Add GDB Stub (ryubing/ryujinx!71)

See merge request ryubing/ryujinx!71

src/Ryujinx.Cpu/LightningJit/State/ExecutionContext.cs

@@ -1,6 +1,8 @@
+using ARMeilleure;
 using ARMeilleure.Memory;
 using ARMeilleure.State;
 using System;
+using System.Threading;
 
 namespace Ryujinx.Cpu.LightningJit.State
 {
@@ -51,6 +53,8 @@ namespace Ryujinx.Cpu.LightningJit.State
         }
 
         public bool IsAarch32 { get; set; }
+        
+        public ulong ThreadUid { get; set; }
 
         internal ExecutionMode ExecutionMode
         {
@@ -77,15 +81,20 @@ namespace Ryujinx.Cpu.LightningJit.State
 
         private readonly ExceptionCallbackNoArgs _interruptCallback;
         private readonly ExceptionCallback _breakCallback;
+        private readonly ExceptionCallbackNoArgs _stepCallback;
         private readonly ExceptionCallback _supervisorCallback;
         private readonly ExceptionCallback _undefinedCallback;
 
+        internal int ShouldStep;
+        public ulong DebugPc { get; set; }
+
         public ExecutionContext(IJitMemoryAllocator allocator, ICounter counter, ExceptionCallbacks exceptionCallbacks)
         {
             _nativeContext = new NativeContext(allocator);
             _counter = counter;
             _interruptCallback = exceptionCallbacks.InterruptCallback;
             _breakCallback = exceptionCallbacks.BreakCallback;
+            _stepCallback = exceptionCallbacks.StepCallback;
             _supervisorCallback = exceptionCallbacks.SupervisorCallback;
             _undefinedCallback = exceptionCallbacks.UndefinedCallback;
 
@@ -117,6 +126,17 @@ namespace Ryujinx.Cpu.LightningJit.State
             _interrupted = true;
         }
 
+        public void StepHandler()
+        {
+            _stepCallback?.Invoke(this);
+        }
+
+        public void RequestDebugStep()
+        {
+            Interlocked.Exchange(ref ShouldStep, 1);
+            RequestInterrupt();
+        }
+
         internal void OnBreak(ulong address, int imm)
         {
             _breakCallback?.Invoke(this, address, imm);