[coreboot] [solved] Re: [Flashrom] No EEPROM/flash device found. on Syntax SV266A

[Carl-Daniel Hailfinger]

On 21.03.2009 18:57, Paul Menzel wrote:
> Am Sonntag, den 22.03.2009, 01:28 +0800 schrieb FENG Yu Ning:
>   
>> Paul Menzel wrote:
>>     
>>> Right. Removing the sticker sure helps. Atmel AT49F002NT is written on
>>> the chip, which is supposed to be supported by Flashrom.
>>>
>>> test.rom also has not only null written to it, so it seems to be
>>> working.
>>>
>>> What could be done, that the chip is auto-detected?
>>>
>>> Anything else I can do?
>>>       
>> Since the reported IDs differ from those(id1 = 1Fh, id2 = 08h) in
>> datasheet of AT49F002NT, I am not sure whether access to the flash is
>> properly done. Let's do some investigation before going further.
>>
>> You may want to take a closer look at test.rom.
>> * How do the first few bytes look like? Do they look like magic
>> numbers(0xff00, 0x55aa, ..)?
>>     
>
> What is the correct command for doing this. hexdump first lines look
> like
>
> 0000000 e425 6c2d 3568 6f2d 0129 0000 0200 0000
>   

OK, the ID cycle is not working. Basically, if the first two bytes of a
dump are identical to id1,id2 then id1,id2 are not responses to the ID
command. Try shorter (down to 10 us) or longer (up to 40 ms) delays in
probe_jedec.

By the way, using "xxd" or "hexdump -C" makes sure the bytes in the
output are not switched around pairwise.

Regards,
Carl-Daniel

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