using Ryujinx.HLE.Exceptions; using Ryujinx.HLE.HOS.Tamper.Operations; namespace Ryujinx.HLE.HOS.Tamper.CodeEmitters { /// <summary> /// Code type 6 allows writing a fixed value to a memory address specified by a register. /// </summary> class StoreConstantToMemory { private const int OperationWidthIndex = 1; private const int AddressRegisterIndex = 3; private const int IncrementAddressRegisterIndex = 4; private const int UseOffsetRegisterIndex = 5; private const int OffsetRegisterIndex = 6; private const int ValueImmediateIndex = 8; private const int ValueImmediateSize = 16; public static void Emit(byte[] instruction, CompilationContext context) { // 6T0RIor0 VVVVVVVV VVVVVVVV // T: Width of memory write(1, 2, 4, or 8 bytes). // R: Register used as base memory address. // I: Increment register flag(0 = do not increment R, 1 = increment R by T). // o: Offset register enable flag(0 = do not add r to address, 1 = add r to address). // r: Register used as offset when o is 1. // V: Value to write to memory. byte operationWidth = instruction[OperationWidthIndex]; Register sourceRegister = context.GetRegister(instruction[AddressRegisterIndex]); byte incrementAddressRegister = instruction[IncrementAddressRegisterIndex]; byte useOffsetRegister = instruction[UseOffsetRegisterIndex]; ulong immediate = InstructionHelper.GetImmediate(instruction, ValueImmediateIndex, ValueImmediateSize); Value<ulong> storeValue = new Value<ulong>(immediate); Pointer destinationMemory; switch (useOffsetRegister) { case 0: // Don't offset the address register by another register. destinationMemory = MemoryHelper.EmitPointer(sourceRegister, context); break; case 1: // Replace the source address by the sum of the base and offset registers. Register offsetRegister = context.GetRegister(instruction[OffsetRegisterIndex]); destinationMemory = MemoryHelper.EmitPointer(sourceRegister, offsetRegister, context); break; default: throw new TamperCompilationException($"Invalid offset mode {useOffsetRegister} in Atmosphere cheat"); } InstructionHelper.EmitMov(operationWidth, context, destinationMemory, storeValue); switch (incrementAddressRegister) { case 0: // Don't increment the address register by operationWidth. break; case 1: // Increment the address register by operationWidth. IOperand increment = new Value<ulong>(operationWidth); context.CurrentOperations.Add(new OpAdd<ulong>(sourceRegister, sourceRegister, increment)); break; default: throw new TamperCompilationException($"Invalid increment mode {incrementAddressRegister} in Atmosphere cheat"); } } } }