So on my x99-ud4p board I don’t have this option present in the gui or hidden. I have confirmed it’s not there in amibcp and scewin. However it shows in setup via hex editor. I have bios files from a couple other gigabyte x99 boards that are very similar that do show the option but I had my doubts I could just replace the setup module with uefi tool. Looking for a little guidance.
So I think I want to create a new nvram variable using scewin. I am a little unsure how to go about this though. Having a hard time following the documentation for it anyways. from the IFR data I have on the board that does have the option it is as follows
EqIdVal QuestionId: 0x302, Value: 0x1 { 12 06 02 03 01 00 }
0x1D150: OneOf Prompt: “Above 4G Decoding”, Help: “Enables or Disables 64bit capable Devices to be Decoded in Above 4G Address Space (Only if System Supports 64 bit PCI Decoding).”, QuestionFlags: 0x10, QuestionId: 0x25D, VarStoreId: 0x1, VarOffset: 0x489, Flags: 0x10, Size: 8, Min: 0x0, Max: 0x1, Step: 0x0 { 05 91 7F 08 80 08 5D 02 01 00 89 04 10 10 00 01 00 }
0x1D161: OneOfOption Option: “Disabled” Value: 0, Default { 09 07 04 00 10 00 00 }
0x1D168: OneOfOption Option: “Enabled” Value: 1 { 09 07 03 00 00 00 01 }
The guid is and is the same on both boards. VarStore Guid: EC87D643-EBA4-4BB5-A1E5-3F3E36B20DA9, VarStoreId: 0x1,