Add disable-telemetry-load iGPU property to disable telemetry loading

Disables iGPU telemetry loading that may cause a freeze during startup on certain laptops such as Chromebooks

Changelog.md

@@ -2,6 +2,7 @@ WhateverGreen Changelog
 =======================
 #### v1.6.3
 - Added various GPU identifiers from different Macs
+- Added `disable-telemetry-load` to disable iGPU telemetry loading that may cause a freeze during startup on certain laptops such as Chromebooks.
 
 #### v1.6.2
 - Added W7170M/S7100X ID

README.md

@@ -104,6 +104,7 @@ Read [FAQs](https://github.com/acidanthera/WhateverGreen/blob/master/Manual/) an
 | `-igfxmlr` 		    | `enable-dpcd-max-link-rate-fix` property on IGPU 	| Apply the maximum link rate fix 	|
 | `-igfxmpc` 		    | `enable-max-pixel-clock-override` and `max-pixel-clock-frequency` properties on IGPU 	| Increase max pixel clock (as an alternative to patching `CoreDisplay.framework` 	|
 | `-igfxnohdmi` 	  | `disable-hdmi-patches` 	| Disable DP to HDMI conversion patches for digital sound 	|
+| `-igfxnotelemetryload` | `disable-telemetry-load` property on IGPU  | Disables iGPU telemetry loading that may cause a freeze during startup on certain laptops such as Chromebooks
 | `-igfxsklaskbl` 	| N/A 	| Enforce Kaby Lake (KBL) graphics kext being loaded and used on Skylake models (KBL `device-id` and `ig-platform-id` are required. Not required on macOS 13 and above) 	|
 | `-igfxtypec` 		 	| N/A 	| Force DP connectivity for Type-C platforms 	|
 | `-igfxvesa` 		  | N/A 	| Disable Intel Graphics acceleration 	|

WhateverGreen/kern_igfx.cpp

@@ -190,6 +190,8 @@ void IGFX::processKernel(KernelPatcher &patcher, DeviceInfo *info) {
 
 		disableAccel = checkKernelArgument("-igfxvesa");
 
+		disableIGTelemetry = info->videoBuiltin->getProperty("disable-telemetry-load") != nullptr || checkKernelArgument("-igfxnotelemetryload");
+
 		bool connectorLessFrame = info->reportedFramebufferIsConnectorLess;
 
 		int gl = info->videoBuiltin->getProperty("disable-metal") != nullptr;
@@ -249,6 +251,8 @@ void IGFX::processKernel(KernelPatcher &patcher, DeviceInfo *info) {
 				return true;
 			if (disableAccel)
 				return true;
+			if (disableIGTelemetry)
+				return true;
 			return false;
 		};
 
@@ -279,6 +283,23 @@ bool IGFX::processKext(KernelPatcher &patcher, size_t index, mach_vm_address_t a
 	auto cpuGeneration = BaseDeviceInfo::get().cpuGeneration;
 
 	if (currentGraphics && currentGraphics->loadIndex == index) {
+		if (disableIGTelemetry) {
+			auto symTelemetry = patcher.solveSymbol(index, "__ZN18IGTelemetryManager16prepareTelemetryEj");
+			if (symTelemetry) {
+				uint8_t ret[] {0xC3};
+				patcher.routeBlock(symTelemetry, ret, sizeof(ret));
+				if (patcher.getError() == KernelPatcher::Error::NoError) {
+					DBGLOG("igfx", "disabled __ZN18IGTelemetryManager16prepareTelemetryEj");
+				} else {
+					SYSLOG("igfx", "failed to disable __ZN18IGTelemetryManager16prepareTelemetryEj with code %d", patcher.getError());
+					patcher.clearError();
+				}
+			} else {
+				SYSLOG("igfx", "failed to resolve __ZN18IGTelemetryManager16prepareTelemetryE code %d", patcher.getError());
+				patcher.clearError();
+			}
+		}
+
 		if (forceOpenGL || forceMetal || forceSKLAsKBL || moderniseAccelerator || fwLoadMode != FW_APPLE || disableAccel) {
 			KernelPatcher::RouteRequest request("__ZN16IntelAccelerator5startEP9IOService", wrapAcceleratorStart, orgAcceleratorStart);
 			patcher.routeMultiple(index, &request, 1, address, size);

WhateverGreen/kern_igfx.hpp

@@ -289,6 +289,11 @@ class IGFX {
 	 */
 	bool forceMetal {false};
 
+	/**
+	 *  Set to true to disable telemetry loading for IGTelemetryManager.
+	 */
+	bool disableIGTelemetry {false};
+
 	/**
 	 *  Set to true if Sandy Bridge Gen6Accelerator should be renamed
 	 */