Cannot correct padding error on Asus Maximus V Gene

[kcajjones]

System

• Motherboard: Asus Maximus V Gene
• BIOS Version: 1903
• GPU: Palit RTX 3080
• [Y ] CSM is turned off. Make sure to confirm this in the BIOS and not with GPU-Z or similar since it can be inaccurate
• [ Y] 4G decoding is enabled. Make sure to confirm this in the BIOS and not with GPU-Z or similar since it can be inaccurate
• [ N] UEFIPatch is applied (see Using UEFIPatch for more information). On some motherboards DSDT Patching is also needed
• [ Y] I have read Common issues (and fixes)

Description

I have succesfully injected the RebarDxe FFS module, modified the BIOS menu to show PCI Settings -> Above 4G Decoding option but cannot use UEFIPatch to correct the various issues with limited BAR size on my Ivy Bridge / Z77 platform.
As described in the guide, the patches are applied but padding errors are introduced. I have tried to follow the further "fixes" but these lead to a Hex edit to move the changes from the patched (but glitched) file to the original file. This does not work as the PciBus and PciHostBridge modules are compressed and the file sizes are different. If I extract the "Body only" with UEFITool then I can see that the body data is the same size, with the hex editor confirming the correct changes, however the header/compression (?) has somehow been altered and the total size is different so the whole structure beyond the PciBus module is corrupt, including the padding errors.

I've not been able to work out how to fix this issue as MMTool does the exact same thing.

I see in the list of compatible motherboards that a user (who is no longer an active username on github?!) has confirmed this motherboard works with UEFIPatch. I can confirm Resizable BAR is enabled, but limited to 2GB until I can get the UEFI patches to work.

Any help would be greatly appreciated as I have Rebar enabled with 2GB but the system fails to boot if I set it to >=4GB.

[Ruffy47]

Hey I tried to modify the BIOS file from Asus. I don´t own this board and can´t test it, but you can try if you want. I added the NVME5 and NVStrapsRebar module too.

https://easyupload.io/ievkuc

[kcajjones]

Hey I tried to modify the BIOS file from Asus. I don´t own this board and can´t test it, but you can try if you want. I added the NVME5 and NVStrapsRebar module too.

https://easyupload.io/ievkuc

Thanks for trying, but on inspection with UEFITool, this is not correct. There are padding errors.

Upon inspection, the PciBus and PciHostBridge modules are different sizes from the original BIOS, with the PciBus module not having a compressed section at all.
I (think) this is what causes the padding errors.

[Ruffy47]

I checked again right now and the padding looks the same like in the original BIOS file from Asus. Where do you see the errors?

[kcajjones]

I'm using UEFITool 0.28 but it also shows the same in UEFITool NE A68.
What are you using?

Original:

Yours:

[Ruffy47]

Can you try BIOS flashback? Then I can upload the cap file for you and you can test it and flash your original if it doesn´t work.

https://easyupload.io/q6zamf

[Ruffy47]

I just downloaded the original file from ASUS and there it looks exactly the same like in my modified file.

[kcajjones]

I just downloaded the original file from ASUS and there it looks exactly the same like in my modified file.

How does it look exactly the same? Via which app?

[Ruffy47]

UEFI Tool

[Ruffy47]

Ok anyway, you can try the mod file if you want or not. That´s ok too of course, I just tried to help. :)

[kcajjones]

UEFI Tool

Which version?
Can you show a screenshot comparison to confirm your modified version has the correct padding?