How to extract firmware

This instruction describes how to extract Onkyo firmware on the Linux workstation.

• Download new firmware from Onkyo site, for example from here You will have following file:

_NKNAP0002_0000000000NANO_N_124.zip

• Unzip it and you obtain following files:

unzip _NKNAP0002_0000000000NANO_N_124.zip

Archive: ONKNAP0002_0000000000NANO_N_124.zip extracting: ONKNAP0002_0000000000NANO.of0
extracting: ONKNAP0002_0000000000NANO.of1
inflating: ONKNAP0002_0000000000NANO.of2
inflating: ONKNAP0002_0000000000NANO.of3
extracting: ONKNAP0002_0000000000NANO_N.of0
extracting: ONKNAP0002_0000000000NANO_N.of1
inflating: ONKNAP0002_0000000000NANO_N.of2
inflating: ONKNAP0002_0000000000NANO_N.of3

• The firmware is decrypted. Here you can find a good description how to decrypt it.

• For decryption, download this utility in the directory where *.of files are extracted and compile it:

gcc -o onkyo-dec onkyo-decrypt64.c

• Run this utility

onkyo-dec

• you obtain new directory "extracted" with a set of files. You can check the file types using command "file". One of this file is an UBI image, version 1 that contains Linux distribution

file *

of2.AM335XNA_010203040506.07299: UBI image, version 1

• This UBI image can be extracted using this tool

python ./ubidump.py --savedir ubi of2.AM335XNA_010203040506.07299

Desired output is

==> of2.AM335XNA_010203040506.07299 <== 1 named volumes found, 2 physical volumes, blocksize=0x20000 == volume rootfs == saved 563 files

and you will have a new directory "ubi". This is a rootfs of the Linux system.

• Directory "ubi/rootfs/home/root/" contains two files:

ll ubi/rootfs/home/root/

-rw-rw-r--. 1 family family 25964544 Oct 15 22:39 system.img

-rw-rw-r--. 1 family family 40263680 Oct 15 22:39 usr.img

One file is the Google chrome, and the second - the player software. You can simply mount these files using squashfs

su

cd ubi/rootfs/

mkdir usr

mount -t squashfs -o loop home/root/usr.img ./usr

mkdir system

mount -t squashfs -o loop home/root/system.img ./system

• After it, you can explore the whole firmware.