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OpenCore Configuration

Emulate

  1. Cpuid1Data
    • Type: plist data, 16 bytes
    • Failsafe: All zero
    • Description: Sequence of EAX, EBX, ECX, EDX values to replace CPUID (1) call in XNU kernel.

    This property primarily meets three requirements: - Enabling support for an unsupported CPU model (e.g. Intel Pentium). - Enabling support for a CPU model not yet supported by a specific version of macOS (typically old versions). - Enabling XCPM support for an unsupported CPU variant.

    Note 1: It may also be the case that the CPU model is supported but there is no power management supported (e.g. virtual machines). In this case, MinKernel and MaxKernel can be set to restrict CPU virtualisation and dummy power management patches to the particular macOS kernel version.

    Note 2: Only the value of EAX, which represents the full CPUID, typically needs to be accounted for and remaining bytes should be left as zeroes. The byte order is Little Endian. For example, C3 06 03 00 stands for CPUID 0x0306C3 (Haswell).

    Note 3: For XCPM support it is recommended to use the following combinations. Be warned that one is required to set the correct frequency vectors matching the installed CPU.

    • Haswell-E (0x0306F2) to Haswell (0x0306C3):
      • Cpuid1Data: C3 06 03 00 00 00 00 00 00 00 00 00 00 00 00 00
      • Cpuid1Mask: FF FF FF FF 00 00 00 00 00 00 00 00 00 00 00 00
    • Broadwell-E (0x0406F1) to Broadwell (0x0306D4):
      • Cpuid1Data: D4 06 03 00 00 00 00 00 00 00 00 00 00 00 00 00
      • Cpuid1Mask: FF FF FF FF 00 00 00 00 00 00 00 00 00 00 00 00
    • Comet Lake U62 (0x0A0660) to Comet Lake U42 (0x0806EC):
      • Cpuid1Data: EC 06 08 00 00 00 00 00 00 00 00 00 00 00 00 00
      • Cpuid1Mask: FF FF FF FF 00 00 00 00 00 00 00 00 00 00 00 00
    • Rocket Lake (0x0A0670) to Comet Lake (0x0A0655):
      • Cpuid1Data: 55 06 0A 00 00 00 00 00 00 00 00 00 00 00 00 00
      • Cpuid1Mask: FF FF FF FF 00 00 00 00 00 00 00 00 00 00 00 00
    • Alder Lake (0x090672) to Comet Lake (0x0A0655):
      • Cpuid1Data: 55 06 0A 00 00 00 00 00 00 00 00 00 00 00 00 00
      • Cpuid1Mask: FF FF FF FF 00 00 00 00 00 00 00 00 00 00 00 00

    Note 4: Be aware that the following configurations are unsupported by XCPM (at least out of the box):

    • Consumer Ivy Bridge (0x0306A9) as Apple disabled XCPM for Ivy Bridge and recommends legacy power management for these CPUs. _xcpm_bootstrap should manually be patched to enforce XCPM on these CPUs instead of this option.
    • Low-end CPUs (e.g. Haswell+ Pentium) as they are not supported properly by macOS. Legacy workarounds for older models can be found in the Special NOTES section of acidanthera/bugtracker#365.
  2. Cpuid1Mask
    • Type: plist data, 16 bytes
    • Failsafe: All zero
    • Description: Bit mask of active bits in Cpuid1Data.

    When each Cpuid1Mask bit is set to 0, the original CPU bit is used, otherwise set bits take the value of Cpuid1Data.

  3. DummyPowerManagement
    • Type: plist boolean
    • Failsafe: false
    • Requirement: 10.4-12
    • Description: Disables AppleIntelCpuPowerManagement.

    Note 1: This option is a preferred alternative to NullCpuPowerManagement.kext for CPUs without native power management driver in macOS.

    Note 2: While this option is typically needed to disable AppleIntelCpuPowerManagement on unsupported platforms, it can also be used to disable this kext in other situations (e.g. with Cpuid1Data left blank).

  4. MaxKernel
    • Type: plist string
    • Failsafe: Empty
    • Description: Emulates CPUID and applies DummyPowerManagement on specified macOS version or older.

    Note: Refer to the Add MaxKernel description for matching logic.

  5. MinKernel
    • Type: plist string
    • Failsafe: Empty
    • Description: Emulates CPUID and applies DummyPowerManagement on specified macOS version or newer.

    Note: Refer to the Add MaxKernel description for matching logic.