VoodooHDA-Legion

Audio on macOS Tahoe for the Realtek ALC257 behind Intel's Arrow Lake-HX HDA controller (8086:7F50, Intel Smart Sound in DSP mode), as found in the Lenovo Legion 5 15IAX10. Tahoe removed AppleHDA, so AppleALC has nothing to patch and the usual alcid= route is gone. VoodooHDA is a self-contained HDA driver that does not need AppleHDA. This repository is a small patch on top of it plus a build script that produces the LE variant (links the system IOAudioFamily, installs to /Library/Extensions) with the Xcode Command Line Tools, matched to the 7F50 controller only, with the ALC257 pin configuration for layout 18. No VoodooHDA code is copied here; the script clones upstream at an audited commit and applies legion.patch.

On macOS Sequoia the same codec works with AppleALC 1.9.8 and alcid=18; this is for Tahoe.

legion.patch, 3 hunks against tranc/VoodooHDADevice.cpp:

1. A nonzero LayoutId in the kext's own personality wins over the layout-id PCI property. OpenCore and AppleALC set layout-id for AppleHDA (7 on this laptop), which is not a VoodooHDA pin-config layout; with this, the personality's LayoutId 18 (the AppleALC pin configuration for 10EC0257 layout 18, which VoodooHDA carries in AppleALCPinConfigs.cpp) is used.
2. A bound check in audioCtlOssMixerSet and changeSliderValue: the slider number comes from the user client (0 to 255) and indexed left[] / right[] arrays of 25 entries with no check, a kernel out-of-bounds write reachable from any process that opens the user client.
3. A null check on engine->mChannel in setMath.

The build script also edits the Info.plist: IOPCIMatch 0x7f508086 instead of the class match (which would also grab the NVIDIA and iGPU HDMI audio functions with a probe score above Apple's driver), the HDMI personality removed, LayoutId 18.

• VoodooHDA is not AppleHDA: no Apple codec-specific tuning, and the usual VoodooHDA caveats (volume curve, no jack-sense configuration beyond what the parser finds).
• The LE variant has to live in /Library/Extensions, which on a hackintosh needs SIP configured to allow unsigned and unapproved kexts. The test laptop runs csr-active-config 0x0A43. The BL variant (OpenCore-injectable, with IOAudioFamily compiled in) is not used here because Tahoe still has Apple's IOAudioFamily in the kernel collection and the duplicate class names would clash.
• One laptop, one codec, one controller.

./build.sh                 # clones CloverHackyColor/VoodooHDA at beb415a into ./VoodooHDA on first run,
                           # applies legion.patch to a copy, builds out/VoodooHDA.kext with the Command Line Tools

The script refuses to run if the clone is not at the audited commit. It prints the undefined symbols and asks kmutil which installed libraries resolve them (read-only), so a missing KPI shows up before you install anything.

With SIP allowing unsigned kexts (see above):

sudo cp -R out/VoodooHDA.kext /Library/Extensions/
sudo chown -R root:wheel /Library/Extensions/VoodooHDA.kext
sudo kmutil install --volume-root / --update-all
sudo reboot

Check with kmutil showloaded | grep VoodooHDA and system_profiler SPAudioDataType. Rollback: remove the kext from /Library/Extensions, run kmutil install --volume-root / --update-all again, reboot.

• VoodooHDA (Slice, chris1111 and contributors, BSD-2-Clause), based on FreeBSD snd_hda.
• AppleALC (acidanthera): the ALC257 layout 18 pin configuration VoodooHDA ships.

BSD-2-Clause, the same as VoodooHDA, for the patch and the script (LICENSE).