sign image

secure:

​ #imgheaderinsert will create "xxx-sign.bin"

​ imgheaderinsert xxx.bin 0 0

​ #old#sprd_sign xxx-sign.bin config pkcs15

​ sprd_sign xxx-sign.bin config pss

insecure:

​ imgheaderinsert xxx.bin 1 0

sign vbmeta

based on VBMetaKeysExtractor

Usage: generate_sign_script_for_vbmeta vbmeta-sign.img