checksum check

Discussion in 'Windows Vista' started by 911medic, Sep 20, 2008.

  1. 911medic

    911medic MDL Guru

    Aug 13, 2008
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    How many modders check the bios checksum after mods, and how many actually adjust them??

    Do you think the individual modules are necessary or just the main bios file..??

    I am just curious..I have my own ideas on this and have logged some results from my own experience...

    If you don't mind..I wouldn't mind hearing some of your opinions..
     
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  2. Yen

    Yen Admin
    Staff Member

    May 6, 2007
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    When I make a manual Award bios mod, I have a look if the 8-bit checksum is appended after each module (or the modules I've modified) and adjust them of course.
    There are 3 kinds of Award bioses:

    8 bit checksum byte appended after EACH module.
    8 bit checksum byte appended after mainmodule only.
    No 8 bit checksum byte appended, but FFh byte after mainbios module. THIS byte counts to the length of module, shown at cbrom /D

    I'm also using SLIC's which sum to zero only. At manual Phoenix mods (Lenovo way) I don't need to adjust. (prepare.exe will do the job).

    Also using cbrom or amimmwin / mmtool 3.19 I don't need to adjust....

    At AMI SSV2 for MSI I correct the header which is 10h bytes in front of 1b module (as described at my instructions).
    I also add 89h to correct the entire checksum of bios after I've inserted the SLIC (as described there as well).
     
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