Need help with OcQuirks?
Click the “chat” button below for chat support from the developer who created it, or find similar developers for support.

About the developer

135 Stars 20 Forks BSD 3-Clause "New" or "Revised" License 67 Commits 3 Opened issues


A work-in-progress attempt to port OpenCore's boot quirks to Clover in order to replace AptioMemoryFix.

Services available


Need anything else?

Contributors list

# 243,968
53 commits
# 418,998
6 commits
# 525,489
4 commits
# 474,705
1 commit


OcQuirks is a drop in replacement EFI driver for Clover that replaces AptioMemoryFix and all OsxAptioFix variants. It is built against the OpenCore source tree, and supports OpenCore's quirks model.


The OcQuirks EFI driver has a dependency on OpenRuntime.efi, and they must be installed together in the CLOVER EFI drivers directory. OpenRuntime.efi can be found in the release zip and is built along with OcQuirks.


To install OcQuirks, download the latest release or build it using the instructions below and then install it into your EFI replacing any existing memory fix driver.

  • Mount your EFI volume.
  • Back your EFI volume up to a bootable USB drive and verify that it works.
  • Remove AptioMemoryFix, and any OsxAptioFix variants from the Clover drivers folder on your EFI volume.
  • Add OcQuirks.efi, OpenRuntime.efi, and OcQuirks.plist to the Clover drivers folder on your EFI volume.
  • Reboot.

If your system has trouble booting, use your USB stick to boot back into macOS and revert by reversing the process. Inspect the parameters below and configure OcQuirks.plist with parameters that better match your system.

Default settings are based on AptioMemoryFix and are designed with new Intel systems in mind. Your system may require custom settings, (e.g., Z390 may need DevirtualiseMmio+ProtectUefiServices, Older 100-200 series might need EnableWriteUnprotector). It is also assumed that all slides are valid (no slide=X).


The parameters listed below can be changed by dropping in OcQuirks.plist into your Clover drivers folder. This can be found in either the release zip or the root of the OcQuirks repository. If no plist is found, then the defaults below are used.

|Quirk|Default Value|Description| |---|---|---| |AvoidRuntimeDefrag|True|Fix UEFI runtime services support on many firmwares.| |DevirtualiseMmio|False|Reduce stolen memory footprint from memory map, incompatible with some systems| |DisableSingleUser|False|A security option to ignore single user mode arguments.| |DisableVariableWrite|False|A security option to protect macOS NVRAM write access.| |DiscardHibernateMap|False|A legacy parameter to work around buggy memory maps. Preserves runtime memory size and location after wake from S4 sleep.| |EnableSafeModeSlide|True|Patch the bootloader to enable KASLR in safe mode.| |EnableWriteUnprotector|False|Permits write access to UEFI runtime services code. Use RebuildAppleMemoryMap if possible.| |ForceExitBootServices|True|Ensures that calls to ExitBootServices succeed even with an outdated MemoryMap key.| |MmioWhitelist|Array|Designed to be filled with plist dict values, describing addresses critical for particular firmware functioning when DevirtualiseMmio quirk is in use. |ProtectMemoryRegions|False|Protect memory regions from incorrect access. Only needed by very old firmwares.| |ProtectSecureBoot|False|Protect UEFI Secure Boot variables from being written.| |ProtectUefiServices|False|Protect UEFI services from being overridden by the firmware.| |ProvideConsoleGopEnable|True|Install Graphics Output Protocol if missing from the console handle.| |ProvideCustomSlide|True|Force macOS to use a pseudorandom value among available slide values.| |ProvideMaxSlide|0|Overrides the maximum slide instead of 256 when ProvideCustomSlide is enabled.| |RebuildAppleMemoryMap|True|Generate Memory Map compatible with macOS.| |SetupVirtualMap|True|Workaround issues in some firmwares that access memory after SetVirtualAddress calls often resulting in boot crashes.| |SignalAppleOS|False|This quirk is useful on Mac firmwares, which behave differently in different OS.| |SyncRuntimePermissions|True|Update memory permissions for runtime environment.|

For a more indepth description of quirks, review the OpenCore Configuration Manual.


Building OcQuirks is simple, you just need macOS and time. You do not need to configure OcQuirks before building now, so all you need to do is follow the process below to build.

Clone the Repository

$ git clone
$ cd OcQuirks

Build OcQuirks

Now build OcQuirks using the macbuild tool. You may be prompted to install additional tools before compilation begins.

$ ./macbuild.tool


Follow the installation procedures found earlier in the documentation, using the newly compiled version of OcQuirks which can be found in the OcQuirks/Binaries/RELEASE folder.


We use cookies. If you continue to browse the site, you agree to the use of cookies. For more information on our use of cookies please see our Privacy Policy.