# 1. root権限で実行するためsuに 
su
※suコマンドを実行できないGSIの場合は一旦exitでadb shellを抜けて以下を実行
adb root
adb shell

# 2. 各イメージがあるパスへ移動する (/dev/block/bootdevice/by-name/ の場合もあります)
cd /dev/block/by-name/

# 3. バックアップ保存用ディレクトリを作成
mkdir /sdcard/backup_img

# 4. /sdcard/backup_imgへバックアップする
for file in *; do
    if [[ "${file}" = boot* || "${file}" = devcfg* || "${file}" = dtbo* || "${file}" = oem* || "${file}" = recovery* || "${file}" = rpm* || "${file}" = sbl1* || "${file}" = system* || "${file}" = tz* || "${file}" = vbmeta* || "${file}" = modem* || "${file}" = vendor* ]]; then dd if="${file}" of=/sdcard/backup_img/"${file}".img ; else continue ; fi
done

# 5. バックアップ元とバックアップ先が完全に一致しているかチェック
echo "" > /sdcard/backup_img/md5.txt
for file in *; do
    if [[ "${file}" = boot* || "${file}" = devcfg* || "${file}" = dtbo* || "${file}" = oem* || "${file}" = recovery* || "${file}" = rpm* || "${file}" = sbl1* || "${file}" = system* || "${file}" = tz* || "${file}" = vbmeta* || "${file}" = modem* || "${file}" = vendor* ]]; then
	if cmp -s "${file}" /sdcard/backup_img/"${file}".img; then
		echo "${file} - OK" >> /sdcard/backup_img/md5.txt
	else
		echo "${file} - NG, you have to backup again!" >> /sdcard/backup_img/md5.txt
	fi
	else continue ; fi
done