Add PatchCallsInRange API

llde · Sep 15, 2023 · ee793c6 · ee793c6
1 parent b91e36a
commit ee793c6
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Showing 2 changed files with 27 additions and 1 deletion.
diff --git a/obse/obse_common/SafeWrite.cpp b/obse/obse_common/SafeWrite.cpp
@@ -75,4 +75,28 @@ void WriteNop(UInt32 nopAddr, UInt8 numOfByte) {
 	for (UInt8 i = 0; i < numOfByte; i++) {
 		SafeWrite8(nopAddr + i, 0x90);
 	}
+}
+
+void PatchCallsInRange(UInt32 start, UInt32 end, UInt32 CallToPatch, UInt32 HookCall) {
+	UInt32	oldProtect;
+
+	VirtualProtect((void*)start , end - start, PAGE_EXECUTE_READWRITE, &oldProtect);
+	for (UInt32 current = start; current < end; current++) {
+		if (*(UInt8*)current == 0xE8) {
+			UInt32 callTarget = *(UInt32*)(current + 1) + current + 1 + 4;
+	//		_MESSAGE("%08X", callTarget);
+			if (callTarget == CallToPatch) {
+	//			_MESSAGE("Call found");
+				SafeWrite32(current + 1, HookCall - current - 1 - 4);
+			}
+		}
+	}
+	VirtualProtect((void*)start, end - start, oldProtect, &oldProtect);
+
+	/*
+	006020FB 054                 db  61h ; a
+.text:006020FC 054                 db  59h ; Y
+.text:006020FD 054                 db 0EAh ; ê
+.text:006020FE 054                 db 0FFh ; ÿ
+	*/
 }
diff --git a/obse/obse_common/SafeWrite.h b/obse/obse_common/SafeWrite.h
@@ -15,4 +15,6 @@ void WriteRelJnz(UInt32 jumpSrc, UInt32 jumpTgt);
 void WriteRelJle(UInt32 jumpSrc, UInt32 jumpTgt);
 
 //Write arbitrary nop
-void WriteNop(UInt32 nopAddr, UInt8 numOfByte);
+void WriteNop(UInt32 nopAddr, UInt8 numOfByte);
+//PAtch calls to address in a certain range
+void PatchCallsInRange(UInt32 start, UInt32 end, UInt32 CallToPatch, UInt32 HookCall);