Option 3: SSDT

For most this is considered the hardest as this requires the most amount of work, we'll be using Rehabman's SSDT patching to accomplish our Spoofing. The benefit of this method is that you can use a Kepler GPU with your system without any issues as we'll be blocking a device on the PCIe level

To start, you'll need the following:

If you open your EFI and go within EFI/CLOVER/ACPI/origin, you'll find a bunch of .aml files. These are the files we'll be playing with so grab them and put them in a folder somewhere on your hack

Now you'll want to grab an AISL Complier to analyze these files, you can grab Rehabman's Compiler here.

Within finder, press Command+Shift+G, enter /usr/bin and paste the IASL file here(you will need to authenticate)

Now in terminal, running the following command will disassemble our .aml files:

cd "to directory where you placed all SSDT/DSDT"
iasl -da -dl DSDT.aml SSDT*.aml

Now you'll find a bunch of .dsl files in that folder as well

Next lets try and find _OFF, this is what is needed for disabling your GPU

cd "to directory where you placed all SSDT/DSDT"
grep -l Method.*_OFF *.dsl

Terminal should return a list of SSDT's with _OFF within them

Example:

SSDT-2-PegSsdt.dsl
SSDT-3-Ther_Rvp.dsl

We can also check where the _INI files are, these files are likely going to have some that match with _OFF which are likely the files we want

cd "to directory where you placed all SSDT/DSDT"
grep -l Method.*_INI *.dsl

Terminal should return a list of SSDT's with _INI within them

Example:

SSDT-2-PegSsdt.dsl

You'll need to open both of these files and examine, we want the file that corresponds to your GPU. My GPU was found under SSDT-2 but this isn't the same for everyone, you'll need to check whether the _OFF method is within a PowerShell macro or by itself(We want it by itself)

My GPU was found here:

\_SB.PCI0.PEG0.PEGP

And for those having issues finding the device path, you can also find it in windows by following the ACPI path in device Manager.

Properties->Details of the Nvidia device, scroll through the properties until you find "BIOS name"

  • Rehabman

Now we can create our SSDT!

Let's open MaciASL, create a file, paste the text below and replace the device path with the one you have:

For Nvidia Users:

DefinitionBlock ("", "SSDT", 2, "hack", "spoof", 0)
{
Method(_SB.PCI0.PEG0.PEGP._DSM, 4)
{
If (!Arg2) { Return (Buffer() { 0x03 } ) }
Return (Package()
{
"name", Buffer() { "#display" },
"IOName", "#display",
"class-code", Buffer() { 0xFF, 0xFF, 0xFF, 0xFF },
})
}
}

For AMD users:

DefinitionBlock ("", "SSDT", 2, "hack", "spoof", 0)
{
Method(_SB.PCI0.PEG0.PEGP._DSM, 4)
{
If (!Arg2) { Return (Buffer() { 0x03 } ) }
Return (Package()
{
"name", Buffer() { "#display" },
"IOName", "#display",
"class-code", Buffer() { 0xFF, 0xFF, 0xFF, 0xFF },
"vendor-id", Buffer() { 0xFF, 0xFF, 0, 0 },
"device-id", Buffer() { 0xFF, 0xFF, 0, 0 },
})
}
}

Now save your file as a ACPI Machine Language Binary and place it in EFI/Clover/ACPI/patched/SSDT-DiscreteSpoof.aml

(Don't forget to specify it in your Config.plist)