[flashrom] Difference of factory bios and dumped image

[Idwer Vollering]

2011/12/31 Prakash Punnoor <prakashp at arcor.de>:
> On 31.12.2011 11:39, Paul Menzel wrote:
>
>> Am Samstag, den 31.12.2011, 10:55 +0100 schrieb Prakash Punnoor:
>>
>>> flashrom kind of works on my system, but not with the factory images. If I
>>> read it out with flashrom and write it back with flashrom (also to a different
>>> chip) it works. The sizes of factory and dumped image are same but they are
>>> somewhat binary different. Any idea? The motherboard is Abit A-S78H. As I am
>>> playing around with coreboot - so far unsuccessfully - I want to know whether
>>> flashrom is writing the generated image correctly... I can upload both images
>>> somewhere if interested. This is flashrom output on my system:
>>>
>>>
>>> flashrom v0.9.4-r1395 on Linux 3.2.0-rc7+ (x86_64), built with libpci 3.1.7,
>>> GCC 4.5.2, little endian
>>> flashrom is free software, get the source code at http://www.flashrom.org
>>>
>>> Calibrating delay loop... OK.
>>> Found chipset "AMD SB700/SB710/SB750/SB850". Enabling flash write... OK.
>>> This chipset supports the following protocols: LPC, FWH, SPI.
>>> Found Macronix flash chip "MX25L8005" (1024 kB, SPI) at physical address
>>> 0xfff00000.
>>> No operations were specified.
>> Unfortunately this question seems not be listed in the FAQ. Most of the
>> time some areas differ because the MAC address and other configuration
>> data of the downloaded images differs [2]. I hope you mean the
>> downloaded image by factory/vendor image.
> To clarify:
> - Image I got from vendor web page: Flashed with flashrom won't work
> (machine doesn't POST). Flashed with awdflash works.

Is the bootblock in the downloaded image intact/present? You can use
bios_extract: http://cgit.freedesktop.org/~libv/bios_extract

What happens when you reset the CMOS/ESCD data after flashing with
flashrom? awdflash does that with the /cp parameter, see
http://www.plasma-online.de/textual/howto/flash_award.html

> - Image flashed with awdflash, dumped from bios chip using flashrom and
> writing back using flashrom (to an empty chip also) works (machine does
> POST and I can boot my OS)
> - I haven't tried writing flashrom dumped image using awdflash.
> - If I write a dumped image using flashrom and later do a flashrom -v it
> will complain about some difference. But flashrom -w verify pass was OK.
>
> This makes my head scratch and I wonder whether flashrom is working 100%
> correctly - especially using the generated coreboot rom.

Do you have a POST card? You can get one off dealextreme..
http://www.dealextreme.com/p/pc-motherboard-repair-troubleshoot-boot-failure-diagnostic-pci-card-21997

>
> Regards,
>
> Prakash
>
>
>
>
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