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need help to calculate the checksum of my mobility hd4250 bios

Discussion in 'AMD / ATI' started by mikmak, Mar 4, 2014.

  1. mikmak

    mikmak

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    Hi All, as the title says I need some help in figuring which is / are the offsets where to place the correct checksum and which are the bios segments to use for the calculation.
    The bios has a standard atom structure and I managed to figure where to place my hands...now however I would like to make it genuine by replacing the old checksums.
    Hope someone can help.
    Thank you!
  2. mikmak

    mikmak

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    It seems that there is a lot of silence here in a forum where that kind of stuff should be well known.
    Maybe I am breaking the forum rules?
    I have discovered that the crc block offset is located at 0xe901 and it is the same for the mobility 4570 bios.
    What is curious and mostly probable is that rbe does not alter the checksum at apposite it preserves the original value by trying to remap some "safe" bytes values.
    I would like to use rbe for the crc "calculation"...I however have encountered an issue...the mobility 4250 bios I have is a customized one and it stores the frequency table values in a different location.
    Atomdis seems to work pretty well, this is achieved by the fact that it uses some ati headers to perform the dump while rbe works by performing its own built int bios structure recognizing procedure and it fails.
    The author, authors of rbe did ever planned to update their code with the atomdis one?
  3. Law-II

    Law-II

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    Hi

    As far as I am aware RBE is no longer in development and thus is no longer supported / no new features will be added anytime soon if atall.

    Official RBE thread here

    atb

    Law-II

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