From 7951abde0054f0ce43c7d53e94da2b009f2786f6 Mon Sep 17 00:00:00 2001
From: Adrian Conlon <adrian.conlon@gmail.com>
Date: Wed, 13 Aug 2025 14:01:14 +0100
Subject: [PATCH] Add support for "Gameboy Doctor" log checker.

---
 LR35902/IoRegisters.cs              |  7 ++++-
 LR35902/LR35902.BlarggTest/Board.cs | 42 ++++++++++++++++++++++++++++-
 2 files changed, 47 insertions(+), 2 deletions(-)

diff --git a/LR35902/IoRegisters.cs b/LR35902/IoRegisters.cs
index e3b37ae..9a32215 100644
--- a/LR35902/IoRegisters.cs
+++ b/LR35902/IoRegisters.cs
@@ -404,7 +404,6 @@ namespace LR35902
                         break;
                     case SCY:
                     case SCX:
-                    case LY:
                     case LYC:
                     case DMA:
                     case BGP:
@@ -414,6 +413,12 @@ namespace LR35902
                     case WX:
                         break;
 
+                    case LY:
+#if GAMEBOY_DOCTOR
+                        this.Poke(port, 0x90);
+#endif
+                        break;
+
                     default:
                         this.ApplyMask(port, 0);
                         break;
diff --git a/LR35902/LR35902.BlarggTest/Board.cs b/LR35902/LR35902.BlarggTest/Board.cs
index d99c375..8cef5b8 100644
--- a/LR35902/LR35902.BlarggTest/Board.cs
+++ b/LR35902/LR35902.BlarggTest/Board.cs
@@ -19,6 +19,9 @@ namespace LR35902.BlarggTest
 
         public override void Initialize()
         {
+#if GAMEBOY_DOCTOR
+            this.CPU.ExecutingInstruction += this.CPU_ExecutingInstruction_Debug;
+#else
             this.WrittenByte += this.Board_WrittenByte;
             if (this.configuration.DebugMode)
             {
@@ -26,8 +29,27 @@ namespace LR35902.BlarggTest
             }
 
             this.LoadBootRom(this.configuration.RomDirectory + "/DMG_ROM.bin");
+#endif
         }
 
+#if GAMEBOY_DOCTOR
+        public override void RaisePOWER()
+        {
+            base.RaisePOWER();
+            this.CPU.A = 0x01;
+            this.CPU.F = 0xB0;
+            this.CPU.B = 0x00;
+            this.CPU.C = 0x13;
+            this.CPU.D = 0x00;
+            this.CPU.E = 0xD8;
+            this.CPU.H = 0x01;
+            this.CPU.L = 0x4D;
+            this.CPU.SP.Assign(0xfe, 0xff);
+            this.CPU.PC.Assign(0x00, 0x01);
+            this.CPU.RaiseRESET();
+        }
+#endif
+
         public void Plug(string path) => this.LoadGameRom(this.configuration.RomDirectory + "/" + path);
 
         private void Board_WrittenByte(object? sender, System.EventArgs e)
@@ -39,12 +61,30 @@ namespace LR35902.BlarggTest
             }
         }
 
-        private void CPU_ExecutingInstruction_Debug(object? sender, System.EventArgs e)
+        private void CPU_ExecutingInstruction_Debug(object? sender, System.EventArgs _)
         {
+#if GAMEBOY_DOCTOR
+            var a = this.CPU.A;
+            var f = this.CPU.F;
+            var b = this.CPU.B;
+            var c = this.CPU.C;
+            var d = this.CPU.D;
+            var e = this.CPU.E;
+            var h = this.CPU.H;
+            var l = this.CPU.L;
+            var sp = this.CPU.SP.Word;
+            var pc = this.CPU.PC.Word;
+            var aa = this.Peek(pc);
+            var bb = this.Peek((ushort)(pc + 1));
+            var cc = this.Peek((ushort)(pc + 2));
+            var dd = this.Peek((ushort)(pc + 3));
+            System.Console.WriteLine($"A:{a:X2} F:{f:X2} B:{b:X2} C:{c:X2} D:{d:X2} E:{e:X2} H:{h:X2} L:{l:X2} SP:{sp:X4} PC:{pc:X4} PCMEM:{aa:X2},{bb:X2},{cc:X2},{dd:X2}");
+#else
             if (this.IO.BootRomDisabled)
             {
                 System.Console.Error.WriteLine($"{Disassembler.State(this.CPU)} {this.disassembler.Disassemble(this.CPU)}");
             }
+#endif
         }
     }
 }