Rockbox mail archive
Subject: Re: Telechips-based players
Re: Telechips-based players
I just found these image thanks to Google (not a clue on which DAP it
This is the forum post they came from, translation anyone?
Hopefully it helps someone :)
On 7/31/07, Punit Agrawal <punit_at_cs.mcgill.ca> wrote:
> On July 31, 2007 05:21:08 Dave Chapman wrote:
> > Basil Dozhdalev wrote:
> > > Hello,
> > >
> > > Had anyone ever try to develop Rockbox for Telechips-based
> > > MP3-players?
> > I wouldn't say I'm trying to develop Rockbox for the Telechips
> > players, but I do have such a device (a small flash-based MP3/WMA
> > player with DAB radio). This has a TCC773L.
> I have the Cowon D2 (TCC7801) which I was trying to understand to check
> the feasibility of a port. There are still a lot of unknowns but some
> of what you say about the firmware matches up with my notes too. Except
> that I didn't know about the jump. So one more piece of the puzzle in
> > I've been collecting the firmware files for various telechips-based
> > players, and it seems the firmware is unencrypted, but there are two
> > 32-bit numbers in the headers (most likely a checksum and/or
> > signature) which I haven't been able to figure out.
> > So if your SDK can provide any clues to those, it would be helpful.
> > Hopefully the 77x and 76x share a lot in common.
> > As an example, the header for the firmware update for my Logik
> > MP3/DAB player looks like this:
> > 0000000: a0f3 9fe5 0601 ffff 5665 723a 3030 3731 ........Ver:0071
> > 0000010: 05e8 fdea 0000 0000 be26 f687 18cd 0c00 .........&......
> > My understanding so far is as follows:
> > 0x00 - An ARM branch instruction (ldr pc, [pc, #xxx]) to the entry
> > point on the firmware.
> > 0x04 - 0601 in all firmwares I've looked at - version?
> > 0x06 - 0xffff in all firmwares I've looked at
> > 0x08 - "Ver:0071" string (in all firmwares)
> > 0x10 - Unknown 32-bit number
> > 0x14 - Zero in all firmwares I've looked at
> > 0x18 - Unknown 32-bit number
> > 0x1c - Length of firmware file in bytes
> > Understanding those two unknown numbers and hence being able to
> > generate firmware files accepted by the firmware upgrade feature of
> > the original firmware would be a good start to any port.
> Yeah it would be a bit help if from the SDK, you can find the
> tools/method used to create the firmware and pack the files etc. Having
> one SDK might just make it possible for a lot of dependent devices to
> be understood/ported.
> There are a few people on Cowon forums interested in a rockbox port for
> the D2. If things start moving I have a feeling more people will join
> in the efforts.
> > Regards,
> > Dave.
Received on 2007-07-31
Page was last modified "Jan 10 2012" The Rockbox Crew