1 files changed, 71 insertions, 0 deletions
diff --git a/src/Ryujinx.HLE/HOS/Tamper/CodeEmitters/StoreConstantToMemory.cs b/src/Ryujinx.HLE/HOS/Tamper/CodeEmitters/StoreConstantToMemory.cs
new file mode 100644
index 00000000..5f036969
--- /dev/null
+++ b/src/Ryujinx.HLE/HOS/Tamper/CodeEmitters/StoreConstantToMemory.cs
@@ -0,0 +1,71 @@
+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");
+            }
+        }
+    }
+}