NCPatcher/docs.txt at main · TheGameratorT/NCPatcher · GitHub

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================================ Static Patching ================================

C/C++:
	Patching jumps and calls can be done through function tags (not stackable)

		ncp_jump(int address, [int overlay])
		ncp_call(int address, [int overlay])
		ncp_hook(int address, [int overlay])

		Example:

			ncp_jump(0x02000000)
			void MyFunction1() {
				// A jump to this function will be placed at 0x02000000
			}

			ncp_call(0x02010000, 0)
			void MyFunction2() {
				// A call to this function will be placed at 0x02010000 in overlay 0
			}

	or through labels (stackable)

		ncp_set_jump(int address, [int overlay], void* function)
		ncp_set_call(int address, [int overlay], void* function)
		ncp_set_hook(int address, [int overlay], void* function)

		Example:

			void MyFunction() {}

			ncp_set_jump(0x02000000, MyFunction)    // A jump to MyFunction will be placed at 0x02000000
			ncp_set_jump(0x02000004, MyFunction)    // A jump to MyFunction will be placed at 0x02000004
			ncp_set_call(0x02010000, 0, MyFunction) // A call to MyFunction will be placed at 0x02010000 in overlay 0
			ncp_set_call(0x02010004, 0, MyFunction) // A call to MyFunction will be placed at 0x02010004 in overlay 0

	Patching chunks of data can be done using

		ncp_over(int address, [int overlay])
		ncp_repl(int address, [int overlay], char assembly[])

		Example:

			ncp_over(0x02000000)
			void MyFunction() {} // This function will be placed at 0x02000000

			ncp_over(0x02010000, 4)
			int MyArray[] = {}; // This array will be placed at 0x02010000 in overlay 0

			ncp_repl(0x02000000, "MOV R0, R0") // This instruction will be placed at 0x02000000

			ncp_repl(0x02010000, 0, R"(
				MOV     R0, R0
				BX      LR
				.int    0
				.int    0
			)") // This assembly code will be placed at 0x02010000 in overlay 0

Assembly:
	Patching in assembly is done with labels

		ncp_jump_address[_ovXX]
		ncp_call_address[_ovXX]
		ncp_hook_address[_ovXX]
		ncp_over_address[_ovXX]
		ncp_over_address[_ovXX]_end

		Example:

			ncp_jump_0x02000000:     // A jump to MyFunction will be placed at 0x02000000
			ncp_jump_0x02000004:     // A jump to MyFunction will be placed at 0x02000004
			ncp_jump_0x02010000_ov0: // A call to MyFunction will be placed at 0x02010000 in overlay 0
			MyFunction:
				BX      LR

			ncp_over_0x02000000:     // Places the following code at 0x02000000
				MOV     R0, #1
				MOV     R1, R0
				BX      LR
			ncp_over_0x02000000_end:

================================ Real Time Patching ================================

C/C++:

	void ncprt_set(int address, int value);
	void ncprt_set_jump(int address, void* function);
	void ncprt_set_call(int address, void* function);
	void ncprt_repl(int address, char name[]);

	ncprt_repl_type(name)

	Example:

		class MyClass
		{
		public:
			static void MyFunction(); // Function must be static, otherwise it can't be used as pointer
		}

		void MyFunction() {}
		void MyClass::MyFunction() {}

		ncprt_repl_type(patch0) // Must be a unique name for each patch
		void MyPatch()
		{
		asm(R"(
			MOV     R0, #0
			BX      LR
		)");
		}

		void MyPatcher()
		{
			ncprt_set(0x02000000, 0);                        // Sets the value at 0x02000000 to 0
			ncprt_set_jump(0x02000004, MyFunction);          // Sets the value at 0x02000004 to a jump to MyFunction
			ncprt_set_call(0x02000008, MyClass::MyFunction); // Sets the value at 0x02000008 to a jump to MyClass::MyFunction
			ncprt_repl(0x0200000C, patch0);                  // Writes the contents of patch0 (MyPatch) to 0x0200000C
		}

Assembly:
	Not supported.