Hackintosh HDMI Audio Issue - HD4600 Haswell Desktop

[diegori466]

Hackintosh HDMI Audio Issue - HD4600 Haswell Desktop

System specs:
- CPU: Intel Core i5-4440 (Haswell)
- GPU: Intel HD Graphics 4600
- Motherboard: Gigabyte B85 series
- macOS: Sequoia 15.4.8 with OCLP root patch
- OpenCore: 0.8.8 (via OpCore Simplify)
- SMBIOS: iMac14,4
- Framebuffer: 0x0D220003

Problem: IOHDACodecDevice@3,0 stays !registered, !matched — HDMI audio never initializes.

What we confirmed works:
- Video acceleration with OCLP root patch ✅
- Analog audio (ALC892, layout-id 1) ✅
- All connectors showing as HDMI (connector-type = 00080000) ✅
- hda-gfx = onboard-1 injected on HDEF, IGPU and HDAU ✅
- device-id = 0x0C0A spoof on HDAU ✅
- AppleHDAController loads and creates child IOHDACodecDevice@3,0 ✅

What we tried without success:
- All BusID values (0x01, 0x02, 0x04, 0x05, 0x06) on con1/con2
- framebuffer-conX patches (type, busid, flags, pipe)
- framebuffer-con0-alldata replacement
- hda-gfx on all three PCI paths
- device-id spoofing (0x0C0A)
- WhateverGreen boot args (-igfxhdmidivfix)
- Modified CodecAddressFilterArray in both /System and /Library AppleHDAController.kext to include Intel codec PCIVendorDeviceID = 2155905031 (0x80862807)
- Rebuilt kext cache after modification

Root cause identified: AppleHDAController has a CodecAddressFilterArray that only whitelists Realtek codecs. Even after modifying both copies of the kext, the IOHDACodecDevice@3,0 still won't register. The OCLP legacy framebuffer driver (AppleIntelFramebufferAzul) appears to not send the display-active signal that the HDA codec needs to initialize.

Question: Has anyone successfully achieved HDMI audio with HD4600 iGPU on macOS Sequoia with OCLP? What specific fix was required? Help me