Backup System ROM Different for Every Extraction?

Discussion in 'BIOS Mods' started by cyf, Nov 22, 2012.

  1. cyf

    cyf MDL Novice

    Nov 12, 2012
    I noticed something recently and I'm not sure if this is normal.

    Recently, I extracted my UEFI bios as a backup from my laptop and, because I had thought I deleted it, re-extracted it a second time. I used the afuefi64 tool executed from UEFI shell, so I think that's as low-level as I could get in terms of directly extracting the bios.

    Upon finding the first backup (I had actually just copied it to a directory that was one above where I thought it was, so I didn't delete it), I did an experiment to hex compare the first and second backups. I found that they were different in several places. I also did another experiment after this, and two extracted bios WITHIN the same boot is the same.

    Just curious as to whether this is normal.