graphics_audio.py: Add AMD Navi patch

CHANGELOG.md

@@ -15,6 +15,8 @@
 - Increase model range for S1X/S3X patching to include Haswell Macs and `MacPro6,1`
   - Helps avoid an issue where older machines with newer, unsupported SSDs would fail to boot
   - Only affects building EFI from another machine
+- Resolve AMD Navi MXM GPU detection for modded iMac9,x-12,x
+  - Thanks @Ausdauersportler for the patch!
 - Increment Binaries:
   - PatcherSupportPkg 1.6.3 - release
 

opencore_legacy_patcher/efi_builder/graphics_audio.py

@@ -142,11 +142,15 @@ def _backlight_path_detection(self) -> None:
         iMac MXM dGPU Backlight DevicePath Detection
         """
 
-        if not self.constants.custom_model and self.computer.dgpu and self.computer.dgpu.pci_path:
+        if not self.constants.custom_model:
             for i, device in enumerate(self.computer.gpus):
                     logging.info(f"- Found dGPU ({i + 1}): {utilities.friendly_hex(device.vendor_id)}:{utilities.friendly_hex(device.device_id)}")
                     self.config["#Revision"][f"Hardware-iMac-dGPU-{i + 1}"] = f"{utilities.friendly_hex(device.vendor_id)}:{utilities.friendly_hex(device.device_id)}"
 
+                    # Work-around for AMD Navi MXM cards with PCIe bridge
+                    if not self.computer.dgpu:
+                        self.computer.dgpu=self.computer.gpus[i]
+
                     if device.pci_path != self.computer.dgpu.pci_path:
                         logging.info("- device path and GFX0 Device path are different")
                         self.gfx0_path = device.pci_path