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OpenCore Configuration

Introduction

This section allows the application of different types of UEFI modifications to operating system bootloaders, primarily the Apple bootloader (boot.efi). The modifications currently provide various patches and environment alterations for different firmware types. Some of these features were originally implemented as part of AptioMemoryFix.efi, which is no longer maintained. Refer to the Tips and Tricks section for instructions on migration.

Booter changes apply with the following effective order:

  • Quirks are processed.
  • Patch is processed.

If this is used for the first time on customised firmware, the following requirements should be met before starting:

  • Most up-to-date UEFI firmware (check the motherboard vendor website).
  • Fast Boot and Hardware Fast Boot disabled in firmware settings if present.
  • Above 4G Decoding or similar enabled in firmware settings if present. Note that on some motherboards, notably the ASUS WS-X299-PRO, this option results in adverse effects and must be disabled. While no other motherboards with the same issue are known, this option should be checked first whenever erratic boot failures are encountered.
  • DisableIoMapper quirk enabled, or VT-d disabled in firmware settings if present, or ACPI DMAR table deleted.
  • No ‘slide‘ boot argument present in NVRAM or anywhere else. It is not necessary unless the system cannot be booted at all or No slide values are usable! Use custom slide! message can be seen in the log.
  • CFG Lock (MSR 0xE2 write protection) disabled in firmware settings if present. Refer to the ControlMsrE2 notes for details.
  • CSM (Compatibility Support Module) disabled in firmware settings if present. On NVIDIA 6xx/AMD 2xx or older, GOP ROM may have to be flashed first. Use GopUpdate (see the second post) or AMD UEFI GOP MAKER in case of any potential confusion.
  • EHCI/XHCI Hand-off enabled in firmware settings only if boot stalls unless USB devices are disconnected.
  • VT-x, Hyper Threading, Execute Disable Bit enabled in firmware settings if present.
  • While it may not be required, sometimes Thunderbolt support, Intel SGX, and Intel Platform Trust may have to be disabled in firmware settings present.

When debugging sleep issues, Power Nap and automatic power off (which appear to sometimes cause wake to black screen or boot loop issues on older platforms) may be temporarily disabled. The specific issues may vary, but ACPI tables should typically be looked at first.

Here is an example of a defect found on some Z68 motherboards. To turn Power Nap and the others off, run the following commands in Terminal:

sudo pmset autopoweroff 0
sudo pmset powernap 0
sudo pmset standby 0

Note: These settings may be reset by hardware changes and in certain other circumstances. To view their current state, use the pmset -g command in Terminal.