[flashrom] AT25F512 recognized as AT25F1024

Stefan Tauner stefan.tauner at student.tuwien.ac.at
Fri Apr 19 11:51:39 CEST 2013

On Fri, 19 Apr 2013 12:32:15 +0800
Chi Zhang <zhangchi866 at gmail.com> wrote:

> 在 2013年4月2日 星期二 15:19:25,Stefan Tauner 写道:
> > 
> > Thank you very much for this information. I had to guess the device IDs
> > because they are not mentioned in the datasheet.
> > The AT25F1024A has 0x60, the AT25F512A has 0x65, the AT25F025B has
> > 0x6500... but apparently assuming at least some sanity has failed to
> > reflect the truth.
> > 
> > So, according to your verbose log your AT25F512 has the same ID as the
> > AT25F1024A (according to its datasheet). *sigh*
> > Before I'll make some changes to the code I'll try to find someone with
> > a AT25F1024 chip to test.
> Bought an AT25F1024(without A) recently and tested.
> http://paste.flashrom.org/view.php?id=1620
> Found a PCN from Atmel, stating that AT25F512's device code is 0x60, and the 
> new AT25F512A's is 0x65:
> http://www.baite.com.hk/uploadFiles/service/SB_serial_mod_PCN_25F512.pdf

Oh that's very interesting. Thanks a lot for digging this up!

> Another interesting thing is that my AT25F512 can actually hold 128KBytes of 
> data. I generated the test data from /dev/urandom and confirmed that it 
> contains no repetitive patterns with lzma -9 (a fake 128KB "random" data file 
> made up with two 64KB ones with same content can be compressed into ~65KB 
> while mine can not). All bytes seems to be functional, I had zeroed out and 
> erased the whole chip and I got 128KB 0x00 an 128KB 0xff. After a power cycle 
> the random data written to the chip can be preserved.

That's very odd. Maybe they just relabelled the AT25F1024s as AT25F512?
I am only aware of (non-functional) fakes the other way round (and you
too obviously ;)

I'll change the ID of AT25F512 and commit that later. Thanks a lot for
your efforts.

Kind regards/Mit freundlichen Grüßen, Stefan Tauner

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