A python script for building and booting OpenCore on legacy Macs, see Supported SMBIOS on whether your model is supported.

Supported features:

• System Integrity Protection, FileVault 2 and .im4m Secure Boot
• Native OTA OS updates
• Recovery OS, Safe Mode and Single-user Mode booting
• Zero firmware patching required(ie. APFS ROM patching)
• GPU Switching on MacBook Pro models(2012 and newer)

Note: Only clean-installs and upgrades are supported, installs already patched with Patched-Sur or bigmac cannot be used due to broken file integrity with APFS snapshots and SIP.

• You can however reinstall macOS with this patcher and retain your original data

Note 2: Currently OpenCore Legacy Patcher only supports macOS 11, Big Sur installs. For older OSes, please use Dosdude1's patchers

To use, simply:

1. Ensure your hardware is compatible(See Supported SMBIOS)
2. Download and build macOS Installer
3. Download the latest release: OpenCore Legacy Patcher Releases
4. Run the OpenCore-Patcher.app
5. Run Build OpenCore(if building for another machine, please select Change Model)

First Run	Build EFI

• Note: When the patcher ask you to if you want to use original serials, we recommend doing so. To determine yourself if you want:
  • Original: Mac is nearly identical to pre-patcher, with only minor changes in SMBIOS. Ideal configuration for iServices to work correctly
  • Custom: Rebuilds SMBIOS table to Mac you're spoofing, generally recommended when troubleshooting such as APFS support missing in the installer

6. Run Install OpenCore to USB/internal drive

Select Drive	Select EFI/FAT32 Partition

• Ensure you install OpenCore onto a FAT32 partition to ensure your Mac is able to boot it, you may need to format your drive as GUID/GPT in Disk Utility

7. Reboot machine while holding Option to select OpenCore, then boot the macOS Installer

Mac Boot Picker	OpenCore Picker

For nightly builds, you can either run OpenCore-Patcher.command from main or grab the binary from Github Actions. Note the latter does not require a py3 install.

To remove OpenCore is actually quite simply:

1. Remove OpenCore either from the USB or internal drive

• You'll need to mount the drive's EFI partition, and delete the EFI folder
• See here for example how to mount

2. Reset NVRAM

• Reset NVRAM or PRAM on your Mac

Know that if you are on Big Sur when you remove the EFI folder, your Mac will no longer boot and show the prohibited symbol. Be ready to install an older version of macOS before you uninstall OpenCore.

Since this patcher tricks macOS into thinking you're running a newer Mac, certain functionality may be broken:

• Boot Camp Assistant.app
  • We recommend running the assistant on a natively supported OS
• Legacy Windows Booting
  • Currently OpenCore cannot boot MBR-based installs, so Ivy Bridge and older Machines may not be able to see Windows in OpenCore's Boot Picker