_README.md

For enabling Universal Control on older Macs, there are three ways.

(All of these requires you to enable the feature flag and disable SIP)

• Use khronokernel's kext: https://twitter.com/khronokernel/status/1428407216931999749

(I haven't tried this but it looks like it'd work)

• use DYLD_INSERT_LIBRARIES:

clang -o liboverride_model.dylib override_model.c -framework IOKit -framework CoreFoundation -shared
sudo launchctl debug gui/$UID/com.apple.ensemble --environment DYLD_INSERT_LIBRARIES="/Users/zhuowei/liboverride_model.dylib"
launchctl stop com.apple.ensemble
launchctl start com.apple.ensemble

• use lldb:

sudo launchctl debug gui/$UID/com.apple.ensemble --start-suspended
launchctl stop com.apple.ensemble
launchctl start com.apple.ensemble
lldb -n UniversalControl
b PlatformModelIsSupported
c
thread return 1
c
thread return 1
c

override_model.c

#include <IOKit/IOKitLib.h>

#define DYLD_INTERPOSE(_replacement,_replacee) \
   __attribute__((used)) static struct{ const void* replacement; const void* replacee; } _interpose_##_replacee \
            __attribute__ ((section ("__DATA,__interpose"))) = { (const void*)(unsigned long)&_replacement, (const void*)(unsigned long)&_replacee }

CFTypeRef hook_IORegistryEntryCreateCFProperty(io_registry_entry_t entry, CFStringRef key, CFAllocatorRef allocator, IOOptionBits options) {
	if (CFEqual(key, CFSTR("model"))) {
		return CFSTR("MacBookPro17,1");
	}
	return IORegistryEntryCreateCFProperty(entry, key, allocator, options);
}

DYLD_INTERPOSE(hook_IORegistryEntryCreateCFProperty, IORegistryEntryCreateCFProperty);

opening the Displays prefpane no advanced tab is shown.

I didn't override the check for the Display pane with the dylib method (it's an XPC service and I don't know how to inject code into them). You'll have to connect either by moving your mouse to the side or using the Display panel from a supported computer.

The Kext linked in the other gist would probably work for that, although I haven't tested it. Using lldb to attach to the XPC service also works.