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A101it mainboard hacking and chipset information

OP scholbert

5th August 2011, 09:49 AM   |  #11  
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Guy, it's so nice! Keep up the good work!
8th August 2011, 05:50 PM   |  #12  
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datasheet collection
Hey,

i was lucky last week. My device is up and running.
Fortunately the eMMC data structure was O.K. In the end my device refused to boot, because of that broken connection to the RAM.
So there'd been no need to fiddle around with eMMC for now.
Maybe i'll do some investigation at a later point.

Feel free to set up your device for peripheral boot and try the Ti Flash tool debugging possibilities.

Right now i decided to re-assemble the device and use it for a while.
I must assume that i know nothing about the internal structure of the firmware. So it would be essential to get some insights

I got some additional information about the eMMC/microSD data lines.
If there's some interest i might post further pics.

To get some background about the chips on the A101 mainboard, i collected some datasheets of the main components.
Grab the zip-file here.

Most of them are easy to find other's are not
Anyway, saves your time i guess.

BTW, is there any tool to unpack gen8 AOS files?

Regards,

scholbert
Last edited by scholbert; 6th January 2012 at 09:40 PM.
8th August 2011, 06:20 PM   |  #13  
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yes it would be great if we could find one, maybe we could find a way to get inside and change some things
8th August 2011, 08:13 PM   |  #14  
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Quote:
Originally Posted by scholbert

...

Most of them are easy to find other's are not
Anyway, saves your time i guess.

BTW, is there any tool to unpack gen8 AOS files?

Regards,

scholbert

As far as i know we can't extract aos files since they are encrrypted and we don't have they proper KEY - its saved inside the device somewhere

But good luck with going on! Rly sounds interesting who knows what it's good for in future
12th August 2011, 04:23 PM   |  #15  
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good news - check out:
http://forum.xda-developers.com/show....php?t=1214674
seems we got a way to extract soon
12th August 2011, 10:08 PM   |  #16  
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..... uuuh great!!!
Quote:
Originally Posted by FrEcP

good news - check out:
http://forum.xda-developers.com/show....php?t=1214674
seems we got a way to extract soon

Yupp, that's awesome. I just joined that thread.

In the meantime i disassembled my device again, because i want to spent some more time on research.
I found out some more details about the chips and the design in general.
The A101 seems a pretty neat device for extensive hacking, because archos did a good job and made a very clear design.

I started to prepare a pin map by looking at the kernel sources again.
Maybe i'll be able to find some other useful testpoints on the mainboard (e.g. UART2)

As you might know, the touchscreen is connected to USB using OHCI mode.
To attach it to the OMAP ports they also used a chip from Ti.
See this datasheet for more information:
http://focus.ti.com/docs/prod/folder...tusb2551a.html

If i'll find some time i'll try to make kind of a floor plan from the mainboard and post some pics as well.

P.S.: If someone knows the manufaturer of the speaker drivers, please tell me! The parts are marked as 8JAM892 and are located near the soldering points for the speaker.

Keep on hackin'

scholbert
15th August 2011, 01:25 AM   |  #17  
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What I would like to find out is what component it is that dies when the USB port fails (and it stops sleeping as well). Maybe it's replaceable (if you can do SMD soldering).
15th August 2011, 01:24 PM   |  #18  
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Quote:
Originally Posted by pbarrett

What I would like to find out is what component it is that dies when the USB port fails (and it stops sleeping as well). Maybe it's replaceable (if you can do SMD soldering).

Mmmh... without being affected by this issue it's hard to tell.
If the port dies, there could be many reasons of course.

Maybe the 5V power supply for Vbus is dying on these devices, due to "over-current" issue. I have not identified that part right now.

The signal lines itself usually won't be harmed... apart from injecting ESD pulses right to the connector.
The USB host port is directly connected to data lines of the USB PHY inside TPS65921 (Power Management chip).
OMAP3630 itself uses ULPI mode to connect to this part.

That's all i could say for now.

Regards,

scholbert
16th August 2011, 02:47 PM   |  #19  
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Quote:
Originally Posted by FrEcP

good news - check out:
http://forum.xda-developers.com/show....php?t=1214674
seems we got a way to extract soon

If we can't extract those AOS files - how are custom ROM builders such as $auron getting their hands on the upper layer of the firmware? I know I am not expressing myself technically correct, but what I understand is that for instance $auron's UrukDroid is a custom Linux kernel etc. with on top of it the modules, GUI etc of the official Archos packages...
16th August 2011, 03:52 PM   |  #20  
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you don't need to extract the aos file to get the filesystem of the archos android. you simply have to root your device or just install angstrom (which comes with SDE) and then you can copy the squashfs file to your computer so you can extract whatever you need. it's not encrypted but signed, you only have to skip the first 256 bytes (if I remember correctly) of the file to get a valid squashfs image.

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