M include/mgba/internal/ds/ds.h → include/mgba/internal/ds/ds.h

@@ -69,6 +69,10 @@
 	struct mCoreSync* sync;
 	struct mTiming timing7;
 	struct mTiming timing9;
+	struct mTimingEvent slice;
+	struct ARMCore* activeCpu;
+	uint32_t sliceStart;
+	int32_t cycleDrift;
 
 	struct ARMDebugger* debugger;
 
@@ -129,6 +133,10 @@ };
 
 void DSCreate(struct DS* ds);
 void DSDestroy(struct DS* ds);
+
+void DSRunLoop(struct DS* ds);
+void DS7Step(struct DS* ds);
+void DS9Step(struct DS* ds);
 
 void DSAttachDebugger(struct DS* ds, struct mDebugger* debugger);
 void DSDetachDebugger(struct DS* ds);

M src/ds/core.c → src/ds/core.c

@@ -15,8 +15,6 @@ #include <mgba-util/memory.h>
 #include <mgba-util/patch.h>
 #include <mgba-util/vfs.h>
 
-#define SLICE_CYCLES 2048
-
 struct DSCore {
 	struct mCore d;
 	struct ARMCore* arm7;
@@ -25,7 +23,6 @@ int keys;
 	struct mCPUComponent* components[CPU_COMPONENT_MAX];
 	struct mDebuggerPlatform* debuggerPlatform;
 	struct mCheatDevice* cheatDevice;
-	int32_t cycleDrift;
 };
 
 static bool _DSCoreInit(struct mCore* core) {
@@ -47,7 +44,6 @@ dscore->arm7 = arm7;
 	dscore->arm9 = arm9;
 	dscore->debuggerPlatform = NULL;
 	dscore->cheatDevice = NULL;
-	dscore->cycleDrift = 0;
 
 	DSCreate(ds);
 	memset(dscore->components, 0, sizeof(dscore->components));
@@ -165,7 +161,6 @@ struct DSCore* dscore = (struct DSCore*) core;
 	struct DS* ds = (struct DS*) core->board;
 	ARMReset(ds->arm7);
 	ARMReset(ds->arm9);
-	dscore->cycleDrift = 0;
 }
 
 static void _DSCoreRunFrame(struct mCore* core) {
@@ -173,47 +168,20 @@ struct DSCore* dscore = (struct DSCore*) core;
 	struct DS* ds = core->board;
 	int32_t frameCounter = ds->video.frameCounter;
 	while (ds->video.frameCounter == frameCounter) {
-		if (dscore->cycleDrift < SLICE_CYCLES) {
-			dscore->cycleDrift += ARMv5RunCycles(dscore->arm9, SLICE_CYCLES);
-		}
-		if (dscore->cycleDrift >= SLICE_CYCLES) {
-			dscore->cycleDrift -= ARMv4RunCycles(dscore->arm7, dscore->cycleDrift >> 1) << 1;
-		}
+		DSRunLoop(core->board);
 	}
 }
 
 static void _DSCoreRunLoop(struct mCore* core) {
-	struct DSCore* dscore = (struct DSCore*) core;
-	if (dscore->cycleDrift < SLICE_CYCLES) {
-		dscore->cycleDrift += ARMv5RunCycles(dscore->arm9, SLICE_CYCLES);
-	}
-	if (dscore->cycleDrift >= SLICE_CYCLES) {
-		dscore->cycleDrift -= ARMv4RunCycles(dscore->arm7, dscore->cycleDrift >> 1) << 1;
-	}
+	DSRunLoop(core->board);
 }
 
 static void _DSCoreStep(struct mCore* core) {
 	struct DSCore* dscore = (struct DSCore*) core;
 	if (core->cpu == dscore->arm9) {
-		do {
-			if (dscore->cycleDrift >= SLICE_CYCLES) {
-				dscore->cycleDrift -= ARMv4RunCycles(dscore->arm7, dscore->cycleDrift >> 1) << 1;
-			}
-			if (dscore->cycleDrift < SLICE_CYCLES) {
-				dscore->cycleDrift += ARMv5RunCycles(dscore->arm9, 1);
-				break;
-			}
-		} while (dscore->cycleDrift >= SLICE_CYCLES);
+		DS9Step(core->board);
 	} else {
-		do {
-			if (dscore->cycleDrift < SLICE_CYCLES) {
-				dscore->cycleDrift += ARMv5RunCycles(dscore->arm9, SLICE_CYCLES - dscore->cycleDrift);
-			}
-			if (dscore->cycleDrift >= SLICE_CYCLES) {
-				dscore->cycleDrift -= ARMv4RunCycles(dscore->arm7, 1) << 1;
-				break;
-			}
-		} while (dscore->cycleDrift < SLICE_CYCLES);
+		DS7Step(core->board);
 	}
 }
 

M src/ds/ds.c → src/ds/ds.c

@@ -15,6 +15,8 @@ #include <mgba-util/memory.h>
 #include <mgba-util/math.h>
 #include <mgba-util/vfs.h>
 
+#define SLICE_CYCLES 2048
+
 mLOG_DEFINE_CATEGORY(DS, "DS");
 
 const uint32_t DS_ARM946ES_FREQUENCY = 0x1FF61FE;
@@ -39,17 +41,38 @@
 static void DS7Reset(struct ARMCore* cpu);
 static void DS7TestIRQ(struct ARMCore* cpu);
 static void DS7InterruptHandlerInit(struct ARMInterruptHandler* irqh);
+static void DS7ProcessEvents(struct ARMCore* cpu);
 
 static void DS9Reset(struct ARMCore* cpu);
 static void DS9TestIRQ(struct ARMCore* cpu);
 static void DS9WriteCP15(struct ARMCore* cpu, int crn, int crm, int opcode1, int opcode2, uint32_t value);
 static void DS9InterruptHandlerInit(struct ARMInterruptHandler* irqh);
+static void DS9ProcessEvents(struct ARMCore* cpu);
 
-static void DSProcessEvents(struct ARMCore* cpu);
+static void DSProcessEvents(struct DS* ds, struct mTiming* timing);
 static void DSHitStub(struct ARMCore* cpu, uint32_t opcode);
 static void DSIllegal(struct ARMCore* cpu, uint32_t opcode);
 static void DSBreakpoint(struct ARMCore* cpu, int immediate);
 
+static void _slice(struct mTiming* timing, void* context, uint32_t cyclesLate) {
+	UNUSED(cyclesLate);
+	struct DS* ds = context;
+	uint32_t cycles = mTimingCurrentTime(timing) - ds->sliceStart;
+	if (ds->activeCpu == ds->arm9) {
+		ds->activeCpu = ds->arm7;
+		ds->cycleDrift += cycles;
+		cycles = ds->cycleDrift >> 1;
+		timing = &ds->timing7;
+	} else {
+		ds->activeCpu = ds->arm9;
+		ds->cycleDrift -= cycles << 1;
+		cycles = ds->cycleDrift + SLICE_CYCLES;
+		timing = &ds->timing9;
+	}
+	mTimingSchedule(timing, &ds->slice, cycles);
+	ds->sliceStart = mTimingCurrentTime(timing);
+}
+
 void DSCreate(struct DS* ds) {
 	ds->d.id = DS_COMPONENT_MAGIC;
 	ds->d.init = DSInit;
@@ -69,9 +92,15 @@ ds->sync = 0;
 		return;
 	}
 	ds->arm9 = cpu;
+	ds->activeCpu = NULL;
 
 	ds->arm9->cp15.r1.c0 = ARMControlRegFillVE(0);
 
+	ds->slice.name = "DS CPU Time Slicing";
+	ds->slice.callback = _slice;
+	ds->slice.context = ds;
+	ds->slice.priority = UINT_MAX;
+
 	DS7InterruptHandlerInit(&ds->arm7->irqh);
 	DS9InterruptHandlerInit(&ds->arm9->irqh);
 	DSMemoryInit(ds);
@@ -109,7 +138,7 @@ }
 
 void DS7InterruptHandlerInit(struct ARMInterruptHandler* irqh) {
 	irqh->reset = DS7Reset;
-	irqh->processEvents = DSProcessEvents;
+	irqh->processEvents = DS7ProcessEvents;
 	irqh->swi16 = DS7Swi16;
 	irqh->swi32 = DS7Swi32;
 	irqh->hitIllegal = DSIllegal;
@@ -122,7 +151,7 @@ }
 
 void DS9InterruptHandlerInit(struct ARMInterruptHandler* irqh) {
 	irqh->reset = DS9Reset;
-	irqh->processEvents = DSProcessEvents;
+	irqh->processEvents = DS9ProcessEvents;
 	irqh->swi16 = NULL;
 	irqh->swi32 = NULL;
 	irqh->hitIllegal = DSIllegal;
@@ -176,6 +205,11 @@
 	struct DS* ds = (struct DS*) cpu->master;
 	mTimingClear(&ds->timing9);
 	DS9IOInit(ds);
+
+	ds->activeCpu = cpu;
+	mTimingSchedule(&ds->timing9, &ds->slice, SLICE_CYCLES);
+	ds->cycleDrift = 0;
+	ds->sliceStart = mTimingCurrentTime(&ds->timing9);
 
 	struct DSCartridge* header = ds->romVf->map(ds->romVf, sizeof(*header), MAP_READ);
 	if (header) {
@@ -196,14 +230,28 @@ ds->romVf->unmap(ds->romVf, header, sizeof(*header));
 	}
 }
 
-static void DSProcessEvents(struct ARMCore* cpu) {
+static void DS7ProcessEvents(struct ARMCore* cpu) {
 	struct DS* ds = (struct DS*) cpu->master;
 
 	if (ds->springIRQ7 && !cpu->cpsr.i) {
 		ARMRaiseIRQ(cpu);
 		ds->springIRQ7 = 0;
 	}
+	DSProcessEvents(ds, &ds->timing7);
+}
 
+static void DS9ProcessEvents(struct ARMCore* cpu) {
+	struct DS* ds = (struct DS*) cpu->master;
+
+	if (ds->springIRQ9 && !cpu->cpsr.i) {
+		ARMRaiseIRQ(cpu);
+		ds->springIRQ9 = 0;
+	}
+	DSProcessEvents(ds, &ds->timing9);
+}
+
+static void DSProcessEvents(struct DS* ds, struct mTiming* timing) {
+	struct ARMCore* cpu = ds->activeCpu;
 	int32_t nextEvent = cpu->nextEvent;
 	while (cpu->cycles >= nextEvent) {
 		int32_t cycles = cpu->cycles;
@@ -218,7 +266,7 @@ }
 #endif
 		nextEvent = cycles;
 		do {
-			nextEvent = mTimingTick(&ds->timing7, nextEvent);
+			nextEvent = mTimingTick(timing, nextEvent);
 		} while (ds->cpuBlocked);
 
 		cpu->nextEvent = nextEvent;
@@ -236,6 +284,28 @@ mLOG(DS, FATAL, "Negative cycles will pass: %i", nextEvent);
 		}
 #endif
 	}
+}
+
+void DSRunLoop(struct DS* ds) {
+	if (ds->activeCpu == ds->arm9) {
+		ARMv5RunLoop(ds->arm9);
+	} else {
+		ARMv4RunLoop(ds->arm7);
+	}
+}
+
+void DS7Step(struct DS* ds) {
+	while (ds->activeCpu == ds->arm9) {
+		ARMv5RunLoop(ds->arm9);
+	}
+	ARMv4Run(ds->arm7);
+}
+
+void DS9Step(struct DS* ds) {
+	while (ds->activeCpu == ds->arm7) {
+		ARMv4RunLoop(ds->arm7);
+	}
+	ARMv5Run(ds->arm9);
 }
 
 void DSAttachDebugger(struct DS* ds, struct mDebugger* debugger) {