GBCHawk: Halt test rom work, ppu still needs re-work

Dwedit · May 4, 2018 · e29b741 · e29b741
1 parent d4eb3da
commit e29b741
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Showing 3 changed files with 30 additions and 18 deletions.
diff --git a/BizHawk.Emulation.Cores/CPUs/LR35902/LR35902.cs b/BizHawk.Emulation.Cores/CPUs/LR35902/LR35902.cs
@@ -301,7 +301,15 @@ public void ExecuteOne(ref byte interrupt_src, byte interrupt_enable)
 										IDLE,
 										GBC_INTERRUPT };
 										*/
-							INTERRUPT_GBC_NOP();
+							if (!Halt_bug_3)
+							{
+								INTERRUPT_GBC_NOP();							
+							}
+							else
+							{
+								INTERRUPT_();
+								Halt_bug_3 = false;
+							}
 						}
 						else
 						{					
@@ -324,16 +332,26 @@ public void ExecuteOne(ref byte interrupt_src, byte interrupt_enable)
 						if (OnExecFetch != null) OnExecFetch(RegPC);
 						if (TraceCallback != null && !CB_prefix) TraceCallback(State());
 
+
 						if (is_GBC)
 						{
 							// extra 4 cycles for GBC
-							cur_instr = new ushort[]
+							if (Halt_bug_3)
+							{
+								RegPC++;
+								FetchInstruction(ReadMemory(RegPC));
+								Halt_bug_3 = false;
+							}
+							else
+							{
+								cur_instr = new ushort[]
 										{IDLE,
 										IDLE,
 										IDLE,
 										OP };
+							}
 						}
-						else
+						else			
 						{					
 							if (Halt_bug_3)
 							{
@@ -363,11 +381,9 @@ public void ExecuteOne(ref byte interrupt_src, byte interrupt_enable)
 						else
 						{
 							cur_instr = new ushort[]
-										{
-											IDLE,
+										{IDLE,
 										HALT_CHK,
-										IDLE,
-
+										IDLE,										
 										HALT, 0 };
 						}
 
@@ -492,12 +508,11 @@ public void ExecuteOne(ref byte interrupt_src, byte interrupt_enable)
 					instr_pntr = 0;
 					break;
 				case HALT_CHK:
-					// only used when exiting HALT from GBC, an extra NOP is added to avoid HALT bug
 					I_use = FlagI;
 					if (Halt_bug_2 && I_use)
 					{
 						RegPC--;
-						if (!interrupts_enabled) { Halt_bug_3 = true; }					
+						Halt_bug_3 = true;
 					}
 
 					Halt_bug_2 = false;

diff --git a/BizHawk.Emulation.Cores/CPUs/LR35902/Tables_Direct.cs b/BizHawk.Emulation.Cores/CPUs/LR35902/Tables_Direct.cs
@@ -86,11 +86,7 @@ private void HALT_()
 							{IDLE,
 							IDLE,
 							IDLE,
-							IDLE,
-							IDLE,
-							IDLE,
-							IDLE,
-							OP};
+							OP_G};
 				}
 				else
 				{	// if interrupts are disabled,
@@ -112,7 +108,8 @@ private void HALT_()
 						HALT_CHK,
 						IDLE,
 						HALT, 0 };
-				skip_once = true;
+
+				if (!is_GBC) { skip_once = true; }
 				// If the interrupt flag is not currently set, but it does get set in the first check
 				// then a bug is triggered 
 				// With interrupts enabled, this runs the halt command twice 

diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/GBC_PPU.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/GBC_PPU.cs
@@ -402,7 +402,7 @@ public override void tick()
 
 					// also, the LCD does not enter mode 2 on scanline 0 when first turned on
 					no_scan = true;
-					cycle = 8;
+					cycle = 4;
 				}
 
 				// the VBL stat is continuously asserted
@@ -420,7 +420,7 @@ public override void tick()
 						}
 					}
 
-					if ((cycle == 4) && (LY == 144)) {
+					if ((cycle == 0) && (LY == 144)) {
 
 						HBL_INT = false;
 
@@ -454,7 +454,7 @@ public override void tick()
 						// there is no mode 2  (presumably it missed the trigger)
 						// mode 3 is very short, probably in some self test mode before turning on?
 
-						if (cycle == 12)
+						if (cycle == 8)
 						{
 							LYC_INT = false;
 							STAT &= 0xFB;