When using the guide to find the right var offset numbers etc. ifrextractor extracts over 11 .txt files and I can’t find anything of value in them. I used the latest downloadable file from MSI’s website.
I have tried both UEFITOOL and UEFITOOL NE.
Also asked MSI for a BIOS with the 4G Decoding option but they said it wasn’t available.
Hello @BasedGabe o/
Above 4G Decode appears to be in the Setup already.
It’s in the Advanced > PCI Subsystem settings
Are you able to see this menu in the bios setup?
Hello @68k-dude,
Thanks a lot for the fast reply!
Well, that’s the tricky part, there’s no such option in my bios. Maybe it was to make miners buy a more expensive motherboard back in the day, who knows.
See the picture for an overlook of my bios (ignore ram values etc, I just bricked my system after trying to change the var offset and it didn’t work. The values I found seem to be funky)
Hi @BasedGabe ,
There are two Advanced menus it appears.
I wonder if there is a keyboard combo to get into the more advanced Advanced menu 
Thanks for the tip @68k-dude ! I can only find shortcuts for people who have MSI laptops and I can’t find any information about the Z97 s02. Could I instead, even if it seemingly is an available setting, just change the var offset? I’d appreciate if you could take a look and maybe find the right values.
Edit: Searching for MMIO, 4G Decod, Above 4G all yields results. Anyone else with an MSI motherboard who can chip in and explain what they did to enable 4G decoding (as it’s seemingly hidden)
Hi @BasedGabe,
Have you looked into the program called AMIBCP ?
That’s the screenshot I sent you up above.
You can make changes to the Default and Optimal settings.
You could set Above 4G Decode to be enabled by Default or in the Optimal settings.
I would try setting it to ON in the Optimal only at first, just in the case where it makes the system unable to boot.
Do you have any way to recover from a failed modification? An external programmer?
Hello @68k-dude ,
Unfortunately I don’t have an external programmer. However, from my understanding, many people have successfully gotten MSI z97 motherboards to support rebar. Even if my particular motherboard is a budget variant, I doubt it would be any different. I know that I am doing this at my own risk, and I want to be careful, but I believe it’s worth a shot.
If I use AMIBCP and change the Above 4G Decode setting to on in optimal, would a simple CMOS reset make the system bootable if it becomes unbootable due to the change?
Thanks again for the help, it’s very appreciated.
EDIT: When trying to open the latest BIOS file AMIBCP says “The input image is not Aptio V”? In your screenshot you successfully opened it so I am not sure there’s any need for another tool like this: GitHub - BoringBoredom/UEFI-Editor: Aptio V UEFI Editor: an alternative to AMIBCP
Hi @BasedGabe,
That’s the plan. A CMOS reset should load the Failsafe defaults. So If when you set it to ON in the Optimal settings and there is an issue, you can recover it.
You need AMIBCP 4.55 to open Aptio IV files.
Hi @68k-dude ,
Wow, I am sorry for the oversight. Of course I need a version number that starts with 4 if I am working with Aptio IV files… I changed the optimal settings to enabled.
I suppose all I need to do is put the new file on a USB and flash via m-flash in my current bios setup menu, right? If the system boots then it’s enabled and working, otherwise I reset CMOS and it reverts back to failsafe values, correct?
Sorry if I sound stupid. Trust me, I am usually smarter than this! 
H @68k-dude,
Followed all the steps. It flashed successfully. Afterwards there’s simply a black screen, nothing happens. Not even bios splash screen shows up.
I am 100% sure that I put failsafe value at disabled. Yet when I turn the Psu off, remove power cable and remove cmos battery I still get a black screen (black as in getting video output but it’s black, not black as in no display).
Seems like this board might be bricked. If that’s the case then it’s not that big of a deal, I’ll simply upgrade my PC.
oh no 
you need to leave everything unplugged for a few minutes after cmos bat remove
