macOS Hibernation

macOS by default will try to use hibernation after sleeping for a predetermined amount of time.
Some fixes in the config.plist are required in order to take advantage of this:

• Disable Booter->Quirks->DevirtualiseMmio

• Set Misc->Boot->HibernateMode to Auto

  • By default, OpenCore will not look for hibernated images of macOS.

• Set Misc->Boot->HibernationSkipsPicker to True to skip the picker when resuming from hibernation

  • While not strictly required, this speeds up resume times and prevents accidently booting another OS and changing hardware state underneath macOS.

• Create a reserved memory region under UEFI->ReservedMemory with the properties:

  Field	Type	Value
  Comment	String	Fix black screen on wake from hibernation
  Enabled	Boolean	True
  Address	Number	569344
  Enabled	Boolean	True
  Size	Number	4096
  Type	String	RuntimeCode

Testing Hibernation

To test hibernation, it is recommended to run sudo pmset -a hibernatemode 25.
This will force macOS to hibernate immediately whenever the lid is closed or Sleep is selected in the menu at the top left.

macOS enters S3 sleep instead of shutting down

Some models (such as KLED) have drives not marked as internal, which prevents macOS from entering hibernation.
To fix this, add the built-in property to the PCI device under DeviceProperties->Add-><storage device path>:

Field	Type	Value
built-in	Data	<01000000>

You may need to add an ACPI device as well. If an ACPI device does not exist to represent the NVMe or eMMC drive, then device properties will not be applied. An example SSDT can be found here.

Hibernate Modes

Pmset exposes a few different hibernation modes which can be set through sudo pmset -a hibernatemode <value>:

• 0: Disables hibernation
• 3: Hibernates after either standbydelaylow or standbydelayhigh seconds of sleep
  • Which one is used is dependent on the battery percentage. Anything above highstandbythreshold will use standbydelayhigh instead of standbydelaylow.
• 25: Hibernates instead of S3 sleep

When using hibernate mode 3, macOS may keep sleeping even after the standby time has elapsed. HibernationFixup.kext may be required in this case, and provides options to fine tune when the Chromebook is allowed to sleep.