iMac de meados de 2011: Sem áudio no modo UEFI do Windows 11
Título:
Windows 11 on iMac12,1 - no audio, HDA controller Code 10 in UEFI mode
Description:
I have a mid-2011 iMac (iMac12,1) running Windows 11, installed in UEFI mode rather than through Boot Camp. There is no audio whatsoever - Settings shows "No output device found", and the volume slider is greyed out at zero.
What I have narrowed it down to:
The Intel 6 Series HD Audio controller (PCI\VEN_8086&DEV_1C20) reports Code 10, "This device cannot start". Because that controller never starts, the Cirrus Logic CS4206 codec (VEN_1013) is never enumerated, so there is nothing for the audio drivers to attach to. The Cirrus drivers themselves are installed and signed (cs420x.inf and cs420x_45.inf are both in the driver store).
The interesting part: the Mac still plays the startup chime through the internal speakers on every boot. That sound goes through the same Cirrus codec, so the hardware is clearly alive and the EFI firmware can drive it. It seems the firmware initializes the audio for its own use and then hands the machine to Windows in a state Windows cannot pick up.
Everything I have tried, with no change:
- The controller was found disabled (Code 22); enabling it moved it to Code 10
- Removed and re-enumerated the device with pnputil
- Several cold boots
- NVRAM reset and SMC reset
- MSISupported = 0 in the registry for that device
- bcdedit configaccesspolicy DisallowMmConfig
- bcdedit x2apicpolicy disable and uselegacyapicmode yes
Windows Audio services are running fine, and the AMD HDMI audio on the graphics card enumerates and reports OK - so the Windows audio stack itself is healthy. The failure is isolated to the built-in controller.
My question: has anyone got the analog audio working on a 2011 iMac with Windows installed in UEFI mode? Everything I read points to Legacy/CSM being required for the firmware to hand off the HDA controller properly, which would mean a full reinstall through Boot Camp. Before I go through that, I would like to know if anyone has found another way.
Machine: iMac12,1 (mid 2011)
OS: Windows 11, build 10.0.26100
Boot mode: UEFI (winload.efi)