#!/bin/sh
# Tool for recovering VISTA & Windows7 MBR disk signature by guessing it
#  from the information in Boot/BCD
# Originally written by Kiyoshi SUZUKI in Fukui, Japan
#  at 2010/9/8
readloop () {
  while [ a = a ]
  do
    read a
    if [ $a -ge 0 ]
    then
      if [ $? = 1 ]
      then
      echo "Please type number"
      continue
    elif [ $a -lt "$(echo $*|tr ' ' '\n'|wc -l)" ]
    then
      break
    else
      echo "Please type number smaller than $(echo $*|tr ' ' '\n'|wc -l)"
      continue
    fi
      echo "Please type number larger than 0 or 0"
    fi
  done
}
deviceslist=$(blkid|cut -d: -f1)
okdeviceslist=""
for a in $deviceslist
do
  umount -l /mnt 2>/dev/null
  mount -t $(blkid $a|sed -e "s/.*TYPE=\"//"|sed -e "s/\".*//") $a /mnt 2>/dev/null || continue
  if [ "$(ls /mnt/Boot/BCD 2>/dev/null)" ]
  then
    okdeviceslist="${okdeviceslist} $a"
  fi
  umount -l /mnt 2>/dev/null
done
if [ "$(echo $okdeviceslist|grep \ )" ]
then
  echo "Boot/BCD is found in the partitions the device file name of which is shown below:"
  echo
  i=0
  for a in ${okdeviceslist}
  do
    echo $i":"$(blkid|grep "${a}:")
    echo
    i=$(expr $i + 1)
  done
  echo
  echo "You can look upper by pushing SHIFT and PageUp keys at the same time."
  echo "Please type the number of the device file name of the partition of Boot/BCD you want to deal with"
  readloop $okdeviceslist
  okdeviceslist=$(echo $okdeviceslist|cut -d" " -f$(expr $a + 1))
fi
echo Boot/BCD in $okdeviceslist will be used to search disk signature
echo disk signature candidates shown below are found in Boot/BCD in $okdeviceslist
echo ======================================================================
mount -t $(blkid $okdeviceslist|sed -e "s/.*TYPE=\"//"|sed -e "s/\".*//") $okdeviceslist /mnt 2>/dev/null
hd /mnt/Boot/BCD | grep "  00 00 00 00 00 00 00 00  01 00 00 00 .. .. .. ..  "|sed -e "s/.*  01 00 00 00 //"|sed -e "s/  |.*$//" > /tmp/kiyoplog1
hd /mnt/Boot/BCD | grep "  01 00 00 00 .. .. .. ..  00 00 00 00 00 00 00 00  "|sed -e "s/.*  01 00 00 00 //"|sed -e "s/  .*$//" >> /tmp/kiyoplog1
sort /tmp/kiyoplog1|uniq -c|sed -e "s/^[^0-9]*//"|sed -e "s/ /times /" > /tmp/kiyoplog2
num=$(wc -l /tmp/kiyoplog2|cut -d" " -f1)
i=0
while [ $i -lt $num ]
do
  echo $i:$(sed -n -e "$(expr $i + 1)p" /tmp/kiyoplog2)
  i=$(expr $i + 1)
done
echo ======================================================================
echo "Please type the number of the disk signature suitable to be written in MBR"
readloop $(cat /tmp/kiyoplog2|cut -d" " -f1)
disksignature=$(sed -n -e $(expr $a + 1)p /tmp/kiyoplog2|sed -e "s/.*times //")
echo you selected $a:$disksignature
bcdline=$(hd /mnt/Boot/BCD|grep "  01 00 00 00 $disksignature  "|sed -n -e 1p)
num=$(echo "obase=10;ibase=16;$(echo $bcdline|tr a-f A-F|cut -d" " -f1) + 4"|bc)
if [ -n "$(echo "$bcdline"|grep " 00  01 00 00 00 $disksignature")" ]
then
  num=$(expr $num + 8)
fi
if [ "$disksignature" = "$(dd if=/mnt/Boot/BCD bs=1 count=4 skip=$num 2>/dev/null|hd|cut -d" " -f3-6|sed -n -e 1p)" ]
then
  echo "Please type yes if disk signature: \"$disksignature\" may be written to address 0x1b8-0x1bb in MBR(/dev/sda)."
  read a
  if [ "$a" = "yes" ]
  then
    dd if=/dev/sda bs=512 count=1 of=sdambr_$(date --iso-8601=minutes|tr -d " ") 2>/dev/null
    echo Present MBR of /dev/sda is saved in the file: $PWD/sdambr_$(date --iso-8601=minutes|tr -d " ")
    dd if=/mnt/Boot/BCD bs=1 count=4 skip=$num seek=440 of=/dev/sda 2>/dev/null&& echo $disksignature is successfully written in MBR of /dev/sda || echo Error in writting disk signature to MBR 
  else
    echo MBR is not changed.
  fi
else
  echo "Something wrong happened. MBR has not been changed."
fi
exit 0