Revert the mainhook on error

src/kernel.cpp

@@ -19,6 +19,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <coreinit/cache.h>
+#include <coreinit/memorymap.h>
 
 #include "kernel.h"
 
@@ -30,6 +31,27 @@ extern "C" void SaveAndResetDataBATs_And_SRs_hook(void);
 
 void __attribute__ ((noinline)) kern_write(void *addr, uint32_t value);
 
+extern "C" void SC_0x25_KernelCopyData(unsigned int addr, unsigned int src, unsigned int len);
+
+extern "C" void SCKernelCopyData(unsigned int addr, unsigned int src, unsigned int len);
+
+void KernelWriteU32(uint32_t addr, uint32_t value) {
+    ICInvalidateRange(&value, 4);
+    DCFlushRange(&value, 4);
+
+    auto dst = (uint32_t) OSEffectiveToPhysical(addr);
+    auto src = (uint32_t) OSEffectiveToPhysical((uint32_t) &value);
+
+    SC_0x25_KernelCopyData(dst, src, 4);
+
+    DCFlushRange((void *) addr, 4);
+    ICInvalidateRange((void *) addr, 4);
+}
+
+void revertMainHook() {
+    KernelWriteU32(0x0101c56c, 0x4E800421);
+}
+
 void doKernelSetup() {
     kern_write((void *) (KERN_SYSCALL_TBL_1 + (0x36 * 4)), (unsigned int) KernelPatches);
     kern_write((void *) (KERN_SYSCALL_TBL_2 + (0x36 * 4)), (unsigned int) KernelPatches);
@@ -52,6 +74,13 @@ void doKernelSetup2() {
     kern_write((void *) (KERN_SYSCALL_TBL_5 + (0x36 * 4)), (unsigned int) KernelPatchesFinal);
 
     Syscall_0x36();
+
+    kern_write((void *) (KERN_SYSCALL_TBL_1 + (0x25 * 4)), (unsigned int) SCKernelCopyData);
+    kern_write((void *) (KERN_SYSCALL_TBL_2 + (0x25 * 4)), (unsigned int) SCKernelCopyData);
+    kern_write((void *) (KERN_SYSCALL_TBL_3 + (0x25 * 4)), (unsigned int) SCKernelCopyData);
+    kern_write((void *) (KERN_SYSCALL_TBL_4 + (0x25 * 4)), (unsigned int) SCKernelCopyData);
+    kern_write((void *) (KERN_SYSCALL_TBL_5 + (0x25 * 4)), (unsigned int) SCKernelCopyData);
+
 }
 
 /* Write a 32-bit word with kernel permissions */

src/kernel.h

@@ -31,6 +31,8 @@ void doKernelSetup();
 
 void doKernelSetup2();
 
+void revertMainHook();
+
 #ifdef __cplusplus
 }
 #endif

src/kernel_copy.S

@@ -0,0 +1,27 @@
+.global SCKernelCopyData
+SCKernelCopyData:
+	// Disable data address translation
+	mfmsr %r6
+	li %r7, 0x10
+	andc %r6, %r6, %r7
+	mtmsr %r6
+
+	// Copy data
+	addi %r3, %r3, -1
+	addi %r4, %r4, -1
+	mtctr %r5
+SCKernelCopyData_loop:
+	lbzu %r5, 1(%r4)
+	stbu %r5, 1(%r3)
+	bdnz SCKernelCopyData_loop
+
+	// Enable data address translation
+	ori %r6, %r6, 0x10
+	mtmsr %r6
+blr
+
+.global SC_0x25_KernelCopyData
+SC_0x25_KernelCopyData:
+	li %r0, 0x2500
+	sc
+blr

src/main.cpp

@@ -105,7 +105,8 @@ extern "C" int _start(int argc, char **argv) {
         ((int (*)(int, char **)) moduleData->getEntrypoint())(argc, argv);
         doProcUI = true;
     } else {
-        DEBUG_FUNCTION_LINE("Failed to load module");
+        DEBUG_FUNCTION_LINE("Failed to load module, revert main_hook");
+        revertMainHook();
     }
 
     if (doProcUI) {