M src/gb/gb.c → src/gb/gb.c

@@ -425,6 +425,7 @@ cpu->sp = 0xFFFE;
 		cpu->pc = 0x100;
 	}
 
+	gb->cpuBlocked = false;
 	gb->eiPending = INT_MAX;
 	gb->doubleSpeed = 0;
 
@@ -546,7 +547,11 @@ nextEvent = gb->eiPending;
 			}
 		}
 
-		cpu->nextEvent = mTimingTick(&gb->timing, cycles);
+		nextEvent = cycles;
+		do {
+			nextEvent = mTimingTick(&gb->timing, nextEvent);
+		} while (gb->cpuBlocked);
+		cpu->nextEvent = nextEvent;
 
 		if (cpu->halted) {
 			cpu->cycles = cpu->nextEvent;

M src/gb/gb.h → src/gb/gb.h

@@ -78,6 +78,7 @@
 	struct mCoreCallbacks* coreCallbacks;
 	struct mAVStream* stream;
 
+	bool cpuBlocked;
 	int32_t eiPending;
 	unsigned doubleSpeed;
 };

M src/gb/memory.c → src/gb/memory.c

@@ -381,6 +381,7 @@ bool wasHdma = gb->memory.isHdma;
 	gb->memory.isHdma = value & 0x80;
 	if ((!wasHdma && !gb->memory.isHdma) || gb->video.mode == 0) {
 		gb->memory.hdmaRemaining = ((value & 0x7F) + 1) * 0x10;
+		gb->cpuBlocked = true;
 		mTimingSchedule(&gb->timing, &gb->memory.hdmaEvent, 0);
 		gb->cpu->nextEvent = gb->cpu->cycles;
 	}
@@ -404,14 +405,17 @@ }
 
 void _GBMemoryHDMAService(struct mTiming* timing, void* context, uint32_t cyclesLate) {
 	struct GB* gb = context;
+	gb->cpuBlocked = true;
 	uint8_t b = gb->cpu->memory.load8(gb->cpu, gb->memory.hdmaSource);
 	gb->cpu->memory.store8(gb->cpu, gb->memory.hdmaDest, b);
 	++gb->memory.hdmaSource;
 	++gb->memory.hdmaDest;
 	--gb->memory.hdmaRemaining;
 	if (gb->memory.hdmaRemaining) {
+		mTimingDeschedule(timing, &gb->memory.hdmaEvent);
 		mTimingSchedule(timing, &gb->memory.hdmaEvent, 2 - cyclesLate);
 	} else {
+		gb->cpuBlocked = false;
 		gb->memory.io[REG_HDMA1] = gb->memory.hdmaSource >> 8;
 		gb->memory.io[REG_HDMA2] = gb->memory.hdmaSource;
 		gb->memory.io[REG_HDMA3] = gb->memory.hdmaDest >> 8;
@@ -425,7 +429,6 @@ } else {
 			gb->memory.io[REG_HDMA5] = 0xFF;
 		}
 	}
-	gb->cpu->cycles += 2;
 }
 
 struct OAMBlock {

M src/gb/video.c → src/gb/video.c

@@ -206,6 +206,7 @@ GBUpdateIRQs(video->p);
 	}
 	if (video->ly < GB_VIDEO_VERTICAL_PIXELS && video->p->memory.isHdma && video->p->memory.io[REG_HDMA5] != 0xFF) {
 		video->p->memory.hdmaRemaining = 0x10;
+		mTimingDeschedule(timing, &video->p->memory.hdmaEvent);
 		mTimingSchedule(timing, &video->p->memory.hdmaEvent, 0);
 	}
 	video->mode = 0;