BIOS Updates forum

Hi, pipomolo42

I works for a EFI bios vendor. I know Apple use default algorithm, but we don't. Intel also use customized version fot its own board.

AMI use default on some engineering sample bios, but use customized one in its product bios.

EFI based bios image format is FFS which stands for Firmware File System.

Every EFI bios image is devided into at least 3 FVs. Here FV means firmware volume. FV is just looks like disk partitions for firmware device.

There are so many modules or files stored on each FV. These files, or eModules ...

For many of leagacy bios, your design may work as expected if you re-compute the cmos checksum to the correct value.

But for newly UEFI based bios, your design won't work as expcted. Because these bios store the seetings in system flash directly.

Newly Intel's bios is based on EFI, which doesn't use CMOS to store setup settings. There is a driver to emulate the CMOS usage.

Intel's bios use system flash to store setup seetings directly.