What modules in bios safe to compress?

BIOS/UEFI Modding BIOS Modding Guides and Problems
1

Hi,

Out of curiosity was wondering what bios modules in AMI bios’s are safe to compress? I mean could I compress every single module and expect to have a working rom bios?

Thanks

2

It depends on actual image structure.
If you have a compressed volume, adding any other compression of files/sections will make things worse and will also probably don’t work.
If you have a normal volume, there will be 2 option: 1. EDK1-based images used compressed sections with various compression types (EFI11/Tiano/LZMA variations), 2. EDK2-based images are using GUID-defined sections with predefined GUIDs for different compression types. You can try compressing some uncompressed files the way it’s done in your image, but only if there are files of the same type compressed the same way.
PEI modules from boot volume are executable-in-place and therefore shouldn’t ever be compressed.
As a matter of fact, trial and error is the best option here. Try your compression out, if the board does boot - it’s probably fine.

3

How can you tell if you have an EDK1 image vs EDK2 image? About PEI modules I agree. Sounds dangerous. What about DXE modules?

Thanks CodeRush.

PS: Is OZMTool your creation? I’m trying to mod OZMtool to compress all those networking modules as opposed to delete them straight out.

Thanks again.

4

You can tell it by the image structure, if it has “Compressed” sections (i.e. UEFITool shows them with this name) - it’s EDK1 for sure.
OZMTool is written by TuxUser, he’s active on insanelymac.org forums.

5

I had you confused because TuxUser uses the same Robot Chicken mad scientist gif also. Anyhow thanks for the info…