Basic save type detection based on code from GBARunner2 (thanks Gericom).

Note: Some EEPROM types are definitely broken right now.

include/hardware/lgy.h

@@ -107,7 +107,7 @@ Result LGY_setGbaRtc(const GbaRtc rtc);
 Result LGY_getGbaRtc(GbaRtc *const out);
 Result LGY_backupGbaSave(void);
 #ifdef ARM11
-Result LGY_prepareGbaMode(bool gbaBios, u16 saveType, const char *const romPath, const char *const savePath);
+Result LGY_prepareGbaMode(bool gbaBios, const char *const romPath, const char *const savePath);
 void LGY_switchMode(void);
 void LGY_handleEvents(void);
 void LGY_deinit(void);

source/arm11/hardware/lgy.c

@@ -10,6 +10,9 @@
 #include "arm11/hardware/pdn.h"
 #include "arm11/hardware/mcu.h"
 #include "arm11/hardware/lgyfb.h"
+#ifndef NDEBUG
+#include "arm11/fmt.h"
+#endif
 
 
 #define LGY_REGS_BASE     (IO_MEM_ARM9_ARM11 + 0x41100)
@@ -38,7 +41,7 @@ static void lgySleepIrqHandler(u32 intSource)
 	}
 }
 
-static Result loadRom(const char *const path)
+static Result loadRom(const char *const path, u32 *const rsOut)
 {
 	Result res;
 	FHandle f;
@@ -54,6 +57,7 @@ static Result loadRom(const char *const path)
 
 			if(res == RES_OK)
 			{
+				*rsOut = romSize;
 				// Pad ROM area with "open bus" value.
 				memset((void*)(ROM_LOC + romSize), 0xFFFFFFFFu, romSize);
 			}
@@ -66,6 +70,103 @@ static Result loadRom(const char *const path)
 	return res;
 }
 
+// Code based on: https://github.com/Gericom/GBARunner2/blob/master/arm9/source/save/Save.vram.cpp
+static void tryDetectSaveType(u32 romSize, u16 *const stOut)
+{
+#ifndef NDEBUG
+	ee_puts("Trying to detect save type...");
+#endif
+
+	u8 saveChipKind = 0; // 0 = none, 1 = EEPROM, 2 = Flash, 3 = SRAM.
+	const u32 *romPtr = (u32*)(ROM_LOC + 0xE4u); // Skip headers.
+	for(; romPtr < (u32*)(ROM_LOC + romSize); romPtr++)
+	{
+		u32 tmp = *romPtr;
+
+		// "EEPR"
+		if(tmp == 0x52504545u)
+		{
+			saveChipKind = 1;
+			break;
+		}
+
+		// "FLAS"
+		if(tmp == 0x53414C46u)
+		{
+			saveChipKind = 2;
+			break;
+		}
+
+		// "SRAM"
+		if(tmp == 0x4D415253u)
+		{
+			saveChipKind = 3;
+			break;
+		}
+	}
+
+	if(saveChipKind != 0)
+	{
+		static const struct
+		{
+			char *str;
+			u16 saveType;
+		} saveTypeLut[25] =
+		{
+			// EEPROM
+			// TODO: Which ones are SAVE_TYPE_EEPROM_64k_2?
+			{"EEPROM_V111", SAVE_TYPE_EEPROM_8k},  // 512 bytes.
+			{"EEPROM_V120", SAVE_TYPE_EEPROM_64k},
+			{"EEPROM_V121", SAVE_TYPE_EEPROM_64k},
+			{"EEPROM_V122", SAVE_TYPE_EEPROM_64k},
+			{"EEPROM_V124", SAVE_TYPE_EEPROM_64k},
+			{"EEPROM_V125", SAVE_TYPE_EEPROM_64k},
+			{"EEPROM_V126", SAVE_TYPE_EEPROM_64k},
+
+			// FLASH
+			// Assume they all have RTC.
+			{"FLASH_V120",    SAVE_TYPE_FLASH_512k_PSC_RTC},
+			{"FLASH_V121",    SAVE_TYPE_FLASH_512k_PSC_RTC},
+			{"FLASH_V123",    SAVE_TYPE_FLASH_512k_PSC_RTC},
+			{"FLASH_V124",    SAVE_TYPE_FLASH_512k_PSC_RTC},
+			{"FLASH_V125",    SAVE_TYPE_FLASH_512k_PSC_RTC},
+			{"FLASH_V126",    SAVE_TYPE_FLASH_512k_PSC_RTC},
+			{"FLASH512_V130", SAVE_TYPE_FLASH_512k_PSC_RTC},
+			{"FLASH512_V131", SAVE_TYPE_FLASH_512k_PSC_RTC},
+			{"FLASH512_V133", SAVE_TYPE_FLASH_512k_PSC_RTC},
+			{"FLASH1M_V102",  SAVE_TYPE_FLASH_1m_MRX_RTC},
+			{"FLASH1M_V103",  SAVE_TYPE_FLASH_1m_MRX_RTC},
+
+			// FRAM & SRAM
+			{"SRAM_F_V100", SAVE_TYPE_SRAM_256k},
+			{"SRAM_F_V102", SAVE_TYPE_SRAM_256k},
+			{"SRAM_F_V103", SAVE_TYPE_SRAM_256k},
+
+			{"SRAM_V110",   SAVE_TYPE_SRAM_256k},
+			{"SRAM_V111",   SAVE_TYPE_SRAM_256k},
+			{"SRAM_V112",   SAVE_TYPE_SRAM_256k},
+			{"SRAM_V113",   SAVE_TYPE_SRAM_256k}
+		};
+
+		for(u32 i = 0; i < 25; i++)
+		{
+			const char *const str = saveTypeLut[i].str;
+			const u16 saveType = saveTypeLut[i].saveType;
+
+			if(memcmp(romPtr, str, strlen(str)) == 0)
+			{
+#ifndef NDEBUG
+				ee_printf("Found save type %s.", str);
+#endif
+				*stOut = saveType;
+			}
+		}
+	}
+#ifndef NDEBUG
+	else ee_puts("Could not identify save type. Using none.");
+#endif
+}
+
 static void setupFcramForGbaMode(void)
 {
 	// FCRAM reset and clock disable.
@@ -78,12 +179,17 @@ static void setupFcramForGbaMode(void)
 	while(REG_PDN_FCRAM_CNT & PDN_FCRAM_CNT_CLK_E_ACK); // Wait until clock is disabled.
 }
 
-Result LGY_prepareGbaMode(bool gbaBios, u16 saveType, const char *const romPath, const char *const savePath)
+Result LGY_prepareGbaMode(bool gbaBios, const char *const romPath, const char *const savePath)
 {
 	// Load the ROM image.
-	Result res = loadRom(romPath);
+	u32 romSize;
+	Result res = loadRom(romPath, &romSize);
 	if(res != RES_OK) return res;
 
+	// Try to detect the save type.
+	u16 saveType = SAVE_TYPE_NONE;
+	tryDetectSaveType(romSize, &saveType);
+
 	// Prepare ARM9 for GBA mode + settings and save loading.
 	u32 cmdBuf[2];
 	cmdBuf[0] = (u32)savePath;
@@ -132,7 +238,6 @@ void LGY_switchMode(void)
 }
 
 #ifndef NDEBUG
-#include "arm11/fmt.h"
 void debugTests(void)
 {
 	const u32 kDown = hidKeysDown();

source/arm11/main.c

@@ -39,7 +39,7 @@ int main(void)
 
 	ee_puts("Reading ROM and save...");
 	Result res;
-	if((res = LGY_prepareGbaMode(false, SAVE_TYPE_SRAM_256k, "sdmc:/rom.gba", "sdmc:/rom.sav")) == RES_OK)
+	if((res = LGY_prepareGbaMode(false, "sdmc:/rom.gba", "sdmc:/rom.sav")) == RES_OK)
 	{
 #ifdef NDEBUG
 		GFX_setForceBlack(false, true);