Grub-install - Revision history

Brantgurga: I corrected a typo.

2010-11-15T18:02:48Z

I corrected a typo.

Brantgurga: I placed this into the Grub category.

2010-11-15T00:39:11Z

I placed this into the Grub category.

Brantgurga: I finished up about what grub-install is doing.

2010-11-15T00:15:20Z

I finished up about what grub-install is doing.

Brantgurga: I annotated a bit more of what grub-install is doing.

2010-11-14T22:52:33Z

I annotated a bit more of what grub-install is doing.

Brantgurga: I began annotating the source code.

2010-11-14T22:39:12Z

I began annotating the source code.

New page

This is an annotation about what grub-install does. This is based on the <code>=sys-boot/grub-1.98-r1</code> version.

<syntaxhighlight lang="bash">
#! /bin/sh
</syntaxhighlight>
This tells the Linux kernel that this script will be executed with <code>/bin/sh</code>.
<syntaxhighlight lang="bash">

# 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/>.
</syntaxhighlight>
This section tells that this script falls under the GNU General Public License.
<syntaxhighlight lang="bash">

# 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}`
</syntaxhighlight>
These are some variables set when Grub was configured for the system.
<syntaxhighlight lang="bash">

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
</syntaxhighlight>
Further variables were initialized some of which were done so in a platform-dependent manner such as <code>disk_module</code> being set to <code>biosdisk</code> on i386-pc systems.
<syntaxhighlight lang="bash">

# 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
}
</syntaxhighlight>
This sets up the usage message that <code>grub-install</code> prints if it doesn't understand what arguments it was given.
<syntaxhighlight lang="bash">
# 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
</syntaxhighlight>
This section parses the command line arguments and sets variables appropriately.
<syntaxhighlight lang="bash">

# 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

# If the debugging feature is enabled, print commands.
setup_verbose=
if test $debug = yes; then
set -x
setup_verbose="--verbose"
fi

# 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

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

# 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

# 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

# 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

# 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"

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

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
</syntaxhighlight>

@@ Line 411: / Line 411: @@
 exit 0
 </syntaxhighlight>
-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. That image is then installed to the desired installation device with <code>grub-setup</code>.
 [[Category:Grub]]

← Older revision		Revision as of 00:39, 15 November 2010
Line 412:		Line 412:
	</syntaxhighlight>		</syntaxhighlight>
	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]]

@@ Line 215: / Line 215: @@
      ;;
 esac
 grubdir=${bootdir}/`echo grub | sed ${transform}`
@@ Line 247: / Line 250: @@
      exit 1
 fi
+</syntaxhighlight>
 # Create the GRUB directory if it is not present.
 test -d "$bootdir" || mkdir "$bootdir" || exit 1
@@ Line 266: / Line 271: @@
      $grub_mkdevicemap --device-map=$device_map $no_floppy || exit 1
 fi
 # Make sure that there is no duplicated entry.
@@ Line 274: / Line 282: @@
      exit 1
 fi
 # Copy the GRUB images to the GRUB directory.
@@ Line 299: / Line 310: @@
      fi
 done
 # Write device to a variable so we don't have to traverse /dev every time.
@@ Line 326: / Line 340: @@
 modules="$modules $disk_module"
 modules="$modules $fs_module $partmap_module $devabstraction_module"
 relative_grubdir=`make_system_path_relative_to_its_root ${grubdir}` || exit 1
@@ Line 373: / Line 390: @@
      prefix_drive=`$grub_probe --target=drive --device ${grub_device}`
 fi
 if [ "${target_cpu}-${platform}" = "i386-pc" ] || [ "${target_cpu}-${platform}" = "sparc64-ieee1275" ] ; then
@@ Line 391: / Line 411: @@
 exit 0
 </syntaxhighlight>

@@ Line 184: / Line 184: @@
      exit 1
 fi
 # If the debugging feature is enabled, print commands.
@@ Line 191: / Line 196: @@
      setup_verbose="--verbose"
 fi
 # Initialize these directories here, since ROOTDIR was initialized.