get_magic_at() { local file="$1" local pos="$2" get_image "$file" | dd bs=1 count=2 skip="$pos" 2>/dev/null | hexdump -v -n 2 -e '1/1 "%02x"' } platform_check_image_sdcard() { local file="$1" local magic diskdev partdev diff magic=$(get_magic_at "$file" 510) [ "$magic" != "55aa" ] && { echo "Failed to verify MBR boot signature." return 1 } export_bootdevice && export_partdevice diskdev 0 || { echo "Unable to determine upgrade device" return 1 } get_partitions "/dev/$diskdev" bootdisk #extract the boot sector from the image get_image "$@" | dd of=/tmp/image.bs count=1 bs=512b 2>/dev/null get_partitions /tmp/image.bs image #compare tables diff="$(grep -F -x -v -f /tmp/partmap.bootdisk /tmp/partmap.image)" rm -f /tmp/image.bs /tmp/partmap.bootdisk /tmp/partmap.image if [ -n "$diff" ]; then echo "Partition layout has changed. Full image will be written." ask_bool 0 "Abort" && exit 1 return 0 fi } platform_do_upgrade_sdcard() { local board=$(board_name) local diskdev partdev diff export_bootdevice && export_partdevice diskdev 0 || { echo "Unable to determine upgrade device" return 1 } sync if [ "$UPGRADE_OPT_SAVE_PARTITIONS" = "1" ]; then get_partitions "/dev/$diskdev" bootdisk #extract the boot sector from the image get_image "$@" | dd of=/tmp/image.bs count=1 bs=512b get_partitions /tmp/image.bs image #compare tables diff="$(grep -F -x -v -f /tmp/partmap.bootdisk /tmp/partmap.image)" else diff=1 fi if [ -n "$diff" ]; then get_image "$@" | dd of="/dev/$diskdev" bs=4096 conv=fsync # Separate removal and addtion is necessary; otherwise, partition 1 # will be missing if it overlaps with the old partition 2 partx -d - "/dev/$diskdev" partx -a - "/dev/$diskdev" else #write uboot image get_image "$@" | dd of="$diskdev" bs=512 skip=1 seek=1 count=2048 conv=fsync #iterate over each partition from the image and write it to the boot disk while read part start size; do if export_partdevice partdev $part; then echo "Writing image to /dev/$partdev..." get_image "$@" | dd of="/dev/$partdev" ibs="512" 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 fi sleep 1 } platform_copy_config_sdcard() { local partdev if export_partdevice partdev 1; then mkdir -p /boot [ -f /boot/kernel.img ] || mount -o rw,noatime /dev/$partdev /boot cp -af "$UPGRADE_BACKUP" "/boot/$BACKUP_FILE" sync umount /boot fi }