-added fds support, make sure to have your fds files in the same fold…

…er as the fds bios named disksys.rom to use it

-added new keyboard command "B" to switch disk sides in fds titles that need it

README.md

@@ -6,6 +6,7 @@ NTSC and PAL .nes ROMs are supported right now, it also creates .sav files if th
 Supported Mappers: 0,1,2,3,4,7,9,10,11,13,15,36,37,38,44,46,47,66,71,79,87,99,101,113,133,140,144,145,146,147,148,149,185,240 and 242.  
 To start a game, simply drag and drop its .nes file into it or call it via command line with the .nes file as argument.  
 If you are starting a PAL NES title then make sure it has (E) in the name to be started in PAL mode.  
+You can also play FDS titles if you have the FDS BIOS named disksys.rom in the same folder as your .fds files.  
 You can also listen to .nsf files by dragging them in, changing tracks works by pressing left/right.    
 
 Controls right now are keyboard only and do the following:  
@@ -16,6 +17,7 @@ S is select
 Arrow Keys is DPad  
 Keys 1-9 integer-scale the window to number  
 P is Pause  
+B is Disk Switching (for FDS)  
 O is Enable/Disable vertical Overscan    
 
 That is all I can say about it right now, who knows if I will write some more on it.  

cpu.c

@@ -30,6 +30,8 @@ static bool interrupt;
 bool dmc_interrupt;
 bool mmc5_dmc_interrupt;
 bool apu_interrupt;
+bool fds_interrupt;
+bool fds_transfer_interrupt;
 uint32_t cpu_oam_dma;
 extern bool nesPause;
 
@@ -40,6 +42,8 @@ void cpuInit()
 	dmc_interrupt = false;
 	mmc5_dmc_interrupt = false;
 	apu_interrupt = false;
+	fds_interrupt = false;
+	fds_transfer_interrupt = false;
 	cpu_oam_dma = 0;
 	p = (P_FLAG_IRQ_DISABLE | P_FLAG_S1 | P_FLAG_S2);
 	a = 0;
@@ -415,6 +419,8 @@ bool cpuCycle()
 		#endif
 		if(interrupt)
 			interrupt = false;
+		if(fds_transfer_interrupt)
+			fds_transfer_interrupt = false;
 		waitCycles+=5;
 	}
 	uint16_t instrPtr = pc;
@@ -1906,7 +1912,8 @@ bool cpuCycle()
 	}
 	//update interrupt values
 	ppu_nmi_handler_req = ppuNMI();
-	cpu_interrupt_req = (interrupt || ((mapper_interrupt || dmc_interrupt || apu_interrupt || mmc5_dmc_interrupt) && !(p & P_FLAG_IRQ_DISABLE)));
+	cpu_interrupt_req = (interrupt || ((mapper_interrupt || dmc_interrupt || apu_interrupt || 
+			fds_interrupt || fds_transfer_interrupt || mmc5_dmc_interrupt) && !(p & P_FLAG_IRQ_DISABLE)));
 	//if(instrPtr > 0xa980 && instrPtr < 0xa9C0) printf("%d %d %d %04x %04x\n",a,x,y,instrPtr,memGet8(instrPtr)|(memGet8(instrPtr+1)<<8));
 	return true;
 }

main.c

@@ -28,11 +28,12 @@
 #define DEBUG_KEY 0
 #define DEBUG_LOAD_INFO 1
 
-static const char *VERSION_STRING = "fixNES Alpha v0.5.4";
+static const char *VERSION_STRING = "fixNES Alpha v0.5.5";
 
 static void nesEmuDisplayFrame(void);
 static void nesEmuMainLoop(void);
 static void nesEmuDeinit(void);
+static void nesEmuFdsSetup(uint8_t *src, uint8_t *dst);
 
 static void nesEmuHandleKeyDown(unsigned char key, int x, int y);
 static void nesEmuHandleKeyUp(unsigned char key, int x, int y);
@@ -54,6 +55,7 @@ bool nesEmuNSFPlayback = false;
 static bool inPause = false;
 static bool inOverscanToggle = false;
 static bool inResize = false;
+static bool inDiskSwitch = false;
 
 #if WINDOWS_BUILD
 #include <windows.h>
@@ -72,6 +74,7 @@ static DWORD emuTotalElapsed = 0;
 static const int visibleImg = VISIBLE_DOTS*VISIBLE_LINES*4;
 static int scaleFactor = 2;
 static bool emuSaveEnabled = false;
+static bool emuFdsHasSideB = false;
 static int emuApuClockCycles;
 static int emuApuClock;
 static int mainLoopRuns;
@@ -178,6 +181,101 @@ int main(int argc, char** argv)
 		}
 		nesEmuNSFPlayback = true;
 	}
+	else if(argc >= 2 && (strstr(argv[1],".fds") != NULL || strstr(argv[1],".FDS") != NULL
+						|| strstr(argv[1],".qd") != NULL || strstr(argv[1],".QD") != NULL))
+	{
+		emuSaveName = strdup(argv[1]);
+		memcpy(emuSaveName+strlen(emuSaveName)-3,"sav",3);
+		bool saveValid = false;
+		FILE *save = fopen(emuSaveName, "rb");
+		if(save)
+		{
+			fseek(save,0,SEEK_END);
+			size_t saveSize = ftell(save);
+			if(saveSize == 0x10000 || saveSize == 0x20000)
+			{
+				emuNesROM = malloc(saveSize);
+				rewind(save);
+				fread(emuNesROM,1,saveSize,save);
+				saveValid = true;
+				if(saveSize == 0x20000)
+					emuFdsHasSideB = true;
+			}
+			else
+				printf("Save file ignored\n");
+			fclose(save);
+		}
+		if(!saveValid)
+		{
+			FILE *nesF = fopen(argv[1],"rb");
+			if(!nesF) return EXIT_SUCCESS;
+			fseek(nesF,0,SEEK_END);
+			size_t fsize = ftell(nesF);
+			rewind(nesF);
+			uint8_t *nesFread = malloc(fsize);
+			fread(nesFread,1,fsize,nesF);
+			fclose(nesF);
+			uint8_t *fds_src;
+			uint32_t fds_src_len;
+			if(nesFread[0] == 0x46 && nesFread[1] == 0x44 && nesFread[2] == 0x53)
+			{
+				fds_src = nesFread+0x10;
+				fds_src_len = fsize-0x10;
+			}
+			else
+			{
+				fds_src = nesFread;
+				fds_src_len = fsize;
+			}
+			bool fds_no_crc = (fds_src[0x38] == 0x02 && fds_src[0x3A] == 0x03 && fds_src[0x3A] != 0x02 && fds_src[0x3E] != 0x03);
+			if(fds_no_crc)
+			{
+				if(fds_src_len == 0x1FFB8)
+				{
+					emuFdsHasSideB = true;
+					emuNesROM = malloc(0x20000);
+					memset(emuNesROM, 0, 0x20000);
+					nesEmuFdsSetup(fds_src, emuNesROM); //setup individually
+					nesEmuFdsSetup(fds_src+0xFFDC, emuNesROM+0x10000);
+				}
+				else if(fds_src_len == 0xFFDC)
+				{
+					emuNesROM = malloc(0x10000);
+					memset(emuNesROM, 0, 0x10000);
+					nesEmuFdsSetup(fds_src, emuNesROM);
+				}
+			}
+			else
+			{
+				if(fds_src_len == 0x20000)
+				{
+					emuFdsHasSideB = true;
+					emuNesROM = malloc(0x20000);
+					memcpy(emuNesROM, fds_src, 0x20000);
+				}
+				else if(fds_src_len == 0x10000)
+				{
+					emuNesROM = malloc(0x10000);
+					memcpy(emuNesROM, fds_src, 0x10000);
+				}
+			}
+			free(nesFread);
+		}
+		emuPrgRAMsize = 0x8000;
+		emuPrgRAM = malloc(emuPrgRAMsize);
+		cpuInit();
+		ppuInit();
+		memInit();
+		apuInit();
+		inputInit();
+		if(!mapperInitFDS(emuNesROM, emuFdsHasSideB, emuPrgRAM, emuPrgRAMsize))
+		{
+			printf("FDS init failed!\n");
+			free(emuNesROM);
+			emuNesROM = NULL;
+			return EXIT_SUCCESS;
+		}
+	}
 	if(emuNesROM == NULL)
 		return EXIT_SUCCESS;
 	#if WINDOWS_BUILD
@@ -236,7 +334,21 @@ static void nesEmuDeinit(void)
 	audioDeinit();
 	apuDeinit();
 	if(emuNesROM != NULL)
+	{
+		if(fdsEnabled)
+		{
+			FILE *save = fopen(emuSaveName, "wb");
+			if(save)
+			{
+				if(emuFdsHasSideB)
+					fwrite(emuNesROM,1,0x20000,save);
+				else
+					fwrite(emuNesROM,1,0x10000,save);
+				fclose(save);
+			}
+		}
 		free(emuNesROM);
+	}
 	emuNesROM = NULL;
 	if(emuPrgRAM != NULL)
 	{
@@ -344,7 +456,7 @@ void nesEmuResetApuClock(void)
 {
 	emuApuClock = 0;
 }
-
+extern bool fdsSwitch;
 static void nesEmuHandleKeyDown(unsigned char key, int x, int y)
 {
 	(void)x;
@@ -397,6 +509,14 @@ static void nesEmuHandleKeyDown(unsigned char key, int x, int y)
 			memDumpMainMem();
 			exit(EXIT_SUCCESS);
 			break;
+		case 'b':
+		case 'B':
+			if(!inDiskSwitch)
+			{
+				fdsSwitch = true;
+				inDiskSwitch = true;
+			}
+			break;
 		case 'p':
 		case 'P':
 			if(!inPause)
@@ -528,6 +648,10 @@ static void nesEmuHandleKeyUp(unsigned char key, int x, int y)
 			#endif
 			inValReads[BUTTON_START]=0;
 			break;
+		case 'b':
+		case 'B':
+			inDiskSwitch = false;
+			break;
 		case 'p':
 		case 'P':
 			#if DEBUG_KEY
@@ -670,3 +794,24 @@ static void nesEmuDisplayFrame()
 
 	glutSwapBuffers();
 }
+
+static void nesEmuFdsSetup(uint8_t *src, uint8_t *dst)
+{
+	memcpy(dst, src, 0x38);
+	memcpy(dst+0x3A, src+0x38, 2);
+	uint16_t cDiskPos = 0x3E;
+	uint16_t cROMPos = 0x3A;
+	do
+	{
+		if(src[cROMPos] != 0x03)
+			break;
+		memcpy(dst+cDiskPos, src+cROMPos, 0x10);
+		uint16_t copySize = (*(uint16_t*)(src+cROMPos+0xD))+1;
+		cDiskPos+=0x12;
+		cROMPos+=0x10;
+		memcpy(dst+cDiskPos, src+cROMPos, copySize);
+		cDiskPos+=copySize+2;
+		cROMPos+=copySize;
+	} while(cROMPos < 0xFFDC && cDiskPos < 0xFFFF);
+	printf("%04x -> %04x\n", cROMPos, cDiskPos);
+}

mapper.c

@@ -11,6 +11,7 @@
 #include "mapper.h"
 #include "mapperList.h"
 #include "mapper_h/nsf.h"
+#include "mapper_h/fds.h"
 
 get8FuncT mapperGet8;
 set8FuncT mapperSet8;
@@ -45,3 +46,37 @@ bool mapperInitNSF(uint8_t *nsfBIN, uint32_t nsfBINsize, uint8_t *prgRAM, uint32
 	mapperCycle = nsfcycle;
 	return true;
 }
+
+static uint8_t fdsBIOS[0x2000];
+bool mapperInitFDS(uint8_t *fdsFile, bool fdsSideB, uint8_t *prgRAM, uint32_t prgRAMsize)
+{
+	if(fdsFile == NULL)
+	{
+		printf("No FDS loaded!\n");
+		return false;
+	}
+	FILE *f = fopen("disksys.rom","rb");
+	if(f == NULL)
+	{
+		printf("disksys.rom not found!\n");
+		return false;
+	}
+	fseek(f,0,SEEK_END);
+	size_t fsize = ftell(f);
+	rewind(f);
+	if(fsize != 0x2000)
+	{
+		printf("disksys.rom has a wrong size, is %i bytes, should be 8192 bytes!\n", fsize);
+		fclose(f);
+		return false;
+	}
+	fread(fdsBIOS, 1, 0x2000, f);
+	fclose(f);
+	fdsinit(fdsBIOS, fsize, fdsFile, fdsSideB, prgRAM, prgRAMsize);
+	mapperGet8 = fdsget8;
+	mapperSet8 = fdsset8;
+	mapperChrGet8 = fdschrGet8;
+	mapperChrSet8 = fdschrSet8;
+	mapperCycle = fdscycle;
+	return true;
+}

mapper.h

@@ -18,6 +18,7 @@ typedef void (*cycleFuncT)();
 
 bool mapperInit(uint8_t mapper, uint8_t *prgROM, uint32_t prgROMsize, uint8_t *prgRAM, uint32_t prgRAMsize, uint8_t *chrROM, uint32_t chrROMsize);
 bool mapperInitNSF(uint8_t *nsfBIN, uint32_t nsfBINsize, uint8_t *prgRAM, uint32_t prgRAMsize);
+bool mapperInitFDS(uint8_t *fdsFile, bool fdsSideB, uint8_t *prgRAM, uint32_t prgRAMsize);
 
 extern get8FuncT mapperGet8;
 extern set8FuncT mapperSet8;