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OpenCore-EFI-Laptop-Lenovo-Yoga-C740-14IML

Stable and well-tested OpenCore EFI files for Lenovo Yoga C740-14IML.

Choosing the right files for your macOS version

The EFI files in the main branch and the latest release of this repository only supports the latest major version of macOS. If you are on a previous macOS version, you should checkout the branch named archive/macos-<major version> depending on your situation. Please note that you will not get any support using files from those branches.

Details of the machine used in debugging

Problems

Existing

• The built-in microphone doesn't work

Fixed

Sorted by date discovered, latest to oldest.

• The boot picker doesn't show up (neither when Misc -> Boot -> PickerMode is set to Builtin nor External)

  Fixed by resetting NVRAM. But without knowing which entry in the boot picker is Reset NVRAM, some guesswork is required.

• The touchscreen doesn't work

  Fully fixed in commit 73aa198. It also worked in macOS versions prior to macOS Monterey by switching to SSDT-XOSI from SSDT-GPI0, adding XOSI patches, patching VoodooI2CPCIController.cpp (credit to @MJYINMC), and after a sleep. Now it works out of box.

• System Preferences app crashes (or freeze or throw a "Could not load ... preference pane" error) when trying to open the following panes:
  • Siri
  • Accessibility
  • Network
  • Bluetooth
  • Mouse

  Fixed by removing IntelBluetoothInjector.kext and adding BlueToolFixup.kext, credit to extra instructions for Monterey users by OpenIntelWireless.

• OS start-up takes too long

  Same cause and solution as the crash of System Preferences.

• Built-in audio output doesn't work

  AppleALC.kext with layout-id 61 works.

• Unable to boot into macOS 11.0.1 Installer (Neither download and prepare within the OS, nor through a USB drive)

  You have to set the value of DVMT pre-allocated by patching the BIOS (configuring related entries in the config.plist for OpenCore doesn't work on this device). See here for the instructions and thanks @MJYINMC.

• Stuck on apfs_module_start... Previous shutdown cause... while booting into the installer

  Not problems with EFI files, solved after reflashing the USB Installer.

• Stuck on IOG flags ... Generation from SMC report as ... IOPPF ... while booting into the installer

  Solved after fixing SSDTs, adding some kernel extensions, etc.

• Stuck on [ PCI configuration end, bridges 2, devices 20 ] while booting into the installer

  Solved after reordering the SSDTs.