -* grub-mkpasswd-pbkdf2: (grub)Invoking grub-mkpasswd-pbkdf2. -* grub-mkrescue: (grub)Invoking grub-mkrescue. Make a GRUB rescue image -END-INFO-DIR-ENTRY - - -File: grub.info, Node: Top, Next: Introduction, Up: (dir) - -GNU GRUB manual -*************** - -This is the documentation of GNU GRUB, the GRand Unified Bootloader, a -flexible and powerful boot loader program for a wide range of -architectures. - - This edition documents version 1.99. - - This manual is for GNU GRUB (version 1.99, 14 May 2011). - - Copyright (C) 1999,2000,2001,2002,2004,2006,2008,2009,2010 Free -Software Foundation, Inc. - - Permission is granted to copy, distribute and/or modify this - document under the terms of the GNU Free Documentation License, - Version 1.2 or any later version published by the Free Software - Foundation; with no Invariant Sections. - -* Menu: - -* Introduction:: Capturing the spirit of GRUB -* Naming convention:: Names of your drives in GRUB -* Installation:: Installing GRUB on your drive -* Booting:: How to boot different operating systems -* Configuration:: Writing your own configuration file -* Theme file format:: Format of GRUB theme files -* Network:: Downloading OS images from a network -* Serial terminal:: Using GRUB via a serial line -* Vendor power-on keys:: Changing GRUB behaviour on vendor power-on keys -* Images:: GRUB image files -* Filesystem:: Filesystem syntax and semantics -* Interface:: The menu and the command-line -* Environment:: GRUB environment variables -* Commands:: The list of available builtin commands -* Security:: Authentication and authorisation -* Supported kernels:: The list of supported kernels -* Troubleshooting:: Error messages produced by GRUB -* Invoking grub-install:: How to use the GRUB installer -* Invoking grub-mkconfig:: Generate a GRUB configuration file -* Invoking grub-mkpasswd-pbkdf2:: - Generate GRUB password hashes -* Invoking grub-mkrescue:: Make a GRUB rescue image -* Obtaining and Building GRUB:: How to obtain and build GRUB -* Reporting bugs:: Where you should send a bug report -* Future:: Some future plans on GRUB -* Copying This Manual:: Copying This Manual -* Index:: - - -File: grub.info, Node: Introduction, Next: Naming convention, Prev: Top, Up: Top - -1 Introduction to GRUB -********************** - -* Menu: - -* Overview:: What exactly GRUB is and how to use it -* History:: From maggot to house fly -* Changes from GRUB Legacy:: Differences from previous versions -* Features:: GRUB features -* Role of a boot loader:: The role of a boot loader - - -File: grub.info, Node: Overview, Next: History, Up: Introduction - -1.1 Overview -============ - -Briefly, a "boot loader" is the first software program that runs when a -computer starts. It is responsible for loading and transferring -control to an operating system "kernel" software (such as Linux or GNU -Mach). The kernel, in turn, initializes the rest of the operating -system (e.g. a GNU system). - - GNU GRUB is a very powerful boot loader, which can load a wide -variety of free operating systems, as well as proprietary operating -systems with chain-loading(1) (*note Overview-Footnote-1::). GRUB is -designed to address the complexity of booting a personal computer; both -the program and this manual are tightly bound to that computer platform, -although porting to other platforms may be addressed in the future. - - One of the important features in GRUB is flexibility; GRUB -understands filesystems and kernel executable formats, so you can load -an arbitrary operating system the way you like, without recording the -physical position of your kernel on the disk. Thus you can load the -kernel just by specifying its file name and the drive and partition -where the kernel resides. - - When booting with GRUB, you can use either a command-line interface -(*note Command-line interface::), or a menu interface (*note Menu -interface::). Using the command-line interface, you type the drive -specification and file name of the kernel manually. In the menu -interface, you just select an OS using the arrow keys. The menu is -based on a configuration file which you prepare beforehand (*note -Configuration::). While in the menu, you can switch to the command-line -mode, and vice-versa. You can even edit menu entries before using them. - - In the following chapters, you will learn how to specify a drive, a -partition, and a file name (*note Naming convention::) to GRUB, how to -install GRUB on your drive (*note Installation::), and how to boot your -OSes (*note Booting::), step by step. - - -File: grub.info, Node: Overview-Footnotes, Up: Overview - - (1) "chain-load" is the mechanism for loading unsupported operating -systems by loading another boot loader. It is typically used for -loading DOS or Windows. - - -File: grub.info, Node: History, Next: Changes from GRUB Legacy, Prev: Overview, Up: Introduction - -1.2 History of GRUB -=================== - -GRUB originated in 1995 when Erich Boleyn was trying to boot the GNU -Hurd with the University of Utah's Mach 4 microkernel (now known as GNU -Mach). Erich and Brian Ford designed the Multiboot Specification -(*note Multiboot Specification: (multiboot)Top.), because they were -determined not to add to the large number of mutually-incompatible PC -boot methods. - - Erich then began modifying the FreeBSD boot loader so that it would -understand Multiboot. He soon realized that it would be a lot easier to -write his own boot loader from scratch than to keep working on the -FreeBSD boot loader, and so GRUB was born. - - Erich added many features to GRUB, but other priorities prevented him -from keeping up with the demands of its quickly-expanding user base. In -1999, Gordon Matzigkeit and Yoshinori K. Okuji adopted GRUB as an -official GNU package, and opened its development by making the latest -sources available via anonymous CVS. *Note Obtaining and Building -GRUB::, for more information. - - Over the next few years, GRUB was extended to meet many needs, but it -quickly became clear that its design was not keeping up with the -extensions being made to it, and we reached the point where it was very -difficult to make any further changes without breaking existing -features. Around 2002, Yoshinori K. Okuji started work on PUPA -(Preliminary Universal Programming Architecture for GNU GRUB), aiming -to rewrite the core of GRUB to make it cleaner, safer, more robust, and -more powerful. PUPA was eventually renamed to GRUB 2, and the original -version of GRUB was renamed to GRUB Legacy. Small amounts of -maintenance continued to be done on GRUB Legacy, but the last release -(0.97) was made in 2005 and at the time of writing it seems unlikely -that there will be another. - - By around 2007, GNU/Linux distributions started to use GRUB 2 to -limited extents, and by the end of 2009 multiple major distributions -were installing it by default. - - -File: grub.info, Node: Changes from GRUB Legacy, Next: Features, Prev: History, Up: Introduction - -1.3 Differences from previous versions -====================================== - -GRUB 2 is a rewrite of GRUB (*note History::), although it shares many -characteristics with the previous version, now known as GRUB Legacy. -Users of GRUB Legacy may need some guidance to find their way around -this new version. - - * The configuration file has a new name (`grub.cfg' rather than - `menu.lst' or `grub.conf'), new syntax (*note Configuration::) and - many new commands (*note Commands::). Configuration cannot be - copied over directly, although most GRUB Legacy users should not - find the syntax too surprising. - - * `grub.cfg' is typically automatically generated by `grub-mkconfig' - (*note Simple configuration::). This makes it easier to handle - versioned kernel upgrades. - - * Partition numbers in GRUB device names now start at 1, not 0 - (*note Naming convention::). - - * The configuration file is now written in something closer to a full - scripting language: variables, conditionals, and loops are - available. - - * A small amount of persistent storage is available across reboots, - using the `save_env' and `load_env' commands in GRUB and the - `grub-editenv' utility. This is not available in all - configurations (*note Environment block::). - - * GRUB 2 has more reliable ways to find its own files and those of - target kernels on multiple-disk systems, and has commands (*note - search::) to find devices using file system labels or Universally - Unique Identifiers (UUIDs). - - * GRUB 2 is available for several other types of system in addition - to the PC BIOS systems supported by GRUB Legacy: PC EFI, PC - coreboot, PowerPC, SPARC, and MIPS Lemote Yeeloong are all - supported. - - * Many more file systems are supported, including but not limited to - ext4, HFS+, and NTFS. - - * GRUB 2 can read files directly from LVM and RAID devices. - - * A graphical terminal and a graphical menu system are available. - - * GRUB 2's interface can be translated, including menu entry names. - - * The image files (*note Images::) that make up GRUB have been - reorganised; Stage 1, Stage 1.5, and Stage 2 are no more. - - * GRUB 2 puts many facilities in dynamically loaded modules, - allowing the core image to be smaller, and allowing the core image - to be built in more flexible ways. - - -File: grub.info, Node: Features, Next: Role of a boot loader, Prev: Changes from GRUB Legacy, Up: Introduction - -1.4 GRUB features -================= - -The primary requirement for GRUB is that it be compliant with the -"Multiboot Specification", which is described in *note Multiboot -Specification: (multiboot)Top. - - The other goals, listed in approximate order of importance, are: - - * Basic functions must be straightforward for end-users. - - * Rich functionality to support kernel experts and designers. - - * Backward compatibility for booting FreeBSD, NetBSD, OpenBSD, and - Linux. Proprietary kernels (such as DOS, Windows NT, and OS/2) are - supported via a chain-loading function. - - Except for specific compatibility modes (chain-loading and the Linux -"piggyback" format), all kernels will be started in much the same state -as in the Multiboot Specification. Only kernels loaded at 1 megabyte or -above are presently supported. Any attempt to load below that boundary -will simply result in immediate failure and an error message reporting -the problem. - - In addition to the requirements above, GRUB has the following -features (note that the Multiboot Specification doesn't require all the -features that GRUB supports): - -Recognize multiple executable formats - Support many of the "a.out" variants plus "ELF". Symbol tables are - also loaded. - -Support non-Multiboot kernels - Support many of the various free 32-bit kernels that lack Multiboot - compliance (primarily FreeBSD, NetBSD, OpenBSD, and Linux). - Chain-loading of other boot loaders is also supported. - -Load multiples modules - Fully support the Multiboot feature of loading multiple modules. - -Load a configuration file - Support a human-readable text configuration file with preset boot - commands. You can also load another configuration file dynamically - and embed a preset configuration file in a GRUB image file. The - list of commands (*note Commands::) are a superset of those - supported on the command-line. An example configuration file is - provided in *note Configuration::. - -Provide a menu interface - A menu interface listing preset boot commands, with a programmable - timeout, is available. There is no fixed limit on the number of - boot entries, and the current implementation has space for several - hundred. - -Have a flexible command-line interface - A fairly flexible command-line interface, accessible from the menu, - is available to edit any preset commands, or write a new boot - command set from scratch. If no configuration file is present, - GRUB drops to the command-line. - - The list of commands (*note Commands::) are a subset of those - supported for configuration files. Editing commands closely - resembles the Bash command-line (*note Bash: (features)Command - Line Editing.), with <TAB>-completion of commands, devices, - partitions, and files in a directory depending on context. - -Support multiple filesystem types - Support multiple filesystem types transparently, plus a useful - explicit blocklist notation. The currently supported filesystem - types are "Amiga Fast FileSystem (AFFS)", "AtheOS fs", "BeFS", - "cpio", "Linux ext2/ext3/ext4", "DOS FAT12/FAT16/FAT32", "HFS", - "HFS+", "ISO9660", "JFS", "Minix fs", "nilfs2", "NTFS", - "ReiserFS", "Amiga Smart FileSystem (SFS)", "tar", "UDF", "BSD - UFS/UFS2", and "XFS". *Note Filesystem::, for more information. - -Support automatic decompression - Can decompress files which were compressed by `gzip' or `xz'(1) - (*note Features-Footnote-1::). This function is both automatic and - transparent to the user (i.e. all functions operate upon the - uncompressed contents of the specified files). This greatly - reduces a file size and loading time, a particularly great benefit - for floppies.(2) (*note Features-Footnote-2::) - - It is conceivable that some kernel modules should be loaded in a - compressed state, so a different module-loading command can be - specified to avoid uncompressing the modules. - -Access data on any installed device - Support reading data from any or all floppies or hard disk(s) - recognized by the BIOS, independent of the setting of the root - device. - -Be independent of drive geometry translations - Unlike many other boot loaders, GRUB makes the particular drive - translation irrelevant. A drive installed and running with one - translation may be converted to another translation without any - adverse effects or changes in GRUB's configuration. - -Detect all installed RAM - GRUB can generally find all the installed RAM on a PC-compatible - machine. It uses an advanced BIOS query technique for finding all - memory regions. As described on the Multiboot Specification (*note - Multiboot Specification: (multiboot)Top.), not all kernels make - use of this information, but GRUB provides it for those who do. - -Support Logical Block Address mode - In traditional disk calls (called "CHS mode"), there is a geometry - translation problem, that is, the BIOS cannot access over 1024 - cylinders, so the accessible space is limited to at least 508 MB - and to at most 8GB. GRUB can't universally solve this problem, as - there is no standard interface used in all machines. However, - several newer machines have the new interface, Logical Block - Address ("LBA") mode. GRUB automatically detects if LBA mode is - available and uses it if available. In LBA mode, GRUB can access - the entire disk. - -Support network booting - GRUB is basically a disk-based boot loader but also has network - support. You can load OS images from a network by using the "TFTP" - protocol. - -Support remote terminals - To support computers with no console, GRUB provides remote terminal - support, so that you can control GRUB from a remote host. Only - serial terminal support is implemented at the moment. - - -File: grub.info, Node: Features-Footnotes, Up: Features - - (1) Only CRC32 data integrity check is supported (xz default is -CRC64 so one should use -check=crc32 option). LZMA BCJ filters are -supported. - - (2) There are a few pathological cases where loading a very badly -organized ELF kernel might take longer, but in practice this never -happen. - - -File: grub.info, Node: Role of a boot loader, Prev: Features, Up: Introduction - -1.5 The role of a boot loader -============================= - -The following is a quotation from Gordon Matzigkeit, a GRUB fanatic: - - Some people like to acknowledge both the operating system and - kernel when they talk about their computers, so they might say - they use "GNU/Linux" or "GNU/Hurd". Other people seem to think - that the kernel is the most important part of the system, so they - like to call their GNU operating systems "Linux systems." - - I, personally, believe that this is a grave injustice, because the - _boot loader_ is the most important software of all. I used to - refer to the above systems as either "LILO"(1) (*note Role of a - boot loader-Footnote-1::) or "GRUB" systems. - - Unfortunately, nobody ever understood what I was talking about; - now I just use the word "GNU" as a pseudonym for GRUB. - - So, if you ever hear people talking about their alleged "GNU" - systems, remember that they are actually paying homage to the best - boot loader around... GRUB! - - We, the GRUB maintainers, do not (usually) encourage Gordon's level -of fanaticism, but it helps to remember that boot loaders deserve -recognition. We hope that you enjoy using GNU GRUB as much as we did -writing it. - - -File: grub.info, Node: Role of a boot loader-Footnotes, Up: Role of a boot loader - - (1) The LInux LOader, a boot loader that everybody uses, but nobody -likes. - - -File: grub.info, Node: Naming convention, Next: Installation, Prev: Introduction, Up: Top - -2 Naming convention -******************* - -The device syntax used in GRUB is a wee bit different from what you may -have seen before in your operating system(s), and you need to know it so -that you can specify a drive/partition. - - Look at the following examples and explanations: - - (fd0) - - First of all, GRUB requires that the device name be enclosed with -`(' and `)'. The `fd' part means that it is a floppy disk. The number -`0' is the drive number, which is counted from _zero_. This expression -means that GRUB will use the whole floppy disk. - - (hd0,msdos2) - - Here, `hd' means it is a hard disk drive. The first integer `0' -indicates the drive number, that is, the first hard disk, the string -`msdos' indicates the partition scheme, while the second integer, `2', -indicates the partition number (or the PC slice number in the BSD -terminology). The partition numbers are counted from _one_, not from -zero (as was the case in previous versions of GRUB). This expression -means the second partition of the first hard disk drive. In this case, -GRUB uses one partition of the disk, instead of the whole disk. - - (hd0,msdos5) - - This specifies the first "extended partition" of the first hard disk -drive. Note that the partition numbers for extended partitions are -counted from `5', regardless of the actual number of primary partitions -on your hard disk. - - (hd1,msdos1,bsd1) - - This means the BSD `a' partition on first PC slice number of the -second hard disk. - - Of course, to actually access the disks or partitions with GRUB, you -need to use the device specification in a command, like `set -root=(fd0)' or `parttool (hd0,msdos3) hidden-'. To help you find out -which number specifies a partition you want, the GRUB command-line -(*note Command-line interface::) options have argument completion. This -means that, for example, you only need to type - - set root=( - - followed by a <TAB>, and GRUB will display the list of drives, -partitions, or file names. So it should be quite easy to determine the -name of your target partition, even with minimal knowledge of the -syntax. - - Note that GRUB does _not_ distinguish IDE from SCSI - it simply -counts the drive numbers from zero, regardless of their type. Normally, -any IDE drive number is less than any SCSI drive number, although that -is not true if you change the boot sequence by swapping IDE and SCSI -drives in your BIOS. - - Now the question is, how to specify a file? Again, consider an -example: - - (hd0,msdos1)/vmlinuz - - This specifies the file named `vmlinuz', found on the first -partition of the first hard disk drive. Note that the argument -completion works with file names, too. - - That was easy, admit it. Now read the next chapter, to find out how -to actually install GRUB on your drive. - - -File: grub.info, Node: Installation, Next: Booting, Prev: Naming convention, Up: Top - -3 Installation -************** - -In order to install GRUB as your boot loader, you need to first install -the GRUB system and utilities under your UNIX-like operating system -(*note Obtaining and Building GRUB::). You can do this either from the -source tarball, or as a package for your OS. - - After you have done that, you need to install the boot loader on a -drive (floppy or hard disk) by using the utility `grub-install' (*note -Invoking grub-install::) on a UNIX-like OS. - - GRUB comes with boot images, which are normally put in the directory -`/usr/lib/grub/<cpu>-<platform>' (for BIOS-based machines -`/usr/lib/grub/i386-pc'). Hereafter, the directory where GRUB images are -initially placed (normally `/usr/lib/grub/<cpu>-<platform>') will be -called the "image directory", and the directory where the boot loader -needs to find them (usually `/boot') will be called the "boot -directory". - -* Menu: - -* Installing GRUB using grub-install:: -* Making a GRUB bootable CD-ROM:: -* Device map:: -* BIOS installation:: - - -File: grub.info, Node: Installing GRUB using grub-install, Next: Making a GRUB bootable CD-ROM, Up: Installation - -3.1 Installing GRUB using grub-install -====================================== - -For information on where GRUB should be installed on PC BIOS platforms, -*note BIOS installation::. - - In order to install GRUB under a UNIX-like OS (such as GNU), invoke -the program `grub-install' (*note Invoking grub-install::) as the -superuser ("root"). - - The usage is basically very simple. You only need to specify one -argument to the program, namely, where to install the boot loader. The -argument has to be either a device file (like `/dev/hda'). For -example, under Linux the following will install GRUB into the MBR of -the first IDE disk: - - # grub-install /dev/hda - - Likewise, under GNU/Hurd, this has the same effect: - - # grub-install /dev/hd0 - - But all the above examples assume that GRUB should put images under -the `/boot' directory. If you want GRUB to put images under a directory -other than `/boot', you need to specify the option `--boot-directory'. -The typical usage is that you create a GRUB boot floppy with a -filesystem. Here is an example: - - # mke2fs /dev/fd0 - # mount -t ext2 /dev/fd0 /mnt - # mkdir /mnt/boot - # grub-install --boot-directory=/mnt/boot /dev/fd0 - # umount /mnt - - Some BIOSes have a bug of exposing the first partition of a USB -drive as a floppy instead of exposing the USB drive as a hard disk -(they call it "USB-FDD" boot). In such cases, you need to install like -this: - - # losetup /dev/loop0 /dev/sdb1 - # mount /dev/loop0 /mnt/usb - # grub-install --boot-directory=/mnt/usb/bugbios --force --allow-floppy /dev/loop0 - - This install doesn't conflict with standard install as long as they -are in separate directories. - - Note that `grub-install' is actually just a shell script and the -real task is done by `grub-mkimage' and `grub-setup'. Therefore, you -may run those commands directly to install GRUB, without using -`grub-install'. Don't do that, however, unless you are very familiar -with the internals of GRUB. Installing a boot loader on a running OS -may be extremely dangerous. - - -File: grub.info, Node: Making a GRUB bootable CD-ROM, Next: Device map, Prev: Installing GRUB using grub-install, Up: Installation - -3.2 Making a GRUB bootable CD-ROM -================================= - -GRUB supports the "no emulation mode" in the El Torito specification(1) -(*note Making a GRUB bootable CD-ROM-Footnote-1::). This means that you -can use the whole CD-ROM from GRUB and you don't have to make a floppy -or hard disk image file, which can cause compatibility problems. - - For booting from a CD-ROM, GRUB uses a special image called -`cdboot.img', which is concatenated with `core.img'. The `core.img' -used for this should be built with at least the `iso9660' and -`biosdisk' modules. Your bootable CD-ROM will usually also need to -include a configuration file `grub.cfg' and some other GRUB modules. - - To make a simple generic GRUB rescue CD, you can use the -`grub-mkrescue' program (*note Invoking grub-mkrescue::): - - $ grub-mkrescue -o grub.iso - - You will often need to include other files in your image. To do -this, first make a top directory for the bootable image, say, `iso': - - $ mkdir iso - - Make a directory for GRUB: - - $ mkdir -p iso/boot/grub - - If desired, make the config file `grub.cfg' under `iso/boot/grub' -(*note Configuration::), and copy any files and directories for the -disc to the directory `iso/'. - - Finally, make the image: - - $ grub-mkrescue -o grub.iso iso - - This produces a file named `grub.iso', which then can be burned into -a CD (or a DVD), or written to a USB mass storage device. - - The root device will be set up appropriately on entering your -`grub.cfg' configuration file, so you can refer to file names on the CD -without needing to use an explicit device name. This makes it easier to -produce rescue images that will work on both optical drives and USB mass -storage devices. - - -File: grub.info, Node: Making a GRUB bootable CD-ROM-Footnotes, Up: Making a GRUB bootable CD-ROM - - (1) El Torito is a specification for bootable CD using BIOS -functions. - - -File: grub.info, Node: Device map, Next: BIOS installation, Prev: Making a GRUB bootable CD-ROM, Up: Installation - -3.3 The map between BIOS drives and OS devices -============================================== - -The `grub-mkdevicemap' program can be used to create the "device map -file". It is often run automatically by tools such as `grub-install' -if the device map file does not already exist. The file name -`/boot/grub/device.map' is preferred. - - If the device map file exists, the GRUB utilities (`grub-probe', -`grub-setup', etc.) read it to map BIOS drives to OS devices. This -file consists of lines like this: - - DEVICE FILE - - DEVICE is a drive specified in the GRUB syntax (*note Device -syntax::), and FILE is an OS file, which is normally a device file. - - Historically, the device map file was used because GRUB device names -had to be used in the configuration file, and they were derived from -BIOS drive numbers. The map between BIOS drives and OS devices cannot -always be guessed correctly: for example, GRUB will get the order wrong -if you exchange the boot sequence between IDE and SCSI in your BIOS. - - Unfortunately, even OS device names are not always stable. Modern -versions of the Linux kernel may probe drives in a different order from -boot to boot, and the prefix (`/dev/hd*' versus `/dev/sd*') may change -depending on the driver subsystem in use. As a result, the device map -file required frequent editing on some systems. - - GRUB avoids this problem nowadays by using UUIDs or file system -labels when generating `grub.cfg', and we advise that you do the same -for any custom menu entries you write. If the device map file does not -exist, then the GRUB utilities will assume a temporary device map on -the fly. This is often good enough, particularly in the common case of -single-disk systems. - - However, the device map file is not entirely obsolete yet, and there -are still some situations that require it to exist. If necessary, you -may edit the file if `grub-mkdevicemap' makes a mistake. You can put -any comments in the file if needed, as the GRUB utilities assume that a -line is just a comment if the first character is `#'. - - -File: grub.info, Node: BIOS installation, Prev: Device map, Up: Installation - -3.4 BIOS installation -===================== - -MBR -=== - -The partition table format traditionally used on PC BIOS platforms is -called the Master Boot Record (MBR) format; this is the format that -allows up to four primary partitions and additional logical partitions. -With this partition table format, there are two ways to install GRUB: -it can be embedded in the area between the MBR and the first partition -(called by various names, such as the "boot track", "MBR gap", or -"embedding area", and which is usually at least 31 KiB), or the core -image can be installed in a file system and a list of the blocks that -make it up can be stored in the first sector of that partition. - - Each of these has different problems. There is no way to reserve -space in the embedding area with complete safety, and some proprietary -software is known to use it to make it difficult for users to work -around licensing restrictions; and systems are sometimes partitioned -without leaving enough space before the first partition. On the other -hand, installing to a filesystem means that GRUB is vulnerable to its -blocks being moved around by filesystem features such as tail packing, -or even by aggressive fsck implementations, so this approach is quite -fragile; and this approach can only be used if the `/boot' filesystem -is on the same disk that the BIOS boots from, so that GRUB does not -have to rely on guessing BIOS drive numbers. - - The GRUB development team generally recommends embedding GRUB before -the first partition, unless you have special requirements. You must -ensure that the first partition starts at least 31 KiB (63 sectors) -from the start of the disk; on modern disks, it is often a performance -advantage to align partitions on larger boundaries anyway, so the first -partition might start 1 MiB from the start of the disk. - -GPT -=== - -Some newer systems use the GUID Partition Table (GPT) format. This was -specified as part of the Extensible Firmware Interface (EFI), but it can -also be used on BIOS platforms if system software supports it; for -example, GRUB and GNU/Linux can be used in this configuration. With -this format, it is possible to reserve a whole partition for GRUB, -called the BIOS Boot Partition. GRUB can then be embedded into that -partition without the risk of being overwritten by other software and -without being contained in a filesystem which might move its blocks -around. - - When creating a BIOS Boot Partition on a GPT system, you should make -sure that it is at least 31 KiB in size. (GPT-formatted disks are not -usually particularly small, so we recommend that you make it larger -than the bare minimum, such as 1 MiB, to allow plenty of room for -growth.) You must also make sure that it has the proper partition -type. Using GNU Parted, you can set this using a command such as the -following: - - # parted /dev/DISK set PARTITION-NUMBER bios_grub on - - If you are using gdisk, set the partition type to `0xEF02'. With -partitioning programs that require setting the GUID directly, it should -be `21686148-6449-6e6f-744e656564454649'. - - *Caution:* Be very careful which partition you select! When GRUB -finds a BIOS Boot Partition during installation, it will automatically -overwrite part of it. Make sure that the partition does not contain any -other data. - - -File: grub.info, Node: Booting, Next: Configuration, Prev: Installation, Up: Top - -4 Booting -********* - -GRUB can load Multiboot-compliant kernels in a consistent way, but for -some free operating systems you need to use some OS-specific magic. - -* Menu: - -* General boot methods:: How to boot OSes with GRUB generally -* OS-specific notes:: Notes on some operating systems - - -File: grub.info, Node: General boot methods, Next: OS-specific notes, Up: Booting - -4.1 How to boot operating systems -================================= - -GRUB has two distinct boot methods. One of the two is to load an -operating system directly, and the other is to chain-load another boot -loader which then will load an operating system actually. Generally -speaking, the former is more desirable, because you don't need to -install or maintain other boot loaders and GRUB is flexible enough to -load an operating system from an arbitrary disk/partition. However, the -latter is sometimes required, since GRUB doesn't support all the -existing operating systems natively. - -* Menu: - -* Loading an operating system directly:: -* Chain-loading:: - - -File: grub.info, Node: Loading an operating system directly, Next: Chain-loading, Up: General boot methods - -4.1.1 How to boot an OS directly with GRUB ------------------------------------------- - -Multiboot (*note Multiboot Specification: (multiboot)Top.) is the -native format supported by GRUB. For the sake of convenience, there is -also support for Linux, FreeBSD, NetBSD and OpenBSD. If you want to -boot other operating systems, you will have to chain-load them (*note -Chain-loading::). - - FIXME: this section is incomplete. - - 1. Run the command `boot' (*note boot::). - - However, DOS and Windows have some deficiencies, so you might have to -use more complicated instructions. *Note DOS/Windows::, for more -information. - - -File: grub.info, Node: Chain-loading, Prev: Loading an operating system directly, Up: General boot methods - -4.1.2 Chain-loading an OS -------------------------- - -Operating systems that do not support Multiboot and do not have specific -support in GRUB (specific support is available for Linux, FreeBSD, -NetBSD and OpenBSD) must be chain-loaded, which involves loading -another boot loader and jumping to it in real mode. - - The `chainloader' command (*note chainloader::) is used to set this -up. It is normally also necessary to load some GRUB modules and set the -appropriate root device. Putting this together, we get something like -this, for a Windows system on the first partition of the first hard -disk: - -menuentry "Windows" { - insmod chain - insmod ntfs - set root=(hd0,1) - chainloader +1 -} - - On systems with multiple hard disks, an additional workaround may be -required. *Note DOS/Windows::. - - Chain-loading is only supported on PC BIOS and EFI platforms. - - -File: grub.info, Node: OS-specific notes, Prev: General boot methods, Up: Booting - -4.2 Some caveats on OS-specific issues -====================================== - -Here, we describe some caveats on several operating systems. - -* Menu: - -* GNU/Hurd:: -* GNU/Linux:: -* DOS/Windows:: - - -File: grub.info, Node: GNU/Hurd, Next: GNU/Linux, Up: OS-specific notes - -4.2.1 GNU/Hurd --------------- - -Since GNU/Hurd is Multiboot-compliant, it is easy to boot it; there is -nothing special about it. But do not forget that you have to specify a -root partition to the kernel. - - 1. Set GRUB's root device to the same drive as GNU/Hurd's. The - command `search --file --set /boot/gnumach.gz' or similar may help - you (*note search::). - - 2. Load the kernel and the modules, like this: - - grub> multiboot /boot/gnumach.gz root=device:hd0s1 - grub> module /hurd/ext2fs.static ext2fs --readonly \ - --multiboot-command-line='${kernel-command-line}' \ - --host-priv-port='${host-port}' \ - --device-master-port='${device-port}' \ - --exec-server-task='${exec-task}' -T typed '${root}' \ - '$(task-create)' '$(task-resume)' - grub> module /lib/ld.so.1 exec /hurd/exec '$(exec-task=task-create)' - - 3. Finally, run the command `boot' (*note boot::). - - -File: grub.info, Node: GNU/Linux, Next: DOS/Windows, Prev: GNU/Hurd, Up: OS-specific notes - -4.2.2 GNU/Linux ---------------- - -It is relatively easy to boot GNU/Linux from GRUB, because it somewhat -resembles to boot a Multiboot-compliant OS. - - 1. Set GRUB's root device to the same drive as GNU/Linux's. The - command `search --file --set /vmlinuz' or similar may help you - (*note search::). - - 2. Load the kernel using the command `linux' (*note linux::): - - grub> linux /vmlinuz root=/dev/sda1 - - If you need to specify some kernel parameters, just append them to - the command. For example, to set `acpi' to `off', do this: - - grub> linux /vmlinuz root=/dev/sda1 acpi=off - - See the documentation in the Linux source tree for complete - information on the available options. - - With `linux' GRUB uses 32-bit protocol. Some BIOS services like APM - or EDD aren't available with this protocol. In this case you need - to use `linux16' - - grub> linux16 /vmlinuz root=/dev/sda1 acpi=off - - 3. If you use an initrd, execute the command `initrd' (*note initrd::) - after `linux': - - grub> initrd /initrd - - If you used `linux16' you need to use `initrd16': - - grub> initrd16 /initrd - - 4. Finally, run the command `boot' (*note boot::). - - *Caution:* If you use an initrd and specify the `mem=' option to the -kernel to let it use less than actual memory size, you will also have -to specify the same memory size to GRUB. To let GRUB know the size, run -the command `uppermem' _before_ loading the kernel. *Note uppermem::, -for more information. - - -File: grub.info, Node: DOS/Windows, Prev: GNU/Linux, Up: OS-specific notes - -4.2.3 DOS/Windows ------------------ - -GRUB cannot boot DOS or Windows directly, so you must chain-load them -(*note Chain-loading::). However, their boot loaders have some critical -deficiencies, so it may not work to just chain-load them. To overcome -the problems, GRUB provides you with two helper functions. - - If you have installed DOS (or Windows) on a non-first hard disk, you -have to use the disk swapping technique, because that OS cannot boot -from any disks but the first one. The workaround used in GRUB is the -command `drivemap' (*note drivemap::), like this: - - drivemap -s (hd0) (hd1) - - This performs a "virtual" swap between your first and second hard -drive. - - *Caution:* This is effective only if DOS (or Windows) uses BIOS to -access the swapped disks. If that OS uses a special driver for the -disks, this probably won't work. - - Another problem arises if you installed more than one set of -DOS/Windows onto one disk, because they could be confused if there are -more than one primary partitions for DOS/Windows. Certainly you should -avoid doing this, but there is a solution if you do want to do so. Use -the partition hiding/unhiding technique. - - If GRUB "hides" a DOS (or Windows) partition (*note parttool::), DOS -(or Windows) will ignore the partition. If GRUB "unhides" a DOS (or -Windows) partition, DOS (or Windows) will detect the partition. Thus, -if you have installed DOS (or Windows) on the first and the second -partition of the first hard disk, and you want to boot the copy on the -first partition, do the following: - - parttool (hd0,1) hidden- - parttool (hd0,2) hidden+ - set root=(hd0,1) - chainloader +1 - parttool ${root} boot+ - boot - - -File: grub.info, Node: Configuration, Next: Theme file format, Prev: Booting, Up: Top - -5 Writing your own configuration file -************************************* - -GRUB is configured using `grub.cfg', usually located under -`/boot/grub'. This file is quite flexible, but most users will not -need to write the whole thing by hand. - -* Menu: - -* Simple configuration:: Recommended for most users -* Shell-like scripting:: For power users and developers -* Embedded configuration:: Embedding a configuration file into GRUB - - -File: grub.info, Node: Simple configuration, Next: Shell-like scripting, Up: Configuration - -5.1 Simple configuration handling -================================= - -The program `grub-mkconfig' (*note Invoking grub-mkconfig::) generates -`grub.cfg' files suitable for most cases. It is suitable for use when -upgrading a distribution, and will discover available kernels and -attempt to generate menu entries for them. - - `grub-mkconfig' does have some limitations. While adding extra -custom menu entries to the end of the list can be done by editing -`/etc/grub.d/40_custom' or creating `/boot/grub/custom.cfg', changing -the order of menu entries or changing their titles may require making -complex changes to shell scripts stored in `/etc/grub.d/'. This may be -improved in the future. In the meantime, those who feel that it would -be easier to write `grub.cfg' directly are encouraged to do so (*note -Booting::, and *note Shell-like scripting::), and to disable any system -provided by their distribution to automatically run `grub-mkconfig'. - - The file `/etc/default/grub' controls the operation of -`grub-mkconfig'. It is sourced by a shell script, and so must be valid -POSIX shell input; normally, it will just be a sequence of `KEY=value' -lines, but if the value contains spaces or other special characters -then it must be quoted. For example: - - GRUB_TERMINAL_INPUT="console serial" - - Valid keys in `/etc/default/grub' are as follows: - -`GRUB_DEFAULT' - The default menu entry. This may be a number, in which case it - identifies the Nth entry in the generated menu counted from zero, - or the title of a menu entry, or the special string `saved'. - Using the title may be useful if you want to set a menu entry as - the default even though there may be a variable number of entries - before it. - - For example, if you have: - - menuentry 'Example GNU/Linux distribution' --class gnu-linux { - ... - } - - then you can make this the default using: - - GRUB_DEFAULT='Example GNU/Linux distribution' - - If you set this to `saved', then the default menu entry will be - that saved by `GRUB_SAVEDEFAULT', `grub-set-default', or - `grub-reboot'. - - The default is `0'. - -`GRUB_SAVEDEFAULT' - If this option is set to `true', then, when an entry is selected, - save it as a new default entry for use by future runs of GRUB. - This is only useful if `GRUB_DEFAULT=saved'; it is a separate - option because `GRUB_DEFAULT=saved' is useful without this option, - in conjunction with `grub-set-default' or `grub-reboot'. Unset by - default. This option relies on the environment block, which may - not be available in all situations (*note Environment block::). - -`GRUB_TIMEOUT' - Boot the default entry this many seconds after the menu is - displayed, unless a key is pressed. The default is `5'. Set to - `0' to boot immediately without displaying the menu, or to `-1' to - wait indefinitely. - -`GRUB_HIDDEN_TIMEOUT' - Wait this many seconds for a key to be pressed before displaying - the menu. If no key is pressed during that time, boot - immediately. Unset by default. - -`GRUB_HIDDEN_TIMEOUT_QUIET' - In conjunction with `GRUB_HIDDEN_TIMEOUT', set this to `true' to - suppress the verbose countdown while waiting for a key to be - pressed before displaying the menu. Unset by default. - -`GRUB_DEFAULT_BUTTON' -`GRUB_TIMEOUT_BUTTON' -`GRUB_HIDDEN_TIMEOUT_BUTTON' -`GRUB_BUTTON_CMOS_ADDRESS' - Variants of the corresponding variables without the `_BUTTON' - suffix, used to support vendor-specific power buttons. *Note - Vendor power-on keys::. - -`GRUB_DISTRIBUTOR' - Set by distributors of GRUB to their identifying name. This is - used to generate more informative menu entry titles. - -`GRUB_TERMINAL_INPUT' - Select the terminal input device. You may select multiple devices - here, separated by spaces. - - Valid terminal input names depend on the platform, but may include - `console' (PC BIOS and EFI consoles), `serial' (serial terminal), - `ofconsole' (Open Firmware console), `at_keyboard' (PC AT - keyboard, mainly useful with Coreboot), or `usb_keyboard' (USB - keyboard using the HID Boot Protocol, for cases where the firmware - does not handle this). - - The default is to use the platform's native terminal input. - -`GRUB_TERMINAL_OUTPUT' - Select the terminal output device. You may select multiple - devices here, separated by spaces. - - Valid terminal output names depend on the platform, but may include - `console' (PC BIOS and EFI consoles), `serial' (serial terminal), - `gfxterm' (graphics-mode output), `ofconsole' (Open Firmware - console), or `vga_text' (VGA text output, mainly useful with - Coreboot). - - The default is to use the platform's native terminal output. - -`GRUB_TERMINAL' - If this option is set, it overrides both `GRUB_TERMINAL_INPUT' and - `GRUB_TERMINAL_OUTPUT' to the same value. - -`GRUB_SERIAL_COMMAND' - A command to configure the serial port when using the serial - console. *Note serial::. Defaults to `serial'. - -`GRUB_CMDLINE_LINUX' - Command-line arguments to add to menu entries for the Linux kernel. - -`GRUB_CMDLINE_LINUX_DEFAULT' - Unless `GRUB_DISABLE_RECOVERY' is set to `true', two menu entries - will be generated for each Linux kernel: one default entry and one - entry for recovery mode. This option lists command-line arguments - to add only to the default menu entry, after those listed in - `GRUB_CMDLINE_LINUX'. - -`GRUB_CMDLINE_NETBSD' -`GRUB_CMDLINE_NETBSD_DEFAULT' - As `GRUB_CMDLINE_LINUX' and `GRUB_CMDLINE_LINUX_DEFAULT', but for - NetBSD. - -`GRUB_CMDLINE_XEN' -`GRUB_CMDLINE_XEN_DEFAULT' - As `GRUB_CMDLINE_LINUX' and `GRUB_CMDLINE_LINUX_DEFAULT', but for - Linux and Xen. - -`GRUB_DISABLE_LINUX_UUID' - Normally, `grub-mkconfig' will generate menu entries that use - universally-unique identifiers (UUIDs) to identify the root - filesystem to the Linux kernel, using a `root=UUID=...' kernel - parameter. This is usually more reliable, but in some cases it - may not be appropriate. To disable the use of UUIDs, set this - option to `true'. - -`GRUB_DISABLE_RECOVERY' - If this option is set to `true', disable the generation of recovery - mode menu entries. - -`GRUB_VIDEO_BACKEND' - If graphical video support is required, either because the - `gfxterm' graphical terminal is in use or because - `GRUB_GFXPAYLOAD_LINUX' is set, then `grub-mkconfig' will normally - load all available GRUB video drivers and use the one most - appropriate for your hardware. If you need to override this for - some reason, then you can set this option. - - After `grub-install' has been run, the available video drivers are - listed in `/boot/grub/video.lst'. - -`GRUB_GFXMODE' - Set the resolution used on the `gfxterm' graphical terminal. Note - that you can only use modes which your graphics card supports via - VESA BIOS Extensions (VBE), so for example native LCD panel - resolutions may not be available. The default is `640x480'. - *Note gfxmode::. - -`GRUB_BACKGROUND' - Set a background image for use with the `gfxterm' graphical - terminal. The value of this option must be a file readable by - GRUB at boot time, and it must end with `.png', `.tga', `.jpg', or - `.jpeg'. The image will be scaled if necessary to fit the screen. - -`GRUB_THEME' - Set a theme for use with the `gfxterm' graphical terminal. - -`GRUB_GFXPAYLOAD_LINUX' - Set to `text' to force the Linux kernel to boot in normal text - mode, `keep' to preserve the graphics mode set using - `GRUB_GFXMODE', `WIDTHxHEIGHT'[`xDEPTH'] to set a particular - graphics mode, or a sequence of these separated by commas or - semicolons to try several modes in sequence. *Note gfxpayload::. - - Depending on your kernel, your distribution, your graphics card, - and the phase of the moon, note that using this option may cause - GNU/Linux to suffer from various display problems, particularly - during the early part of the boot sequence. If you have problems, - set this option to `text' and GRUB will tell Linux to boot in - normal text mode. - -`GRUB_DISABLE_OS_PROBER' - Normally, `grub-mkconfig' will try to use the external `os-prober' - program, if installed, to discover other operating systems - installed on the same system and generate appropriate menu entries - for them. Set this option to `true' to disable this. - -`GRUB_INIT_TUNE' - Play a tune on the speaker when GRUB starts. This is particularly - useful for users unable to see the screen. The value of this - option is passed directly to *note play::. - -`GRUB_BADRAM' - If this option is set, GRUB will issue a *note badram:: command to - filter out specified regions of RAM. - -`GRUB_PRELOAD_MODULES' - This option may be set to a list of GRUB module names separated by - spaces. Each module will be loaded as early as possible, at the - start of `grub.cfg'. - - - For more detailed customisation of `grub-mkconfig''s output, you may -edit the scripts in `/etc/grub.d' directly. `/etc/grub.d/40_custom' is -particularly useful for adding entire custom menu entries; simply type -the menu entries you want to add at the end of that file, making sure -to leave at least the first two lines intact. - - -File: grub.info, Node: Shell-like scripting, Next: Embedded configuration, Prev: Simple configuration, Up: Configuration - -5.2 Writing full configuration files directly -============================================= - -`grub.cfg' is written in GRUB's built-in scripting language, which has -a syntax quite similar to that of GNU Bash and other Bourne shell -derivatives. - -Words -===== - -A "word" is a sequence of characters considered as a single unit by -GRUB. Words are separated by "metacharacters", which are the following -plus space, tab, and newline: - - { } | & $ ; < > - - Quoting may be used to include metacharacters in words; see below. - -Reserved words -============== - -Reserved words have a special meaning to GRUB. The following words are -recognised as reserved when unquoted and either the first word of a -simple command or the third word of a `for' command: - - ! [[ ]] { } - case do done elif else esac fi for function - if in menuentry select then time until while - - Not all of these reserved words have a useful purpose yet; some are -reserved for future expansion. - -Quoting -======= - -Quoting is used to remove the special meaning of certain characters or -words. It can be used to treat metacharacters as part of a word, to -prevent reserved words from being recognised as such, and to prevent -variable expansion. - - There are three quoting mechanisms: the escape character, single -quotes, and double quotes. - - A non-quoted backslash (\) is the "escape character". It preserves -the literal value of the next character that follows, with the -exception of newline. - - Enclosing characters in single quotes preserves the literal value of -each character within the quotes. A single quote may not occur between -single quotes, even when preceded by a backslash. - - Enclosing characters in double quotes preserves the literal value of -all characters within the quotes, with the exception of `$' and `\'. -The `$' character retains its special meaning within double quotes. -The backslash retains its special meaning only when followed by one of -the following characters: `$', `"', `\', or newline. A -backslash-newline pair is treated as a line continuation (that is, it is -removed from the input stream and effectively ignored(1) (*note -Shell-like scripting-Footnote-1::)). A double quote may be quoted -within double quotes by preceding it with a backslash. - -Variable expansion -================== - -The `$' character introduces variable expansion. The variable name to -be expanded may be enclosed in braces, which are optional but serve to -protect the variable to be expanded from characters immediately -following it which could be interpreted as part of the name. - - Normal variable names begin with an alphabetic character, followed -by zero or more alphanumeric characters. These names refer to entries -in the GRUB environment (*note Environment::). - - Positional variable names consist of one or more digits. They -represent parameters passed to function calls, with `$1' representing -the first parameter, and so on. - - The special variable name `?' expands to the exit status of the most -recently executed command. When positional variable names are active, -other special variable names `@', `*' and `#' are defined and they -expand to all positional parameters with necessary quoting, positional -parameters without any quoting, and positional parameter count -respectively. - -Comments -======== - -A word beginning with `#' causes that word and all remaining characters -on that line to be ignored. - -Simple commands -=============== - -A "simple command" is a sequence of words separated by spaces or tabs -and terminated by a semicolon or a newline. The first word specifies -the command to be executed. The remaining words are passed as -arguments to the invoked command. - - The return value of a simple command is its exit status. If the -reserved word `!' precedes the command, then the return value is -instead the logical negation of the command's exit status. - -Compound commands -================= - -A "compound command" is one of the following: - -for NAME in WORD ...; do LIST; done - The list of words following `in' is expanded, generating a list of - items. The variable NAME is set to each element of this list in - turn, and LIST is executed each time. The return value is the - exit status of the last command that executes. If the expansion - of the items following `in' results in an empty list, no commands - are executed, and the return status is 0. - -if LIST; then LIST; [elif LIST; then LIST;] ... [else LIST;] fi - The `if' LIST is executed. If its exit status is zero, the `then' - LIST is executed. Otherwise, each `elif' LIST is executed in - turn, and if its exit status is zero, the corresponding `then' - LIST is executed and the command completes. Otherwise, the `else' - LIST is executed, if present. The exit status is the exit status - of the last command executed, or zero if no condition tested true. - -while COND; do LIST; done -until COND; do LIST; done - The `while' command continuously executes the `do' LIST as long as - the last command in COND returns an exit status of zero. The - `until' command is identical to the `while' command, except that - the test is negated; the `do' LIST is executed as long as the last - command in COND returns a non-zero exit status. The exit status - of the `while' and `until' commands is the exit status of the last - `do' LIST command executed, or zero if none was executed. - -function NAME { COMMAND; ... } - This defines a function named NAME. The "body" of the function is - the list of commands within braces, each of which must be - terminated with a semicolon or a newline. This list of commands - will be executed whenever NAME is specified as the name of a - simple command. Function definitions do not affect the exit - status in `$?'. When executed, the exit status of a function is - the exit status of the last command executed in the body. - -menuentry TITLE [`--class=class' ...] [`--users=users'] [`--hotkey=key'] { COMMAND; ... } - *Note menuentry::. - -Built-in Commands -================= - -Some built-in commands are also provided by GRUB script to help script -writers perform actions that are otherwise not possible. For example, -these include commands to jump out of a loop without fully completing -it, etc. - -break [`n'] - Exit from within a `for', `while', or `until' loop. If `n' is - specified, break `n' levels. `n' must be greater than or equal to - 1. If `n' is greater than the number of enclosing loops, all - enclosing loops are exited. The return value is 0 unless `n' is - not greater than or equal to 1. - -continue [`n'] - Resume the next iteration of the enclosing `for', `while' or - `until' loop. If `n' is specified, resume at the `n'th enclosing - loop. `n' must be greater than or equal to 1. If `n' is greater - than the number of enclosing loops, the last enclosing loop (the - "top-level" loop) is resumed. The return value is 0 unless `n' is - not greater than or equal to 1. - -return [`n'] - Causes a function to exit with the return value specified by `n'. - If `n' is omitted, the return status is that of the last command - executed in the function body. If used outside a function the - return status is false. - -shift [`n'] - The positional parameters from `n'+1 ... are renamed to `$1'.... - Parameters represented by the numbers `$#' down to `$#'-`n'+1 are - unset. `n' must be a non-negative number less than or equal to - `$#'. If `n' is 0, no parameters are changed. If `n' is not - given, it is assumed to be 1. If `n' is greater than `$#', the - positional parameters are not changed. The return status is - greater than zero if `n' is greater than `$#' or less than zero; - otherwise 0. - - - -File: grub.info, Node: Shell-like scripting-Footnotes, Up: Shell-like scripting - - (1) Currently a backslash-newline pair within a variable name is not -handled properly, so use this feature with some care. - - -File: grub.info, Node: Embedded configuration, Prev: Shell-like scripting, Up: Configuration - -5.3 Embedding a configuration file into GRUB -============================================ - -GRUB supports embedding a configuration file directly into the core -image, so that it is loaded before entering normal mode. This is -useful, for example, when it is not straightforward to find the real -configuration file, or when you need to debug problems with loading -that file. `grub-install' uses this feature when it is not using BIOS -disk functions or when installing to a different disk from the one -containing `/boot/grub', in which case it needs to use the `search' -command (*note search::) to find `/boot/grub'. - - To embed a configuration file, use the `-c' option to -`grub-mkimage'. The file is copied into the core image, so it may -reside anywhere on the file system, and may be removed after running -`grub-mkimage'. - - After the embedded configuration file (if any) is executed, GRUB -will load the `normal' module (*note normal::), which will then read -the real configuration file from `$prefix/grub.cfg'. By this point, the -`root' variable will also have been set to the root device name. For -example, `prefix' might be set to `(hd0,1)/boot/grub', and `root' might -be set to `hd0,1'. Thus, in most cases, the embedded configuration -file only needs to set the `prefix' and `root' variables, and then drop -through to GRUB's normal processing. A typical example of this might -look like this: - - search.fs_uuid 01234567-89ab-cdef-0123-456789abcdef root - set prefix=($root)/boot/grub - - (The `search_fs_uuid' module must be included in the core image for -this example to work.) - - In more complex cases, it may be useful to read other configuration -files directly from the embedded configuration file. This allows such -things as reading files not called `grub.cfg', or reading files from a -directory other than that where GRUB's loadable modules are installed. -To do this, include the `configfile' and `normal' modules in the core -image, and embed a configuration file that uses the `configfile' -command to load another file. The following example of this also -requires the `echo', `search_label', and `test' modules to be included -in the core image: - - search.fs_label grub root - if [ -e /boot/grub/example/test1.cfg ]; then - set prefix=($root)/boot/grub - configfile /boot/grub/example/test1.cfg - else - if [ -e /boot/grub/example/test2.cfg ]; then - set prefix=($root)/boot/grub - configfile /boot/grub/example/test2.cfg - else - echo "Could not find an example configuration file!" - fi - fi - - The embedded configuration file may not contain menu entries -directly, but may only read them from elsewhere using `configfile'. - - -File: grub.info, Node: Theme file format, Next: Network, Prev: Configuration, Up: Top - -6 Theme file format -******************* - -6.1 Introduction -================ - -The GRUB graphical menu supports themes that can customize the layout -and appearance of the GRUB boot menu. The theme is configured through -a plain text file that specifies the layout of the various GUI -components (including the boot menu, timeout progress bar, and text -messages) as well as the appearance using colors, fonts, and images. -Example is available in docs/example_theme.txt - -6.2 Theme Elements -================== - -6.2.1 Colors ------------- - -Colors can be specified in several ways: - - * HTML-style "#RRGGBB" or "#RGB" format, where *R*, *G*, and *B* are - hexadecimal digits (e.g., "#8899FF") - - * as comma-separated decimal RGB values (e.g., "128, 128, 255") - - * with "SVG 1.0 color names" (e.g., "cornflowerblue") which must be - specified in lowercase. - -6.2.2 Fonts ------------ - -The fonts GRUB uses "PFF2 font format" bitmap fonts. Fonts are -specified with full font names. Currently there is no provision for a -preference list of fonts, or deriving one font from another. Fonts are -loaded with the "loadfont" command in GRUB. To see the list of loaded -fonts, execute the "lsfonts" command. If there are too many fonts to -fit on screen, do "set pager=1" before executing "lsfonts". - -6.2.3 Progress Bar ------------------- - -Figure 6.1 - -Figure 6.2 - - Progress bars are used to display the remaining time before GRUB -boots the default menu entry. To create a progress bar that will -display the remaining time before automatic boot, simply create a -"progress_bar" component with the id "__timeout__". This indicates to -GRUB that the progress bar should be updated as time passes, and it -should be made invisible if the countdown to automatic boot is -interrupted by the user. - - Progress bars may optionally have text displayed on them. This is -controlled through the "show_text" property, which can be set to either -"true" or "false" to control whether text is displayed. When GRUB is -counting down to automatic boot, the text informs the user of the -number of seconds remaining. - -6.2.4 Circular Progress Indicator ---------------------------------- - -The circular progress indicator functions similarly to the progress -bar. When given an id of "__timeout__", GRUB updates the circular -progress indicator's value to indicate the time remaining. For the -circular progress indicator, there are two images used to render it: -the *center* image, and the *tick* image. The center image is rendered -in the center of the component, while the tick image is used to render -each mark along the circumference of the indicator. - -6.2.5 Labels ------------- - -Text labels can be placed on the boot screen. The font, color, and -horizontal alignment can be specified for labels. If a label is given -the id "__timeout__", then the "text" property for that label is also -updated with a message informing the user of the number of seconds -remaining until automatic boot. This is useful in case you want the -text displayed somewhere else instead of directly on the progress bar. - -6.2.6 Boot Menu ---------------- - -The boot menu where GRUB displays the menu entries from the "grub.cfg" -file. It is a list of items, where each item has a title and an -optional icon. The icon is selected based on the *classes* specified -for the menu entry. If there is a PNG file named "myclass.png" in the -"grub/themes/icons" directory, it will be displayed for items which -have the class *myclass*. The boot menu can be customized in several -ways, such as the font and color used for the menu entry title, and by -specifying styled boxes for the menu itself and for the selected item -highlight. - -6.2.7 Styled Boxes ------------------- - -One of the most important features for customizing the layout is the -use of *styled boxes*. A styled box is composed of 9 rectangular (and -potentially empty) regions, which are used to seamlessly draw the -styled box on screen: - -Northwest (nw) North (n) Northeast (ne) -West (w) Center (c) East (e) -Southwest (sw) South (s) Southeast (se) - - To support any size of box on screen, the center slice and the -slices for the top, bottom, and sides are all scaled to the correct -size for the component on screen, using the following rules: - - 1. The edge slices (north, south, east, and west) are scaled in the - direction of the edge they are adjacent to. For instance, the - west slice is scaled vertically. - - 2. The corner slices (northwest, northeast, southeast, and southwest) - are not scaled. - - 3. The center slice is scaled to fill the remaining space in the - middle. - - As an example of how an image might be sliced up, consider the -styled box used for a terminal view. - -Figure 6.3 - -6.2.8 Creating Styled Box Images --------------------------------- - -The Inkscape_ scalable vector graphics editor is a very useful tool for -creating styled box images. One process that works well for slicing a -drawing into the necessary image slices is: - - 1. Create or open the drawing you'd like use. - - 2. Create a new layer on the top of the layer stack. Make it - visible. Select this layer as the current layer. - - 3. Draw 9 rectangles on your drawing where you'd like the slices to - be. Clear the fill option, and set the stroke to 1 pixel wide - solid stroke. The corners of the slices must meet precisely; if - it is off by a single pixel, it will probably be evident when the - styled box is rendered in the GRUB menu. You should probably go - to File | Document Properties | Grids and enable a grid or create - a guide (click on one of the rulers next to the drawing and drag - over the drawing; release the mouse button to place the guide) to - help place the rectangles precisely. - - 4. Right click on the center slice rectangle and choose Object - Properties. Change the "Id" to "slice_c" and click Set. Repeat - this for the remaining 8 rectangles, giving them Id values of - "slice_n", "slice_ne", "slice_e", and so on according to the - location. - - 5. Save the drawing. - - 6. Select all the slice rectangles. With the slice layer selected, - you can simply press Ctrl+A to select all rectangles. The status - bar should indicate that 9 rectangles are selected. - - 7. Click the layer hide icon for the slice layer in the layer - palette. The rectangles will remain selected, even though they - are hidden. - - 8. Choose File | Export Bitmap and check the *Batch export 9 selected - objects* box. Make sure that *Hide all except selected* is - unchecked. click *Export*. This will create PNG files in the same - directory as the drawing, named after the slices. These can now - be used for a styled box in a GRUB theme. - -6.3 Theme File Manual -===================== - -The theme file is a plain text file. Lines that begin with "#" are -ignored and considered comments. (Note: This may not be the case if -the previous line ended where a value was expected.) - - The theme file contains two types of statements: - 1. Global properties. - - 2. Component construction. - -6.3.1 Global Properties ------------------------ - -6.3.2 Format ------------- - -Global properties are specified with the simple format: - * name1: value1 - - * name2: "value which may contain spaces" - - * name3: #88F - - In this example, name3 is assigned a color value. - -6.3.3 Global Property List --------------------------- - -title-text Specifies the text to display at the top - center of the screen as a title. -title-font Defines the font used for the title - message at the top of the screen. -title-color Defines the color of the title message. -message-font Defines the font used for messages, such - as when GRUB is unable to automatically - boot an entry. -message-color Defines the color of the message text. -message-bg-color Defines the background color of the - message text area. -desktop-image Specifies the image to use as the - background. It will be scaled to fit the - screen size. -desktop-color Specifies the color for the background if - *desktop-image* is not specified. -terminal-box Specifies the file name pattern for the - styled box slices used for the command - line terminal window. For example, - "terminal-box: terminal_*.png" will use - the images "terminal_c.png" as the center - area, "terminal_n.png" as the north (top) - edge, "terminal_nw.png" as the northwest - (upper left) corner, and so on. If the - image for any slice is not found, it will - simply be left empty. - -6.3.4 Component Construction ----------------------------- - -Greater customizability comes is provided by components. A tree of -components forms the user interface. *Containers* are components that -can contain other components, and there is always a single root -component which is an instance of a *canvas* container. - - Components are created in the theme file by prefixing the type of -component with a '+' sign: - - ` + label { text="GRUB" font="aqui 11" color="#8FF" } ' - - properties of a component are specified as "name = value" (whitespace -surrounding tokens is optional and is ignored) where *value* may be: - * a single word (e.g., "align = center", "color = #FF8080"), - - * a quoted string (e.g., "text = "Hello, World!""), or - - * a tuple (e.g., "preferred_size = (120, 80)"). - -6.3.5 Component List --------------------- - -The following is a list of the components and the properties they -support. - - * label A label displays a line of text. - - Properties: - text The text to display. - font The font to use for text display. - color The color of the text. - align The horizontal alignment of the text within - the component. Options are "left", "center", - and "right". - - * image A component that displays an image. The image is scaled - to fit the component, although the preferred size defaults to - the image's original size unless the "preferred_size" property - is explicitly set. - - Properties: - - file The full path to the image file to load. - - * progress_bar Displays a horizontally oriented progress bar. It - can be rendered using simple solid filled rectangles, or using - a pair of pixmap styled boxes. - - Properties: - - fg_color The foreground color for plain solid color - rendering. - bg_color The background color for plain solid color - rendering. - border_color The border color for plain solid color - rendering. - text_color The text color. - show_text Boolean value indicating whether or not text - should be displayed on the progress bar. If - set to *false*, then no text will be displayed - on the bar. If set to any other value, text - will be displayed on the bar. - bar_style The styled box specification for the frame of - the progress bar. Example: - "progress_frame_*.png" - highlight_styleThe styled box specification for the - highlighted region of the progress bar. This - box will be used to paint just the highlighted - region of the bar, and will be increased in - size as the bar nears completion. Example: - "progress_hl_*.png". - text The text to display on the progress bar. If - the progress bar's ID is set to "__timeout__", - then GRUB will updated this property with an - informative message as the timeout approaches. - value The progress bar current value. Normally not - set manually. - start The progress bar start value. Normally not - set manually. - end The progress bar end value. Normally not set - manually. - - * circular_progress Displays a circular progress indicator. The - appearance of this component is determined by two images: the - *center* image and the *tick* image. The center image is - generally larger and will be drawn in the center of the - component. Around the circumference of a circle within the - component, the tick image will be drawn a certain number of - times, depending on the properties of the component. - - Properties: - - center_bitmap The file name of the image to draw in - the center of the component. - tick_bitmap The file name of the image to draw for - the tick marks. - num_ticks The number of ticks that make up a full - circle. - ticks_disappear Boolean value indicating whether tick - marks should progressively appear, - or progressively disappear as *value* - approaches *end*. Specify "true" - or "false". - value The progress indicator current value. - Normally not set manually. - start The progress indicator start value. - Normally not set manually. - end The progress indicator end value. - Normally not set manually. - - * boot_menu Displays the GRUB boot menu. It allows selecting - items and executing them. - - Properties: - - item_font The font to use for the menu item - titles. - selected_item_font The font to use for the selected - menu item, or "inherit" (the - default) to use "item_font" - for the selected menu item as - well. - item_color The color to use for the menu - item titles. - selected_item_color The color to use for the selected - menu item, or "inherit" (the - default) to use - "item_color" for the selected - menu item as well. - icon_width The width of menu item icons. - Icons are scaled to the specified - size. - icon_height The height of menu item icons. - item_height The height of each menu item in - pixels. - item_padding The amount of space in pixels to - leave on each side of the menu - item contents. - item_icon_space The space between an item's icon - and the title text, in pixels. - item_spacing The amount of space to leave - between menu items, in pixels. - menu_pixmap_style The image file pattern for the - menu frame styled box. - Example: "menu_*.png" (this will - use images such as "menu_c.png", - "menu_w.png", `menu_nw.png", - etc.) - selected_item_pixmap_style The image file pattern for the - selected item highlight styled - box. - scrollbar Boolean value indicating whether - the scroll bar should be drawn if - the frame and thumb styled - boxes are configured. - scrollbar_frame The image file pattern for the - entire scroll bar. - Example: "scrollbar_*.png" - scrollbar_thumb The image file pattern for the - scroll bar thumb (the part of the - scroll bar that moves as - scrolling occurs). - Example: "scrollbar_thumb_*.png" - max_items_shown The maximum number of items to - show on the menu. If there are - more than *max_items_shown* - items in the menu, the list will - scroll to make all items - accessible. - - * canvas Canvas is a container that allows manual placement of - components within it. It does not alter the positions of its - child components. It assigns all child components their - preferred sizes. - - * hbox The *hbox* container lays out its children from left to - right, giving each one its preferred width. The height of each - child is set to the maximum of the preferred heights of all - children. - - * vbox The *vbox* container lays out its children from top to - bottom, giving each one its preferred height. The width of - each child is set to the maximum of the preferred widths of all - children. - -6.3.6 Common properties ------------------------ - -The following properties are supported by all components: -`left' - The distance from the left border of container to left border of - the object in either of three formats: - x Value in pixels - p% Percentage - p%+x mixture of both - -`top' - The distance from the left border of container to left border of - the object in same format. - -`width' - The width of object in same format. - -`height' - The height of object in same format. - -`id' - The identifier for the component. This can be any arbitrary - string. The ID can be used by scripts to refer to various - components in the GUI component tree. Currently, there is one - special ID value that GRUB recognizes: - - "__timeout__" Any component with this ID will have its - *text*, *start*, *end*, *value*, and *visible* - properties set by GRUB when it is counting - down to an automatic boot of the default menu - entry. - - -File: grub.info, Node: Network, Next: Serial terminal, Prev: Theme file format, Up: Top - -7 Booting GRUB from the network -******************************* - -The following instructions only work on PC BIOS systems where the -Preboot eXecution Environment (PXE) is available. - - To generate a PXE boot image, run: - - grub-mkimage --format=i386-pc-pxe --output=grub.pxe --prefix='(pxe)/boot/grub' pxe pxecmd - - Copy `grub.pxe', `/boot/grub/*.mod', and `/boot/grub/*.lst' to the -PXE (TFTP) server, ensuring that `*.mod' and `*.lst' are accessible via -the `/boot/grub/' path from the TFTP server root. Set the DHCP server -configuration to offer `grub.pxe' as the boot file (the `filename' -option in ISC dhcpd). - - You can also use the `grub-mknetdir' utility to generate an image -and a GRUB directory tree, rather than copying files around manually. - - After GRUB has started, files on the TFTP server will be accessible -via the `(pxe)' device. - - The server and gateway IP address can be controlled by changing the -`(pxe)' device name to `(pxe:SERVER-IP)' or -`(pxe:SERVER-IP:GATEWAY-IP)'. Note that this should be changed both in -the prefix and in any references to the device name in the -configuration file. - - GRUB provides several environment variables which may be used to -inspect or change the behaviour of the PXE device: - -`net_pxe_ip' - The IP address of this machine. Read-only. - -`net_pxe_mac' - The network interface's MAC address. Read-only. - -`net_pxe_hostname' - The client host name provided by DHCP. Read-only. - -`net_pxe_domain' - The client domain name provided by DHCP. Read-only. - -`net_pxe_rootpath' - The path to the client's root disk provided by DHCP. Read-only. - -`net_pxe_extensionspath' - The path to additional DHCP vendor extensions provided by DHCP. - Read-only. - -`net_pxe_boot_file' - The boot file name provided by DHCP. Read-only. - -`net_pxe_dhcp_server_name' - The name of the DHCP server responsible for these boot parameters. - Read-only. - -`pxe_blksize' - The PXE transfer block size. Read-write, defaults to 512. - -`pxe_default_server' - The default PXE server. Read-write, although setting this is only - useful before opening a PXE device. - -`pxe_default_gateway' - The default gateway to use when contacting the PXE server. - Read-write, although setting this is only useful before opening a - PXE device. - - -File: grub.info, Node: Serial terminal, Next: Vendor power-on keys, Prev: Network, Up: Top - -8 Using GRUB via a serial line -****************************** - -This chapter describes how to use the serial terminal support in GRUB. - - If you have many computers or computers with no display/keyboard, it -could be very useful to control the computers through serial -communications. To connect one computer with another via a serial line, -you need to prepare a null-modem (cross) serial cable, and you may need -to have multiport serial boards, if your computer doesn't have extra -serial ports. In addition, a terminal emulator is also required, such as -minicom. Refer to a manual of your operating system, for more -information. - - As for GRUB, the instruction to set up a serial terminal is quite -simple. Here is an example: - - grub> serial --unit=0 --speed=9600 - grub> terminal_input serial; terminal_output serial - - The command `serial' initializes the serial unit 0 with the speed -9600bps. The serial unit 0 is usually called `COM1', so, if you want to -use COM2, you must specify `--unit=1' instead. This command accepts -many other options, so please refer to *note serial::, for more details. - - The commands `terminal_input' (*note terminal_input::) and -`terminal_output' (*note terminal_output::) choose which type of -terminal you want to use. In the case above, the terminal will be a -serial terminal, but you can also pass `console' to the command, as -`terminal_input serial console'. In this case, a terminal in which you -press any key will be selected as a GRUB terminal. In the example above, -note that you need to put both commands on the same command line, as you -will lose the ability to type commands on the console after the first -command. - - However, note that GRUB assumes that your terminal emulator is -compatible with VT100 by default. This is true for most terminal -emulators nowadays, but you should pass the option `--dumb' to the -command if your terminal emulator is not VT100-compatible or implements -few VT100 escape sequences. If you specify this option then GRUB -provides you with an alternative menu interface, because the normal -menu requires several fancy features of your terminal. - - -File: grub.info, Node: Vendor power-on keys, Next: Images, Prev: Serial terminal, Up: Top - -9 Using GRUB with vendor power-on keys -************************************** - -Some laptop vendors provide an additional power-on button which boots -another OS. GRUB supports such buttons with the `GRUB_TIMEOUT_BUTTON', -`GRUB_DEFAULT_BUTTON', `GRUB_HIDDEN_TIMEOUT_BUTTON' and -`GRUB_BUTTON_CMOS_ADDRESS' variables in default/grub (*note Simple -configuration::). `GRUB_TIMEOUT_BUTTON', `GRUB_DEFAULT_BUTTON' and -`GRUB_HIDDEN_TIMEOUT_BUTTON' are used instead of the corresponding -variables without the `_BUTTON' suffix when powered on using the special -button. `GRUB_BUTTON_CMOS_ADDRESS' is vendor-specific and partially -model-specific. Values known to the GRUB team are: - -<Dell XPS M1530> - 85:3 - -<Asus EeePC 1005PE> - 84:1 (unconfirmed) - - To take full advantage of this function, install GRUB into the MBR -(*note Installing GRUB using grub-install::). - - If you have a laptop which has a similar feature and not in the -above list could you figure your address and contribute? To discover -the address do the following: - * boot normally - - * sudo modprobe nvram - sudo cat /dev/nvram | xxd > normal_button.txt - - * boot using vendor button - - * sudo modprobe nvram - sudo cat /dev/nvram | xxd > normal_vendor.txt - - Then compare these text files and find where a bit was toggled. E.g. -in case of Dell XPS it was: - byte 0x47: 20 --> 28 - It's a bit number 3 as seen from following table: -0 01 -1 02 -2 04 -3 08 -4 10 -5 20 -6 40 -7 80 - - 0x47 is decimal 71. Linux nvram implementation cuts first 14 bytes of -CMOS. So the real byte address in CMOS is 71+14=85 So complete address -is 85:3 - - -File: grub.info, Node: Images, Next: Filesystem, Prev: Vendor power-on keys, Up: Top - -10 GRUB image files -******************* - -GRUB consists of several images: a variety of bootstrap images for -starting GRUB in various ways, a kernel image, and a set of modules -which are combined with the kernel image to form a core image. Here is -a short overview of them. - -`boot.img' - On PC BIOS systems, this image is the first part of GRUB to start. - It is written to a master boot record (MBR) or to the boot sector - of a partition. Because a PC boot sector is 512 bytes, the size - of this image is exactly 512 bytes. - - The sole function of `boot.img' is to read the first sector of the - core image from a local disk and jump to it. Because of the size - restriction, `boot.img' cannot understand any file system - structure, so `grub-setup' hardcodes the location of the first - sector of the core image into `boot.img' when installing GRUB. - -`diskboot.img' - This image is used as the first sector of the core image when - booting from a hard disk. It reads the rest of the core image - into memory and starts the kernel. Since file system handling is - not yet available, it encodes the location of the core image using - a block list format. - -`cdboot.img' - This image is used as the first sector of the core image when - booting from a CD-ROM drive. It performs a similar function to - `diskboot.img'. - -`pxeboot.img' - This image is used as the start of the core image when booting - from the network using PXE. *Note Network::. - -`lnxboot.img' - This image may be placed at the start of the core image in order - to make GRUB look enough like a Linux kernel that it can be booted - by LILO using an `image=' section. - -`kernel.img' - This image contains GRUB's basic run-time facilities: frameworks - for device and file handling, environment variables, the rescue - mode command-line parser, and so on. It is rarely used directly, - but is built into all core images. - -`core.img' - This is the core image of GRUB. It is built dynamically from the - kernel image and an arbitrary list of modules by the `grub-mkimage' - program. Usually, it contains enough modules to access - `/boot/grub', and loads everything else (including menu handling, - the ability to load target operating systems, and so on) from the - file system at run-time. The modular design allows the core image - to be kept small, since the areas of disk where it must be - installed are often as small as 32KB. - - *Note BIOS installation::, for details on where the core image can - be installed on PC systems. - -`*.mod' - Everything else in GRUB resides in dynamically loadable modules. - These are often loaded automatically, or built into the core image - if they are essential, but may also be loaded manually using the - `insmod' command (*note insmod::). - -For GRUB Legacy users -===================== - -GRUB 2 has a different design from GRUB Legacy, and so correspondences -with the images it used cannot be exact. Nevertheless, GRUB Legacy -users often ask questions in the terms they are familiar with, and so -here is a brief guide to how GRUB 2's images relate to that. - -`stage1' - Stage 1 from GRUB Legacy was very similar to `boot.img' in GRUB 2, - and they serve the same function. - -`*_stage1_5' - In GRUB Legacy, Stage 1.5's function was to include enough - filesystem code to allow the much larger Stage 2 to be read from - an ordinary filesystem. In this respect, its function was similar - to `core.img' in GRUB 2. However, `core.img' is much more capable - than Stage 1.5 was; since it offers a rescue shell, it is - sometimes possible to recover manually in the event that it is - unable to load any other modules, for example if partition numbers - have changed. `core.img' is built in a more flexible way, - allowing GRUB 2 to support reading modules from advanced disk - types such as LVM and RAID. - - GRUB Legacy could run with only Stage 1 and Stage 2 in some limited - configurations, while GRUB 2 requires `core.img' and cannot work - without it. - -`stage2' - GRUB 2 has no single Stage 2 image. Instead, it loads modules from - `/boot/grub' at run-time. - -`stage2_eltorito' - In GRUB 2, images for booting from CD-ROM drives are now - constructed using `cdboot.img' and `core.img', making sure that - the core image contains the `iso9660' module. It is usually best - to use the `grub-mkrescue' program for this. - -`nbgrub' - There is as yet no equivalent for `nbgrub' in GRUB 2; it was used - by Etherboot and some other network boot loaders. - -`pxegrub' - In GRUB 2, images for PXE network booting are now constructed using - `pxeboot.img' and `core.img', making sure that the core image - contains the `pxe' and `pxecmd' modules. *Note Network::. - - -File: grub.info, Node: Filesystem, Next: Interface, Prev: Images, Up: Top - -11 Filesystem syntax and semantics -********************************** - -GRUB uses a special syntax for specifying disk drives which can be -accessed by BIOS. Because of BIOS limitations, GRUB cannot distinguish -between IDE, ESDI, SCSI, or others. You must know yourself which BIOS -device is equivalent to which OS device. Normally, that will be clear if -you see the files in a device or use the command `search' (*note -search::). - -* Menu: - -* Device syntax:: How to specify devices -* File name syntax:: How to specify files -* Block list syntax:: How to specify block lists - - -File: grub.info, Node: Device syntax, Next: File name syntax, Up: Filesystem - -11.1 How to specify devices -=========================== - -The device syntax is like this: - - `(DEVICE[,PART-NUM][,BSD-SUBPART-LETTER])' - - `[]' means the parameter is optional. DEVICE should be either `fd' -or `hd' followed by a digit, like `fd0'. But you can also set DEVICE -to a hexadecimal or a decimal number which is a BIOS drive number, so -the following are equivalent: - - (hd0) - (0x80) - (128) - - PART-NUM represents the partition number of DEVICE, starting from -one for primary partitions and from five for extended partitions, and -BSD-SUBPART-LETTER represents the BSD disklabel subpartition, such as -`a' or `e'. - - A shortcut for specifying BSD subpartitions is -`(DEVICE,BSD-SUBPART-LETTER)', in this case, GRUB searches for the -first PC partition containing a BSD disklabel, then finds the -subpartition BSD-SUBPART-LETTER. Here is an example: - - (hd0,a) - - The syntax `(hd0)' represents using the entire disk (or the MBR when -installing GRUB), while the syntax `(hd0,1)' represents using the first -partition of the disk (or the boot sector of the partition when -installing GRUB). - - If you enabled the network support, the special drive `(pxe)' is -also available. Before using the network drive, you must initialize the -network. *Note Network::, for more information. - - If you boot GRUB from a CD-ROM, `(cd)' is available. *Note Making a -GRUB bootable CD-ROM::, for details. - - -File: grub.info, Node: File name syntax, Next: Block list syntax, Prev: Device syntax, Up: Filesystem - -11.2 How to specify files -========================= - -There are two ways to specify files, by "absolute file name" and by -"block list". - - An absolute file name resembles a Unix absolute file name, using `/' -for the directory separator (not `\' as in DOS). One example is -`(hd0,1)/boot/grub/grub.cfg'. This means the file `/boot/grub/grub.cfg' -in the first partition of the first hard disk. If you omit the device -name in an absolute file name, GRUB uses GRUB's "root device" -implicitly. So if you set the root device to, say, `(hd1,1)' by the -command `set root=(hd1,1)' (*note set::), then `/boot/kernel' is the -same as `(hd1,1)/boot/kernel'. - - -File: grub.info, Node: Block list syntax, Prev: File name syntax, Up: Filesystem - -11.3 How to specify block lists -=============================== - -A block list is used for specifying a file that doesn't appear in the -filesystem, like a chainloader. The syntax is -`[OFFSET]+LENGTH[,[OFFSET]+LENGTH]...'. Here is an example: - - `0+100,200+1,300+300' - - This represents that GRUB should read blocks 0 through 99, block 200, -and blocks 300 through 599. If you omit an offset, then GRUB assumes -the offset is zero. - - Like the file name syntax (*note File name syntax::), if a blocklist -does not contain a device name, then GRUB uses GRUB's "root device". So -`(hd0,2)+1' is the same as `+1' when the root device is `(hd0,2)'. - - -File: grub.info, Node: Interface, Next: Environment, Prev: Filesystem, Up: Top - -12 GRUB's user interface -************************ - -GRUB has both a simple menu interface for choosing preset entries from a -configuration file, and a highly flexible command-line for performing -any desired combination of boot commands. - - GRUB looks for its configuration file as soon as it is loaded. If one -is found, then the full menu interface is activated using whatever -entries were found in the file. If you choose the "command-line" menu -option, or if the configuration file was not found, then GRUB drops to -the command-line interface. - -* Menu: - -* Command-line interface:: The flexible command-line interface -* Menu interface:: The simple menu interface -* Menu entry editor:: Editing a menu entry - - -File: grub.info, Node: Command-line interface, Next: Menu interface, Up: Interface - -12.1 The flexible command-line interface -======================================== - -The command-line interface provides a prompt and after it an editable -text area much like a command-line in Unix or DOS. Each command is -immediately executed after it is entered(1) (*note Command-line -interface-Footnote-1::). The commands (*note Command-line and menu -entry commands::) are a subset of those available in the configuration -file, used with exactly the same syntax. - - Cursor movement and editing of the text on the line can be done via a -subset of the functions available in the Bash shell: - -<C-f> -<PC right key> - Move forward one character. - -<C-b> -<PC left key> - Move back one character. - -<C-a> -<HOME> - Move to the start of the line. - -<C-e> -<END> - Move the the end of the line. - -<C-d> -<DEL> - Delete the character underneath the cursor. - -<C-h> -<BS> - Delete the character to the left of the cursor. - -<C-k> - Kill the text from the current cursor position to the end of the - line. - -<C-u> - Kill backward from the cursor to the beginning of the line. - -<C-y> - Yank the killed text back into the buffer at the cursor. - -<C-p> -<PC up key> - Move up through the history list. - -<C-n> -<PC down key> - Move down through the history list. - - When typing commands interactively, if the cursor is within or before -the first word in the command-line, pressing the <TAB> key (or <C-i>) -will display a listing of the available commands, and if the cursor is -after the first word, the `<TAB>' will provide a completion listing of -disks, partitions, and file names depending on the context. Note that -to obtain a list of drives, one must open a parenthesis, as `root ('. - - Note that you cannot use the completion functionality in the TFTP -filesystem. This is because TFTP doesn't support file name listing for -the security. - - -File: grub.info, Node: Command-line interface-Footnotes, Up: Command-line interface - - (1) However, this behavior will be changed in the future version, in -a user-invisible way. - - -File: grub.info, Node: Menu interface, Next: Menu entry editor, Prev: Command-line interface, Up: Interface - -12.2 The simple menu interface -============================== - -The menu interface is quite easy to use. Its commands are both -reasonably intuitive and described on screen. - - Basically, the menu interface provides a list of "boot entries" to -the user to choose from. Use the arrow keys to select the entry of -choice, then press <RET> to run it. An optional timeout is available -to boot the default entry (the first one if not set), which is aborted -by pressing any key. - - Commands are available to enter a bare command-line by pressing <c> -(which operates exactly like the non-config-file version of GRUB, but -allows one to return to the menu if desired by pressing <ESC>) or to -edit any of the "boot entries" by pressing <e>. - - If you protect the menu interface with a password (*note Security::), -all you can do is choose an entry by pressing <RET>, or press <p> to -enter the password. - - -File: grub.info, Node: Menu entry editor, Prev: Menu interface, Up: Interface - -12.3 Editing a menu entry -========================= - -The menu entry editor looks much like the main menu interface, but the -lines in the menu are individual commands in the selected entry instead -of entry names. - - If an <ESC> is pressed in the editor, it aborts all the changes made -to the configuration entry and returns to the main menu interface. - - Each line in the menu entry can be edited freely, and you can add -new lines by pressing <RET> at the end of a line. To boot the edited -entry, press <Ctrl-x>. - - Although GRUB unfortunately does not support "undo", you can do -almost the same thing by just returning to the main menu using <ESC>. - - -File: grub.info, Node: Environment, Next: Commands, Prev: Interface, Up: Top - -13 GRUB environment variables -***************************** - -GRUB supports environment variables which are rather like those offered -by all Unix-like systems. Environment variables have a name, which is -unique and is usually a short identifier, and a value, which is an -arbitrary string of characters. They may be set (*note set::), unset -(*note unset::), or looked up (*note Shell-like scripting::) by name. - - A number of environment variables have special meanings to various -parts of GRUB. Others may be used freely in GRUB configuration files. - -* Menu: - -* Special environment variables:: -* Environment block:: - - -File: grub.info, Node: Special environment variables, Next: Environment block, Up: Environment - -13.1 Special environment variables -================================== - -These variables have special meaning to GRUB. - -* Menu: - -* biosnum:: -* chosen:: -* color_highlight:: -* color_normal:: -* debug:: -* default:: -* fallback:: -* gfxmode:: -* gfxpayload:: -* gfxterm_font:: -* icondir:: -* lang:: -* locale_dir:: -* menu_color_highlight:: -* menu_color_normal:: -* net_pxe_boot_file:: -* net_pxe_dhcp_server_name:: -* net_pxe_domain:: -* net_pxe_extensionspath:: -* net_pxe_hostname:: -* net_pxe_ip:: -* net_pxe_mac:: -* net_pxe_rootpath:: -* pager:: -* prefix:: -* pxe_blksize:: -* pxe_default_gateway:: -* pxe_default_server:: -* root:: -* superusers:: -* theme:: -* timeout:: - - -File: grub.info, Node: biosnum, Next: chosen, Up: Special environment variables - -13.1.1 biosnum --------------- - -When chain-loading another boot loader (*note Chain-loading::), GRUB may -need to know what BIOS drive number corresponds to the root device -(*note root::) so that it can set up registers properly. If the -BIOSNUM variable is set, it overrides GRUB's own means of guessing this. - - For an alternative approach which also changes BIOS drive mappings -for the chain-loaded system, *note drivemap::. - - -File: grub.info, Node: chosen, Next: color_highlight, Prev: biosnum, Up: Special environment variables - -13.1.2 chosen -------------- - -When executing a menu entry, GRUB sets the CHOSEN variable to the title -of the entry being executed. - - If the menu entry is in one or more submenus, then CHOSEN is set to -the titles of each of the submenus starting from the top level followed -by the title of the menu entry itself, separated by `>'. - - -File: grub.info, Node: color_highlight, Next: color_normal, Prev: chosen, Up: Special environment variables - -13.1.3 color_highlight ----------------------- - -This variable contains the "highlight" foreground and background -terminal colors, separated by a slash (`/'). Setting this variable -changes those colors. For the available color names, *note -color_normal::. - - The default is `black/white'. - - -File: grub.info, Node: color_normal, Next: debug, Prev: color_highlight, Up: Special environment variables - -13.1.4 color_normal -------------------- - -This variable contains the "normal" foreground and background terminal -colors, separated by a slash (`/'). Setting this variable changes -those colors. Each color must be a name from the following list: - - * black - - * blue - - * green - - * cyan - - * red - - * magenta - - * brown - - * light-gray - - * dark-gray - - * light-blue - - * light-green - - * light-cyan - - * light-red - - * light-magenta - - * yellow - - * white - - The default is `white/black'. - - -File: grub.info, Node: debug, Next: default, Prev: color_normal, Up: Special environment variables - -13.1.5 debug ------------- - -This variable may be set to enable debugging output from various -components of GRUB. The value is a list of debug facility names -separated by whitespace or `,', or `all' to enable all available -debugging output. - - -File: grub.info, Node: default, Next: fallback, Prev: debug, Up: Special environment variables - -13.1.6 default --------------- - -If this variable is set, it identifies a menu entry that should be -selected by default, possibly after a timeout (*note timeout::). The -entry may be identified by number or by title. - - If the entry is in a submenu, then it must be identified using the -titles of each of the submenus starting from the top level followed by -the number or title of the menu entry itself, separated by `>'. For -example, take the following menu structure: - - Submenu 1 - Menu Entry 1 - Menu Entry 2 - Submenu 2 - Submenu 3 - Menu Entry 3 - Menu Entry 4 - Menu Entry 5 - - "Menu Entry 3" would then be identified as `Submenu 2>Submenu 3>Menu -Entry 3'. - - This variable is often set by `GRUB_DEFAULT' (*note Simple -configuration::), `grub-set-default', or `grub-reboot'. - - -File: grub.info, Node: fallback, Next: gfxmode, Prev: default, Up: Special environment variables - -13.1.7 fallback ---------------- - -If this variable is set, it identifies a menu entry that should be -selected if the default menu entry fails to boot. Entries are -identified in the same way as for `default' (*note default::). - - -File: grub.info, Node: gfxmode, Next: gfxpayload, Prev: fallback, Up: Special environment variables - -13.1.8 gfxmode --------------- - -If this variable is set, it sets the resolution used on the `gfxterm' -graphical terminal. Note that you can only use modes which your -graphics card supports via VESA BIOS Extensions (VBE), so for example -native LCD panel resolutions may not be available. The default is -`auto', which selects a platform-specific default that should look -reasonable. - - The resolution may be specified as a sequence of one or more modes, -separated by commas (`,') or semicolons (`;'); each will be tried in -turn until one is found. Each mode should be either `auto', -`WIDTHxHEIGHT', or `WIDTHxHEIGHTxDEPTH'. - - -File: grub.info, Node: gfxpayload, Next: gfxterm_font, Prev: gfxmode, Up: Special environment variables - -13.1.9 gfxpayload ------------------ - -If this variable is set, it controls the video mode in which the Linux -kernel starts up, replacing the `vga=' boot option (*note linux::). It -may be set to `text' to force the Linux kernel to boot in normal text -mode, `keep' to preserve the graphics mode set using `gfxmode', or any -of the permitted values for `gfxmode' to set a particular graphics mode -(*note gfxmode::). - - Depending on your kernel, your distribution, your graphics card, and -the phase of the moon, note that using this option may cause GNU/Linux -to suffer from various display problems, particularly during the early -part of the boot sequence. If you have problems, set this variable to -`text' and GRUB will tell Linux to boot in normal text mode. - - The default is platform-specific. On platforms with a native text -mode (such as PC BIOS platforms), the default is `text'. Otherwise the -default may be `auto' or a specific video mode. - - This variable is often set by `GRUB_GFXPAYLOAD_LINUX' (*note Simple -configuration::). - - -File: grub.info, Node: gfxterm_font, Next: icondir, Prev: gfxpayload, Up: Special environment variables - -13.1.10 gfxterm_font --------------------- - -If this variable is set, it names a font to use for text on the -`gfxterm' graphical terminal. Otherwise, `gfxterm' may use any -available font. - - -File: grub.info, Node: icondir, Next: lang, Prev: gfxterm_font, Up: Special environment variables - -13.1.11 icondir ---------------- - -If this variable is set, it names a directory in which the GRUB -graphical menu should look for icons after looking in the theme's -`icons' directory. *Note Theme file format::. - - -File: grub.info, Node: lang, Next: locale_dir, Prev: icondir, Up: Special environment variables - -13.1.12 lang ------------- - -If this variable is set, it names the language code that the `gettext' -command (*note gettext::) uses to translate strings. For example, -French would be named as `fr', and Simplified Chinese as `zh_CN'. - - `grub-mkconfig' (*note Simple configuration::) will try to set a -reasonable default for this variable based on the system locale. - - -File: grub.info, Node: locale_dir, Next: menu_color_highlight, Prev: lang, Up: Special environment variables - -13.1.13 locale_dir ------------------- - -If this variable is set, it names the directory where translation files -may be found (*note gettext::), usually `/boot/grub/locale'. Otherwise, -internationalization is disabled. - - `grub-mkconfig' (*note Simple configuration::) will set a reasonable -default for this variable if internationalization is needed and any -translation files are available. - - -File: grub.info, Node: menu_color_highlight, Next: menu_color_normal, Prev: locale_dir, Up: Special environment variables - -13.1.14 menu_color_highlight ----------------------------- - -This variable contains the foreground and background colors to be used -for the highlighted menu entry, separated by a slash (`/'). Setting -this variable changes those colors. For the available color names, -*note color_normal::. - - The default is the value of `color_highlight' (*note -color_highlight::). - - -File: grub.info, Node: menu_color_normal, Next: net_pxe_boot_file, Prev: menu_color_highlight, Up: Special environment variables - -13.1.15 menu_color_normal -------------------------- - -This variable contains the foreground and background colors to be used -for non-highlighted menu entries, separated by a slash (`/'). Setting -this variable changes those colors. For the available color names, -*note color_normal::. - - The default is the value of `color_normal' (*note color_normal::). - - -File: grub.info, Node: net_pxe_boot_file, Next: net_pxe_dhcp_server_name, Prev: menu_color_normal, Up: Special environment variables - -13.1.16 net_pxe_boot_file -------------------------- - -*Note Network::. - - -File: grub.info, Node: net_pxe_dhcp_server_name, Next: net_pxe_domain, Prev: net_pxe_boot_file, Up: Special environment variables - -13.1.17 net_pxe_dhcp_server_name --------------------------------- - -*Note Network::. - - -File: grub.info, Node: net_pxe_domain, Next: net_pxe_extensionspath, Prev: net_pxe_dhcp_server_name, Up: Special environment variables - -13.1.18 net_pxe_domain ----------------------- - -*Note Network::. - - -File: grub.info, Node: net_pxe_extensionspath, Next: net_pxe_hostname, Prev: net_pxe_domain, Up: Special environment variables - -13.1.19 net_pxe_extensionspath ------------------------------- - -*Note Network::. - - -File: grub.info, Node: net_pxe_hostname, Next: net_pxe_ip, Prev: net_pxe_extensionspath, Up: Special environment variables - -13.1.20 net_pxe_hostname ------------------------- - -*Note Network::. - - -File: grub.info, Node: net_pxe_ip, Next: net_pxe_mac, Prev: net_pxe_hostname, Up: Special environment variables - -13.1.21 net_pxe_ip ------------------- - -*Note Network::. - - -File: grub.info, Node: net_pxe_mac, Next: net_pxe_rootpath, Prev: net_pxe_ip, Up: Special environment variables - -13.1.22 net_pxe_mac -------------------- - -*Note Network::. - - -File: grub.info, Node: net_pxe_rootpath, Next: pager, Prev: net_pxe_mac, Up: Special environment variables - -13.1.23 net_pxe_rootpath ------------------------- - -*Note Network::. - - -File: grub.info, Node: pager, Next: prefix, Prev: net_pxe_rootpath, Up: Special environment variables - -13.1.24 pager -------------- - -If set to `1', pause output after each screenful and wait for keyboard -input. The default is not to pause output. - - -File: grub.info, Node: prefix, Next: pxe_blksize, Prev: pager, Up: Special environment variables - -13.1.25 prefix --------------- - -The location of the `/boot/grub' directory as an absolute file name -(*note File name syntax::). This is normally set by GRUB at startup -based on information provided by `grub-install'. GRUB modules are -dynamically loaded from this directory, so it must be set correctly in -order for many parts of GRUB to work. - - -File: grub.info, Node: pxe_blksize, Next: pxe_default_gateway, Prev: prefix, Up: Special environment variables - -13.1.26 pxe_blksize -------------------- - -*Note Network::. - - -File: grub.info, Node: pxe_default_gateway, Next: pxe_default_server, Prev: pxe_blksize, Up: Special environment variables - -13.1.27 pxe_default_gateway ---------------------------- - -*Note Network::. - - -File: grub.info, Node: pxe_default_server, Next: root, Prev: pxe_default_gateway, Up: Special environment variables - -13.1.28 pxe_default_server --------------------------- - -*Note Network::. - - -File: grub.info, Node: root, Next: superusers, Prev: pxe_default_server, Up: Special environment variables - -13.1.29 root ------------- - -The root device name (*note Device syntax::). Any file names that do -not specify an explicit device name are read from this device. The -default is normally set by GRUB at startup based on the value of -`prefix' (*note prefix::). - - For example, if GRUB was installed to the first partition of the -first hard disk, then `prefix' might be set to `(hd0,msdos1)/boot/grub' -and `root' to `hd0,msdos1'. - - -File: grub.info, Node: superusers, Next: theme, Prev: root, Up: Special environment variables - -13.1.30 superusers ------------------- - -This variable may be set to a list of superuser names to enable -authentication support. *Note Security::. - - -File: grub.info, Node: theme, Next: timeout, Prev: superusers, Up: Special environment variables - -13.1.31 theme -------------- - -This variable may be set to a directory containing a GRUB graphical menu -theme. *Note Theme file format::. - - This variable is often set by `GRUB_THEME' (*note Simple -configuration::). - - -File: grub.info, Node: timeout, Prev: theme, Up: Special environment variables - -13.1.32 timeout ---------------- - -If this variable is set, it specifies the time in seconds to wait for -keyboard input before booting the default menu entry. A timeout of `0' -means to boot the default entry immediately without displaying the -menu; a timeout of `-1' (or unset) means to wait indefinitely. - - This variable is often set by `GRUB_TIMEOUT' or -`GRUB_HIDDEN_TIMEOUT' (*note Simple configuration::). - - -File: grub.info, Node: Environment block, Prev: Special environment variables, Up: Environment - -13.2 The GRUB environment block -=============================== - -It is often useful to be able to remember a small amount of information -from one boot to the next. For example, you might want to set the -default menu entry based on what was selected the last time. GRUB -deliberately does not implement support for writing files in order to -minimise the possibility of the boot loader being responsible for file -system corruption, so a GRUB configuration file cannot just create a -file in the ordinary way. However, GRUB provides an "environment -block" which can be used to save a small amount of state. - - The environment block is a preallocated 1024-byte file, which -normally lives in `/boot/grub/grubenv' (although you should not assume -this). At boot time, the `load_env' command (*note load_env::) loads -environment variables from it, and the `save_env' (*note save_env::) -command saves environment variables to it. From a running system, the -`grub-editenv' utility can be used to edit the environment block. - - For safety reasons, this storage is only available when installed on -a plain disk (no LVM or RAID), using a non-checksumming filesystem (no -ZFS), and using BIOS or EFI functions (no ATA, USB or IEEE1275). - - `grub-mkconfig' uses this facility to implement `GRUB_SAVEDEFAULT' -(*note Simple configuration::). - - -File: grub.info, Node: Commands, Next: Security, Prev: Environment, Up: Top - -14 The list of available commands -********************************* - -In this chapter, we list all commands that are available in GRUB. - - Commands belong to different groups. A few can only be used in the -global section of the configuration file (or "menu"); most of them can -be entered on the command-line and can be used either anywhere in the -menu or specifically in the menu entries. - - In rescue mode, only the `insmod' (*note insmod::), `ls' (*note -ls::), `set' (*note set::), and `unset' (*note unset::) commands are -normally available. If you end up in rescue mode and do not know what -to do, then *note GRUB only offers a rescue shell::. - -* Menu: - -* Menu-specific commands:: -* General commands:: -* Command-line and menu entry commands:: - - -File: grub.info, Node: Menu-specific commands, Next: General commands, Up: Commands - -14.1 The list of commands for the menu only -=========================================== - -The semantics used in parsing the configuration file are the following: - - * The files _must_ be in plain-text format. - - * `#' at the beginning of a line in a configuration file means it is - only a comment. - - * Options are separated by spaces. - - * All numbers can be either decimal or hexadecimal. A hexadecimal - number must be preceded by `0x', and is case-insensitive. - - These commands can only be used in the menu: - -* Menu: - -* menuentry:: Start a menu entry -* submenu:: Group menu entries - - -File: grub.info, Node: menuentry, Next: submenu, Up: Menu-specific commands - -14.1.1 menuentry ----------------- - - -- Command: menuentry TITLE [`--class=class' ...] [`--users=users'] - [`--hotkey=key'] { COMMAND; ... } - This defines a GRUB menu entry named TITLE. When this entry is - selected from the menu, GRUB will set the CHOSEN environment - variable to TITLE, execute the list of commands given within - braces, and if the last command in the list returned successfully - and a kernel was loaded it will execute the `boot' command. - - The `--class' option may be used any number of times to group menu - entries into classes. Menu themes may display different classes - using different styles. - - The `--users' option grants specific users access to specific menu - entries. *Note Security::. - - The `--hotkey' option associates a hotkey with a menu entry. KEY - may be a single letter, or one of the aliases `backspace', `tab', - or `delete'. - - -File: grub.info, Node: submenu, Prev: menuentry, Up: Menu-specific commands - -14.1.2 submenu --------------- - - -- Command: submenu TITLE [`--class=class' ...] [`--users=users'] - [`--hotkey=key'] { MENU ENTRIES ... } - This defines a submenu. An entry called TITLE will be added to the - menu; when that entry is selected, a new menu will be displayed - showing all the entries within this submenu. - - All options are the same as in the `menuentry' command (*note - menuentry::). - - -File: grub.info, Node: General commands, Next: Command-line and menu entry commands, Prev: Menu-specific commands, Up: Commands - -14.2 The list of general commands -================================= - -Commands usable anywhere in the menu and in the command-line. - -* Menu: - -* serial:: Set up a serial device -* terminal_input:: Manage input terminals -* terminal_output:: Manage output terminals -* terminfo:: Define terminal type - - -File: grub.info, Node: serial, Next: terminal_input, Up: General commands - -14.2.1 serial -------------- - - -- Command: serial [`--unit=unit'] [`--port=port'] [`--speed=speed'] - [`--word=word'] [`--parity=parity'] [`--stop=stop'] - Initialize a serial device. UNIT is a number in the range 0-3 - specifying which serial port to use; default is 0, which - corresponds to the port often called COM1. PORT is the I/O port - where the UART is to be found; if specified it takes precedence - over UNIT. SPEED is the transmission speed; default is 9600. WORD - and STOP are the number of data bits and stop bits. Data bits must - be in the range 5-8 and stop bits must be 1 or 2. Default is 8 data - bits and one stop bit. PARITY is one of `no', `odd', `even' and - defaults to `no'. - - The serial port is not used as a communication channel unless the - `terminal_input' or `terminal_output' command is used (*note - terminal_input::, *note terminal_output::). - - See also *note Serial terminal::. - - -File: grub.info, Node: terminal_input, Next: terminal_output, Prev: serial, Up: General commands - -14.2.2 terminal_input ---------------------- - - -- Command: terminal_input [`--append'|`--remove'] [terminal1] - [terminal2] ... - List or select an input terminal. - - With no arguments, list the active and available input terminals. - - With `--append', add the named terminals to the list of active - input terminals; any of these may be used to provide input to GRUB. - - With `--remove', remove the named terminals from the active list. - - With no options but a list of terminal names, make only the listed - terminal names active. - - -File: grub.info, Node: terminal_output, Next: terminfo, Prev: terminal_input, Up: General commands - -14.2.3 terminal_output ----------------------- - - -- Command: terminal_output [`--append'|`--remove'] [terminal1] - [terminal2] ... - List or select an output terminal. - - With no arguments, list the active and available output terminals. - - With `--append', add the named terminals to the list of active - output terminals; all of these will receive output from GRUB. - - With `--remove', remove the named terminals from the active list. - - With no options but a list of terminal names, make only the listed - terminal names active. - - -File: grub.info, Node: terminfo, Prev: terminal_output, Up: General commands - -14.2.4 terminfo ---------------- - - -- Command: terminfo [-a|-u|-v] [term] - Define the capabilities of your terminal by giving the name of an - entry in the terminfo database, which should correspond roughly to - a `TERM' environment variable in Unix. - - The currently available terminal types are `vt100', `vt100-color', - `ieee1275', and `dumb'. If you need other terminal types, please - contact us to discuss the best way to include support for these in - GRUB. - - The `-a' (`--ascii'), `-u' (`--utf8'), and `-v' (`--visual-utf8') - options control how non-ASCII text is displayed. `-a' specifies - an ASCII-only terminal; `-u' specifies logically-ordered UTF-8; - and `-v' specifies "visually-ordered UTF-8" (in other words, - arranged such that a terminal emulator without bidirectional text - support will display right-to-left text in the proper order; this - is not really proper UTF-8, but a workaround). - - If no option or terminal type is specified, the current terminal - type is printed. - - -File: grub.info, Node: Command-line and menu entry commands, Prev: General commands, Up: Commands - -14.3 The list of command-line and menu entry commands -===================================================== - -These commands are usable in the command-line and in menu entries. If -you forget a command, you can run the command `help' (*note help::). - -* Menu: - -* acpi:: Load ACPI tables -* badram:: Filter out bad regions of RAM -* blocklist:: Print a block list -* boot:: Start up your operating system -* cat:: Show the contents of a file -* chainloader:: Chain-load another boot loader -* cmp:: Compare two files -* configfile:: Load a configuration file -* cpuid:: Check for CPU features -* crc:: Calculate CRC32 checksums -* date:: Display or set current date and time -* drivemap:: Map a drive to another -* echo:: Display a line of text -* export:: Export an environment variable -* false:: Do nothing, unsuccessfully -* gettext:: Translate a string -* gptsync:: Fill an MBR based on GPT entries -* halt:: Shut down your computer -* help:: Show help messages -* initrd:: Load a Linux initrd -* initrd16:: Load a Linux initrd (16-bit mode) -* insmod:: Insert a module -* keystatus:: Check key modifier status -* linux:: Load a Linux kernel -* linux16:: Load a Linux kernel (16-bit mode) -* list_env:: List variables in environment block -* load_env:: Load variables from environment block -* loopback:: Make a device from a filesystem image -* ls:: List devices or files -* normal:: Enter normal mode -* normal_exit:: Exit from normal mode -* parttool:: Modify partition table entries -* password:: Set a clear-text password -* password_pbkdf2:: Set a hashed password -* play:: Play a tune -* pxe_unload:: Unload the PXE environment -* read:: Read user input -* reboot:: Reboot your computer -* save_env:: Save variables to environment block -* search:: Search devices by file, label, or UUID -* sendkey:: Emulate keystrokes -* set:: Set an environment variable -* true:: Do nothing, successfully -* unset:: Unset an environment variable -* uppermem:: Set the upper memory size - - -File: grub.info, Node: acpi, Next: badram, Up: Command-line and menu entry commands - -14.3.1 acpi ------------ - - -- Command: acpi [`-1'|`-2'] - [`--exclude=table1,...'|`--load-only=table1,...'] - [`--oemid=id'] [`--oemtable=table'] [`--oemtablerev=rev'] - [`--oemtablecreator=creator'] [`--oemtablecreatorrev=rev'] - [`--no-ebda'] filename ... - Modern BIOS systems normally implement the Advanced Configuration - and Power Interface (ACPI), and define various tables that - describe the interface between an ACPI-compliant operating system - and the firmware. In some cases, the tables provided by default - only work well with certain operating systems, and it may be - necessary to replace some of them. - - Normally, this command will replace the Root System Description - Pointer (RSDP) in the Extended BIOS Data Area to point to the new - tables. If the `--no-ebda' option is used, the new tables will be - known only to GRUB, but may be used by GRUB's EFI emulation. - - -File: grub.info, Node: badram, Next: blocklist, Prev: acpi, Up: Command-line and menu entry commands - -14.3.2 badram -------------- - - -- Command: badram addr,mask[,addr,mask...] - Filter out bad RAM. - - This command notifies the memory manager that specified regions of -RAM ought to be filtered out (usually, because they're damaged). This -remains in effect after a payload kernel has been loaded by GRUB, as -long as the loaded kernel obtains its memory map from GRUB. Kernels -that support this include Linux, GNU Mach, the kernel of FreeBSD and -Multiboot kernels in general. - - Syntax is the same as provided by the Memtest86+ utility -(http://www.memtest.org/): a list of address/mask pairs. Given a -page-aligned address and a base address / mask pair, if all the bits of -the page-aligned address that are enabled by the mask match with the -base address, it means this page is to be filtered. This syntax makes -it easy to represent patterns that are often result of memory damage, -due to physical distribution of memory cells. - - -File: grub.info, Node: blocklist, Next: boot, Prev: badram, Up: Command-line and menu entry commands - -14.3.3 blocklist ----------------- - - -- Command: blocklist file - Print a block list (*note Block list syntax::) for FILE. - - -File: grub.info, Node: boot, Next: cat, Prev: blocklist, Up: Command-line and menu entry commands - -14.3.4 boot ------------ - - -- Command: boot - Boot the OS or chain-loader which has been loaded. Only necessary - if running the fully interactive command-line (it is implicit at - the end of a menu entry). - - -File: grub.info, Node: cat, Next: chainloader, Prev: boot, Up: Command-line and menu entry commands - -14.3.5 cat ----------- - - -- Command: cat [`--dos'] file - Display the contents of the file FILE. This command may be useful - to remind you of your OS's root partition: - - grub> cat /etc/fstab - - If the `--dos' option is used, then carriage return / new line - pairs will be displayed as a simple new line. Otherwise, the - carriage return will be displayed as a control character (`<d>') - to make it easier to see when boot problems are caused by a file - formatted using DOS-style line endings. - - -File: grub.info, Node: chainloader, Next: cmp, Prev: cat, Up: Command-line and menu entry commands - -14.3.6 chainloader ------------------- - - -- Command: chainloader [`--force'] file - Load FILE as a chain-loader. Like any other file loaded by the - filesystem code, it can use the blocklist notation (*note Block - list syntax::) to grab the first sector of the current partition - with `+1'. If you specify the option `--force', then load FILE - forcibly, whether it has a correct signature or not. This is - required when you want to load a defective boot loader, such as - SCO UnixWare 7.1. - - -File: grub.info, Node: cmp, Next: configfile, Prev: chainloader, Up: Command-line and menu entry commands - -14.3.7 cmp ----------- - - -- Command: cmp file1 file2 - Compare the file FILE1 with the file FILE2. If they differ in - size, print the sizes like this: - - Differ in size: 0x1234 [foo], 0x4321 [bar] - - If the sizes are equal but the bytes at an offset differ, then - print the bytes like this: - - Differ at the offset 777: 0xbe [foo], 0xef [bar] - - If they are completely identical, nothing will be printed. - - -File: grub.info, Node: configfile, Next: cpuid, Prev: cmp, Up: Command-line and menu entry commands - -14.3.8 configfile ------------------ - - -- Command: configfile file - Load FILE as a configuration file. If FILE defines any menu - entries, then show a menu containing them immediately. - - -File: grub.info, Node: cpuid, Next: crc, Prev: configfile, Up: Command-line and menu entry commands - -14.3.9 cpuid ------------- - - -- Command: cpuid [-l] - Check for CPU features. This command is only available on x86 - systems. - - With the `-l' option, return true if the CPU supports long mode - (64-bit). - - If invoked without options, this command currently behaves as if - it had been invoked with `-l'. This may change in the future. - - -File: grub.info, Node: crc, Next: date, Prev: cpuid, Up: Command-line and menu entry commands - -14.3.10 crc ------------ - - -- Command: crc file - Display the CRC32 checksum of FILE. - - -File: grub.info, Node: date, Next: drivemap, Prev: crc, Up: Command-line and menu entry commands - -14.3.11 date ------------- - - -- Command: date [[year-]month-day] [hour:minute[:second]] - With no arguments, print the current date and time. - - Otherwise, take the current date and time, change any elements - specified as arguments, and set the result as the new date and - time. For example, `date 01-01' will set the current month and - day to January 1, but leave the year, hour, minute, and second - unchanged. - - -File: grub.info, Node: drivemap, Next: echo, Prev: date, Up: Command-line and menu entry commands - -14.3.12 drivemap ----------------- - - -- Command: drivemap `-l'|`-r'|[`-s'] from_drive to_drive - Without options, map the drive FROM_DRIVE to the drive TO_DRIVE. - This is necessary when you chain-load some operating systems, such - as DOS, if such an OS resides at a non-first drive. For - convenience, any partition suffix on the drive is ignored, so you - can safely use ${root} as a drive specification. - - With the `-s' option, perform the reverse mapping as well, swapping - the two drives. - - With the `-l' option, list the current mappings. - - With the `-r' option, reset all mappings to the default values. - - For example: - - drivemap -s (hd0) (hd1) - - -File: grub.info, Node: echo, Next: export, Prev: drivemap, Up: Command-line and menu entry commands - -14.3.13 echo ------------- - - -- Command: echo [`-n'] [`-e'] string ... - Display the requested text and, unless the `-n' option is used, a - trailing new line. If there is more than one string, they are - separated by spaces in the output. As usual in GRUB commands, - variables may be substituted using `${var}'. - - The `-e' option enables interpretation of backslash escapes. The - following sequences are recognised: - - `\\' - backslash - - `\a' - alert (BEL) - - `\c' - suppress trailing new line - - `\f' - form feed - - `\n' - new line - - `\r' - carriage return - - `\t' - horizontal tab - - `\v' - vertical tab - - When interpreting backslash escapes, backslash followed by any - other character will print that character. - - -File: grub.info, Node: export, Next: false, Prev: echo, Up: Command-line and menu entry commands - -14.3.14 export --------------- - - -- Command: export envvar - Export the environment variable ENVVAR. Exported variables are - visible to subsidiary configuration files loaded using - `configfile'. - - -File: grub.info, Node: false, Next: gettext, Prev: export, Up: Command-line and menu entry commands - -14.3.15 false -------------- - - -- Command: false - Do nothing, unsuccessfully. This is mainly useful in control - constructs such as `if' and `while' (*note Shell-like scripting::). - - -File: grub.info, Node: gettext, Next: gptsync, Prev: false, Up: Command-line and menu entry commands - -14.3.16 gettext ---------------- - - -- Command: gettext string - Translate STRING into the current language. - - The current language code is stored in the `lang' variable in - GRUB's environment (*note lang::). Translation files in MO format - are read from `locale_dir' (*note locale_dir::), usually - `/boot/grub/locale'. - - -File: grub.info, Node: gptsync, Next: halt, Prev: gettext, Up: Command-line and menu entry commands - -14.3.17 gptsync ---------------- - - -- Command: gptsync device [partition[+/-[type]]] ... - Disks using the GUID Partition Table (GPT) also have a legacy - Master Boot Record (MBR) partition table for compatibility with - the BIOS and with older operating systems. The legacy MBR can - only represent a limited subset of GPT partition entries. - - This command populates the legacy MBR with the specified PARTITION - entries on DEVICE. Up to three partitions may be used. - - TYPE is an MBR partition type code; prefix with `0x' if you want - to enter this in hexadecimal. The separator between PARTITION and - TYPE may be `+' to make the partition active, or `-' to make it - inactive; only one partition may be active. If both the separator - and type are omitted, then the partition will be inactive. - - -File: grub.info, Node: halt, Next: help, Prev: gptsync, Up: Command-line and menu entry commands - -14.3.18 halt ------------- - - -- Command: halt `--no-apm' - The command halts the computer. If the `--no-apm' option is - specified, no APM BIOS call is performed. Otherwise, the computer - is shut down using APM. - - -File: grub.info, Node: help, Next: initrd, Prev: halt, Up: Command-line and menu entry commands - -14.3.19 help ------------- - - -- Command: help [pattern ...] - Display helpful information about builtin commands. If you do not - specify PATTERN, this command shows short descriptions of all - available commands. - - If you specify any PATTERNS, it displays longer information about - each of the commands whose names begin with those PATTERNS. - - -File: grub.info, Node: initrd, Next: initrd16, Prev: help, Up: Command-line and menu entry commands - -14.3.20 initrd --------------- - - -- Command: initrd file - Load an initial ramdisk for a Linux kernel image, and set the - appropriate parameters in the Linux setup area in memory. This - may only be used after the `linux' command (*note linux::) has - been run. See also *note GNU/Linux::. - - -File: grub.info, Node: initrd16, Next: insmod, Prev: initrd, Up: Command-line and menu entry commands - -14.3.21 initrd16 ----------------- - - -- Command: initrd16 file - Load an initial ramdisk for a Linux kernel image to be booted in - 16-bit mode, and set the appropriate parameters in the Linux setup - area in memory. This may only be used after the `linux16' command - (*note linux16::) has been run. See also *note GNU/Linux::. - - This command is only available on x86 systems. - - -File: grub.info, Node: insmod, Next: keystatus, Prev: initrd16, Up: Command-line and menu entry commands - -14.3.22 insmod --------------- - - -- Command: insmod module - Insert the dynamic GRUB module called MODULE. - - -File: grub.info, Node: keystatus, Next: linux, Prev: insmod, Up: Command-line and menu entry commands - -14.3.23 keystatus ------------------ - - -- Command: keystatus [`--shift'] [`--ctrl'] [`--alt'] - Return true if the Shift, Control, or Alt modifier keys are held - down, as requested by options. This is useful in scripting, to - allow some user control over behaviour without having to wait for - a keypress. - - Checking key modifier status is only supported on some platforms. - If invoked without any options, the `keystatus' command returns - true if and only if checking key modifier status is supported. - - -File: grub.info, Node: linux, Next: linux16, Prev: keystatus, Up: Command-line and menu entry commands - -14.3.24 linux -------------- - - -- Command: linux file ... - Load a Linux kernel image from FILE. The rest of the line is - passed verbatim as the "kernel command-line". Any initrd must be - reloaded after using this command (*note initrd::). - - On x86 systems, the kernel will be booted using the 32-bit boot - protocol. Note that this means that the `vga=' boot option will - not work; if you want to set a special video mode, you will need - to use GRUB commands such as `set gfxpayload=1024x768' or `set - gfxpayload=keep' (to keep the same mode as used in GRUB) instead. - GRUB can automatically detect some uses of `vga=' and translate - them to appropriate settings of `gfxpayload'. The `linux16' - command (*note linux16::) avoids this restriction. - - -File: grub.info, Node: linux16, Next: list_env, Prev: linux, Up: Command-line and menu entry commands - -14.3.25 linux16 ---------------- - - -- Command: linux16 file ... - Load a Linux kernel image from FILE in 16-bit mode. The rest of - the line is passed verbatim as the "kernel command-line". Any - initrd must be reloaded after using this command (*note - initrd16::). - - The kernel will be booted using the traditional 16-bit boot - protocol. As well as bypassing problems with `vga=' described in - *note linux::, this permits booting some other programs that - implement the Linux boot protocol for the sake of convenience. - - This command is only available on x86 systems. - - -File: grub.info, Node: list_env, Next: load_env, Prev: linux16, Up: Command-line and menu entry commands - -14.3.26 list_env ----------------- - - -- Command: list_env [`-f' file] - List all variables in the environment block file. *Note - Environment block::. - - The `-f' option overrides the default location of the environment - block. - - -File: grub.info, Node: load_env, Next: loopback, Prev: list_env, Up: Command-line and menu entry commands - -14.3.27 load_env ----------------- - - -- Command: load_env [`-f' file] - Load all variables from the environment block file into the - environment. *Note Environment block::. - - The `-f' option overrides the default location of the environment - block. - - -File: grub.info, Node: loopback, Next: ls, Prev: load_env, Up: Command-line and menu entry commands - -14.3.28 loopback ----------------- - - -- Command: loopback [`-d'] device file - Make the device named DEVICE correspond to the contents of the - filesystem image in FILE. For example: - - loopback loop0 /path/to/image - ls (loop0)/ - - With the `-d' option, delete a device previously created using this - command. - - -File: grub.info, Node: ls, Next: normal, Prev: loopback, Up: Command-line and menu entry commands - -14.3.29 ls ----------- - - -- Command: ls [arg ...] - List devices or files. - - With no arguments, print all devices known to GRUB. - - If the argument is a device name enclosed in parentheses (*note - Device syntax::), then list all files at the root directory of - that device. - - If the argument is a directory given as an absolute file name - (*note File name syntax::), then list the contents of that - directory. - - -File: grub.info, Node: normal, Next: normal_exit, Prev: ls, Up: Command-line and menu entry commands - -14.3.30 normal --------------- - - -- Command: normal [file] - Enter normal mode and display the GRUB menu. - - In normal mode, commands, filesystem modules, and cryptography - modules are automatically loaded, and the full GRUB script parser - is available. Other modules may be explicitly loaded using - `insmod' (*note insmod::). - - If a FILE is given, then commands will be read from that file. - Otherwise, they will be read from `$prefix/grub.cfg' if it exists. - - `normal' may be called from within normal mode, creating a nested - environment. It is more usual to use `configfile' (*note - configfile::) for this. - - -File: grub.info, Node: normal_exit, Next: parttool, Prev: normal, Up: Command-line and menu entry commands - -14.3.31 normal_exit -------------------- - - -- Command: normal_exit - Exit normal mode (*note normal::). If this instance of normal - mode was not nested within another one, then return to rescue mode. - - -File: grub.info, Node: parttool, Next: password, Prev: normal_exit, Up: Command-line and menu entry commands - -14.3.32 parttool ----------------- - - -- Command: parttool partition commands - Make various modifications to partition table entries. - - Each COMMAND is either a boolean option, in which case it must be - followed with `+' or `-' (with no intervening space) to enable or - disable that option, or else it takes a value in the form - `COMMAND=VALUE'. - - Currently, `parttool' is only useful on DOS partition tables (also - known as Master Boot Record, or MBR). On these partition tables, - the following commands are available: - - `boot' (boolean) - When enabled, this makes the selected partition be the active - (bootable) partition on its disk, clearing the active flag on - all other partitions. This command is limited to _primary_ - partitions. - - `type' (value) - Change the type of an existing partition. The value must be - a number in the range 0-0xFF (prefix with `0x' to enter it in - hexadecimal). - - `hidden' (boolean) - When enabled, this hides the selected partition by setting - the "hidden" bit in its partition type code; when disabled, - unhides the selected partition by clearing this bit. This is - useful only when booting DOS or Wwindows and multiple primary - FAT partitions exist in one disk. See also *note - DOS/Windows::. - - -File: grub.info, Node: password, Next: password_pbkdf2, Prev: parttool, Up: Command-line and menu entry commands - -14.3.33 password ----------------- - - -- Command: password user clear-password - Define a user named USER with password CLEAR-PASSWORD. *Note - Security::. - - -File: grub.info, Node: password_pbkdf2, Next: play, Prev: password, Up: Command-line and menu entry commands - -14.3.34 password_pbkdf2 ------------------------ - - -- Command: password_pbkdf2 user hashed-password - Define a user named USER with password hash HASHED-PASSWORD. Use - `grub-mkpasswd-pbkdf2' (*note Invoking grub-mkpasswd-pbkdf2::) to - generate password hashes. *Note Security::. - - -File: grub.info, Node: play, Next: pxe_unload, Prev: password_pbkdf2, Up: Command-line and menu entry commands - -14.3.35 play ------------- - - -- Command: play file | tempo [pitch1 duration1] [pitch2 duration2] ... - Plays a tune - - If the argument is a file name (*note File name syntax::), play - the tune recorded in it. The file format is first the tempo as an - unsigned 32bit little-endian number, then pairs of unsigned 16bit - little-endian numbers for pitch and duration pairs. - - If the arguments are a series of numbers, play the inline tune. - - The tempo is the base for all note durations. 60 gives a 1-second - base, 120 gives a half-second base, etc. Pitches are Hz. Set - pitch to 0 to produce a rest. - - -File: grub.info, Node: pxe_unload, Next: read, Prev: play, Up: Command-line and menu entry commands - -14.3.36 pxe_unload ------------------- - - -- Command: pxe_unload - Unload the PXE environment (*note Network::). - - This command is only available on PC BIOS systems. - - -File: grub.info, Node: read, Next: reboot, Prev: pxe_unload, Up: Command-line and menu entry commands - -14.3.37 read ------------- - - -- Command: read [var] - Read a line of input from the user. If an environment variable - VAR is given, set that environment variable to the line of input - that was read, with no terminating newline. - - -File: grub.info, Node: reboot, Next: save_env, Prev: read, Up: Command-line and menu entry commands - -14.3.38 reboot --------------- - - -- Command: reboot - Reboot the computer. - - -File: grub.info, Node: save_env, Next: search, Prev: reboot, Up: Command-line and menu entry commands - -14.3.39 save_env ----------------- - - -- Command: save_env [`-f' file] var ... - Save the named variables from the environment to the environment - block file. *Note Environment block::. - - The `-f' option overrides the default location of the environment - block. - - -File: grub.info, Node: search, Next: sendkey, Prev: save_env, Up: Command-line and menu entry commands - -14.3.40 search --------------- - - -- Command: search [`--file'|`--label'|`--fs-uuid'] [`--set' [var]] - [`--no-floppy'] name - Search devices by file (`-f', `--file'), filesystem label (`-l', - `--label'), or filesystem UUID (`-u', `--fs-uuid'). - - If the `--set' option is used, the first device found is set as the - value of environment variable VAR. The default variable is `root'. - - The `--no-floppy' option prevents searching floppy devices, which - can be slow. - - The `search.file', `search.fs_label', and `search.fs_uuid' - commands are aliases for `search --file', `search --label', and - `search --fs-uuid' respectively. - - -File: grub.info, Node: sendkey, Next: set, Prev: search, Up: Command-line and menu entry commands - -14.3.41 sendkey ---------------- - - -- Command: sendkey [`--num'|`--caps'|`--scroll'|`--insert'| - `--pause'|`--left-shift'|`--right-shift'| - `--sysrq'|`--numkey'|`--capskey'|`--scrollkey'| - `--insertkey'|`--left-alt'|`--right-alt'| - `--left-ctrl'|`--right-ctrl' `on'|`off']... [`no-led'] - keystroke - Insert keystrokes into the keyboard buffer when booting. - Sometimes an operating system or chainloaded boot loader requires - particular keys to be pressed: for example, one might need to - press a particular key to enter "safe mode", or when chainloading - another boot loader one might send keystrokes to it to navigate - its menu. - - You may provide up to 16 keystrokes (the length of the BIOS - keyboard buffer). Keystroke names may be upper-case or lower-case - letters, digits, or taken from the following table: - - Name Key - --------------------------------------------------------------- - escape Escape - exclam ! - at @ - numbersign # - dollar $ - percent % - caret ^ - ampersand & - asterisk * - parenleft ( - parenright ) - minus - - underscore _ - equal = - plus + - backspace Backspace - tab Tab - bracketleft [ - braceleft { - bracketright ] - braceright } - enter Enter - control press and release Control - semicolon ; - colon : - quote ' - doublequote " - backquote ` - tilde ~ - shift press and release left Shift - backslash \ - bar | - comma , - less < - period . - greater > - slash / - question ? - rshift press and release right Shift - alt press and release Alt - space space bar - capslock Caps Lock - F1 F1 - F2 F2 - F3 F3 - F4 F4 - F5 F5 - F6 F6 - F7 F7 - F8 F8 - F9 F9 - F10 F10 - F11 F11 - F12 F12 - num1 1 (numeric keypad) - num2 2 (numeric keypad) - num3 3 (numeric keypad) - num4 4 (numeric keypad) - num5 5 (numeric keypad) - num6 6 (numeric keypad) - num7 7 (numeric keypad) - num8 8 (numeric keypad) - num9 9 (numeric keypad) - num0 0 (numeric keypad) - numperiod . (numeric keypad) - numend End (numeric keypad) - numdown Down (numeric keypad) - numpgdown Page Down (numeric keypad) - numleft Left (numeric keypad) - numcenter 5 with Num Lock inactive (numeric - keypad) - numright Right (numeric keypad) - numhome Home (numeric keypad) - numup Up (numeric keypad) - numpgup Page Up (numeric keypad) - numinsert Insert (numeric keypad) - numdelete Delete (numeric keypad) - numasterisk * (numeric keypad) - numminus - (numeric keypad) - numplus + (numeric keypad) - numslash / (numeric keypad) - numenter Enter (numeric keypad) - delete Delete - insert Insert - home Home - end End - pgdown Page Down - pgup Page Up - down Down - up Up - left Left - right Right - - As well as keystrokes, the `sendkey' command takes various options - that affect the BIOS keyboard status flags. These options take an - `on' or `off' parameter, specifying that the corresponding status - flag be set or unset; omitting the option for a given status flag - will leave that flag at its initial state at boot. The `--num', - `--caps', `--scroll', and `--insert' options emulate setting the - corresponding mode, while the `--numkey', `--capskey', - `--scrollkey', and `--insertkey' options emulate pressing and - holding the corresponding key. The other status flag options are - self-explanatory. - - If the `--no-led' option is given, the status flag options will - have no effect on keyboard LEDs. - - If the `sendkey' command is given multiple times, then only the - last invocation has any effect. - - Since `sendkey' manipulates the BIOS keyboard buffer, it may cause - hangs, reboots, or other misbehaviour on some systems. If the - operating system or boot loader that runs after GRUB uses its own - keyboard driver rather than the BIOS keyboard functions, then - `sendkey' will have no effect. - - This command is only available on PC BIOS systems. - - -File: grub.info, Node: set, Next: true, Prev: sendkey, Up: Command-line and menu entry commands - -14.3.42 set ------------ - - -- Command: set [envvar=value] - Set the environment variable ENVVAR to VALUE. If invoked with no - arguments, print all environment variables with their values. - - -File: grub.info, Node: true, Next: unset, Prev: set, Up: Command-line and menu entry commands - -14.3.43 true ------------- - - -- Command: true - Do nothing, successfully. This is mainly useful in control - constructs such as `if' and `while' (*note Shell-like scripting::). - - -File: grub.info, Node: unset, Next: uppermem, Prev: true, Up: Command-line and menu entry commands - -14.3.44 unset -------------- - - -- Command: unset envvar - Unset the environment variable ENVVAR. - - -File: grub.info, Node: uppermem, Prev: unset, Up: Command-line and menu entry commands - -14.3.45 uppermem ----------------- - -This command is not yet implemented for GRUB 2, although it is planned. - - -File: grub.info, Node: Security, Next: Supported kernels, Prev: Commands, Up: Top - -15 Authentication and authorisation -*********************************** - -By default, the boot loader interface is accessible to anyone with -physical access to the console: anyone can select and edit any menu -entry, and anyone can get direct access to a GRUB shell prompt. For -most systems, this is reasonable since anyone with direct physical -access has a variety of other ways to gain full access, and requiring -authentication at the boot loader level would only serve to make it -difficult to recover broken systems. - - However, in some environments, such as kiosks, it may be appropriate -to lock down the boot loader to require authentication before -performing certain operations. - - The `password' (*note password::) and `password_pbkdf2' (*note -password_pbkdf2::) commands can be used to define users, each of which -has an associated password. `password' sets the password in plain -text, requiring `grub.cfg' to be secure; `password_pbkdf2' sets the -password hashed using the Password-Based Key Derivation Function (RFC -2898), requiring the use of `grub-mkpasswd-pbkdf2' (*note Invoking -grub-mkpasswd-pbkdf2::) to generate password hashes. - - In order to enable authentication support, the `superusers' -environment variable must be set to a list of usernames, separated by -any of spaces, commas, semicolons, pipes, or ampersands. Superusers -are permitted to use the GRUB command line, edit menu entries, and -execute any menu entry. If `superusers' is set, then use of the -command line is automatically restricted to superusers. - - Other users may be given access to specific menu entries by giving a -list of usernames (as above) using the `--users' option to the -`menuentry' command (*note menuentry::). If the `--users' option is -not used for a menu entry, then that entry is unrestricted. - - Putting this together, a typical `grub.cfg' fragment might look like -this: - - set superusers="root" - password_pbkdf2 root grub.pbkdf2.sha512.10000.biglongstring - password user1 insecure - - menuentry "May be run by any user" { - set root=(hd0,1) - linux /vmlinuz - } - - menuentry "Superusers only" --users "" { - set root=(hd0,1) - linux /vmlinuz single - } - - menuentry "May be run by user1 or a superuser" --users user1 { - set root=(hd0,2) - chainloader +1 - } - - The `grub-mkconfig' program does not yet have built-in support for -generating configuration files with authentication. You can use -`/etc/grub.d/40_custom' to add simple superuser authentication, by -adding `set superusers=' and `password' or `password_pbkdf2' commands. - - -File: grub.info, Node: Supported kernels, Next: Troubleshooting, Prev: Security, Up: Top - -16 Supported boot targets -************************* - -X86 support is summarised in the following table. "Yes" means that the -kernel works on the given platform, "crashes" means an early kernel -crash which we hope will be fixed by concerned kernel developers. "no" -means GRUB doesn't load the given kernel on a given platform. -"headless" means that the kernel works but lacks console drivers (you -can still use serial or network console). In case of "no" and -"crashes" the reason is given in footnote. - BIOS Coreboot -BIOS chainloading yes no (1) -NTLDR yes no (1) -FreeBSD bootloader yes crashes (1) -32-bit kFreeBSD yes crashes (2,6) -64-bit kFreeBSD yes crashes (2,6) -32-bit kNetBSD yes crashes (1) -64-bit kNetBSD yes crashes (2) -32-bit kOpenBSD yes yes -64-bit kOpenBSD yes yes -Multiboot yes yes -Multiboot2 yes yes -32-bit Linux (legacy protocol) yes no (1) -64-bit Linux (legacy protocol) yes no (1) -32-bit Linux (modern protocol) yes yes -64-bit Linux (modern protocol) yes yes -32-bit XNU yes ? -64-bit XNU yes ? -32-bit EFI chainloader no (3) no (3) -64-bit EFI chainloader no (3) no (3) -Appleloader no (3) no (3) - - Multiboot Qemu -BIOS chainloading no (1) no (1) -NTLDR no (1) no (1) -FreeBSD bootloader crashes (1) crashes (1) -32-bit kFreeBSD crashes (6) crashes (6) -64-bit kFreeBSD crashes (6) crashes (6) -32-bit kNetBSD crashes (1) crashes (1) -64-bit kNetBSD yes yes -32-bit kOpenBSD yes yes -64-bit kOpenBSD yes yes -Multiboot yes yes -Multiboot2 yes yes -32-bit Linux (legacy protocol) no (1) no (1) -64-bit Linux (legacy protocol) no (1) no (1) -32-bit Linux (modern protocol) yes yes -64-bit Linux (modern protocol) yes yes -32-bit XNU ? ? -64-bit XNU ? ? -32-bit EFI chainloader no (3) no (3) -64-bit EFI chainloader no (3) no (3) -Appleloader no (3) no (3) - - 32-bit EFI 64-bit EFI -BIOS chainloading no (1) no (1) -NTLDR no (1) no (1) -FreeBSD bootloader crashes (1) crashes (1) -32-bit kFreeBSD headless headless -64-bit kFreeBSD headless headless -32-bit kNetBSD crashes (1) crashes (1) -64-bit kNetBSD yes yes -32-bit kOpenBSD headless headless -64-bit kOpenBSD headless headless -Multiboot yes yes -Multiboot2 yes yes -32-bit Linux (legacy protocol) no (1) no (1) -64-bit Linux (legacy protocol) no (1) no (1) -32-bit Linux (modern protocol) yes yes -64-bit Linux (modern protocol) yes yes -32-bit XNU yes yes -64-bit XNU yes (5) yes -32-bit EFI chainloader yes no (4) -64-bit EFI chainloader no (4) yes -Appleloader yes yes - - IEEE1275 -BIOS chainloading no (1) -NTLDR no (1) -FreeBSD bootloader crashes (1) -32-bit kFreeBSD crashes (6) -64-bit kFreeBSD crashes (6) -32-bit kNetBSD crashes (1) -64-bit kNetBSD ? -32-bit kOpenBSD ? -64-bit kOpenBSD ? -Multiboot ? -Multiboot2 ? -32-bit Linux (legacy protocol) no (1) -64-bit Linux (legacy protocol) no (1) -32-bit Linux (modern protocol) ? -64-bit Linux (modern protocol) ? -32-bit XNU ? -64-bit XNU ? -32-bit EFI chainloader no (3) -64-bit EFI chainloader no (3) -Appleloader no (3) - - 1. Requires BIOS - - 2. Crashes because the memory at 0x0-0x1000 isn't available - - 3. EFI only - - 4. 32-bit and 64-bit EFI have different structures and work in - different CPU modes so it's not possible to chainload 32-bit - bootloader on 64-bit platform and vice-versa - - 5. Some modules may need to be disabled - - 6. Requires ACPI - - PowerPC and Sparc ports support only Linux. MIPS port supports Linux -and multiboot2. - -17 Boot tests -************* - -As you have seen in previous chapter the support matrix is pretty big -and some of the configurations are only rarely used. To ensure the -quality bootchecks are available for all x86 targets except EFI -chainloader, Appleloader and XNU. All x86 platforms have bootcheck -facility except ieee1275. Multiboot, multiboot2, BIOS chainloader, -ntldr and freebsd-bootloader boot targets are tested only with a fake -kernel images. Only Linux is tested among the payloads using Linux -protocols. - - Following variables must be defined: - -GRUB_PAYLOADS_DIR directory containing the required kernels -GRUB_CBFSTOOL cbfstoll from Coreboot package (for coreboot - platform only) -GRUB_COREBOOT_ROM empty Coreboot ROM -GRUB_QEMU_OPTS additional options to be supplied to QEMU - - Required files are: - -kfreebsd_env.i386 32-bit kFreeBSD device hints -kfreebsd.i386 32-bit FreeBSD kernel image -kfreebsd.x86_64, same from 64-bit kFreeBSD -kfreebsd_env.x86_64 -knetbsd.i386 32-bit NetBSD kernel image -knetbsd.miniroot.i386 32-bit kNetBSD miniroot.kmod. -knetbsd.x86_64, same from 64-bit kNetBSD -knetbsd.miniroot.x86_64 -kopenbsd.i386 32-bit OpenBSD kernel bsd.rd image -kopenbsd.x86_64 same from 64-bit kOpenBSD -linux.i386 32-bit Linux -linux.x86_64 64-bit Linux - - -File: grub.info, Node: Troubleshooting, Next: Invoking grub-install, Prev: Supported kernels, Up: Top - -18 Error messages produced by GRUB -********************************** - -* Menu: - -* GRUB only offers a rescue shell:: - - -File: grub.info, Node: GRUB only offers a rescue shell, Up: Troubleshooting - -18.1 GRUB only offers a rescue shell -==================================== - -GRUB's normal start-up procedure involves setting the `prefix' -environment variable to a value set in the core image by -`grub-install', setting the `root' variable to match, loading the -`normal' module from the prefix, and running the `normal' command -(*note normal::). This command is responsible for reading -`/boot/grub/grub.cfg', running the menu, and doing all the useful -things GRUB is supposed to do. - - If, instead, you only get a rescue shell, this usually means that -GRUB failed to load the `normal' module for some reason. It may be -possible to work around this temporarily: for instance, if the reason -for the failure is that `prefix' is wrong (perhaps it refers to the -wrong device, or perhaps the path to `/boot/grub' was not correctly -made relative to the device), then you can correct this and enter -normal mode manually: - - # Inspect the current prefix (and other preset variables): - set - # Find out which devices are available: - ls - # Set to the correct value, which might be something like this: - set prefix=(hd0,1)/grub - set root=(hd0,1) - insmod normal - normal - - However, any problem that leaves you in the rescue shell probably -means that GRUB was not correctly installed. It may be more useful to -try to reinstall it properly using `grub-install DEVICE' (*note -Invoking grub-install::). When doing this, there are a few things to -remember: - - * Drive ordering in your operating system may not be the same as the - boot drive ordering used by your firmware. Do not assume that - your first hard drive (e.g. `/dev/sda') is the one that your - firmware will boot from. `device.map' (*note Device map::) can be - used to override this, but it is usually better to use UUIDs or - file system labels and avoid depending on drive ordering entirely. - - * At least on BIOS systems, if you tell `grub-install' to install - GRUB to a partition but GRUB has already been installed in the - master boot record, then the GRUB installation in the partition - will be ignored. - - * If possible, it is generally best to avoid installing GRUB to a - partition (unless it is a special partition for the use of GRUB - alone, such as the BIOS Boot Partition used on GPT). Doing this - means that GRUB may stop being able to read its core image due to - a file system moving blocks around, such as while defragmenting, - running checks, or even during normal operation. Installing to - the whole disk device is normally more robust. - - * Check that GRUB actually knows how to read from the device and - file system containing `/boot/grub'. It will not be able to read - from encrypted devices, nor from file systems for which support - has not yet been added to GRUB. - - -File: grub.info, Node: Invoking grub-install, Next: Invoking grub-mkconfig, Prev: Troubleshooting, Up: Top - -19 Invoking grub-install -************************ - -The program `grub-install' installs GRUB on your drive using -`grub-mkimage' and (on some platforms) `grub-setup'. You must specify -the device name on which you want to install GRUB, like this: - - grub-install INSTALL_DEVICE - - The device name INSTALL_DEVICE is an OS device name or a GRUB device -name. - - `grub-install' accepts the following options: - -`--help' - Print a summary of the command-line options and exit. - -`--version' - Print the version number of GRUB and exit. - -`--boot-directory=DIR' - Install GRUB images under the directory `DIR/grub/' This option is - useful when you want to install GRUB into a separate partition or - a removable disk. If this option is not specified then it - defaults to `/boot', so - - grub-install /dev/sda - - is equivalent to - - grub-install --boot-directory=/boot/ /dev/sda - - Here is an example in which you have a separate "boot" partition - which is mounted on `/mnt/boot': - - grub-install --boot-directory=/mnt/boot /dev/sdb - -`--recheck' - Recheck the device map, even if `/boot/grub/device.map' already - exists. You should use this option whenever you add/remove a disk - into/from your computer. - - -File: grub.info, Node: Invoking grub-mkconfig, Next: Invoking grub-mkpasswd-pbkdf2, Prev: Invoking grub-install, Up: Top - -20 Invoking grub-mkconfig -************************* - -The program `grub-mkconfig' generates a configuration file for GRUB -(*note Simple configuration::). - - grub-mkconfig -o /boot/grub/grub.cfg - - `grub-mkconfig' accepts the following options: - -`--help' - Print a summary of the command-line options and exit. - -`--version' - Print the version number of GRUB and exit. - -`-o FILE' -`--output=FILE' - Send the generated configuration file to FILE. The default is to - send it to standard output. - - -File: grub.info, Node: Invoking grub-mkpasswd-pbkdf2, Next: Invoking grub-mkrescue, Prev: Invoking grub-mkconfig, Up: Top - -21 Invoking grub-mkpasswd-pbkdf2 -******************************** - -The program `grub-mkpasswd-pbkdf2' generates password hashes for GRUB -(*note Security::). - - grub-mkpasswd-pbkdf2 - - `grub-mkpasswd-pbkdf2' accepts the following options: - -`-c NUMBER' -`--iteration-count=NUMBER' - Number of iterations of the underlying pseudo-random function. - Defaults to 10000. - -`-l NUMBER' -`--buflen=NUMBER' - Length of the generated hash. Defaults to 64. - -`-s NUMBER' -`--salt=NUMBER' - Length of the salt. Defaults to 64. - - -File: grub.info, Node: Invoking grub-mkrescue, Next: Obtaining and Building GRUB, Prev: Invoking grub-mkpasswd-pbkdf2, Up: Top - -22 Invoking grub-mkrescue -************************* - -The program `grub-mkrescue' generates a bootable GRUB rescue image -(*note Making a GRUB bootable CD-ROM::). - - grub-mkrescue -o grub.iso - - All arguments not explicitly listed as `grub-mkrescue' options are -passed on directly to `xorriso' in `mkisofs' emulation mode. Options -passed to `xorriso' will normally be interpreted as `mkisofs' options; -if the option `--' is used, then anything after that will be -interpreted as native `xorriso' options. - - Non-option arguments specify additional source directories. This is -commonly used to add extra files to the image: - - mkdir -p disk/boot/grub - (add extra files to `disk/boot/grub') - grub-mkrescue -o grub.iso disk - - `grub-mkrescue' accepts the following options: - -`--help' - Print a summary of the command-line options and exit. - -`--version' - Print the version number of GRUB and exit. - -`-o FILE' -`--output=FILE' - Save output in FILE. This "option" is required. - -`--modules=MODULES' - Pre-load the named GRUB modules in the image. Multiple entries in - MODULES should be separated by whitespace (so you will probably - need to quote this for your shell). - -`--rom-directory=DIR' - If generating images for the QEMU or Coreboot platforms, copy the - resulting `qemu.img' or `coreboot.elf' files respectively to the - DIR directory as well as including them in the image. - -`--xorriso=FILE' - Use FILE as the `xorriso' program, rather than the built-in - default. - -`--grub-mkimage=FILE' - Use FILE as the `grub-mkimage' program, rather than the built-in - default. - - -File: grub.info, Node: Obtaining and Building GRUB, Next: Reporting bugs, Prev: Invoking grub-mkrescue, Up: Top - -Appendix A How to obtain and build GRUB -*************************************** - - *Caution:* GRUB requires binutils-2.9.1.0.23 or later because the - GNU assembler has been changed so that it can produce real 16bits - machine code between 2.9.1 and 2.9.1.0.x. See - `http://sources.redhat.com/binutils/', to obtain information on - how to get the latest version. - - GRUB is available from the GNU alpha archive site -`ftp://alpha.gnu.org/gnu/grub' or any of its mirrors. The file will be -named grub-version.tar.gz. The current version is 1.99, so the file you -should grab is: - - `ftp://alpha.gnu.org/gnu/grub/grub-1.99.tar.gz' - - To unbundle GRUB use the instruction: - - zcat grub-1.99.tar.gz | tar xvf - - - which will create a directory called `grub-1.99' with all the -sources. You can look at the file `INSTALL' for detailed instructions -on how to build and install GRUB, but you should be able to just do: - - cd grub-1.99 - ./configure - make install - - Also, the latest version is available using Bazaar. See -`http://www.gnu.org/software/grub/grub-download.en.html' for more -information. - - -File: grub.info, Node: Reporting bugs, Next: Future, Prev: Obtaining and Building GRUB, Up: Top - -Appendix B Reporting bugs -************************* - -These are the guideline for how to report bugs. Take a look at this -list below before you submit bugs: - - 1. Before getting unsettled, read this manual through and through. - Also, see the GNU GRUB FAQ - (http://www.gnu.org/software/grub/grub-faq.html). - - 2. Always mention the information on your GRUB. The version number - and the configuration are quite important. If you build it - yourself, write the options specified to the configure script and - your operating system, including the versions of gcc and binutils. - - 3. If you have trouble with the installation, inform us of how you - installed GRUB. Don't omit error messages, if any. Just `GRUB hangs - up when it boots' is not enough. - - The information on your hardware is also essential. These are - especially important: the geometries and the partition tables of - your hard disk drives and your BIOS. - - 4. If GRUB cannot boot your operating system, write down _everything_ - you see on the screen. Don't paraphrase them, like `The foo OS - crashes with GRUB, even though it can boot with the bar boot - loader just fine'. Mention the commands you executed, the messages - printed by them, and information on your operating system - including the version number. - - 5. Explain what you wanted to do. It is very useful to know your - purpose and your wish, and how GRUB didn't satisfy you. - - 6. If you can investigate the problem yourself, please do. That will - give you and us much more information on the problem. Attaching a - patch is even better. - - When you attach a patch, make the patch in unified diff format, and - write ChangeLog entries. But, even when you make a patch, don't - forget to explain the problem, so that we can understand what your - patch is for. - - 7. Write down anything that you think might be related. Please - understand that we often need to reproduce the same problem you - encountered in our environment. So your information should be - sufficient for us to do the same thing--Don't forget that we - cannot see your computer directly. If you are not sure whether to - state a fact or leave it out, state it! Reporting too many things - is much better than omitting something important. - - If you follow the guideline above, submit a report to the Bug -Tracking System (http://savannah.gnu.org/bugs/?group=grub). -Alternatively, you can submit a report via electronic mail to -<bug-grub@gnu.org>, but we strongly recommend that you use the Bug -Tracking System, because e-mail can be passed over easily. - - Once we get your report, we will try to fix the bugs. - - -File: grub.info, Node: Future, Next: Copying This Manual, Prev: Reporting bugs, Up: Top - -Appendix C Where GRUB will go -***************************** - -GRUB 2 is now quite stable and used in many production systems. We are -currently working towards a 2.0 release. - - If you are interested in the development of GRUB 2, take a look at -the homepage (http://www.gnu.org/software/grub/grub.html). - - -File: grub.info, Node: Copying This Manual, Next: Index, Prev: Future, Up: Top - -Appendix D Copying This Manual -****************************** - -* Menu: - -* GNU Free Documentation License:: License for copying this manual. - - -File: grub.info, Node: GNU Free Documentation License, Up: Copying This Manual - -D.1 GNU Free Documentation License -================================== - - Version 1.2, November 2002 - - Copyright (C) 2000,2001,2002 Free Software Foundation, Inc. - 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA - - Everyone is permitted to copy and distribute verbatim copies - of this license document, but changing it is not allowed. - - 0. 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FUTURE REVISIONS OF THIS LICENSE - - The Free Software Foundation may publish new, revised versions of - the GNU Free Documentation License from time to time. Such new - versions will be similar in spirit to the present version, but may - differ in detail to address new problems or concerns. See - `http://www.gnu.org/copyleft/'. - - Each version of the License is given a distinguishing version - number. If the Document specifies that a particular numbered - version of this License "or any later version" applies to it, you - have the option of following the terms and conditions either of - that specified version or of any later version that has been - published (not as a draft) by the Free Software Foundation. If - the Document does not specify a version number of this License, - you may choose any version ever published (not as a draft) by the - Free Software Foundation. - -D.1.1 ADDENDUM: How to use this License for your documents ----------------------------------------------------------- - -To use this License in a document you have written, include a copy of -the License in the document and put the following copyright and license -notices just after the title page: - - Copyright (C) YEAR YOUR NAME. - Permission is granted to copy, distribute and/or modify this document - under the terms of the GNU Free Documentation License, Version 1.2 - or any later version published by the Free Software Foundation; - with no Invariant Sections, no Front-Cover Texts, and no Back-Cover - Texts. A copy of the license is included in the section entitled ``GNU - Free Documentation License''. - - If you have Invariant Sections, Front-Cover Texts and Back-Cover -Texts, replace the "with...Texts." line with this: - - with the Invariant Sections being LIST THEIR TITLES, with - the Front-Cover Texts being LIST, and with the Back-Cover Texts - being LIST. - - If you have Invariant Sections without Cover Texts, or some other -combination of the three, merge those two alternatives to suit the -situation. - - If your document contains nontrivial examples of program code, we -recommend releasing these examples in parallel under your choice of -free software license, such as the GNU General Public License, to -permit their use in free software. - - -File: grub.info, Node: Index, Prev: Copying This Manual, Up: Top - -Index -***** - - -* Menu: - -* acpi: acpi. (line 11) -* badram: badram. (line 7) -* blocklist: blocklist. (line 7) -* boot: boot. (line 7) -* cat: cat. (line 7) -* chainloader: chainloader. (line 7) -* cmp: cmp. (line 7) -* configfile: configfile. (line 7) -* cpuid: cpuid. (line 7) -* crc: crc. (line 7) -* date: date. (line 7) -* drivemap: drivemap. (line 7) -* echo: echo. (line 7) -* export: export. (line 7) -* false: false. (line 7) -* FDL, GNU Free Documentation License: GNU Free Documentation License. - (line 6) -* gettext: gettext. (line 7) -* gptsync: gptsync. (line 7) -* halt: halt. (line 7) -* help: help. (line 7) -* initrd: initrd. (line 7) -* initrd16: initrd16. (line 7) -* insmod: insmod. (line 7) -* keystatus: keystatus. (line 7) -* linux: linux. (line 7) -* linux16: linux16. (line 7) -* list_env: list_env. (line 7) -* load_env: load_env. (line 7) -* loopback: loopback. (line 7) -* ls: ls. (line 7) -* menuentry: menuentry. (line 8) -* normal: normal. (line 7) -* normal_exit: normal_exit. (line 7) -* parttool: parttool. (line 7) -* password: password. (line 7) -* password_pbkdf2: password_pbkdf2. (line 7) -* play: play. (line 7) -* pxe_unload: pxe_unload. (line 7) -* read: read. (line 7) -* reboot: reboot. (line 7) -* save_env: save_env. (line 7) -* search: search. (line 8) -* sendkey: sendkey. (line 12) -* serial: serial. (line 8) -* set: set. (line 7) -* submenu: submenu. (line 8) -* terminal_input: terminal_input. (line 8) -* terminal_output: terminal_output. (line 8) -* terminfo: terminfo. (line 7) -* true: true. (line 7) -* unset: unset. (line 7) - - - -Tag Table: -Node: Top961 -Node: Introduction3282 -Node: Overview3726 -Node: Overview-Footnotes5710 -Ref: Overview-Footnote-15771 -Node: History5932 -Node: Changes from GRUB Legacy8020 -Node: Features10496 -Node: Features-Footnotes16487 -Ref: Features-Footnote-116548 -Ref: Features-Footnote-216694 -Node: Role of a boot loader16839 -Node: Role of a boot loader-Footnotes18177 -Ref: Role of a boot loader-Footnote-118264 -Node: Naming convention18343 -Node: Installation21218 -Node: Installing GRUB using grub-install22321 -Node: Making a GRUB bootable CD-ROM24492 -Node: Making a GRUB bootable CD-ROM-Footnotes26346 -Ref: Making a GRUB bootable CD-ROM-Footnote-126449 -Node: Device map26524 -Node: BIOS installation28701 -Node: Booting32078 -Node: General boot methods32470 -Node: Loading an operating system directly33211 -Node: Chain-loading33942 -Node: OS-specific notes34913 -Node: GNU/Hurd35195 -Node: GNU/Linux36312 -Node: DOS/Windows37935 -Node: Configuration39708 -Node: Simple configuration40250 -Node: Shell-like scripting49686 -Node: Shell-like scripting-Footnotes57596 -Ref: Shell-like scripting-Footnote-157681 -Node: Embedded configuration57808 -Node: Theme file format60641 -Ref: Pixmap-styled progress bar62064 -Ref: Plain progress bar62076 -Ref: An example of the slices (in red) used for a terminal window. This drawing was created and sliced in Inkscape_65505 -Node: Network79727 -Node: Serial terminal82130 -Node: Vendor power-on keys84357 -Node: Images86187 -Node: Filesystem91147 -Node: Device syntax91834 -Node: File name syntax93326 -Node: Block list syntax94080 -Node: Interface94813 -Node: Command-line interface95635 -Node: Command-line interface-Footnotes97576 -Ref: Command-line interface-Footnote-197665 -Node: Menu interface97760 -Node: Menu entry editor98770 -Node: Environment99508 -Node: Special environment variables100212 -Node: biosnum100963 -Node: chosen101477 -Node: color_highlight101919 -Node: color_normal102325 -Node: debug102947 -Node: default103294 -Node: fallback104221 -Node: gfxmode104552 -Node: gfxpayload105285 -Node: gfxterm_font106437 -Node: icondir106736 -Node: lang107052 -Node: locale_dir107521 -Node: menu_color_highlight108030 -Node: menu_color_normal108526 -Node: net_pxe_boot_file109019 -Node: net_pxe_dhcp_server_name109230 -Node: net_pxe_domain109452 -Node: net_pxe_extensionspath109659 -Node: net_pxe_hostname109874 -Node: net_pxe_ip110073 -Node: net_pxe_mac110249 -Node: net_pxe_rootpath110427 -Node: pager110610 -Node: prefix110864 -Node: pxe_blksize111313 -Node: pxe_default_gateway111490 -Node: pxe_default_server111695 -Node: root111891 -Node: superusers112432 -Node: theme112680 -Node: timeout113001 -Node: Environment block113498 -Node: Commands114930 -Node: Menu-specific commands115763 -Node: menuentry116490 -Node: submenu117497 -Node: General commands118005 -Node: serial118501 -Node: terminal_input119546 -Node: terminal_output120212 -Node: terminfo120879 -Node: Command-line and menu entry commands122014 -Node: acpi124985 -Node: badram126024 -Node: blocklist127066 -Node: boot127300 -Node: cat127621 -Node: chainloader128256 -Node: cmp128878 -Node: configfile129429 -Node: cpuid129729 -Node: crc130194 -Node: date130384 -Node: drivemap130923 -Node: echo131726 -Node: export132663 -Node: false132973 -Node: gettext133269 -Node: gptsync133716 -Node: halt134661 -Node: help134987 -Node: initrd135450 -Node: initrd16135862 -Node: insmod136367 -Node: keystatus136589 -Node: linux137227 -Node: linux16138130 -Node: list_env138844 -Node: load_env139198 -Node: loopback139576 -Node: ls140024 -Node: normal140569 -Node: normal_exit141328 -Node: parttool141650 -Node: password143155 -Node: password_pbkdf2143437 -Node: play143845 -Node: pxe_unload144597 -Node: read144876 -Node: reboot145225 -Node: save_env145410 -Node: search145796 -Node: sendkey146574 -Node: set152848 -Node: true153146 -Node: unset153431 -Node: uppermem153637 -Node: Security153838 -Node: Supported kernels156526 -Node: Troubleshooting164014 -Node: GRUB only offers a rescue shell164240 -Node: Invoking grub-install167166 -Node: Invoking grub-mkconfig168544 -Node: Invoking grub-mkpasswd-pbkdf2169181 -Node: Invoking grub-mkrescue169839 -Node: Obtaining and Building GRUB171602 -Node: Reporting bugs172846 -Node: Future175649 -Node: Copying This Manual176049 -Node: GNU Free Documentation License176277 -Node: Index198685 - -End Tag Table |