forked from len0rd/rockbox
Fork of rockbox tailored for ipod classic
44bb2856a5
There must be an evil genius in Sony's Walkman division. Someone who made sure
that each model is close enough to the previous one so that little code is needed
but different enough so that an educated guess is not enough.
Each linux-based Sony player has a model ID (mid) which is a 32-bit integer.
I was able to extract a list of all model IDs and the correspoding name of
the player (see README). This gives us 1) a nice list of all players (because
NWZ-A729 vs NWZ-A729B, really Sony?) 2) an easy way to find the name of player
programatically. It seems that the lower 8-bit of the model ID gives the storage
size but don't bet your life on it. The remaining bytes seem to follow some kind
of pattern but there are exceptions.
From this list, I was able to build a list of all Sony's series (up to quite
recent one). The only safe way to build that is by hand, with a list of series,
each series having a list of model IDs. The notion of series is very important
because all models in a series share the same firmware.
A very important concept on Sony's players is the NVP, an area of the flash
that stores data associated with keys. The README contains more information but
basically this is where is record the model ID, the destination, the boot flags,
the firmware upgrade flags, the boot image, the DRM keys, and a lot of other stuff.
Of course Sony decided to slightly tweak the index of the keys regularly over time
which means that each series has a potentially different map, and we need this map
to talk to the NVP driver. Fortunately, Sony distributes the kernel for all its
players and they contain a kernel header with this information. I wrote a script
to unpack kernel sources and parse this header, producing a bunch of nw-*.txt
files, included in this commit. This map is very specific though: it maps Sony's
3-letter names (bti) to indexes (1). This is not very useful without the
decription (bti = boot image) and its size (262144). This information is harder
to come by, and is only stored in one place: if icx_nvp_emmc.ko drivers, found
on the device. Fortunately, Sony distributes a number of firmware upgrade, that
contain the rootfs, than once extracted contain this driver. The driver is a
standard ELF files with symbols. I wrote a parsing tool (nvptool) that is able
to extract this information from the drivers. Using that, I produced a bunch
of nodes-nw*.txt files. A reasonable assumption is that nodes meaning and
size do not change over time (bti is always the boot image and is always
262144 bytes), so by merging a few of those file, we can get a complete picture
(note that some nodes that existed in older player do not exists anymore so
we really need to merge several ones from different generations).
The advantage of storing all this information in plain text files, is that it
now makes it easy to parse it and produce whatever format we want to use it.
I wrote a python script that parses all this mess and produces a C file and
header with all this information (nwz_db.{c,h}).
Change-Id: Id790581ddd527d64418fe9e4e4df8e0546117b80
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|---|---|---|
| android | ||
| apps | ||
| backdrops | ||
| bootloader | ||
| debian | ||
| docs | ||
| firmware | ||
| flash | ||
| fonts | ||
| gdb | ||
| icons | ||
| lib | ||
| manual | ||
| packaging | ||
| rbutil | ||
| tools | ||
| uisimulator | ||
| utils | ||
| wps | ||
| .gitattributes | ||
| .gitignore | ||
__________ __ ___.
Open \______ \ ____ ____ | | _\_ |__ _______ ___
Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
\/ \/ \/ \/ \/
Build Your Own Rockbox
1. Clone 'rockbox' from git (or extract a downloaded archive).
$ git clone git://git.rockbox.org/rockbox
or
$ tar xjf rockbox.tar.bz2
2. Create a build directory, preferably in the same directory as the firmware/
and apps/ directories. This is where all generated files will be written.
$ cd rockbox
$ mkdir build
$ cd build
3. Make sure you have sh/arm/m68k-elf-gcc and siblings in the PATH. Make sure
that you have 'perl' in your PATH too. Your gcc cross compiler needs to be
a particular version depending on what player you are compiling for. These
can be acquired with the rockboxdev.sh script in the /tools/ folder of the
source, or will have been included if you've installed one of the
toolchains or development environments provided at http://www.rockbox.org/
$ which sh-elf-gcc
$ which perl
4. In your build directory, run the 'tools/configure' script and enter what
target you want to build for and if you want a debug version or not (and a
few more questions). It'll prompt you. The debug version is for making a
gdb version out of it. It is only useful if you run gdb towards your target
Archos.
$ ../tools/configure
5. *ploink*. Now you have got a Makefile generated for you.
6. Run 'make' and soon the necessary pieces from the firmware and the apps
directories have been compiled, linked and scrambled for you.
$ make
$ make zip
7. unzip the rockbox.zip on your music player, reboot it and
*smile*.
If you want to build for more than one target, just create several build
directories and create a setup for each target:
$ mkdir build-fmrecorder
$ cd build-fmrecorder
$ ../tools/configure
$ mkdir build-player
$ cd build-player
$ ../tools/configure
Questions anyone? Ask on the mailing list. We'll be happy to help you!