OpenCore Legacy Patcher
Description
Apple’s policy for upgrading the operating system of its Mac computers has a rhythm to it: with every new release, Apple’s engineers stop supporting a number of older Mac models, severing these machines off from new functionality and, eventually, security updates. MacOS Ventura dropped Macs as recent as 2017 Intel models. macOS Sonoma dropped more. The official answer is to purchase a more modern Mac. OpenCore Legacy Patcher offers a different solution: patch the unsupported Mac to be able to run the newer operating system anyway, with the help of modified bootloaders and kexts which restore the drivers and hardware support Apple removed.
The project is the outgrowth of the OpenCore bootloader community formerly associated with macOS on non-Apple hardware. Mykola Grymalyuk with the help of the dortania team modified the patching infrastructure of OpenCore specifically for the issue of running current macOS versions on officially unsupported Apple hardware. The patching process is automated by the tool with a graphical interface that guides the user through the process of creating a bootable installer, patching the OpenCore configuration to the target Mac, and applying post-installation root patches that restore graphics acceleration, Wi-Fi, and Bluetooth functionality after installation is completed.
OpenCore itself predates OpenCore Legacy Patcher as a project — it originated as a hackintosh tool for installing a macOS operating system on non-Apple Intel based hardware, which offered a flexible bootloader mechanism by which it would spoof identifiers that identified hardware and inject drivers which macOS would expect to find. The documentation by the dortania team for OpenCore became something of a standard reference for the hackintosh community, and resulted the reputation for doing things methodically and in a technically rigorous way.
With the release of macOS Big Sur in 2020 which just started removing support for Intel-based Macs which were just a few years old, hackintosh interest was directed towards getting the patcher to support real Apple hardware instead of hackintosh configurations. OpenCore Legacy Patcher codified that effort with a project for the GUI installer specifically targeting Mac users who weren’t comfortable with the manual editing of configuration files.
The project added to the supported hardware with every new release of macOS. macOS Ventura support added patches for 2017 and 2018 models of MacBook Pro and iMac. Support of Sonoma was expanded to other hardware. The team records which features function fully, which have limitations, and which still need to be fixed for every combination of hardware and macOS, which provides users with realistic expectations before they commit to the process.
KEY FEATURES
Graphical Patch Interface
OpenCore Legacy Patcher’s main window will detect the current Mac model, list which OS versions to natively support and which to patch, and guide the installation process step-by-step. The application manages the download of the macOS installer from Apple’s servers, creates a bootable USB installer with OpenCore pre-configured for the particular piece of hardware, and manages the post-install root patching process.
Post-Installation Patch Root Files
This step makes OpenCore Legacy Patcher unlike just forcefully installing a macOS through command-line hacks. After macOS is installed on the patched drive, OCLP applies root patches — modifications to the macOS system volume — that enable the hardware to work again. Graphics acceleration for older GPUs, including Nvidia Kepler cards and AMD Polaris cards Apple’s current drivers do not support natively gets restored via patched kexts. Wi-Fi cards in older Mac models with Broadcom chips dropped from macOS has the working drivers via the root patch process. Without root patching, the macOS installation would start but run at terrible performance because it was missing GPU acceleration.
Supported Hardware
The project supports a wide range of Intel Mac hardware dropped from recent versions of macOS, including MacBook Pro from 2013 through 2017, MacBook Air from 2013 through 2017, iMac from 2013 through 2017, Mac Mini from 2012 through 2014, and Mac Pro from 2010 and 2012. Support for each model depends on which version of macOS is being installed, and the documentation for the project contains a list of which models work with which version of macOS and what limitations there are.
System Integrity Protection Considerations
Running OpenCore Legacy Patcher requires that System Integrity Protection (SIP) be disabled on the target Mac as root patching involves modifying the sealed system volume that SIP protects. The project offers explicit instructions on how to do this as well as some note on the security implications of the reduced SIP enforcement. Users on patched systems should consider the trade-off between running a current version of OSX with psychotronics disabled SIP and running on an older officially supported version of macOS with full SIP.
Update Management
macOS minor updates — the types of updates you get 14.x to 14.y — can also overwrite root patches and can even break hardware acceleration or Wi-Fi until the user runs OCLP’s root patching process again after updating. The application provides notifications to the users when an applied update of the os x operating system is being required for re-patching and guides the users in re-patching. Major version updates necessitate reinstalling of the full patched installer.
Documentation
The dortania team maintains an extensive amount of documentation on supported hardware, issues known, troubleshooting steps and technical details of what each patch does. The documentation associates each patch with the reason why it is needed for a particular piece of hardware which makes it interesting for the users of the tool that have an interest in understanding what the tool is changing rather than running it as a black box.
