util/mkblankimage.sh

   1 #!/bin/bash
   2 #
   3 # makeblankimage.sh
   4 # Make a blank M5 disk image
   5 #
   6
   7 while getopts "m" OPT
   8 do
   9         case "$OPT" in
  10                 m)  MOUNT_IT=1
  11         esac
  12 done
  13
  14 DEBUG=0
  15
  16 if [ $DEBUG -ne 0 ]; then
  17     set -x -e
  18     OUTPUT=""
  19 else
  20     OUTPUT="> /dev/null 2>&1"
  21 fi
  22
  23 abort() {
  24     echo $@
  25     exec /bin/false
  26 }
  27
  28 find_prog() {
  29     PROG_PATH=`which $1`
  30     if [ $? -ne 0 ]; then
  31         abort "Unable to find program $1, check your PATH variable"
  32     fi
  33     echo $PROG_PATH
  34 }
  35
  36 run_priv() {
  37     if [ "$HAVE_SUDO" = "y" ]; then
  38         eval $SUDO $@ $OUTPUT
  39     else
  40         eval $@ $OUTPUT
  41     fi
  42
  43     if [ $? -ne 0 ]; then
  44         abort "Failed to run $@ as root"
  45     fi
  46 }
  47
  48 usage() {
  49     abort "Usage: $0 [root-path to copy] [extra ownership commands ...]"
  50 }
  51
  52 # Setup PATH to look in the sbins
  53 export PATH=$PATH:/sbin:/usr/sbin
  54
  55 # Get all of the programs needed, or exit
  56 DD=`find_prog dd`
  57 SFDISK=`find_prog sfdisk`
  58 LOSETUP=`find_prog losetup`
  59 SUDO=`find_prog sudo`
  60 MKE2FS=`find_prog mke2fs`
  61 MKDIR=`find_prog mkdir`
  62 MOUNT=`find_prog mount`
  63 UMOUNT=`find_prog umount`
  64 WHOAMI=`find_prog whoami`
  65 CP=`find_prog cp`
  66 CHOWN=`find_prog chown`
  67
  68 # Prompt for the root password, if needed
  69 CUR_USER=`$WHOAMI`
  70
  71 if [ $# -ge 1 ]; then
  72     if [ ! $MOUNT_IT ]; then
  73         ROOT_PATH=$1
  74
  75         if [ ! -d $ROOT_PATH ]; then
  76                 usage
  77         fi
  78    else
  79         ROOT_PATH=""
  80    fi
  81 else
  82     ROOT_PATH=""
  83 fi
  84
  85 if [ ! "$CUR_USER" = "root" ]; then
  86     echo -n "Do you have sudo access? [y/n] "
  87     read HAVE_SUDO
  88
  89     if [ ! "$HAVE_SUDO" = "y" ]; then
  90         abort "You must have sudo access or run this script as root"
  91     fi
  92 fi
  93
  94 echo -n "How large do you want this disk image (in MB): "
  95 read USER_SIZE_MB
  96
  97 # size in bytes = SIZE_MB * 1024 * 1024
  98 # size in blocks = SIZE_BYTE / 512
  99 let BLK_SIZE=$USER_SIZE_MB*1024*2
 100
 101 let MAX_LBA=16383*16*63
 102
 103 if [ $BLK_SIZE -ge $MAX_LBA ]; then
 104     CYLS=16383
 105     HEADS=16
 106     SECTORS=63
 107 else
 108     # Set Sectors
 109     if [ $BLK_SIZE -ge 63 ]; then
 110         SECTORS=63
 111     else
 112         SECTORS=$BLK_SIZE
 113     fi
 114
 115     # Set Heads
 116     let HEAD_SIZE=$BLK_SIZE/$SECTORS
 117
 118     if [ $HEAD_SIZE -ge 16 ]; then
 119         HEADS=16
 120     else
 121         HEADS=$BLK_SIZE
 122     fi
 123
 124     # Set Cylinders
 125     let SEC_HEAD=$SECTORS*$HEADS
 126     let CYLS=$BLK_SIZE/$SEC_HEAD
 127 fi
 128
 129 # Recalculate number of sectors
 130 let BLK_SIZE=$CYLS*$HEADS*$SECTORS
 131
 132 # Get the name of the file and directory to build in
 133 echo -n "What directory would you like to build the image in? "
 134 read IMAGE_DIR
 135
 136 if [ ! -d $IMAGE_DIR ]; then
 137     abort "The directory $IMAGE_DIR does not exist"
 138 fi
 139
 140 echo -n "What would you like to name the image? "
 141 read IMAGE_NAME
 142
 143 IMAGE_FILE=$IMAGE_DIR/$IMAGE_NAME
 144
 145 # DD the blank image
 146 echo
 147 echo "dd'ing the blank image (this make take a while)..."
 148 eval $DD if=/dev/zero of=$IMAGE_FILE bs=512 count=$BLK_SIZE $OUTPUT
 149 if [ $? -ne 0 ]; then
 150     abort "Unable to create the blank image $IMAGE_NAME in $IMAGE_DIR"
 151 fi
 152
 153 # losetup the image with no offset to do the fdisk
 154 echo
 155 echo "Binding the image and partitioning..."
 156 run_priv $LOSETUP /dev/loop0 $IMAGE_FILE
 157 if [ $? -ne 0 ]; then
 158     abort "losetup to /dev/loop0 failed, make sure nothing is setup on loop0 (check by typing 'mount') "
 159 fi
 160
 161 # fdisk the image
 162 run_priv $SFDISK --no-reread -D -C $CYLS -H $HEADS -S $SECTORS /dev/loop0 <<EOF
 163 0,
 164 ;
 165 ;
 166 ;
 167 EOF
 168
 169 # Un-losetup the image
 170 run_priv $LOSETUP -d /dev/loop0
 171
 172 # Mount the image with an offset and make the filesystem
 173 echo
 174 echo "Remounting image and formatting..."
 175 let BASE_OFFSET=63*512
 176
 177 run_priv $LOSETUP -o $BASE_OFFSET /dev/loop0 $IMAGE_FILE
 178
 179 run_priv $MKE2FS /dev/loop0
 180
 181 # If a root path was specified then copy the root path into the image
 182 if [ ! -z "$ROOT_PATH" ]; then
 183     echo "Copying root from $ROOT_PATH to image file"
 184
 185     run_priv $MKDIR -p /tmp/mnt
 186
 187     run_priv $MOUNT /dev/loop0 /tmp/mnt
 188
 189     run_priv $CP -a $ROOT_PATH/* /tmp/mnt
 190
 191     run_priv $CHOWN -R root.root /tmp/mnt
 192
 193     # run extra permissions while disk is mounted
 194     TOPDIR=`pwd`
 195     cd /tmp/mnt
 196     i=2
 197     while [ $i -le $# ]; do
 198         run_priv ${!i}
 199         let i=i+1
 200     done
 201     cd $TOPDIR
 202
 203     run_priv $UMOUNT /tmp/mnt
 204 fi
 205
 206 run_priv $LOSETUP -d /dev/loop0
 207
 208
 209 if [ $MOUNT_IT -eq 1 ]; then
 210         run_priv mount -o loop,offset=$BASE_OFFSET $IMAGE_FILE /tmp/mnt
 211 else
 212         echo
 213         echo "Disk image creation complete."
 214         echo "To mount the image, run the following commands:"
 215         echo "# $MOUNT -o loop,offset=$BASE_OFFSET $IMAGE_FILE /mount/point"
 216         echo
 217         echo "And to unmount the image, run:"
 218         echo "# $UMOUNT /mount/point"
 219 fi;