From b88f8b1d2c98edcbcb2b294c5c9d71957f156a43 Mon Sep 17 00:00:00 2001
From: RocketRobz <bobesh8@gmail.com>
Date: Wed, 1 Jan 2025 18:21:33 -0700
Subject: [PATCH] Fix *Luminous Arc 2* crashing on first boot after
 initializing save data

---
 retail/bootloader/source/arm7/hook_arm7.c     |  4 ++++
 retail/bootloaderi/source/arm7/hook_arm7.c    |  5 ++++-
 retail/cardengine/arm7/source/cardengine.c    | 19 +++++++++++++++++++
 retail/cardenginei/arm7/source/cardengine.c   |  9 ++++++++-
 .../common/include/cardengine_header_arm7.h   |  3 ++-
 5 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/retail/bootloader/source/arm7/hook_arm7.c b/retail/bootloader/source/arm7/hook_arm7.c
index d212f8e08..42303fb54 100644
--- a/retail/bootloader/source/arm7/hook_arm7.c
+++ b/retail/bootloader/source/arm7/hook_arm7.c
@@ -34,6 +34,7 @@
 #include "nocashMessage.h"
 
 #define b_a9IrqHooked BIT(7)
+#define b_delayWrites BIT(8)
 #define b_sleepMode BIT(17)
 
 extern u32 newArm7binarySize;
@@ -224,6 +225,9 @@ int hookNdsRetailArm7(
 	if (patchedCardIrqEnable) {
 		ce7->valueBits |= b_a9IrqHooked;
 	}
+	if (strncmp(romTid, "YL2", 3) == 0) { // Luminous Arc 2
+		ce7->valueBits |= b_delayWrites; // Delay save writes by 1 frame for the first 2 seconds to fix crash on first boot
+	}
 	if (sleepMode) {
 		ce7->valueBits |= b_sleepMode;
 	}
diff --git a/retail/bootloaderi/source/arm7/hook_arm7.c b/retail/bootloaderi/source/arm7/hook_arm7.c
index a68701fb2..11d276b7b 100644
--- a/retail/bootloaderi/source/arm7/hook_arm7.c
+++ b/retail/bootloaderi/source/arm7/hook_arm7.c
@@ -43,7 +43,7 @@
 #define b_dsiSD BIT(5)
 #define b_preciseVolumeControl BIT(6)
 #define b_powerCodeOnVBlank BIT(7)
-#define b_runCardEngineCheck BIT(8)
+#define b_delayWrites BIT(8)
 #define b_igmAccessible BIT(9)
 #define b_hiyaCfwFound BIT(10)
 #define b_slowSoftReset BIT(11)
@@ -391,6 +391,9 @@ int hookNdsRetailArm7(
 		if (consoleModel < 2 && preciseVolumeControl) {
 			ce7->valueBits |= b_preciseVolumeControl;
 		}
+		if (strncmp(romTid, "YL2", 3) == 0) { // Luminous Arc 2
+			ce7->valueBits |= b_delayWrites; // Delay save writes by 1 frame for the first 2 seconds to fix crash on first boot
+		}
 		if (hiyaCfwFound) {
 			ce7->valueBits |= b_hiyaCfwFound;
 		}
diff --git a/retail/cardengine/arm7/source/cardengine.c b/retail/cardengine/arm7/source/cardengine.c
index f0e215784..1ac90981e 100644
--- a/retail/cardengine/arm7/source/cardengine.c
+++ b/retail/cardengine/arm7/source/cardengine.c
@@ -38,6 +38,7 @@
 #include "tonccpy.h"
 
 #define a9IrqHooked BIT(7)
+#define delayWrites BIT(8)
 
 #define RUMBLE_PAK			(*(vuint16 *)0x08000000)
 #define WARIOWARE_PAK		(*(vuint16 *)0x080000C4)
@@ -128,6 +129,14 @@ static PERSONAL_DATA* personalData = NULL;
 	}
 }*/
 
+// Alternative to swiWaitForVBlank()
+static inline void waitFrames(int count) {
+	for (int i = 0; i < count; i++) {
+		while (REG_VCOUNT != 191);
+		while (REG_VCOUNT == 191);
+	}
+}
+
 static void waitForArm9(void) {
     IPC_SendSync(0x4);
 	while (sharedAddr[3] != (vu32)0);
@@ -584,6 +593,16 @@ bool eepromPageWrite(u32 dst, const void *src, u32 len) {
 		return false;
 	}
 
+#ifndef MUSIC
+	if (valueBits & delayWrites) {
+		if (*(int*)((valueBits & isSdk5Set) ? 0x02FFFC3C : 0x027FFC3C) >= 60*2) {
+			valueBits &= ~delayWrites;
+		} else {
+			waitFrames(1);
+		}
+	}
+#endif
+
 	// Send a command to the ARM9 to write the save
 	const u32 commandSaveWrite = 0x53415657;
 
diff --git a/retail/cardenginei/arm7/source/cardengine.c b/retail/cardenginei/arm7/source/cardengine.c
index 65fb52181..0c3917722 100644
--- a/retail/cardenginei/arm7/source/cardengine.c
+++ b/retail/cardenginei/arm7/source/cardengine.c
@@ -63,7 +63,7 @@
 #define b_dsiSD BIT(5)
 #define preciseVolumeControl BIT(6)
 #define powerCodeOnVBlank BIT(7)
-#define b_runCardEngineCheck BIT(8)
+#define delayWrites BIT(8)
 #define igmAccessible BIT(9)
 #define hiyaCfwFound BIT(10)
 #define slowSoftReset BIT(11)
@@ -2105,6 +2105,13 @@ bool eepromPageWrite(u32 dst, const void *src, u32 len) {
 		/*if (saveInRam) {
 			tonccpy((char*)0x02440000 + dst, src, len);
 		}*/
+		if (valueBits & delayWrites) {
+			if (*(int*)((valueBits & isSdk5) ? 0x02FFFC3C : 0x027FFC3C) >= 60*2) {
+				valueBits &= ~delayWrites;
+			} else {
+				waitFrames(1);
+			}
+		}
 		sdmmc_set_ndma_slot(4);
 		if ((dst % saveSize)+len > saveSize) {
 			u32 len2 = len;
diff --git a/retail/common/include/cardengine_header_arm7.h b/retail/common/include/cardengine_header_arm7.h
index cd4f10d06..191030af6 100644
--- a/retail/common/include/cardengine_header_arm7.h
+++ b/retail/common/include/cardengine_header_arm7.h
@@ -90,7 +90,7 @@ typedef struct cardengineArm7 {
 		5: dsiSD
 		6: preciseVolumeControl
 		7: powerCodeOnVBlank
-		8: runCardEngineCheck
+		8: delayWrites
 		9: igmAccessible
 		10: hiyaCfwFound
 		11: slowSoftReset
@@ -140,6 +140,7 @@ typedef struct cardengineArm7B4DS {
 	u32 valueBits;
 	/*
 		7: a9IrqHooked
+		8: delayWrites
 		17: sleepMode
 	*/
 	s32 mainScreen;