1 files changed, 87 insertions, 0 deletions
diff --git a/src/Ryujinx.HLE/HOS/Tamper/CodeEmitters/DebugLog.cs b/src/Ryujinx.HLE/HOS/Tamper/CodeEmitters/DebugLog.cs
new file mode 100644
index 00000000..533b362a
--- /dev/null
+++ b/src/Ryujinx.HLE/HOS/Tamper/CodeEmitters/DebugLog.cs
@@ -0,0 +1,87 @@
+using Ryujinx.HLE.Exceptions;
+using Ryujinx.HLE.HOS.Tamper.Operations;
+
+namespace Ryujinx.HLE.HOS.Tamper.CodeEmitters
+{
+    /// <summary>
+    /// Code type 0xFFF writes a debug log.
+    /// </summary>
+    class DebugLog
+    {
+        private const int OperationWidthIndex = 3;
+        private const int LogIdIndex = 4;
+        private const int OperandTypeIndex = 5;
+        private const int RegisterOrMemoryRegionIndex = 6;
+        private const int OffsetRegisterOrImmediateIndex = 7;
+
+        private const int MemoryRegionWithOffsetImmediate = 0;
+        private const int MemoryRegionWithOffsetRegister = 1;
+        private const int AddressRegisterWithOffsetImmediate = 2;
+        private const int AddressRegisterWithOffsetRegister = 3;
+        private const int ValueRegister = 4;
+
+        private const int OffsetImmediateSize = 9;
+
+        public static void Emit(byte[] instruction, CompilationContext context)
+        {
+            // FFFTIX##
+            // FFFTI0Ma aaaaaaaa
+            // FFFTI1Mr
+            // FFFTI2Ra aaaaaaaa
+            // FFFTI3Rr
+            // FFFTI4V0
+            // T: Width of memory write (1, 2, 4, or 8 bytes).
+            // I: Log id.
+            // X: Operand Type, see below.
+            // M: Memory Type (operand types 0 and 1).
+            // R: Address Register (operand types 2 and 3).
+            // a: Relative Address (operand types 0 and 2).
+            // r: Offset Register (operand types 1 and 3).
+            // V: Value Register (operand type 4).
+
+            byte operationWidth = instruction[OperationWidthIndex];
+            byte logId = instruction[LogIdIndex];
+            byte operandType = instruction[OperandTypeIndex];
+            byte registerOrMemoryRegion = instruction[RegisterOrMemoryRegionIndex];
+            byte offsetRegisterIndex = instruction[OffsetRegisterOrImmediateIndex];
+            ulong immediate;
+            Register addressRegister;
+            Register offsetRegister;
+            IOperand sourceOperand;
+
+            switch (operandType)
+            {
+                case MemoryRegionWithOffsetImmediate:
+                    // *(?x + #a)
+                    immediate = InstructionHelper.GetImmediate(instruction, OffsetRegisterOrImmediateIndex, OffsetImmediateSize);
+                    sourceOperand = MemoryHelper.EmitPointer((MemoryRegion)registerOrMemoryRegion, immediate, context);
+                    break;
+                case MemoryRegionWithOffsetRegister:
+                    // *(?x + $r)
+                    offsetRegister = context.GetRegister(offsetRegisterIndex);
+                    sourceOperand = MemoryHelper.EmitPointer((MemoryRegion)registerOrMemoryRegion, offsetRegister, context);
+                    break;
+                case AddressRegisterWithOffsetImmediate:
+                    // *($R + #a)
+                    addressRegister = context.GetRegister(registerOrMemoryRegion);
+                    immediate = InstructionHelper.GetImmediate(instruction, OffsetRegisterOrImmediateIndex, OffsetImmediateSize);
+                    sourceOperand = MemoryHelper.EmitPointer(addressRegister, immediate, context);
+                    break;
+                case AddressRegisterWithOffsetRegister:
+                    // *($R + $r)
+                    addressRegister = context.GetRegister(registerOrMemoryRegion);
+                    offsetRegister = context.GetRegister(offsetRegisterIndex);
+                    sourceOperand = MemoryHelper.EmitPointer(addressRegister, offsetRegister, context);
+                    break;
+                case ValueRegister:
+                    // $V
+                    sourceOperand = context.GetRegister(registerOrMemoryRegion);
+                    break;
+                default:
+                    throw new TamperCompilationException($"Invalid operand type {operandType} in Atmosphere cheat");
+            }
+
+            InstructionHelper.Emit(typeof(OpLog<>), operationWidth, context, logId, sourceOperand);
+        }
+    }
+}