GBA Hardware: I know this e-Reader code is wrong

include/mgba/gba/interface.h

@@ -88,6 +88,12 @@ struct GBASIOBattlechipGate {
 
 void GBASIOBattlechipGateCreate(struct GBASIOBattlechipGate*);
 
+#define EREADER_BLOCK_SIZE 40
+
+struct GBAEReaderDataSource {
+	bool (*readBlock)(struct GBAEReaderDataSource*, void*);
+};
+
 CXX_GUARD_END
 
 #endif

include/mgba/internal/gba/hardware.h

@@ -172,6 +172,7 @@ struct GBACartridgeHardware {
 	uint8_t eReaderActiveRegister;
 	uint8_t eReaderByte;
 	uint8_t eReaderDelay;
+	struct GBAEReaderDataSource* eReaderSource;
 };
 
 void GBAHardwareInit(struct GBACartridgeHardware* gpio, uint16_t* gpioBase);
@@ -196,6 +197,7 @@ void GBAHardwareEReaderWrite(struct GBACartridgeHardware* hw, uint32_t address,
 void GBAHardwareEReaderWriteFlash(struct GBACartridgeHardware* hw, uint32_t address, uint8_t value);
 uint16_t GBAHardwareEReaderRead(struct GBACartridgeHardware* hw, uint32_t address);
 uint8_t GBAHardwareEReaderReadFlash(struct GBACartridgeHardware* hw, uint32_t address);
+void GBAHardwareEReaderScan(struct GBACartridgeHardware* hw, struct GBAEReaderDataSource* source);
 
 void GBARTCGenericSourceInit(struct GBARTCGenericSource* rtc, struct GBA* gba);
 

src/gba/hardware.c

@@ -39,6 +39,7 @@ static void _gbpSioProcessEvents(struct mTiming* timing, void* user, uint32_t cy
 static void _eReaderReset(struct GBACartridgeHardware* hw);
 static void _eReaderWriteControl0(struct GBACartridgeHardware* hw, uint8_t value);
 static void _eReaderWriteControl1(struct GBACartridgeHardware* hw, uint8_t value);
+static void _eReaderReadData(struct GBACartridgeHardware* hw);
 
 static const int RTC_BYTES[8] = {
 	0, // Force reset
@@ -666,6 +667,14 @@ uint8_t GBAHardwareEReaderReadFlash(struct GBACartridgeHardware* hw, uint32_t ad
 	}
 }
 
+void GBAHardwareEReaderScan(struct GBACartridgeHardware* hw, struct GBAEReaderDataSource* source) {
+	if (!EReaderControl0IsScan(hw->eReaderRegisterControl0)) {
+		return;
+	}
+	hw->eReaderSource = source;
+	_eReaderReadData(hw);
+}
+
 void _eReaderReset(struct GBACartridgeHardware* hw) {
 	memset(hw->eReaderData, 0, sizeof(hw->eReaderData));
 	hw->eReaderRegisterUnk = 0;
@@ -738,7 +747,7 @@ void _eReaderWriteControl0(struct GBACartridgeHardware* hw, uint8_t value) {
 					++hw->eReaderActiveRegister;
 					break;
 				default:
-					mLOG(GBA_HW, ERROR, "???");
+					mLOG(GBA_HW, ERROR, "Hit undefined state in e-Reader state machine");
 					break;
 				}
 				hw->eReaderState = EREADER_SERIAL_BIT_0;
@@ -759,15 +768,33 @@ void _eReaderWriteControl0(struct GBACartridgeHardware* hw, uint8_t value) {
 		control = EReaderControl0ClearData(control);
 	}
 	hw->eReaderRegisterControl0 = control;
+	if (!EReaderControl0IsScan(oldControl) && EReaderControl0IsScan(control)) {
+		_eReaderReadData(hw);
+	}
 	mLOG(GBA_HW, STUB, "Unimplemented e-Reader Control0 write: %02X", value);
 }
 
 void _eReaderWriteControl1(struct GBACartridgeHardware* hw, uint8_t value) {
 	EReaderControl1 control = (value & 0x32) | 0x80;
 	hw->eReaderRegisterControl1 = control;
+	if (EReaderControl0IsScan(hw->eReaderRegisterControl0) && !EReaderControl1IsScanline(control)) {
+		_eReaderReadData(hw);
+	}
 	mLOG(GBA_HW, STUB, "Unimplemented e-Reader Control1 write: %02X", value);
 }
 
+void _eReaderReadData(struct GBACartridgeHardware* hw) {
+	if (!hw->eReaderSource) {
+		return;
+	}
+	memset(hw->eReaderData, 0, EREADER_BLOCK_SIZE);
+	hw->eReaderSource->readBlock(hw->eReaderSource, hw->eReaderData);
+	hw->eReaderRegisterControl1 = EReaderControl1FillScanline(hw->eReaderRegisterControl1);
+	if (EReaderControl0IsLedEnable(hw->eReaderRegisterControl0)) {
+		GBARaiseIRQ(hw->p, IRQ_GAMEPAK, 0);
+	}
+}
+
 // == Serialization
 
 void GBAHardwareSerialize(const struct GBACartridgeHardware* hw, struct GBASerializedState* state) {

src/platform/qt/CoreController.cpp

@@ -680,6 +680,24 @@ void CoreController::setFakeEpoch(const QDateTime& time) {
 	m_threadContext.core->rtc.value = time.toMSecsSinceEpoch();
 }
 
+void CoreController::scanCard(const QString& path) {
+#ifdef M_CORE_GBA
+	if (m_eReader.file.isOpen()) {
+		m_eReader.file.close();
+	}
+	m_eReader.file.setFileName(path);
+	if (!m_eReader.file.open(QIODevice::ReadOnly)) {
+		return;
+	}
+
+	mCoreThreadRunFunction(&m_threadContext, [](mCoreThread* thread) {
+		CoreController* controller = static_cast<CoreController*>(thread->userData);
+		GBAHardwareEReaderScan(&static_cast<GBA*>(thread->core->board)->memory.hw, &controller->m_eReader);
+	});
+#endif
+}
+
+
 void CoreController::importSharkport(const QString& path) {
 #ifdef M_CORE_GBA
 	if (platform() != PLATFORM_GBA) {

src/platform/qt/CoreController.h

@@ -6,6 +6,7 @@
 #pragma once
 
 #include <QByteArray>
+#include <QFile>
 #include <QList>
 #include <QMutex>
 #include <QObject>
@@ -127,6 +128,7 @@ public slots:
 
 	void loadSave(const QString&, bool temporary);
 	void loadPatch(const QString&);
+	void scanCard(const QString&);
 	void replaceGame(const QString&);
 	void yankPak();
 
@@ -256,6 +258,10 @@ private:
 
 #ifdef M_CORE_GBA
 	GBASIOBattlechipGate m_battlechip;
+	struct GameControllerEReader : GBAEReaderDataSource {
+		CoreController* p;
+		QFile file;
+	} m_eReader;
 #endif
 };
 

src/platform/qt/Window.cpp

@@ -423,6 +423,13 @@ void Window::selectPatch() {
 	}
 }
 
+void Window::scanCard() {
+	QString filename = GBAApp::app()->getOpenFileName(this, tr("Select e-Reader dotcode"));
+	if (!filename.isEmpty()) {
+		m_controller->scanCard(filename);
+	}
+}
+
 void Window::openView(QWidget* widget) {
 	connect(this, &Window::shutdown, widget, &QWidget::close);
 	widget->setAttribute(Qt::WA_DeleteOnClose);
@@ -1118,6 +1125,7 @@ void Window::setupMenu(QMenuBar* menubar) {
 #endif
 
 	m_actions.addAction(tr("Replace ROM..."), "replaceROM", this, &Window::replaceROM, "file");
+	m_actions.addAction(tr("Scan e-Reader dotcode..."), "scanCard", this, &Window::scanCard, "file");
 
 	Action* romInfo = addGameAction(tr("ROM &info..."), "romInfo", openControllerTView<ROMInfo>(), "file");
 

src/platform/qt/Window.h

@@ -75,6 +75,7 @@ public slots:
 	void selectSave(bool temporary);
 	void selectState(bool load);
 	void selectPatch();
+	void scanCard();
 	void enterFullScreen();
 	void exitFullScreen();
 	void toggleFullScreen();