#! /bin/sh -e

# update-grub helper script.
# Copyright (C) 2006,2007  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/>.

if [ "x${GRUB_DISTRIBUTOR}" = "" ] ; then
  OS=GNU/Linux
else
  OS="${GRUB_DISTRIBUTOR} GNU/Linux"
fi

test_numeric ()
{
  local a=$1
  local cmp=$2
  local b=$3
  if [ "$a" = "$b" ] ; then
    case $cmp in
      ge|eq|le) return 0 ;;
      gt|lt) return 1 ;;
    esac
  fi
  if [ "$cmp" = "lt" ] ; then
    c=$a
    a=$b
    b=$c
  fi
  if (echo $a ; echo $b) | sort -n | head -n 1 | grep -qx $b ; then
    return 0
  else
    return 1
  fi
}

test_gt ()
{
  local a=`echo $1 | sed -e "s/vmlinu[zx]-//g"`
  local b=`echo $2 | sed -e "s/vmlinu[zx]-//g"`
  local cmp=gt
  if [ "x$b" = "x" ] ; then
    return 0
  fi
  case $a:$b in
    *.old:*.old) ;;
    *.old:*) a=`echo -n $a | sed -e s/\.old$//g` ; cmp=gt ;;
    *:*.old) b=`echo -n $b | sed -e s/\.old$//g` ; cmp=ge ;;
  esac
  test_numeric $a $cmp $b
  return $?
}

find_latest ()
{
  local a=""
  for i in $@ ; do
    if test_gt "$i" "$a" ; then
      a="$i"
    fi
  done
  echo "$a"
}

list=`for i in /boot/vmlinu[xz]-* /vmlinu[xz]-* ; do
        if test -e $i ; then echo -n "$i " ; fi
      done`

while [ "x$list" != "x" ] ; do
  linux=`find_latest $list`
  echo "Found linux image: $linux" >&2
  basename=`basename $linux`
  dirname=`dirname $linux`
  grub_dirname=`echo ${dirname} | sed -e "s%^/boot%${GRUB_DRIVE_BOOT}%g"`
  version=`echo $basename | sed -e "s,^[^0-9]*-,,g"`

  initrd=
  for i in "initrd.img-${version}" "initrd-${version}.img"; do
    if test -e "${dirname}/${i}" ; then
      initrd="$i"
      break
    fi
  done
  if test -n "${initrd}" ; then
    echo "Found initrd image: ${dirname}/${initrd}" >&2
  fi

  cat << EOF
menuentry "${OS}, linux ${version}" {
	linux	${grub_dirname}/${basename} root=${GRUB_DEVICE} ro ${GRUB_CMDLINE_LINUX}
EOF
  if test -n "${initrd}" ; then
    cat << EOF
	initrd	${grub_dirname}/${initrd}
EOF
  fi
  cat << EOF
}
EOF

  cat << EOF
menuentry "${OS}, linux ${version} (single-user mode)" {
	linux	${grub_dirname}/${basename} root=${GRUB_DEVICE} ro single ${GRUB_CMDLINE_LINUX}
EOF
  if test -n "${initrd}" ; then
    cat << EOF
	initrd	${grub_dirname}/${initrd}
EOF
  fi
  cat << EOF
}
EOF

  list=`echo $list | tr ' ' '\n' | grep -vx $linux | tr '\n' ' '`
done