make some things a bit more optimised for web usage

WindCore/arm710.cpp

@@ -664,15 +664,19 @@ uint32_t ARM710::execCP15RegisterTransfer(uint32_t CPOpc, bool L, uint32_t CRn,
 		case 5:
 			if (isTVersion)
 				cp15_faultStatus = what;
+#ifdef ARM710T_TLB
 			else
 				flushTlb();
+#endif
 			break;
 		case 6:
 			if (isTVersion)
 				cp15_faultAddress = what;
+#ifdef ARM710T_TLB
 			else
 				flushTlb(what);
 			break;
+#endif
 		case 7:
 #ifdef ARM710T_CACHE
 			clearCache();
@@ -680,12 +684,14 @@ uint32_t ARM710::execCP15RegisterTransfer(uint32_t CPOpc, bool L, uint32_t CRn,
 #endif
 			break;
 		case 8: {
+#ifdef ARM710T_TLB
 			if (isTVersion) {
 				if (CPOpc == 1)
 					flushTlb(what);
 				else
 					flushTlb();
 			}
+#endif
 			break;
 		}
 		}
@@ -900,6 +906,7 @@ ARM710::MMUFault ARM710::writeVirtual(uint32_t value, uint32_t virtAddr, ValueSi
 
 
 // TLB
+#ifdef ARM710T_TLB
 void ARM710::flushTlb() {
 	for (TlbEntry &e : tlb)
 		e = {0, 0, 0, 0};
@@ -912,21 +919,28 @@ void ARM710::flushTlb(uint32_t virtAddr) {
 		}
 	}
 }
+#endif
 
 ARM710::TlbEntry *ARM710::_allocateTlbEntry(uint32_t addrMask, uint32_t addr) {
+#ifdef ARM710T_TLB
 	TlbEntry *entry = &tlb[nextTlbIndex];
+	nextTlbIndex = (nextTlbIndex + 1) % TlbSize;
+#else
+	TlbEntry *entry = &singleTlbEntry;
+#endif
 	entry->addrMask = addrMask;
 	entry->addr = addr & addrMask;
-	nextTlbIndex = (nextTlbIndex + 1) % TlbSize;
 	return entry;
 }
 
 variant<ARM710::TlbEntry *, ARM710::MMUFault> ARM710::translateAddressUsingTlb(uint32_t virtAddr, TlbEntry *useMe) {
+#ifdef ARM710T_TLB
 	// first things first, do we have a matching entry in the TLB?
 	for (TlbEntry &e : tlb) {
 		if (e.addrMask && (virtAddr & e.addrMask) == e.addr)
 			return &e;
 	}
+#endif
 
 	// no, so do a page table walk
 	TlbEntry *entry;

WindCore/arm710.h

@@ -18,6 +18,7 @@ using namespace std;
 
 // Speedhacks:
 //#define ARM710T_CACHE
+//#define ARM710T_TLB
 
 typedef optional<uint32_t> MaybeU32;
 
@@ -87,7 +88,9 @@ public:
 #ifdef ARM710T_CACHE
 		clearCache();
 #endif
+#ifdef ARM710T_TLB
 		flushTlb();
+#endif
 	}
 
 	void setProcessorID(uint32_t v) { cp15_id = v; }
@@ -239,16 +242,20 @@ private:
 		return (MMUFault)(baseFault | (isPage ? 2 : 0) | (domain << 4) | ((uint64_t)virtAddr << 32));
 	}
 
-	enum { TlbSize = 64 };
 	struct TlbEntry { uint32_t addrMask, addr, lv1Entry, lv2Entry; };
+#ifdef ARM710T_TLB
+	enum { TlbSize = 64 };
 	TlbEntry tlb[TlbSize];
 	int nextTlbIndex = 0;
 
 	void flushTlb();
 	void flushTlb(uint32_t virtAddr);
-	variant<TlbEntry *, MMUFault> translateAddressUsingTlb(uint32_t virtAddr, TlbEntry *useMe=nullptr);
+#else
-	TlbEntry *_allocateTlbEntry(uint32_t addrMask, uint32_t addr);
+	TlbEntry singleTlbEntry;
+#endif	
 
+	TlbEntry *_allocateTlbEntry(uint32_t addrMask, uint32_t addr);
+	variant<TlbEntry *, MMUFault> translateAddressUsingTlb(uint32_t virtAddr, TlbEntry *useMe=nullptr);
 	static uint32_t physAddrFromTlbEntry(TlbEntry *tlbEntry, uint32_t virtAddr);
 	MMUFault checkAccessPermissions(TlbEntry *entry, uint32_t virtAddr, bool isWrite) const;
 

WindCore/clps7111.cpp

@@ -147,12 +147,14 @@ void Emulator::writeReg8(uint32_t reg, uint8_t value) {
 void Emulator::writeReg32(uint32_t reg, uint32_t value) {
 	if (reg == SYSCON1) {
 		kScan = value & 0xF;
-		tc1.config = Timer::ENABLED; // always on with PS-7111!
+		uint8_t tc1cfg = Timer::ENABLED; // always on with PS-7111!
-		if (value & 0x10) tc1.config |= Timer::PERIODIC;
+		if (value & 0x10) tc1cfg |= Timer::PERIODIC;
-		if (value & 0x20) tc1.config |= Timer::MODE_512KHZ;
+		if (value & 0x20) tc1cfg |= Timer::MODE_512KHZ;
-		tc2.config = Timer::ENABLED;
+		uint8_t tc2cfg = Timer::ENABLED;
-		if (value & 0x40) tc2.config |= Timer::PERIODIC;
+		if (value & 0x40) tc2cfg |= Timer::PERIODIC;
-		if (value & 0x80) tc2.config |= Timer::MODE_512KHZ;
+		if (value & 0x80) tc2cfg |= Timer::MODE_512KHZ;
+		tc1.setConfig(tc1cfg);
+		tc2.setConfig(tc2cfg);
 	} else if (reg == INTMR1) {
 		interruptMask &= 0xFFFF0000;;
 		interruptMask |= (value & 0xFFFF);
@@ -277,6 +279,8 @@ void Emulator::configure() {
 	tc2.clockSpeed = CLOCK_SPEED;
 
 	nextTickAt = TICK_INTERVAL;
+	tc1.nextTickAt = tc1.tickInterval();
+	tc2.nextTickAt = tc2.tickInterval();
 	rtc = getRTC();
 
 	reset();

WindCore/emubase.h

@@ -103,7 +103,9 @@ enum EpocKey {
 class EmuBase : public ARM710
 {
 protected:
+#ifndef __EMSCRIPTEN__
 	std::unordered_set<uint32_t> _breakpoints;
+#endif
 	int64_t passedCycles = 0;
 	int64_t nextTickAt = 0;
 	uint8_t readKeyboard(int kScan);
@@ -127,7 +129,9 @@ public:
 	virtual void setKeyboardKey(EpocKey key, bool value) = 0;
 	virtual void updateTouchInput(int32_t x, int32_t y, bool down) = 0;
 
+#ifndef __EMSCRIPTEN__
 	std::unordered_set<uint32_t> &breakpoints() { return _breakpoints; }
+#endif
 	uint64_t currentCycles() const { return passedCycles; }
 };
 

WindCore/hardware.h

@@ -10,7 +10,7 @@ struct Timer {
 		PERIODIC = 1<<6,
 		ENABLED = 1<<7
 	};
-    int64_t lastTicked;
+    int64_t nextTickAt;
 	uint8_t config;
 	uint32_t interval;
 	int32_t value;
@@ -23,9 +23,14 @@ struct Timer {
 		interval = lval;
 		value = lval;
 	}
+	void setConfig(uint8_t cval) {
+		nextTickAt -= tickInterval();
+		config = cval;
+		nextTickAt += tickInterval();
+	}
     bool tick(int64_t cycles) {
-		if (cycles >= (lastTicked + tickInterval())) {
+		if (cycles >= nextTickAt) {
-			lastTicked += tickInterval();
+			nextTickAt += tickInterval();
 
 			if (config & ENABLED) {
 				--value;

WindCore/windermere.cpp

@@ -115,9 +115,9 @@ void Emulator::writeReg8(uint32_t reg, uint8_t value) {
 	} else if ((reg & 0xF00) == 0x700) {
 		uart2.writeReg8(reg & 0xFF, value);
 	} else if (reg == TC1CTRL) {
-		tc1.config = value;
+		tc1.setConfig(value);
 	} else if (reg == TC2CTRL) {
-		tc2.config = value;
+		tc2.setConfig(value);
 	} else if (reg == PADR) {
 		uint32_t oldPorts = portValues;
 		portValues &= 0x00FFFFFF;
@@ -364,6 +364,8 @@ void Emulator::configure() {
 	tc2.clockSpeed = CLOCK_SPEED;
 
 	nextTickAt = TICK_INTERVAL;
+	tc1.nextTickAt = tc1.tickInterval();
+	tc2.nextTickAt = tc2.tickInterval();
 	rtc = getRTC();
 
 	reset();
@@ -413,22 +415,25 @@ void Emulator::executeUntil(int64_t cycles) {
 		// what's running?
 		if (halted) {
 			// keep the clock moving
-			passedCycles++;
+			// when does the next earliest thing happen?
+			// this stops us from spinning needlessly
+			int64_t nextEvent = nextTickAt;
+			if (tc1.nextTickAt < nextEvent) nextEvent = tc1.nextTickAt;
+			if (tc2.nextTickAt < nextEvent) nextEvent = tc2.nextTickAt;
+			if (cycles < nextEvent) nextEvent = cycles;
+			passedCycles = nextEvent;
 		} else {
 			if (auto v = virtToPhys(getGPR(15) - 0xC); v.has_value() && instructionReady())
 				debugPC(v.value());
 			passedCycles += tick();
 
+#ifndef __EMSCRIPTEN__
 			uint32_t new_pc = getGPR(15) - 0xC;
 			if (_breakpoints.find(new_pc) != _breakpoints.end()) {
 				log("⚠️ Breakpoint triggered at %08x!", new_pc);
 				return;
 			}
-			if (new_pc >= 0x80000000 && new_pc <= 0x90000000) {
+#endif
-				log("BAD PC %08x!!", new_pc);
-				logPcHistory();
-				return;
-			}
 		}
 	}
 }

WindWasm/build.sh

@@ -1,6 +1,6 @@
 #!/bin/sh
 
-FLAGS="-O3 --profiling -s WASM_OBJECT_FILES=0 -std=c++17"
+FLAGS="-O3 --profiling -g -s WASM_OBJECT_FILES=0 -std=c++17"
 
 mkdir -p obj
 for i in arm710 emubase etna windermere; do emcc -c $FLAGS -o obj/$i.o ../WindCore/$i.cpp; done

WindWasm/main.cpp

@@ -120,15 +120,8 @@ int main(int argc, char **argv) {
 		printf("SDL_SetVideoMode failed: %s\n", SDL_GetError());
 		return 1;
 	}
-	// window = SDL_CreateWindow(
+
-	// 	"WindEmu",
+	EM_ASM("SDL.defaults.copyOnLock = false; SDL.defaults.discardOnLock = true; SDL.defaults.opaqueFrontBuffer = false;");
-	// 	SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
-	// 	emu->getDigitiserWidth(), emu->getDigitiserHeight(),
-	// 	0);
-	// if (window == NULL) {
-	// 	printf("SDL_CreateWindow failed: %s\n", SDL_GetError());
-	// 	return 1;
-	// }
 
 	emscripten_set_main_loop(&emuEventLoop, 64, 1);