Provide the following functions for the ImageFactory
usage: invoker <function [arguments] >
unpackbootimg unpack android boot.img
mkbootimg make android boot.img
split_app split huawei .app file
sdat2img convert andorid dat file to raw image
simg2img convert sparse image to raw image
img2simg convert raw image to sparse image
minigzip gzip archives operating functions
envalid change file permission to 0755
uncpio extract cpio archives
mkcpio make cpio archives
dd minimal dd function