ota差分包制作说明

工程目录下创建ota目录

前后两版软件分别make otapackage -j48，每次分别拷贝用于升级的ota包到工程目录下的ota目录下，取名字为old和new两版zip

以下报错：

build01@build-pc:~/aml/mx/git_m6_1225$ ./build/tools/releasetools/ota_from_target_files -i ota/old.zip  ota/new.zip ota/update.zip
unzipping target target-files...
Traceback (most recent call last):
  File "./build/tools/releasetools/ota_from_target_files", line 951, in <module>
    main(sys.argv[1:])
  File "./build/tools/releasetools/ota_from_target_files", line 903, in main
    OPTIONS.info_dict = common.LoadInfoDict(input_zip)
  File "/home/build01/aml/mx/git_m6_1225/build/tools/releasetools/common.py", line 114, in LoadInfoDict
    raise ValueError("can't find recovery API version in input target-files")
ValueError: can't find recovery API version in input target-files
build01@build-pc:~/aml/mx/git_m6_1225$

原因是zip文件不对，不是升级用的zip（out/target/pr