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Subject: Re: Another port, is it possible?

Re: Another port, is it possible?

From: Ian Hawdon <ian.hawdon_at_gmail.com>
Date: Wed, 8 Aug 2007 13:06:03 +0100

On 08/08/07, Daniel Stenberg <daniel_at_rockbox.org> wrote:
>
> On Wed, 8 Aug 2007, Ian Hawdon wrote:
>
> > Hello, I am one of the developers from S1MP3.ORG
>
> Welcome to our merry corner of the world!

Thankyou

> I was wondering if it would be possible to extend the rockbox project to
> > these players.
>
> I'm quite sure it can, given enough time and effort. But there are some
> issues, and I'll address them further down.
>
> > Most of the players have an Actions ATJ2085 CPU chip
> > http://www.actions.com.cn/en/product.aspx?id=10 and can indeed play OGG
> > files (though their website doesn't say this)
>
> I'd say that this CPU/microcontroller is the most limiting factor to get
> Rockbox on these players: Rockbox is only built for and running on 32 bit
> cpu
> cores, so this Z80 8/16? bit will require some work to get Rockbox for. We
> once had it buildable for a 16bit CPU (calmrisc for one of the older
> Archos
> gmini models), but that particular port was abandoned and most of the
> long/int
> cleanups of those days are likely gone by now.

There is a datasheet for the CPU/Microcontroller:
http://www.s1mp3.org/files/datasheets/ATJ2085/ATJ2085_datasheet_v1.5.pdf

Is there even a gcc-fork or other free and good compiler for it?

A guy who goes by the name "wiRe" created a load of utilities to access the
player (like firmware backup), he also managed to print words on the screen
via some rewritten code (he called it S1First), his site is here:
http://www.s1mp3.de/

Also, the limited amount of RAM might be a bit tricky to deal with.
>
> Does it really play/decode the music with this CPU? Do you happen to know
> at
> what speed it runs?

Well, there doesn't seem to be any other way for the player to play music,
the codecs are in the firmware files, the binaries can be extracted from any
firmware file on the main site using S1FWX (also on wiRe's site)

I remember someone saying that the chip could run at 50mHz, but im not sure
if there was any evidence to support this, but most of the big technical
questions about the ATJ2085 chip could be answered by looking at the
datasheet

So, it will require a few dedicated and skilled hackers with this hardware
> to
> make a Rockbox port reality.
>
> These are just my opinions of course.

Ok, thankyou

--
>   Daniel Stenberg -- http://www.rockbox.org/ -- http://daniel.haxx.se/
>
-- 
Ian Hawdon (ian_hawdon)
http://www.s1mp3.org (SWAN's home page)
Received on 2007-08-08

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