"TT_AudioOutMask" = "Type: plist integer\nFailsafe: -1\nDescription: Bit field indicating which output channels to use for UEFI sound.\n\nAudio mask is 1 « audio output (equivalently 2 ˆ audio output). E.g. for audio output 0 the bitmask is 1, for output 3 it is 8, and for outputs 0 and 3 it is 9.\n\nThe number of available output nodes (N) for each HDA codec is shown in the debug log (marked in bold-italic), audio outputs 0 to N - 1 may be selected:\nOCAU: 1/3 PciRoot(0x0)/Pci(0x1,0x0)/Pci(0x0,0x1)/VenMsg(<redacted>,00000000) (4 outputs)\nOCAU: 2/3 PciRoot(0x0)/Pci(0x3,0x0)/VenMsg(<redacted>,00000000) (1 outputs)\nOCAU: 3/3 PciRoot(0x0)/Pci(0x1B,0x0)/VenMsg(<redacted>,02000000) (7 outputs)\n\nWhen AudioDxe is used then additional information about each output channel is logged during driver binding, including the bitmask for each output. The bitmask values for the desired outputs should be added together to obtain the AudioOutMask value:\nHDA: | Port widget @ 0x9 is an output (pin defaults 0x2B4020) (bitmask 1)\nHDA: | Port widget @ 0xA is an output (pin defaults 0x90100112) (bitmask 2)\nHDA: | Port widget @ 0xB is an output (pin defaults 0x90100110) (bitmask 4)\nHDA: | Port widget @ 0x10 is an output (pin defaults 0x4BE030) (bitmask 8)\n\nFurther information on the available output channels may be found from a Linux codec dump using the command:
cat /proc/asound/card{n}/codec#{m}\n\nUsing AudioOutMask, it is possible to play sound to more than one channel (e.g. main speaker plus bass speaker; headphones plus speakers) as long as all the chosen outputs support the sound file format in use; if any do not then no sound will play and a warning will be logged.\n\nWhen all available output channels on the codec support the available sound file format, then a value of -1 will play sound to all channels simultaneously. If this does not work, it will usually be quickest to try each available output channel one by one, in order to work out which channel(s) to use.";
"TT_DisconnectHda" = "Type: plist boolean\nFailsafe: false\nDescription: Disconnect HDA controller before loading drivers.\n\nMay be required on some systems (e.g. Apple hardware, VMware Fusion guest) to allow a UEFI sound driver (such as AudioDxe) to take control of the audio hardware.";
