x86: generalize partition discovery for sysupgrade

[librecmc/librecmc.git] / target / linux / x86 / base-files / lib / upgrade / platform.sh

diff --git a/target/linux/x86/base-files/lib/upgrade/platform.sh b/target/linux/x86/base-files/lib/upgrade/platform.sh
index 9871e62c617515cba91c502dd6718aa93e984711..c8bc3f7f608fc82ee3afc049b64af3a740fd2c37 100644 (file)
--- a/target/linux/x86/base-files/lib/upgrade/platform.sh
+++ b/target/linux/x86/base-files/lib/upgrade/platform.sh
@@ -1,10 +1,69 @@
-USE_REFRESH=1
+platform_export_partdevice() {
+       local var="$1" offset="$2"
+       local uevent MAJOR MINOR DEVNAME DEVTYPE
+
+       for uevent in /sys/class/block/*/uevent; do
+               . "$uevent"
+               if [ $BOOTDEV_MAJOR = $MAJOR -a $(($BOOTDEV_MINOR + $offset)) = $MINOR -a -b "/dev/$DEVNAME" ]; then
+                       export "$var=$DEVNAME"
+                       return 0
+               fi
+       done
+
+       return 1
+}
+
+platform_export_bootdevice() {
+       local cmdline uuid disk uevent
+       local MAJOR MINOR DEVNAME DEVTYPE
+
+       if read cmdline < /proc/cmdline; then
+               case "$cmdline" in
+                       *block2mtd=*)
+                               disk="${cmdline##*block2mtd=}"
+                               disk="${disk%%,*}"
+                       ;;
+                       *root=*)
+                               disk="${cmdline##*root=}"
+                               disk="${disk%% *}"
+                       ;;
+               esac
+
+               case "$disk" in
+                       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)
+                               uuid="${disk#PARTUUID=}"
+                               uuid="${uuid%-02}"
+                               for disk in $(find /dev -type b); do
+                                       set -- $(dd if=$disk bs=1 skip=440 count=4 2>/dev/null | hexdump -v -e '4/1 "%02x "')
+                                       if [ "$4$3$2$1" = "$uuid" ]; then
+                                               uevent="/sys/class/block/${disk##*/}/uevent"
+                                               break
+                                       fi
+                               done
+                       ;;
+                       /dev/*)
+                               uevent="/sys/class/block/${disk##*/}/uevent"
+                       ;;
+               esac
+
+               if [ -e "$uevent" ]; then
+                       . "$uevent"
+
+                       export BOOTDEV_MAJOR=$MAJOR
+                       export BOOTDEV_MINOR=$MINOR
+
+                       return 0
+               fi
+       fi
+
+       return 1
+}
 
 platform_check_image() {
-       [ "$ARGC" -gt 1 ] && return 1
+       [ "$#" -gt 1 ] && return 1
 
        case "$(get_magic_word "$1")" in
-               eb48) return 0;;
+               eb48|eb63) return 0;;
                *)
                        echo "Invalid image type"
                        return 1
@@ -12,18 +71,93 @@ platform_check_image() {
        esac
 }
 
-platform_do_upgrade() {
-       sync
-       get_image "$1" > /dev/sda
+platform_copy_config() {
+       local partdev
+
+       if platform_export_partdevice partdev 1; then
+               mount -t ext4 -o rw,noatime "/dev/$partdev" /mnt
+               cp -af "$CONF_TAR" /mnt/
+               umount /mnt
+       fi
+}
+
+get_partitions() { # <device> <filename>
+       local disk="$1"
+       local filename="$2"
+
+       if [ -b "$disk" -o -f "$disk" ]; then
+               echo "Reading partition table from $filename..."
+
+               local magic="$(hexdump -v -n 2 -s 0x1FE -e '1/2 "0x%04X"' "$disk")"
+               if [ "$magic" != 0xAA55 ]; then
+                       echo "Invalid partition table on $disk"
+                       exit
+               fi
+
+               rm -f "/tmp/partmap.$filename"
+
+               local part
+               for part in 1 2 3 4; do
+                       set -- $(hexdump -v -n 12 -s "$((0x1B2 + $part * 16))" -e '3/4 "0x%08X "' "$disk")
+
+                       local type="$(($1 % 256))"
+                       local lba="$(($2))"
+                       local num="$(($3))"
+
+                       [ $type -gt 0 ] || continue
+
+                       printf "%2d %5d %7d\n" $part $lba $num >> "/tmp/partmap.$filename"
+               done
+       fi
 }
 
-x86_prepare_ext2() {
-       # if we're running from ext2, we need to make sure that we have a mtd 
-       # partition that points to the active rootfs partition.
-       # however this only matters if we actually need to preserve the config files
-       [ "$SAVE_CONFIG" -eq 1 ] || return 0
-       grep rootfs /proc/mtd >/dev/null || {
-               echo /dev/hda2,65536,rootfs > /sys/module/block2mtd/parameters/block2mtd
-       }
+platform_do_upgrade() {
+       local diskdev partdev ibs diff
+
+       if platform_export_bootdevice && platform_export_partdevice diskdev 0; then
+               sync
+               if [ "$SAVE_PARTITIONS" = "1" ]; then
+                       get_partitions "/dev/$diskdev" bootdisk
+
+                       #get block size
+                       if [ -f "/sys/block/$diskdev/queue/physical_block_size" ]; then
+                               ibs="$(cat "/sys/block/$diskdev/queue/physical_block_size")"
+                       else
+                               ibs=512
+                       fi
+
+                       #extract the boot sector from the image
+                       get_image "$@" | dd of=/tmp/image.bs count=1 bs=512b
+
+                       get_partitions /tmp/image.bs image
+
+                       #compare tables
+                       diff="$(grep -F -x -v -f /tmp/partmap.bootdisk /tmp/partmap.image)"
+                       if [ -n "$diff" ]; then
+                               echo "Partition layout is changed.  Full image will be written."
+                               ask_bool 0 "Abort" && exit
+
+                               get_image "$@" | dd of="/dev/$diskdev" bs=4096 conv=fsync
+                               return 0
+                       fi
+
+                       #iterate over each partition from the image and write it to the boot disk
+                       while read part start size; do
+                               if platform_export_partdevice partdev $part; then
+                                       echo "Writing image to /dev/$partdev..."
+                                       get_image "$@" | dd of="/dev/$partdev" ibs="$ibs" obs=1M skip="$start" count="$size" conv=fsync
+                               else
+                                       echo "Unable to find partition $part device, skipped."
+                               fi
+                       done < /tmp/partmap.image
+
+                       #copy partition uuid
+                       echo "Writing new UUID to /dev/$diskdev..."
+                       get_image "$@" | dd of="/dev/$diskdev" bs=1 skip=440 count=4 seek=440 conv=fsync
+               else
+                       get_image "$@" | dd of="/dev/$diskdev" bs=4096 conv=fsync
+               fi
+
+               sleep 1
+       fi
 }
-append sysupgrade_pre_upgrade x86_prepare_ext2