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Help to unscramble my NAND flash
http://forum.hddguru.com/viewtopic.php?f=10&t=41665		 Page 2 of 2
Author:  pepe [ September 10th, 2021, 19:28 ]
Post subject:  Re: Help to unscramble my NAND flash
without ecc it does not really matter, you don't know what is good and what is bad.

pepe
Author:  rom1nux [ September 10th, 2021, 20:00 ]
Post subject:  Re: Help to unscramble my NAND flash
pepe wrote:
supply voltage may affect data integrity but you can't really decide what's good and what's wrong without calculating ecc.
Reading same value several times does not mean it is good.
...
without ecc it does not really matter, you don't know what is good and what is bad.

Ok pepe, so I need to apply ECC on XORed (1024 bytes) data area first ?
(I thought that I need to unXOR the data area before correcting with ECC)
(I hope ECC area are not XORed :cry:)

ddrecovery wrote:
Heating or cooling the chip can also make a difference.

Nice tips ddrecovery, it costs nothing to try, It is hot now in France, I got 27°C (80.6°F) in my room now.
I will first take out the soldering iron to make a simple breadboard adapter to remove cra..y dupont wire and shorten connection. I can add proper decoupling capacitor to have more clean power supply. (And if found it in my drawer I will add a small peltier module :D )

thank you both for your help
Author:  pepe [ September 11th, 2021, 5:01 ]
Post subject:  Re: Help to unscramble my NAND flash
since you can see the SA clearly, we can say the SA and ECC is not xored.
But can't say for sure wether ECC is applied before or after XOR, probably before.
And yes, i was about to say something about shortening the wires :)

pepe
Author:  ddrecovery [ September 11th, 2021, 11:19 ]
Post subject:  Re: Help to unscramble my NAND flash
FWIR, ECC is applied before XOR on PS controllers.
Author:  rom1nux [ September 13th, 2021, 3:17 ]
Post subject:  Re: Help to unscramble my NAND flash
Thank you ddrecovery, I will try.
Author:  Amarbir[CDR-Labs] [ September 13th, 2021, 14:20 ]
Post subject:  Re: Help to unscramble my NAND flash
Hello,
Thats a Lot of Effort ,You Can Ship The Device To Me in India And i Will Recover It For No Money ,Once i do this i will upload dump + solution and you can download and carry on with your research .
Author:  rom1nux [ September 14th, 2021, 18:33 ]
Post subject:  Re: Help to unscramble my NAND flash
Amarbir[CDR-Labs] wrote:
Hello,
Thats a Lot of Effort ,You Can Ship The Device To Me in India And i Will Recover It For No Money ,Once i do this i will upload dump + solution and you can download and carry on with your research .

Many Thank Amarbir, this is a really very nice offer, I thank you a lot, let me try a few more hours and if I can't achieve the solution I will send you the device. (Nice YT channel Amarbir ;) you have one more subscriber)
Author:  rom1nux [ September 14th, 2021, 18:41 ]
Post subject:  Re: Help to unscramble my NAND flash
I rebuild my reader to increase reading stability. It seem to wok well.

Attachment:
readerv2.jpg
readerv2.jpg [ 72.57 KiB | Viewed 9753 times ]


Now I can go deep into ECC / BCH....
Author:  lcoughey [ September 15th, 2021, 10:12 ]
Post subject:  Re: Help to unscramble my NAND flash
rom1nux wrote:
I rebuild my reader to increase reading stability. It seem to wok well.

Attachment:
readerv2.jpg


Now I can go deep into ECC / BCH....

I'm curious to know how much it cost you to build your reader (time & $$$) in comparison to the $210USD for the flash-extractor reader (http://www.flash-extractor.com/shop/).

I'd also like to know if your setup will allow you to re-read the bad blocks after ECC is run on the dump.

Either way, you certainly have a lot of drive, persistence and free time to be doing this for your friend. I sure hope that they appreciate what you are doing for them.
Author:  pepe [ September 15th, 2021, 10:54 ]
Post subject:  Re: Help to unscramble my NAND flash
re-read is a question of sw, and it is obvious he can do it if he got this far...
The FE reader would not allow this without the SW which costs 1.5k+ as per my memories.
Hats down for this project :)

pepe
Author:  ddrecovery [ September 15th, 2021, 12:05 ]
Post subject:  Re: Help to unscramble my NAND flash
The OP has put a lot of work an effort into this and has done extremely well so far. He could however have got a free evaluation from a data recovery company first. If it was found to be a PCB issue it might have been $100-$200. But if he is doing it for fun and learning, then that is cool.
Author:  lcoughey [ September 15th, 2021, 12:10 ]
Post subject:  Re: Help to unscramble my NAND flash
pepe wrote:
re-read is a question of sw, and it is obvious he can do it if he got this far...

I assume that he will be able to do that, but figured he hasn't gotten that far yet.
pepe wrote:
The FE reader would not allow this without the SW which costs 1.5k+ as per my memories.

The reader will work fine with NAND Reader without a Flash Extractor license. It is only when you go further with ECC and piecing it together that you need to have the license for Flash Extractor.
Author:  pepe [ September 15th, 2021, 12:15 ]
Post subject:  Re: Help to unscramble my NAND flash
yeah, the FE reader does exactly what he already achieved so far, but he could not get further with FE without the license, so he is better off with his own setup that he can develop it as he wants.

pepe
Author:  lcoughey [ September 15th, 2021, 12:31 ]
Post subject:  Re: Help to unscramble my NAND flash
pepe wrote:
yeah, the FE reader does exactly what he already achieved so far, but he could not get further with FE without the license, so he is better off with his own setup that he can develop it as he wants.

True. Perhaps he'll be able to recoup his costs by marketing his own product.
Author:  rom1nux [ September 15th, 2021, 12:49 ]
Post subject:  Re: Help to unscramble my NAND flash
Hello,

Yes I spend ~30 min per day, not every day. I write my own C console application to download data from the reader. Yes I can set the start block and end block on the command line to download a block series or all.

I build the reader with what I have under my hand. I did not calculate the price of hardware, but it's something like :
Code:
NUCLEO L476RG    15.00 € 
TSOP48 ADAPTER   10.00 €
FT232H BREAKOUT  10.00 €
PROTOBOARD        1.00 €
WIRE+CAPA         1.00 €
-------------------------------
TOTAL            37.00 € (43 $)


It's really interesting technology but the main purpose is to help my friend
Author:  rom1nux [ September 20th, 2021, 7:27 ]
Post subject:  Re: Help to unscramble my NAND flash
Return to deep linear code block theorie for BCH :cry: ...
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