This is no request thread! HP COMPAQ bioses, how to modify the bios?

Discussion in 'BIOS Mods' started by Yen, Aug 6, 2009.

  1. pcotter

    pcotter MDL Novice

    Feb 27, 2008
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  2. Pyotr

    Pyotr MDL Novice

    Sep 6, 2007
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    What you talking about? p4spooky is asking about nc8430 which was successfully modified to SLIC 2.1 and confirmed by me and one other mdl user at least. It might not work with HPqflash and memory mod ... but it working with rompaq from nx9420 package you can find everything for flash there:
    http://forums.mydigitallife.info/showpost.php?p=104021&postcount=23
     
  3. ADMiNZ

    ADMiNZ MDL Novice

    Mar 7, 2008
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  4. ADMiNZ

    ADMiNZ MDL Novice

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  5. ADMiNZ

    ADMiNZ MDL Novice

    Mar 7, 2008
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    Status: Error
     
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  6. gregg

    gregg MDL Novice

    Aug 7, 2009
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    #188 gregg, Aug 11, 2009
    Last edited by a moderator: Apr 20, 2017 at 1:51 PM
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  7. ADMiNZ

    ADMiNZ MDL Novice

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  8. Yen

    Yen Administrator
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    May 6, 2007
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  9. shift-del

    shift-del MDL Novice

    Jul 27, 2008
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    OK, I correct myself. In MY FRIEND's case no modified BIOS has been used. I know there is a modified BIOS for nc8430 but my friend's goal was to confirm the real-time memory mod worked in his case. It might help other people to modify their BIOSes with the mentioned method. He thought it is not restricted to a given model and BIOS version like your confirmed nc8430 F.16 BIOS, that's why he wanted to share the information. No offense please. :D

    It's a pity it is not so general as we thought.
     
  10. Yen

    Yen Administrator
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    May 6, 2007
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    mutante, ADDCC contains a decompressor. If you cut the first FFh byte area from the biosfile it's able to decompress the modules. Do you think there is a way to make the bioscode to read the FIRST occurrence of SLIC which can be modified?
    We have to find the call and modify it that it calls the first occurrence..it's the same code!!! Possible? Too dangerous?
     
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  11. p4spooky

    p4spooky MDL Addicted

    Mar 9, 2008
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    No problems, I saw the response from Pyotr and will use his modified bios tonight :D
     
  12. Pyotr

    Pyotr MDL Novice

    Sep 6, 2007
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    Ok no problem, just want to help p4spooky:D.
    But now I understand thanks!
     
  13. shift-del

    shift-del MDL Novice

    Jul 27, 2008
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    Don't mention it. I hope he could manage to update his laptop. Unfortunatelly I have to wait for mine, because it is a Santa Rosa based one. :cool:
     
  14. mutante

    mutante MDL Novice

    Jul 20, 2009
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    I have decompressed it, but I haven't found where is it verified, I'm affraid that code to do it is not there, perhaps on some ROM hardcoded at the computer.

    So the question right now is, that there is another checksum somewhere that hace to be corrected, because rompaq tell it to us.
     
  15. mutante

    mutante MDL Novice

    Jul 20, 2009
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    #197 mutante, Aug 11, 2009
    Last edited by a moderator: Apr 20, 2017 at 1:51 PM
    Thank you very much I think it clearly tell us that after flashing the ROM (although it is incorrect, checksum I mean) when something is going to install it and checksum fails, it doesn't install it.

    Once again a hidden checksum must be there.

    Yen one question do you know where the additive checksum is stored? I can't find it.


    People what do you think?
     
  16. mutante

    mutante MDL Novice

    Jul 20, 2009
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    Hummm I think it could be dangerous, but we'll try it is everything else fails :)

    I have asked you on another post but I'm going to repeat the question, do you know where is the additive checksum stored? (the addcc checksum) I can't find it.

    And one more, Is there a compressor? the person who do the decompressor should be able to do a compressor, I think.
     
  17. gregg

    gregg MDL Novice

    Aug 7, 2009
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    I agree that hpqflash and rompack check both a hidden checksum in bios. That's why rompaq warn me about an integrity error...

    I think same checksum is checked in hpqflash and rompaq, so maybe it is easiest for you to disassemble hpqflash to find checksum check routine.

    For additiv checksum, ADDCC tool is made for other bios, not 68MAD with double marker. So I'm not sure the current checksum correction is really usefull for us.
    If I try to patch my Bios with modded Bios and modded Bios with checksum corrected, I have exactly same messages when using your patched RomPaq... and original RomPaq is unable to read both modded Bios.

    You patched RomPaq to bypass Bios file check, maybe can we made reverse enginering to find the routine checking Bios file integrity...


    Thanks
     
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  18. sebus

    sebus MDL Guru

    Jul 23, 2008
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    I was saying all along, the 4 byte additive checksum (that only ADDCC seems to be able to calculate, did not find any other utility to do it) is usless in this case.
    As the rompaq is provided PER BIOS file, that means that they can program it to check a very specific part of the file. Would not be surprised if it was checking exactly where the SLIC is.
    So unless you guys can bypass this routine I do not think we can get lucky.

    Or maybe there is a way to produce rom.sig & ver.sig for the modified rom.bin used with hpqflash?
    And use it to flash with original exe, but mod BIOS file?

    sebus