MMU: add some extremely basic Ninja SD support, based on libfat code.

This was my first attempt at getting ndsmail working properly.
All the needed init code is here, but reading and writing operations
are seriously lacking for now.

desmume/src/MMU.cpp

@@ -1167,6 +1167,70 @@ void FASTCALL MMU_writeToGCControl(u32 val)
 			}
 			break;
 
+
+		// --- Ninja SD commands -------------------------------------
+
+		// NJSD init/reset
+		case 0x20:
+			{
+				card.address = 0;
+				card.transfer_count = 0;
+			}
+			break;
+
+		// NJSD_sendCLK()
+		case 0xE0:
+			{
+				card.address = 0;
+				card.transfer_count = 0;
+				NDS_makeInt(PROCNUM, 20);
+			}
+			break;
+
+		// NJSD_sendCMDN() / NJSD_sendCMDR()
+		case 0xF0:
+		case 0xF1:
+			switch (card.command[2])
+			{
+			// GO_IDLE_STATE
+			case 0x40:
+				card.address = 0;
+				card.transfer_count = 0;
+				NDS_makeInt(PROCNUM, 20);
+				break;
+
+			case 0x42:  // ALL_SEND_CID
+			case 0x43:  // SEND_RELATIVE_ADDR
+			case 0x47:  // SELECT_CARD
+			case 0x49:  // SEND_CSD
+			case 0x4D:
+			case 0x77:  // APP_CMD
+			case 0x69:  // SD_APP_OP_COND
+				card.address = 0;
+				card.transfer_count = 6;
+				NDS_makeInt(PROCNUM, 20);
+				break;
+
+			// SET_BLOCKLEN
+			case 0x50:
+				card.address = 0;
+				card.transfer_count = 6;
+				card.blocklen = card.command[6] | (card.command[5] << 8) | (card.command[4] << 16) | (card.command[3] << 24);
+				NDS_makeInt(PROCNUM, 20);
+				break;
+
+			// READ_SINGLE_BLOCK
+			case 0x51:
+				card.address = card.command[6] | (card.command[5] << 8) | (card.command[4] << 16) | (card.command[3] << 24);
+				card.transfer_count = (card.blocklen + 3) >> 2;
+				NDS_makeInt(PROCNUM, 20);
+				break;
+			}
+			break;
+
+		// --- Ninja SD commands end ---------------------------------
+
+
 		default:
 			{
 				LOG("WRITE CARD command: %02X%02X%02X%02X%02X%02X%02X%02X\t", 
@@ -1210,23 +1274,17 @@ u32 MMU_readFromGC()
 	{
 		// Dummy
 		case 0x9F:
-			{
+			val = 0xFFFFFFFF;
-				val = 0xFFFFFFFF;
-			}
 			break;
 
 		// Nand Init?
 		case 0x94:
-			{
+			val = 0; //Unsure what to return here so return 0 for now
-				val = 0; //Unsure what to return here so return 0 for now
-			}
 			break;
 
 		// Nand Error?
 		case 0xD6:
-			{
+			val = 0x80; //0x80 == ok?
-				val = 0x80; //0x80 == ok?
-			}
 			break;
 
 		// Data read
@@ -1263,11 +1321,55 @@ u32 MMU_readFromGC()
 
 		// Switch to KEY1 mode
 		case 0x3C:
+			val = 0xFFFFFFFF;
+			break;
+
+		// --- Ninja SD commands -------------------------------------
+
+		// NJSD_sendCMDN() / NJSD_sendCMDR()
+		case 0xF0:
+		case 0xF1:
+			switch (card.command[2])
 			{
-				val = 0xFFFFFFFF;
+			// ALL_SEND_CID
+			case 0x42:
+				if (card.transfer_count == 2) val = 0x44534A4E;
+				else val = 0x00000000;
+
+			// SEND_RELATIVE_ADDR
+			case 0x43:
+			case 0x47:
+			case 0x49:
+			case 0x50:
+				val = 0x00000000;
+				break;
+
+			case 0x4D:
+				if (card.transfer_count == 2) val = 0x09000000;
+				else val = 0x00000000;
+				break;
+
+			// APP_CMD
+			case 0x77:
+				if (card.transfer_count == 2) val = 0x00000037;
+				else val = 0x00000000;
+				break;
+
+			// SD_APP_OP_COND
+			case 0x69:
+				if (card.transfer_count == 2) val = 0x00008000;
+				else val = 0x00000000;
+				break;
+
+			// READ_SINGLE_BLOCK
+			case 0x51:
+				val = 0x00000000;
+				break;
 			}
 			break;
 
+		// --- Ninja SD commands end ---------------------------------
+
 		default:
 			LOG("READ CARD command: %02X%02X%02X%02X%02X%02X%02X%02X\t", 
 					card.command[0], card.command[1], card.command[2], card.command[3],
@@ -1306,6 +1408,10 @@ void FASTCALL MMU_doDMA(u32 num)
     u32 taille = 0;
 	bool paused = false;
 
+	//if (dst == 0x022DD4E0)
+	//	printf("proc %i dma %i: src=%08X, dst=%08X, size=%i, repmode=%i\n",
+	//	PROCNUM, num, src, dst, (MMU.DMACrt[PROCNUM][num]&0x1FFFFF), MMU.DMAStartTime[PROCNUM][num]);
+
 #ifdef USE_GEOMETRY_FIFO_EMULATION
 	if (MMU.DMAStartTime[PROCNUM][num]== EDMAMode_GXFifo)
 	{

desmume/src/MMU.h

@@ -52,6 +52,9 @@ typedef struct
 	u32 transfer_count;
 
 	ECardMode mode;
+
+	// NJSD stuff
+	int blocklen;
 	
 } nds_dscard;