Add jz4760 tool2048sp5

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

0 files changed, 0 insertions, 0 deletions