target/linux/x86/base-files/lib/upgrade/platform.sh

   1 platform_export_partdevice() {
   2         local var="$1" offset="$2"
   3         local uevent MAJOR MINOR DEVNAME DEVTYPE
   4
   5         for uevent in /sys/class/block/*/uevent; do
   6                 . "$uevent"
   7                 if [ $BOOTDEV_MAJOR = $MAJOR -a $(($BOOTDEV_MINOR + $offset)) = $MINOR -a -b "/dev/$DEVNAME" ]; then
   8                         export "$var=$DEVNAME"
   9                         return 0
  10                 fi
  11         done
  12
  13         return 1
  14 }
  15
  16 platform_export_bootdevice() {
  17         local cmdline uuid disk uevent
  18         local MAJOR MINOR DEVNAME DEVTYPE
  19
  20         if read cmdline < /proc/cmdline; then
  21                 case "$cmdline" in
  22                         *block2mtd=*)
  23                                 disk="${cmdline##*block2mtd=}"
  24                                 disk="${disk%%,*}"
  25                         ;;
  26                         *root=*)
  27                                 disk="${cmdline##*root=}"
  28                                 disk="${disk%% *}"
  29                         ;;
  30                 esac
  31
  32                 case "$disk" in
  33                         PARTUUID=[a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9]-02)
  34                                 uuid="${disk#PARTUUID=}"
  35                                 uuid="${uuid%-02}"
  36                                 for disk in $(find /dev -type b); do
  37                                         set -- $(dd if=$disk bs=1 skip=440 count=4 2>/dev/null | hexdump -v -e '4/1 "%02x "')
  38                                         if [ "$4$3$2$1" = "$uuid" ]; then
  39                                                 uevent="/sys/class/block/${disk##*/}/uevent"
  40                                                 break
  41                                         fi
  42                                 done
  43                         ;;
  44                         /dev/*)
  45                                 uevent="/sys/class/block/${disk##*/}/uevent"
  46                         ;;
  47                 esac
  48
  49                 if [ -e "$uevent" ]; then
  50                         . "$uevent"
  51
  52                         export BOOTDEV_MAJOR=$MAJOR
  53                         export BOOTDEV_MINOR=$MINOR
  54
  55                         return 0
  56                 fi
  57         fi
  58
  59         return 1
  60 }
  61
  62 platform_check_image() {
  63         [ "$#" -gt 1 ] && return 1
  64
  65         case "$(get_magic_word "$1")" in
  66                 eb48|eb63) return 0;;
  67                 *)
  68                         echo "Invalid image type"
  69                         return 1
  70                 ;;
  71         esac
  72 }
  73
  74 platform_copy_config() {
  75         local partdev
  76
  77         if platform_export_partdevice partdev 1; then
  78                 mount -t ext4 -o rw,noatime "/dev/$partdev" /mnt
  79                 cp -af "$CONF_TAR" /mnt/
  80                 umount /mnt
  81         fi
  82 }
  83
  84 get_partitions() { # <device> <filename>
  85         local disk="$1"
  86         local filename="$2"
  87
  88         if [ -b "$disk" -o -f "$disk" ]; then
  89                 echo "Reading partition table from $filename..."
  90
  91                 local magic="$(hexdump -v -n 2 -s 0x1FE -e '1/2 "0x%04X"' "$disk")"
  92                 if [ "$magic" != 0xAA55 ]; then
  93                         echo "Invalid partition table on $disk"
  94                         exit
  95                 fi
  96
  97                 rm -f "/tmp/partmap.$filename"
  98
  99                 local part
 100                 for part in 1 2 3 4; do
 101                         set -- $(hexdump -v -n 12 -s "$((0x1B2 + $part * 16))" -e '3/4 "0x%08X "' "$disk")
 102
 103                         local type="$(($1 % 256))"
 104                         local lba="$(($2))"
 105                         local num="$(($3))"
 106
 107                         [ $type -gt 0 ] || continue
 108
 109                         printf "%2d %5d %7d\n" $part $lba $num >> "/tmp/partmap.$filename"
 110                 done
 111         fi
 112 }
 113
 114 platform_do_upgrade() {
 115         local diskdev partdev ibs diff
 116
 117         if platform_export_bootdevice && platform_export_partdevice diskdev 0; then
 118                 sync
 119                 if [ "$SAVE_PARTITIONS" = "1" ]; then
 120                         get_partitions "/dev/$diskdev" bootdisk
 121
 122                         #get block size
 123                         if [ -f "/sys/block/$diskdev/queue/physical_block_size" ]; then
 124                                 ibs="$(cat "/sys/block/$diskdev/queue/physical_block_size")"
 125                         else
 126                                 ibs=512
 127                         fi
 128
 129                         #extract the boot sector from the image
 130                         get_image "$@" | dd of=/tmp/image.bs count=1 bs=512b
 131
 132                         get_partitions /tmp/image.bs image
 133
 134                         #compare tables
 135                         diff="$(grep -F -x -v -f /tmp/partmap.bootdisk /tmp/partmap.image)"
 136                         if [ -n "$diff" ]; then
 137                                 echo "Partition layout is changed.  Full image will be written."
 138                                 ask_bool 0 "Abort" && exit
 139
 140                                 get_image "$@" | dd of="/dev/$diskdev" bs=4096 conv=fsync
 141                                 return 0
 142                         fi
 143
 144                         #iterate over each partition from the image and write it to the boot disk
 145                         while read part start size; do
 146                                 if platform_export_partdevice partdev $part; then
 147                                         echo "Writing image to /dev/$partdev..."
 148                                         get_image "$@" | dd of="/dev/$partdev" ibs="$ibs" obs=1M skip="$start" count="$size" conv=fsync
 149                                 else
 150                                         echo "Unable to find partition $part device, skipped."
 151                                 fi
 152                         done < /tmp/partmap.image
 153
 154                         #copy partition uuid
 155                         echo "Writing new UUID to /dev/$diskdev..."
 156                         get_image "$@" | dd of="/dev/$diskdev" bs=1 skip=440 count=4 seek=440 conv=fsync
 157                 else
 158                         get_image "$@" | dd of="/dev/$diskdev" bs=4096 conv=fsync
 159                 fi
 160
 161                 sleep 1
 162         fi
 163 }