Difference between revisions of "Grub-install"
(I finished up about what grub-install is doing.) |
(I placed this into the Grub category.) |
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Grub finally uses the information about needed modules to create an image using <code>grub-mkimage</code>. The initial <code>boot.img</code> file is then modified to point to the <code>core.img</code> file that was just generated. Thatr image is then installed to the desired installation device with <code>grub-setup</code>. | Grub finally uses the information about needed modules to create an image using <code>grub-mkimage</code>. The initial <code>boot.img</code> file is then modified to point to the <code>core.img</code> file that was just generated. Thatr image is then installed to the desired installation device with <code>grub-setup</code>. | ||
| + | [[Category:Grub]] | ||
Revision as of 00:39, 15 November 2010
This is an annotation about what grub-install does. This is based on the =sys-boot/grub-1.98-r1 version.
#! /bin/shThis tells the Linux kernel that this script will be executed with /bin/sh.
# Install GRUB on your drive. # Copyright (C) 1999,2000,2001,2002,2003,2004,2005,2006,2007,2008,2009 Free Software Foundation, Inc. # # GRUB is free software: you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation, either version 3 of the License, or # (at your option) any later version. # # GRUB is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with GRUB. If not, see <http://www.gnu.org/licenses/>.
This section tells that this script falls under the GNU General Public License.
# Initialize some variables. transform="s,x,x," prefix=/usr exec_prefix=${prefix} sbindir=/sbin bindir=/bin libdir=/lib64 PACKAGE_NAME=GRUB PACKAGE_TARNAME=grub PACKAGE_VERSION=1.98 target_cpu=i386 platform=pc host_os=linux-gnu font=/usr/share/grub/ascii.pf2 pkglibdir=${libdir}/`echo ${PACKAGE_TARNAME}/${target_cpu}-${platform} | sed ${transform}`
These are some variables set when Grub was configured for the system.
grub_setup=${sbindir}/`echo grub-setup | sed ${transform}` if [ "${target_cpu}-${platform}" = "i386-pc" ] || [ "${target_cpu}-${platform}" = "sparc64-ieee1275" ] || [ "${target_cpu}-${platform}" = "mips-yeeloong" ] ; then grub_mkimage=${bindir}/`echo grub-mkimage | sed ${transform}` else grub_mkimage=${bindir}/`echo grub-mkelfimage | sed ${transform}` fi grub_mkdevicemap=${sbindir}/`echo grub-mkdevicemap | sed ${transform}` grub_probe=${sbindir}/`echo grub-probe | sed ${transform}` grub_editenv=${bindir}/`echo grub-editenv | sed ${transform}` rootdir= grub_prefix=`echo /boot/grub | sed ${transform}` modules= install_device= no_floppy= force_lba= recheck=no debug=no if [ "${target_cpu}-${platform}" = "i386-pc" ] ; then disk_module=biosdisk elif [ "${target_cpu}-${platform}" = "sparc64-ieee1275" ] ; then disk_module= else disk_module=ata fi
Further variables were initialized some of which were done so in a platform-dependent manner such as disk_module being set to biosdisk on i386-pc systems.
# Usage: usage # Print the usage. usage () { cat <<EOF Usage: grub-install [OPTION] install_device Install GRUB on your drive. -h, --help print this message and exit -v, --version print the version information and exit --modules=MODULES pre-load specified modules MODULES --root-directory=DIR install GRUB images under the directory DIR instead of the root directory --grub-setup=FILE use FILE as grub-setup --grub-mkimage=FILE use FILE as grub-mkimage --grub-mkdevicemap=FILE use FILE as grub-mkdevicemap --grub-probe=FILE use FILE as grub-probe --no-floppy do not probe any floppy drive --recheck probe a device map even if it already exists --force install even if problems are detected EOF if [ "${target_cpu}-${platform}" = "i386-pc" ] ; then cat <<EOF --disk-module=MODULE disk module to use EOF fi if [ "${target_cpu}-${platform}" = "mips-yeeloong" ] ; then cat <<EOF --font=FILE font file to use EOF fi cat <<EOF INSTALL_DEVICE can be a GRUB device name or a system device filename. grub-install copies GRUB images into /boot/grub (or /grub on NetBSD and OpenBSD), and uses grub-setup to install grub into the boot sector. If the --root-directory option is used, then grub-install will copy images into the operating system installation rooted at that directory. Report bugs to <bug-grub@gnu.org>. EOF }
This sets up the usage message that grub-install prints if it doesn't understand what arguments it was given.
# Check the arguments. for option in "$@"; do case "$option" in -h | --help) usage exit 0 ;; -v | --version) echo "grub-install (GNU GRUB ${PACKAGE_VERSION})" exit 0 ;; --modules=*) modules=`echo "$option" | sed 's/--modules=//'` ;; --font=*) font=`echo "$option" | sed 's/--font=//'` ;; --root-directory=*) rootdir=`echo "$option" | sed 's/--root-directory=//'` ;; --grub-setup=*) grub_setup=`echo "$option" | sed 's/--grub-setup=//'` ;; --grub-mkimage=*) grub_mkimage=`echo "$option" | sed 's/--grub-mkimage=//'` ;; --grub-mkdevicemap=*) grub_mkdevicemap=`echo "$option" | sed 's/--grub-mkdevicemap=//'` ;; --grub-probe=*) grub_probe=`echo "$option" | sed 's/--grub-probe=//'` ;; --no-floppy) no_floppy="--no-floppy" ;; --recheck) recheck=yes ;; --disk-module=*) if [ "${target_cpu}-${platform}" = "i386-pc" ] ; then disk_module=`echo "$option" | sed 's/--disk-module=//'` fi ;; # This is an undocumented feature... --debug) debug=yes ;; -f | --force) setup_force="--force" ;; -*) echo "Unrecognized option \`$option'" 1>&2 usage exit 1 ;; *) if test "x$install_device" != x; then echo "More than one install_devices?" 1>&2 usage exit 1 fi install_device="${option}" ;; esac done
This section parses the command line arguments and sets variables appropriately.
# for make_system_path_relative_to_its_root() . ${libdir}/grub/grub-mkconfig_lib if test "x$install_device" = x && test "${target_cpu}-${platform}" != "mips-yeeloong"; then echo "install_device not specified." 1>&2 usage exit 1 fi
This block ensures that a destination device was specified to grub-install as an argument.
# If the debugging feature is enabled, print commands. setup_verbose= if test $debug = yes; then set -x setup_verbose="--verbose" fi
This block makes grub-install more verbose if grub was built with debugging enabled.
# Initialize these directories here, since ROOTDIR was initialized. case "$host_os" in netbsd* | openbsd*) # Because /boot is used for the boot block in NetBSD and OpenBSD, use /grub # instead of /boot/grub. grub_prefix=`echo /grub | sed ${transform}` bootdir=${rootdir} ;; *) # Use /boot/grub by default. bootdir=${rootdir}/boot ;; esac
Set up the location where Grub will be installed.
grubdir=${bootdir}/`echo grub | sed ${transform}` device_map=${grubdir}/device.map grub_probe="${grub_probe} --device-map=${device_map}" # Check if GRUB is installed. if [ "${target_cpu}-${platform}" = "i386-pc" ] || [ "${target_cpu}-${platform}" = "sparc64-ieee1275" ] ; then set $grub_setup dummy if test -f "$1"; then : else echo "$1: Not found." 1>&2 exit 1 fi fi set $grub_mkimage dummy if test -f "$1"; then : else echo "$1: Not found." 1>&2 exit 1 fi set $grub_mkdevicemap dummy if test -f "$1"; then : else echo "$1: Not found." 1>&2 exit 1 fi
These blocks ensure that grub components are installed.
# Create the GRUB directory if it is not present. test -d "$bootdir" || mkdir "$bootdir" || exit 1 test -d "$grubdir" || mkdir "$grubdir" || exit 1 # If --recheck is specified, remove the device map, if present. if test $recheck = yes; then rm -f $device_map fi # Create the device map file if it is not present. if test -f "$device_map"; then : else # Create a safe temporary file. test -n "$mklog" && log_file=`$mklog` $grub_mkdevicemap --device-map=$device_map $no_floppy || exit 1 fi
This creates the device map by calling grub-mkdevicemap. That program will create a mapping from the Grub device names to the Linux device nodes.
# Make sure that there is no duplicated entry. tmp=`sed -n '/^([fh]d[0-9]*)/s/\(^(.*)\).*/\1/p' $device_map \ | sort | uniq -d | sed -n 1p` if test -n "$tmp"; then echo "The drive $tmp is defined multiple times in the device map $device_map" 1>&2 exit 1 fi
This does some sanity checks on the device map file in case it has been manually corrected in an erroneous way.
# Copy the GRUB images to the GRUB directory. for file in ${grubdir}/*.mod ${grubdir}/*.lst ${grubdir}/*.img ${grubdir}/efiemu??.o; do if test -f $file && [ "`basename $file`" != menu.lst ]; then rm -f $file || exit 1 fi done for file in ${pkglibdir}/*.mod ${pkglibdir}/*.lst; do cp -f $file ${grubdir} || exit 1 done if [ "${target_cpu}-${platform}" = "i386-pc" ] || [ "${target_cpu}-${platform}" = "sparc64-ieee1275" ] ; then for file in ${pkglibdir}/*.img ${pkglibdir}/efiemu??.o; do if test -f $file; then cp -f $file ${grubdir} || exit 1 fi done fi # Copy gettext files mkdir -p ${grubdir}/locale/ for file in ${grubdir}/locale/*.mo ${pkglibdir}/locale/*.mo; do if test -f "$file"; then cp -f "$file" ${grubdir}/locale/ fi done
This copies grub components and its localization files to the boot directory.
# Write device to a variable so we don't have to traverse /dev every time. grub_device=`$grub_probe --target=device ${grubdir}` if ! test -f ${grubdir}/grubenv; then $grub_editenv ${grubdir}/grubenv create fi # Create the core image. First, auto-detect the filesystem module. fs_module=`$grub_probe --target=fs --device ${grub_device}` if test "x$fs_module" = x -a "x$modules" = x; then echo "Auto-detection of a filesystem module failed." 1>&2 echo "Please specify the module with the option \`--modules' explicitly." 1>&2 exit 1 fi # Then the partition map module. In order to support partition-less media, # this command is allowed to fail (--target=fs already grants us that the # filesystem will be accessible). partmap_module=`$grub_probe --target=partmap --device ${grub_device} 2> /dev/null` # Device abstraction module, if any (lvm, raid). devabstraction_module=`$grub_probe --target=abstraction --device ${grub_device}` # The order in this list is critical. Be careful when modifying it. modules="$modules $disk_module" modules="$modules $fs_module $partmap_module $devabstraction_module"
Since Grub is modular, it needs the modules that allow it to recognize the boot directory. Consequently, it uses the grub-probe command to determine the modules necessary and adds them to the modules list in an appropriate order. Once it can recognize the boot directory, Grub can dynamically load modules as necessary and read its configuration file.
relative_grubdir=`make_system_path_relative_to_its_root ${grubdir}` || exit 1 if [ "x${relative_grubdir}" = "x" ] ; then relative_grubdir=/ fi prefix_drive= config_opt= if [ "x${devabstraction_module}" = "x" ] ; then if [ x"${install_device}" != x ]; then if echo "${install_device}" | grep -qx "(.*)" ; then install_drive="${install_device}" else install_drive="`$grub_probe --target=drive --device ${install_device}`" fi install_drive="`echo ${install_drive} | sed -e s/,[0-9]*[a-z]*//g`" fi grub_drive="`$grub_probe --target=drive --device ${grub_device}`" # Strip partition number grub_drive="`echo ${grub_drive} | sed -e s/,[0-9]*[a-z]*//g`" if [ "$disk_module" = ata ] ; then # generic method (used on coreboot and ata mod) uuid="`$grub_probe --target=fs_uuid --device ${grub_device}`" if [ "x${uuid}" = "x" ] ; then echo "UUID needed with ata mod, but the filesystem containing ${grubdir} does not support UUIDs." 1>&2 exit 1 fi echo "search.fs_uuid ${uuid} root " > ${grubdir}/load.cfg echo 'set prefix=($root)'"${relative_grubdir}" >> ${grubdir}/load.cfg config_opt="-c ${grubdir}/load.cfg " modules="$modules search_fs_uuid" elif [ "x${grub_drive}" != "x${install_drive}" ] ; then uuid="`$grub_probe --target=fs_uuid --device ${grub_device}`" if [ "x${uuid}" = "x" ] ; then echo "You attempted a cross-disk install, but the filesystem containing ${grubdir} does not support UUIDs." 1>&2 exit 1 fi echo "search.fs_uuid ${uuid} root " > ${grubdir}/load.cfg echo 'set prefix=($root)'"${relative_grubdir}" >> ${grubdir}/load.cfg config_opt="-c ${grubdir}/load.cfg " modules="$modules search_fs_uuid" fi else prefix_drive=`$grub_probe --target=drive --device ${grub_device}` fi
Partitions can be moved around or initialized in a different order, so Grub wants to identify filesystems by their UUIDs. It also can load from a drive different from where it is installed. It does further probing to determine if the UUID module will be needed and includes it with the other modules.
if [ "${target_cpu}-${platform}" = "i386-pc" ] || [ "${target_cpu}-${platform}" = "sparc64-ieee1275" ] ; then $grub_mkimage ${config_opt} --output=${grubdir}/core.img --prefix=${prefix_drive}${relative_grubdir} $modules || exit 1 # Now perform the installation. $grub_setup ${setup_verbose} ${setup_force} --directory=${grubdir} --device-map=${device_map} \ ${install_device} || exit 1 elif [ "${target_cpu}-${platform}" = "mips-yeeloong" ] ; then $grub_mkimage ${config_opt} -f ${font} -d ${pkglibdir} -O elf --output=/boot/grub.elf --prefix=${prefix_drive}${relative_grubdir} $modules || exit 1 else $grub_mkimage ${config_opt} -d ${pkglibdir} --output=/boot/multiboot.img --prefix=${prefix_drive}${relative_grubdir} $modules || exit 1 fi echo "Installation finished. No error reported." # Bye. exit 0
Grub finally uses the information about needed modules to create an image using grub-mkimage. The initial boot.img file is then modified to point to the core.img file that was just generated. Thatr image is then installed to the desired installation device with grub-setup.