From: <idc-dragon_at_gmx.de>
Date: Wed, 16 Jul 2003 10:56:41 +0200 (MEST)

> There was one other guy with a JBR which has a completely different boot
> ROM
> and flash structure. My tools won't work for this. All other boot ROMs so
> fare were identical across all the platforms, from player to FM.
>
> Email my those 2 files which are generated by Debug->Dump ROM content and
> I
> tell you. As a first check, you can peek into the larger file and see if
> the
> first 4 letters are "ARCH". If not, you probably have the exotic kind as
> well.
>

From the files I got, it's the same like that other guy (DJP007). I will
make a note about this in my readme, plus do an explicit check in the plugin,
with a more specific error message. FYI, here's what I emailed him:


Interesting, you seem to have a completely different box then we others,
including the CPU-internal boot ROM. So far all units I've seen (from the
early player up to the FM) have an identical boot ROM. It contains just a
little piece of code, to either receive some other code to execute via UART,
or to descramble and execute an image from the flash.
For Recorder and FM, this flash image is not the full thing, instead it is
another loader which will in turn descramble the real one. I didn't care
about this loader, for my firmware I bring in my own loader which does the
decompression, the other one is gone. This loader seems to be able to do
some kind flashing, but I don't know how to use it, only how to invoke it.
Plus, this one won't support my decompressing dual boot, that's for shure.
See my old post for details:
http://rockbox.haxx.se/mail/archive/rockbox-archive-2003-06/0287.shtml

With your boot ROM, it looks like this 2nd stage loader is already in
_there_. The image format in your flash is in turn completely different. I
will look at it in more detail later.

I'm afraid I won't be able to help your version. Understanding how the box
boots was a real major effort, disassembling that "little" boot loader is a
larger task alredy, let alone yours. Then a safety net like the UART boot
would be required for yours, probably a different development. Otherwise
first flashing will most likely result in a dead box. Then your flash format
needs a different authoring. It's like doing all my weeks of work a second
time.

What a pity, I thought they are all alike.

Regards,
Jörg

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Received on 2003-07-16