From edaa27796bbd2c991b5c9ccd2af6f43c361715a4 Mon Sep 17 00:00:00 2001
From: Vicki Pfau <vi@endrift.com>
Date: Wed, 11 Dec 2024 17:24:22 -0800
Subject: [PATCH] GBA: Improve reset behavior of various hardware components

---
 include/mgba/internal/gba/cart/gpio.h |  1 +
 include/mgba/internal/gba/savedata.h  |  1 +
 src/gba/cart/gpio.c                   | 15 +++++++++++++++
 src/gba/memory.c                      | 10 ++++++++++
 src/gba/savedata.c                    |  7 ++++++-
 5 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/include/mgba/internal/gba/cart/gpio.h b/include/mgba/internal/gba/cart/gpio.h
index 77785e612..be3cd9173 100644
--- a/include/mgba/internal/gba/cart/gpio.h
+++ b/include/mgba/internal/gba/cart/gpio.h
@@ -86,6 +86,7 @@ struct GBACartridgeHardware {
 };
 
 void GBAHardwareInit(struct GBACartridgeHardware* gpio, uint16_t* gpioBase);
+void GBAHardwareReset(struct GBACartridgeHardware* gpio);
 void GBAHardwareClear(struct GBACartridgeHardware* gpio);
 
 void GBAHardwareInitRTC(struct GBACartridgeHardware* gpio);
diff --git a/include/mgba/internal/gba/savedata.h b/include/mgba/internal/gba/savedata.h
index 274241a76..e69d07834 100644
--- a/include/mgba/internal/gba/savedata.h
+++ b/include/mgba/internal/gba/savedata.h
@@ -91,6 +91,7 @@ struct GBASavedataRTCBuffer {
 };
 
 void GBASavedataInit(struct GBASavedata* savedata, struct VFile* vf);
+void GBASavedataReset(struct GBASavedata* savedata);
 void GBASavedataDeinit(struct GBASavedata* savedata);
 
 void GBASavedataMask(struct GBASavedata* savedata, struct VFile* vf, bool writeback);
diff --git a/src/gba/cart/gpio.c b/src/gba/cart/gpio.c
index 48cb8c340..a44bab294 100644
--- a/src/gba/cart/gpio.c
+++ b/src/gba/cart/gpio.c
@@ -47,6 +47,20 @@ void GBAHardwareInit(struct GBACartridgeHardware* hw, uint16_t* base) {
 	GBAHardwareClear(hw);
 }
 
+void GBAHardwareReset(struct GBACartridgeHardware* hw) {
+	hw->readWrite = GPIO_WRITE_ONLY;
+	hw->pinState = 0;
+	hw->direction = 0;
+	hw->lightCounter = 0;
+	hw->lightEdge = false;
+	hw->lightSample = 0xFF;
+	hw->gyroSample = 0;
+	hw->gyroEdge = 0;
+	hw->tiltX = 0xFFF;
+	hw->tiltY = 0xFFF;
+	hw->tiltState = 0;
+}
+
 void GBAHardwareClear(struct GBACartridgeHardware* hw) {
 	hw->devices = HW_NONE | (hw->devices & HW_GB_PLAYER_DETECTION);
 	hw->readWrite = GPIO_WRITE_ONLY;
@@ -503,6 +517,7 @@ void GBAHardwareDeserialize(struct GBACartridgeHardware* hw, const struct GBASer
 	hw->devices = state->hw.devices;
 
 	if ((hw->devices & HW_GPIO) && hw->gpioBase) {
+		// TODO: This needs to update the pristine state somehow
 		if (hw->readWrite) {
 			STORE_16(hw->pinState, 0, hw->gpioBase);
 			STORE_16(hw->direction, 2, hw->gpioBase);
diff --git a/src/gba/memory.c b/src/gba/memory.c
index bdaf22c36..4f074657a 100644
--- a/src/gba/memory.c
+++ b/src/gba/memory.c
@@ -138,6 +138,16 @@ void GBAMemoryReset(struct GBA* gba) {
 		mLOG(GBA_MEM, FATAL, "Could not map memory");
 	}
 
+	if (!gba->memory.rom) {
+		gba->isPristine = false;
+	}
+
+	if (gba->memory.hw.devices & HW_GPIO) {
+		_pristineCow(gba);
+	}
+
+	GBASavedataReset(&gba->memory.savedata);
+	GBAHardwareReset(&gba->memory.hw);
 	GBADMAReset(gba);
 	GBAUnlCartReset(gba);
 	memset(&gba->memory.matrix, 0, sizeof(gba->memory.matrix));
diff --git a/src/gba/savedata.c b/src/gba/savedata.c
index a9cd682ca..c0d2c889a 100644
--- a/src/gba/savedata.c
+++ b/src/gba/savedata.c
@@ -45,7 +45,7 @@ static void _ashesToAshes(struct mTiming* timing, void* user, uint32_t cyclesLat
 
 void GBASavedataInit(struct GBASavedata* savedata, struct VFile* vf) {
 	savedata->type = GBA_SAVEDATA_AUTODETECT;
-	savedata->data = 0;
+	savedata->data = NULL;
 	savedata->command = EEPROM_COMMAND_NULL;
 	savedata->flashState = FLASH_STATE_RAW;
 	savedata->vf = vf;
@@ -63,6 +63,11 @@ void GBASavedataInit(struct GBASavedata* savedata, struct VFile* vf) {
 	savedata->dust.callback = _ashesToAshes;
 }
 
+void GBASavedataReset(struct GBASavedata* savedata) {
+	savedata->command = EEPROM_COMMAND_NULL;
+	savedata->flashState = FLASH_STATE_RAW;
+}
+
 void GBASavedataDeinit(struct GBASavedata* savedata) {
 	if (savedata->vf) {
 		size_t size = GBASavedataSize(savedata);