v1.3 revision(2020/11/16)
1.change loader tag into 'LDR '
2.add loader format version into header
3.support to keep cert
4.support to generate sha512 hash

v1.31 revision(2020/12/03)
1.compatible with two loader tag
2.set rc4_off default as true

v1.32 revision(2021/03/22)
1.del np module from code
2.support to pack without 472 entry