Although the jz4740 contains a similar tool to usbboot, its command-line
interface is not very useful, also it does not compile by default because it
relies on some external code, and it contains code specific to some JZ4740
devices.
Change-Id: I22688238d147e21fb0fd524466b333b6003d4ff1
This tool can pack/unpack a jz4760 archive (like the one used for the fiio
x1/x3/x5), and can descramble/scramble (it's the same operation) a firmware
file (the sys.bin file in the archive). I did my best to keep the compatibility
with the leaked Fiio/Ingenic tool which has the same name.
I wrote the tools from scratch, but here are some remarks:
- the format used is a slightly modified IHFS used in the older JZ4640 series,
I used the information on the wiki about the IHFS format
- the CRC computation done was already reversed engineered by someone on the
forums but I realised this later
- There are a few unknown fields in the headers, see comments in the source code
- The firmware scrambling was discovered by pure guess, I realised there were
some repetitve sequences, some I guessed it was a rotative XOR and ran some
analysis to find the most probable sequence
Change-Id: Ib83735b3db8475be5de9c94231714e88668a0340
