mask rom reads outside of range instead of returning 0xFF. clean up some other archaic memory map cruft

desmume/src/MMU.cpp

@@ -82,8 +82,6 @@ u32 _MMU_MAIN_MEM_MASK = 0x3FFFFF;
 u32 _MMU_MAIN_MEM_MASK16 = 0x3FFFFF & ~1;
 u32 _MMU_MAIN_MEM_MASK32 = 0x3FFFFF & ~3;
 
-#define ROM_MASK 3
-
 //#define	_MMU_DEBUG
 
 #ifdef _MMU_DEBUG
@@ -174,7 +172,7 @@ u8 * MMU_struct::MMU_MEM[2][256] = {
 		/* 7X*/	DUP16(MMU.ARM9_OAM),
 		/* 8X*/	DUP16(NULL),
 		/* 9X*/	DUP16(NULL),
-		/* AX*/	DUP16(MMU.CART_RAM),
+		/* AX*/	DUP16(NULL),
 		/* BX*/	DUP16(MMU.UNUSED_RAM),
 		/* CX*/	DUP16(MMU.UNUSED_RAM),
 		/* DX*/	DUP16(MMU.UNUSED_RAM),
@@ -195,7 +193,7 @@ u8 * MMU_struct::MMU_MEM[2][256] = {
 		/* 7X*/	DUP16(MMU.UNUSED_RAM),
 		/* 8X*/	DUP16(NULL),
 		/* 9X*/	DUP16(NULL),
-		/* AX*/	DUP16(MMU.CART_RAM),
+		/* AX*/	DUP16(NULL),
 		/* BX*/	DUP16(MMU.UNUSED_RAM),
 		/* CX*/	DUP16(MMU.UNUSED_RAM),
 		/* DX*/	DUP16(MMU.UNUSED_RAM),
@@ -832,7 +830,6 @@ void MMU_Init(void) {
 	memset(&MMU, 0, sizeof(MMU_struct));
 
 	MMU.CART_ROM = MMU.UNUSED_RAM;
-	MMU.CART_ROM_MASK = 3;
 
 	//MMU.DTCMRegion = 0x027C0000;
 	//even though apps may change dtcm immediately upon startup, this is the correct hardware starting value:
@@ -876,10 +873,6 @@ void MMU_DeInit(void) {
 	Mic_DeInit();
 }
 
-//Card rom & ram
-
-u32 rom_mask = 0;
-
 void MMU_Reset()
 {
 	memset(MMU.ARM9_DTCM, 0, sizeof(MMU.ARM9_DTCM));
@@ -988,15 +981,11 @@ void MMU_Reset()
 void MMU_setRom(u8 * rom, u32 mask)
 {
 	MMU.CART_ROM = rom;
-	MMU.CART_ROM_MASK = mask;
-	rom_mask = mask;
 }
 
 void MMU_unsetRom()
 {
 	MMU.CART_ROM=MMU.UNUSED_RAM;
-	MMU.CART_ROM_MASK = 3;
-	rom_mask = ROM_MASK;
 }
 
 static void execsqrt() {

desmume/src/MMU.h

@@ -361,8 +361,6 @@ struct MMU_struct
 
 	//Card rom & ram
 	u8 * CART_ROM;
-	u32 CART_ROM_MASK;
-	u8 CART_RAM[0x10000];
 
 	//Unused ram
 	u8 UNUSED_RAM[4];

desmume/src/NDSSystem.h

@@ -330,7 +330,7 @@ struct GameInfo
 
 		//now, we actually need to over-allocate, because bytes from anywhere protected by that mask
 		//could be read from the rom
-		allocatedSize = mask+1;
+		allocatedSize = mask+4;
 
 		romdata = new char[allocatedSize];
 		romsize = size;

desmume/src/addons/slot1_retail.cpp

@@ -120,14 +120,20 @@ static u32 read32_GCDATAIN(u8 PROCNUM)
 					card.address = (0x8000 + (card.address&0x1FF));
 				}
 
-				if(card.address >= gameInfo.romsize)
+				//it seems that etrian odyssey 3 doesnt work unless we mask this to cart size.
+				//but, a thought: does the internal rom address counter register wrap around? we may be making a mistake by keeping the extra precision
+				//but there is no test case yet
+				u32 address = card.address & (gameInfo.mask);
+
+				//as a sanity measure for funny-sized roms (homebrew and perhaps truncated retail roms)
+				//we need to protect ourselves by returning 0xFF for things still out of range
+				if(address >= gameInfo.romsize)
 				{
-					DEBUG_Notify.ReadBeyondEndOfCart(card.address,gameInfo.romsize);
+					DEBUG_Notify.ReadBeyondEndOfCart(address,gameInfo.romsize);
 					return 0xFFFFFFFF;
 				}
-				//but, this is actually handled by the cart rom buffer being oversized and full of 0xFF.
+
-				//is this a good idea? We think so.
+				return T1ReadLong(MMU.CART_ROM, address);
-				return T1ReadLong(MMU.CART_ROM, card.address & MMU.CART_ROM_MASK);
 			}
 			break;
 		default:

desmume/src/saves.cpp

@@ -191,7 +191,6 @@ SFORMAT SF_MMU[]={
 	{ "M7RG", 1, sizeof(MMU.ARM7_REG), MMU.ARM7_REG},
 	{ "M7WI", 1, sizeof(MMU.ARM7_WIRAM), MMU.ARM7_WIRAM},
 	{ "MSWI", 1, sizeof(MMU.SWIRAM), MMU.SWIRAM},
-	{ "MCRA", 1, sizeof(MMU.CART_RAM), MMU.CART_RAM},
 	{ "M9RW", 1, 1,       &MMU.ARM9_RW_MODE},
 	{ "MDTC", 4, 1,       &MMU.DTCMRegion},
 	{ "MITC", 4, 1,       &MMU.ITCMRegion},
@@ -680,64 +679,6 @@ void loadstate_slot(int num)
    }
 }
 
-u8 sram_read (u32 address) {
-	address = address - SRAM_ADDRESS;
-
-	if ( address > SRAM_SIZE )
-		return 0;
-
-	return MMU.CART_RAM[address];
-
-}
-
-void sram_write (u32 address, u8 value) {
-
-	address = address - SRAM_ADDRESS;
-
-	if ( address < SRAM_SIZE )
-		MMU.CART_RAM[address] = value;
-
-}
-
-int sram_load (const char *file_name) {
-
-	FILE *file;
-	size_t elems_read;
-
-	file = fopen ( file_name, "rb" );
-	if( file == NULL )
-		return 0;
-
-	elems_read = fread ( MMU.CART_RAM, SRAM_SIZE, 1, file );
-
-	fclose ( file );
-
-	osd->setLineColor(255, 255, 255);
-	osd->addLine("Loaded SRAM");
-
-	return 1;
-
-}
-
-int sram_save (const char *file_name) {
-
-	FILE *file;
-	size_t elems_written;
-
-	file = fopen ( file_name, "wb" );
-	if( file == NULL )
-		return 0;
-
-	elems_written = fwrite ( MMU.CART_RAM, SRAM_SIZE, 1, file );
-
-	fclose ( file );
-
-	osd->setLineColor(255, 255, 255);
-	osd->addLine("Saved SRAM");
-
-	return 1;
-
-}
 
 // note: guessSF is so we don't have to do a linear search through the SFORMAT array every time
 // in the (most common) case that we already know where the next entry is.

desmume/src/texcache.cpp

@@ -127,6 +127,7 @@ static MemSpan MemSpan_TexMem(u32 ofs, u32 len)
 		currofs += curr.len;
 		u8* ptr = MMU.texInfo.textureSlotAddr[slot];
 		
+		//TODO - dont alert if the masterbrightnesses are max or min
 		if(ptr == MMU.blank_memory) {
 			PROGINFO("Tried to reference unmapped texture memory: slot %d\n",slot);
 		}
@@ -158,6 +159,7 @@ static MemSpan MemSpan_TexPalette(u32 ofs, u32 len)
 		currofs += curr.len;
 		u8* ptr = MMU.texInfo.texPalSlot[slot];
 		
+		//TODO - dont alert if the masterbrightnesses are max or min
 		if(ptr == MMU.blank_memory) {
 			PROGINFO("Tried to reference unmapped texture palette memory: 16k slot #%d\n",slot);
 		}