buffering, PCM DMA, memcpy12bswap

git-svn-id: file:///home/notaz/opt/svn/PicoDrive@66 be3aeb3a-fb24-0410-a615-afba39da0efa

Pico/Misc.c

@@ -313,6 +313,15 @@ void memcpy16(unsigned short *dest, unsigned short *src, int count)
 }
 
 
+void memcpy16bswap(unsigned short *dest, void *src, int count)
+{
+	unsigned char *src_ = src;
+
+	for (; count; count--, src_ += 2)
+		*dest++ = (src_[0] << 8) | src_[1];
+}
+
+
 void memcpy32(int *dest, int *src, int count)
 {
 	while (count--)

Pico/Pico.h

@@ -47,6 +47,8 @@ extern void (*PicoWriteSound)(int len); // called once per frame at the best tim
 
 int PicoFrameMCD(void);
 
+extern int PicoCDBuffers;
+
 // Area.c
 typedef size_t (arearw)(void *p, size_t _size, size_t _n, void *file);
 typedef size_t (areaeof)(void *file);
@@ -61,6 +63,10 @@ extern areaseek *areaSeek;
 extern areaclose *areaClose;
 extern void (*PicoStateProgressCB)(const char *str);
 
+// cd/buffering.c
+void PicoCDBufferInit(void);
+void PicoCDBufferFree(void);
+
 // Cart.c
 typedef enum
 {

Pico/PicoInt.h

@@ -300,6 +300,7 @@ void SRAMWriteEEPROM(unsigned int d);
 unsigned int SRAMReadEEPROM();
 void SRAMUpdPending(unsigned int a, unsigned int d);
 void memcpy16(unsigned short *dest, unsigned short *src, int count);
+void memcpy16bswap(unsigned short *dest, void *src, int count);
 void memcpy32(int *dest, int *src, int count);
 void memset32(int *dest, int c, int count);
 

Pico/VideoPort.c

@@ -173,7 +173,7 @@ static void DmaSlow(int len)
       r = Pico.cram;
       for(a2=a&0x7f; len; len--)
       {
-        r[a2>>1] = (u16)*pd++;; // bit 0 is ignored
+        r[a2>>1] = (u16)*pd++; // bit 0 is ignored
         // AutoIncrement
         a2+=inc;
         // didn't src overlap?

Pico/cd/LC89510.c

@@ -70,7 +70,7 @@ void LC89510_Reset(void)
 
 void Update_CDC_TRansfer(int which)
 {
-	unsigned int DMA_Adr, dep, length, len;
+	unsigned int DMA_Adr, dep, length;
 	unsigned short *dest;
 	unsigned char  *src;
 
@@ -96,7 +96,7 @@ void Update_CDC_TRansfer(int which)
 	else length = CDC_DMA_SPEED;
 
 
-	// TODO: dst bounds checking? DAC.N alignment?
+	// TODO: dst bounds checking?
 	src = Pico_mcd->cdc.Buffer + Pico_mcd->cdc.DAC.N;
 	DMA_Adr = (Pico_mcd->s68k_regs[0xA]<<8) | Pico_mcd->s68k_regs[0xB];
 
@@ -112,13 +112,11 @@ void Update_CDC_TRansfer(int which)
 
 			dest = (unsigned short *) (Pico_mcd->word_ram1M[bank] + dep);
 
-			// TODO: bswapcpy
+			memcpy16bswap(dest, src, length);
-			for (len = length; len > 0; len--, src+=2, dest++)
-				*dest = (src[0]<<8) | src[1];
 
 			{ // debug
 				unsigned char *b1 = Pico_mcd->word_ram1M[bank] + dep;
-				unsigned char *b2 = (unsigned char *)dest - 8;
+				unsigned char *b2 = (unsigned char *)(dest+length) - 8;
 				dprintf("%02x %02x %02x %02x .. %02x %02x %02x %02x",
 					b1[0], b1[1], b1[4], b1[5], b2[0], b2[1], b2[4], b2[5]);
 			}
@@ -130,25 +128,26 @@ void Update_CDC_TRansfer(int which)
 					Pico_mcd->cdc.DAC.N, dep, length);
 			dest = (unsigned short *) (Pico_mcd->word_ram2M + dep);
 
-			for (len = length; len > 0; len--, src+=2, dest++)
+			memcpy16bswap(dest, src, length);
-				*dest = (src[0]<<8) | src[1];
 
 			{ // debug
 				unsigned char *b1 = Pico_mcd->word_ram2M + dep;
-				unsigned char *b2 = (unsigned char *)dest - 4;
+				unsigned char *b2 = (unsigned char *)(dest+length) - 4;
 				dprintf("%02x %02x %02x %02x .. %02x %02x %02x %02x",
 					b1[0], b1[1], b1[2], b1[3], b2[0], b2[1], b2[2], b2[3]);
 			}
 		}
 	}
-	else if (which == 4) // PCM RAM
+	else if (which == 4) // PCM RAM (check: popful Mail)
 	{
-#if 0
+		dep = (DMA_Adr & 0x03FF) << 2;
-			dest = (unsigned char *) Ram_PCM;
+		dprintf("CD DMA # %04x -> PCM[%i] # %04x, len=%i",
-			dep = ((DMA_Adr & 0x03FF) << 2) + PCM_Chip.Bank;
+			Pico_mcd->cdc.DAC.N, Pico_mcd->pcm.bank, dep, length);
-#else
+		dest = (unsigned short *) (Pico_mcd->pcm_ram_b[Pico_mcd->pcm.bank] + dep);
-			dprintf("FIXME: CD DMA # %04x -> PCM", Pico_mcd->cdc.DAC.N);
+
-#endif
+		if (Pico_mcd->cdc.DAC.N & 1) /* unaligned src? */
+			memcpy(dest, src, length*2);
+		else	memcpy16(dest, (unsigned short *) src, length);
 	}
 	else if (which == 5) // PRG RAM
 	{
@@ -157,12 +156,11 @@ void Update_CDC_TRansfer(int which)
 		cdprintf("CD DMA # %04x -> prg_ram # %06x, len=%i",
 				Pico_mcd->cdc.DAC.N, dep, length);
 
-		for (len = length; len > 0; len--, src+=2, dest++)
+		memcpy16bswap(dest, src, length);
-			*dest = (src[0]<<8) | src[1];
 
 		{ // debug
 			unsigned char *b1 = Pico_mcd->prg_ram + dep;
-			unsigned char *b2 = (unsigned char *)dest - 4;
+			unsigned char *b2 = (unsigned char *)(dest+length) - 4;
 			dprintf("%02x %02x %02x %02x .. %02x %02x %02x %02x",
 				b1[0], b1[1], b1[2], b1[3], b2[0], b2[1], b2[2], b2[3]);
 		}

Pico/cd/Memory.c

@@ -421,6 +421,7 @@ u16 PicoReadM68k16(u32 a)
            a = (a&2) | (cell_map(a >> 2) << 2); // cell arranged
       else a &= 0x1fffe;
       d = *(u16 *)(Pico_mcd->word_ram1M[bank]+a);
+//d = 0xaaaa;
     } else {
       // allow access in any mode, like Gens does
       d = *(u16 *)(Pico_mcd->word_ram2M+(a&0x3fffe));
@@ -929,6 +930,63 @@ u32 PicoReadS68k32(u32 a)
 }
 
 
+/* check: jaguar xj 220 (draws entire world using decode) */
+static void decode_write8(u32 a, u8 d, int r3)
+{
+  u8 *pd = Pico_mcd->word_ram1M[!(r3 & 1)] + (((a>>1)^1)&0x1ffff);
+  u8 oldmask = (a&1) ? 0xf0 : 0x0f;
+
+  //if ((a & 0x3ffff) < 0x28000) return;
+  //return;
+
+  r3 &= 0x18;
+  d  &= 0x0f;
+  if (!(a&1)) d <<= 4;
+
+  //dprintf("FIXME: decode, r3 = %02x", r3);
+
+  if (r3 == 8) {
+    if ((!(*pd & (~oldmask))) && d) goto do_it;
+  } else if (r3 > 8) {
+    if (d) goto do_it;
+  } else {
+    goto do_it;
+  }
+
+  return;
+do_it:
+  *pd = d | (*pd & oldmask);
+}
+
+
+static void decode_write16(u32 a, u16 d, int r3)
+{
+  u8 *pd = Pico_mcd->word_ram1M[!(r3 & 1)] + (((a>>1)^1)&0x1ffff);
+
+  //if ((a & 0x3ffff) < 0x28000) return;
+
+  r3 &= 0x18;
+  d  &= 0x0f0f;
+  d  |= d >> 4;
+
+  if (r3 == 8) {
+    u8 dold = *pd;
+    if (!(dold & 0xf0)) dold |= d & 0xf0;
+    if (!(dold & 0x0f)) dold |= d & 0x0f;
+    *pd = dold;
+  } else if (r3 > 8) {
+    u8 dold = *pd;
+    if (!(d & 0xf0)) d |= dold & 0xf0;
+    if (!(d & 0x0f)) d |= dold & 0x0f;
+    *pd = d;
+  } else {
+    *pd = d;
+  }
+
+  //dprintf("FIXME: decode");
+}
+
+
 // -----------------------------------------------------------------
 
 void PicoWriteS68k8(u32 a,u8 d)
@@ -958,13 +1016,10 @@ void PicoWriteS68k8(u32 a,u8 d)
 
   // word RAM (2M area)
   if ((a&0xfc0000)==0x080000) { // 080000-0bffff
+    int r3 = Pico_mcd->s68k_regs[3];
     wrdprintf("s68k_wram2M w8: [%06x] %02x @%06x", a, d, SekPcS68k);
-    if (Pico_mcd->s68k_regs[3]&4) { // 1M decode mode?
+    if (r3 & 4) { // 1M decode mode?
-      int bank = !(Pico_mcd->s68k_regs[3]&1);
+      decode_write8(a, d, r3);
-      if (a&1) d &= 0x0f;
-      else d >>= 4;
-      Pico_mcd->word_ram1M[bank][((a>>1)^1)&0x1ffff]=d;
-      dprintf("FIXME: decode");
     } else {
       // allow access in any mode, like Gens does
       *(u8 *)(Pico_mcd->word_ram2M+((a^1)&0x3ffff))=d;
@@ -1039,12 +1094,10 @@ void PicoWriteS68k16(u32 a,u16 d)
 
   // word RAM (2M area)
   if ((a&0xfc0000)==0x080000) { // 080000-0bffff
+    int r3 = Pico_mcd->s68k_regs[3];
     wrdprintf("s68k_wram2M w16: [%06x] %04x @%06x", a, d, SekPcS68k);
-    if (Pico_mcd->s68k_regs[3]&4) { // 1M decode mode?
+    if (r3 & 4) { // 1M decode mode?
-      int bank = !(Pico_mcd->s68k_regs[3]&1);
+      decode_write16(a, d, r3);
-      d &= ~0xf0; d |= d >> 8;
-      Pico_mcd->word_ram1M[bank][((a>>1)^1)&0x1ffff] = d;
-      dprintf("FIXME: decode");
     } else {
       // allow access in any mode, like Gens does
       *(u16 *)(Pico_mcd->word_ram2M+(a&0x3fffe))=d;
@@ -1121,14 +1174,11 @@ void PicoWriteS68k32(u32 a,u32 d)
 
   // word RAM (2M area)
   if ((a&0xfc0000)==0x080000) { // 080000-0bffff
+    int r3 = Pico_mcd->s68k_regs[3];
     wrdprintf("s68k_wram2M w32: [%06x] %08x @%06x", a, d, SekPcS68k);
-    if (Pico_mcd->s68k_regs[3]&4) { // 1M decode mode?
+    if (r3 & 4) { // 1M decode mode?
-      int bank = !(Pico_mcd->s68k_regs[3]&1);
+      decode_write16(a  , d >> 16, r3);
-      a >>= 1;
+      decode_write16(a+2, d      , r3);
-      d &= 0x0f0f0f0f; d |= d >> 4;
-      Pico_mcd->word_ram1M[bank][((a+0)^1)&0x1ffff] = d >> 16;
-      Pico_mcd->word_ram1M[bank][((a+1)^1)&0x1ffff] = d;
-      dprintf("FIXME: decode");
     } else {
       // allow access in any mode, like Gens does
       u16 *pm=(u16 *)(Pico_mcd->word_ram2M+(a&0x3fffe));

Pico/cd/cd_file.c

@@ -141,24 +141,17 @@ void Unload_ISO(void)
 }
 
 
+void PicoCDBufferRead(void *dest, int lba);
+
+
 int FILE_Read_One_LBA_CDC(void)
 {
-	int where_read = 0;
 //	static char cp_buf[2560];
 
 	if (Pico_mcd->s68k_regs[0x36] & 1)					// DATA
 	{
 		if (Pico_mcd->TOC.Tracks[0].F == NULL) return -1;
 
-		if (Pico_mcd->scd.Cur_LBA < 0)
-			where_read = 0;
-		else if (Pico_mcd->scd.Cur_LBA >= Pico_mcd->TOC.Tracks[0].Length)
-			where_read = Pico_mcd->TOC.Tracks[0].Length - 1;
-		else where_read = Pico_mcd->scd.Cur_LBA;
-
-		if (Pico_mcd->TOC.Tracks[0].ftype == TYPE_ISO) where_read <<= 11;
-		else where_read = (where_read * 2352 + 16);
-
 		// moved below..
 		//fseek(Pico_mcd->TOC.Tracks[0].F, where_read, SEEK_SET);
 		//fread(cp_buf, 1, 2048, Pico_mcd->TOC.Tracks[0].F);
@@ -169,7 +162,7 @@ int FILE_Read_One_LBA_CDC(void)
 	{
 		// int rate, channel;
 
-		if (Pico_mcd->TOC.Tracks[Pico_mcd->scd.Cur_Track - 1].ftype == TYPE_MP3)
+		// if (Pico_mcd->TOC.Tracks[Pico_mcd->scd.Cur_Track - 1].ftype == TYPE_MP3)
 		{
 			// TODO
 			// MP3_Update(cp_buf, &rate, &channel, 0);
@@ -189,8 +182,16 @@ int FILE_Read_One_LBA_CDC(void)
 		{
 			if (Pico_mcd->cdc.CTRL.B.B0 & 0x04)	// WRRQ : this bit enable write to buffer
 			{
+				int where_read = 0;
+
 				// CAUTION : lookahead bit not implemented
 
+				if (Pico_mcd->scd.Cur_LBA < 0)
+					where_read = 0;
+				else if (Pico_mcd->scd.Cur_LBA >= Pico_mcd->TOC.Tracks[0].Length)
+					where_read = Pico_mcd->TOC.Tracks[0].Length - 1;
+				else where_read = Pico_mcd->scd.Cur_LBA;
+
 				Pico_mcd->scd.Cur_LBA++;
 
 				Pico_mcd->cdc.WA.N = (Pico_mcd->cdc.WA.N + 2352) & 0x7FFF;		// add one sector to WA
@@ -199,8 +200,9 @@ int FILE_Read_One_LBA_CDC(void)
 				*(unsigned int *)(Pico_mcd->cdc.Buffer + Pico_mcd->cdc.PT.N) = Pico_mcd->cdc.HEAD.N;
 				//memcpy(&Pico_mcd->cdc.Buffer[Pico_mcd->cdc.PT.N + 4], cp_buf, 2048);
 
-				pm_seek(Pico_mcd->TOC.Tracks[0].F, where_read, SEEK_SET);
+				//pm_seek(Pico_mcd->TOC.Tracks[0].F, where_read, SEEK_SET);
-				pm_read(Pico_mcd->cdc.Buffer + Pico_mcd->cdc.PT.N + 4, 2048, Pico_mcd->TOC.Tracks[0].F);
+				//pm_read(Pico_mcd->cdc.Buffer + Pico_mcd->cdc.PT.N + 4, 2048, Pico_mcd->TOC.Tracks[0].F);
+				PicoCDBufferRead(Pico_mcd->cdc.Buffer + Pico_mcd->cdc.PT.N + 4, where_read);
 
 #ifdef DEBUG_CD
 				cdprintf("Read -> WA = %d  Buffer[%d] =", Pico_mcd->cdc.WA.N, Pico_mcd->cdc.PT.N & 0x3FFF);

Pico/cd/gfx_cd.c

@@ -210,7 +210,7 @@ void gfx_cd_reset(void)
 
 typedef unsigned short u16;
 
-// check: Heart of the alien
+// check: Heart of the alien, jaguar xj 220
 void DmaSlowCell(unsigned int source, unsigned int a, int len, unsigned char inc)
 {
   unsigned char *base;

Pico/misc.s

@@ -40,6 +40,84 @@ mcp16_cant_align:
 
 
 
+@ 0x12345678 -> 0x34127856
+@ r4=temp, lr=0x00ff00ff
+.macro bswap reg
+    and     r4,   \reg, lr
+    and     \reg, lr,   \reg, lsr #8
+    orr     \reg, \reg, r4,   lsl #8
+.endm
+
+
+@ dest must be halfword aligned, src can be unaligned
+.global memcpy16bswap @ unsigned short *dest, void *src, int count
+
+memcpy16bswap:
+    tst     r1, #1
+    bne     mcp16bs_cant_align2
+
+    eor     r3, r0, r1
+    tst     r3, #2
+    bne     mcp16bs_cant_align
+
+    tst     r0, #2
+    beq     mcp16bs_aligned
+    ldrh    r3, [r1], #2
+    sub     r2, r2, #1
+    orr     r3, r3, r3, lsl #16
+    mov     r3, r3, lsr #8
+    strh    r3, [r0], #2
+
+mcp16bs_aligned:
+    stmfd   sp!, {r4,lr}
+    mov     lr, #0xff
+    orr     lr, lr, lr, lsl #16
+
+    subs    r2, r2, #4
+    bmi     mcp16bs_fin4
+
+mcp16bs_loop:
+    ldmia   r1!, {r3,r12}
+    subs    r2, r2, #4
+    bswap   r3
+    bswap   r12
+    stmia   r0!, {r3,r12}
+    bpl     mcp16bs_loop
+
+mcp16bs_fin4:
+    tst     r2, #2
+    beq     mcp16bs_fin2
+    ldr     r3, [r1], #4
+    bswap   r3
+    str     r3, [r0], #4
+
+mcp16bs_fin2:
+    ldmfd   sp!, {r4,lr}
+    ands    r2, r2, #1
+    bxeq    lr
+
+mcp16bs_cant_align:
+    ldrh    r3, [r1], #2
+    subs    r2, r2, #1
+    orr     r3, r3, r3, lsl #16
+    mov     r3, r3, lsr #8
+    strh    r3, [r0], #2
+    bne     mcp16bs_cant_align
+    bx      lr
+
+    @ worst case
+mcp16bs_cant_align2:
+    ldrb    r3, [r1], #1
+    ldrb    r12,[r1], #1
+    subs    r2, r2, #1
+    mov     r3, r3, lsl #8
+    orr     r3, r3, r12
+    strh    r3, [r0], #2
+    bne     mcp16bs_cant_align2
+    bx      lr
+
+
+
 .global memcpy32 @ int *dest, int *src, int count
 
 memcpy32:

platform/gp2x/Makefile

@@ -43,7 +43,7 @@ OBJS += ../../Pico/Area.o ../../Pico/Cart.o ../../Pico/Utils.o ../../Pico/Memory
 # Pico - CD
 OBJS += ../../Pico/cd/Pico.o ../../Pico/cd/Memory.o ../../Pico/cd/Sek.o ../../Pico/cd/LC89510.o \
 		../../Pico/cd/cd_sys.o ../../Pico/cd/cd_file.o ../../Pico/cd/gfx_cd.o \
-		../../Pico/cd/Area.o ../../Pico/cd/Misc.o ../../Pico/cd/pcm.o
+		../../Pico/cd/Area.o ../../Pico/cd/Misc.o ../../Pico/cd/pcm.o ../../Pico/cd/buffering.o
 # asm stuff
 ifeq "$(asm_render)" "1"
 DEFINC += -D_ASM_DRAW_C

platform/gp2x/emu.c

@@ -496,6 +496,7 @@ int emu_ReadConfig(int game)
 		currentConfig.KeyBinds[23] = 1<<29; // vol up
 		currentConfig.KeyBinds[22] = 1<<30; // vol down
 		currentConfig.gamma = 100;
+		currentConfig.PicoCDBuffers = 64;
 		strncpy(cfg, PicoConfigFile, 511);
 		cfg[511] = 0;
 	} else {
@@ -517,6 +518,7 @@ int emu_ReadConfig(int game)
 	PsndRate = currentConfig.PsndRate;
 	PicoRegionOverride = currentConfig.PicoRegion;
 	PicoAutoRgnOrder = currentConfig.PicoAutoRgnOrder;
+	PicoCDBuffers = currentConfig.PicoCDBuffers;
 	if (PicoOpt & 0x20) {
 		actionNames[ 8] = "Z"; actionNames[ 9] = "Y";
 		actionNames[10] = "X"; actionNames[11] = "MODE";
@@ -555,6 +557,7 @@ int emu_WriteConfig(int game)
 		currentConfig.PsndRate = PsndRate;
 		currentConfig.PicoRegion = PicoRegionOverride;
 		currentConfig.PicoAutoRgnOrder = PicoAutoRgnOrder;
+		currentConfig.PicoCDBuffers = PicoCDBuffers;
 		bwrite = fwrite(&currentConfig, 1, sizeof(currentConfig), f);
 		fflush(f);
 		fclose(f);
@@ -1068,6 +1071,9 @@ void emu_Loop(void)
 		PsndOut = 0;
 	}
 
+	// prepare CD buffer
+	if (PicoMCD & 1) PicoCDBufferInit();
+
 	// loop?
 	while (engineState == PGS_Running)
 	{
@@ -1253,6 +1259,9 @@ if (Pico.m.frame_count == 31563) {
 		frames_done++; frames_shown++;
 	}
 
+
+	if (PicoMCD & 1) PicoCDBufferFree();
+
 	// save SRAM
 	if((currentConfig.EmuOpt & 1) && SRam.changed) {
 		osd_text(4, 232, "Writing SRAM/BRAM..");

platform/gp2x/emu.h

@@ -31,6 +31,7 @@ typedef struct {
 	int gamma;
 	int JoyBinds[4][32];
 	int PicoAutoRgnOrder;
+	int PicoCDBuffers;
 } currentConfig_t;
 
 extern char romFileName[];

platform/gp2x/menu.c

@@ -729,6 +729,10 @@ static void kc_sel_loop(void)
 static void draw_cd_menu_options(int menu_sel, char *b_us, char *b_eu, char *b_jp)
 {
 	int tl_x = 25, tl_y = 60, y;
+	char ra_buff[16];
+
+	if (PicoCDBuffers > 1) sprintf(ra_buff, "%5iK", PicoCDBuffers * 2);
+	else strcpy(ra_buff, "     OFF");
 
 	y = tl_y;
 	//memset(gp2x_screen, 0, 320*240);
@@ -741,6 +745,7 @@ static void draw_cd_menu_options(int menu_sel, char *b_us, char *b_eu, char *b_j
 	gp2x_text_out8(tl_x, (y+=10), "CDDA audio (using mp3s)    %s", (currentConfig.PicoOpt&0x0800)?"ON":"OFF"); // 4
 	gp2x_text_out8(tl_x, (y+=10), "PCM audio                  %s", (currentConfig.PicoOpt&0x0400)?"ON":"OFF"); // 5
 	gp2x_text_out8(tl_x, (y+=10), "Better sync (very slow)    %s", (currentConfig.PicoOpt&0x2000)?"ON":"OFF"); // 6
+	gp2x_text_out8(tl_x, (y+=10), "ReadAhead buffer      %s", ra_buff); // 7
 	gp2x_text_out8(tl_x, (y+=10), "Done");
 
 	// draw cursor
@@ -756,7 +761,7 @@ static void draw_cd_menu_options(int menu_sel, char *b_us, char *b_eu, char *b_j
 
 static void cd_menu_loop_options(void)
 {
-	int menu_sel = 0, menu_sel_max = 7;
+	int menu_sel = 0, menu_sel_max = 8;
 	unsigned long inp = 0;
 	char bios_us[32], bios_eu[32], bios_jp[32], *bios, *p;
 
@@ -787,7 +792,17 @@ static void cd_menu_loop_options(void)
 				case  4: currentConfig.PicoOpt^=0x0800; break;
 				case  5: currentConfig.PicoOpt^=0x0400; break;
 				case  6: currentConfig.PicoOpt^=0x2000; break;
-				case  7: return;
+				case  7:
+					if (inp & GP2X_LEFT) {
+						PicoCDBuffers >>= 1;
+						if (PicoCDBuffers < 64) PicoCDBuffers = 0;
+					} else {
+						if (PicoCDBuffers < 64) PicoCDBuffers = 64;
+						else PicoCDBuffers <<= 1;
+						if (PicoCDBuffers > 4096) PicoCDBuffers = 4096;
+					}
+					break;
+				case  8: return;
 			}
 		}
 		if(inp & (GP2X_X|GP2X_A)) return;

platform/linux/Makefile

@@ -32,7 +32,7 @@ OBJS += ../../Pico/Area.o ../../Pico/Cart.o ../../Pico/Utils.o ../../Pico/Memory
 # Pico - CD
 OBJS += ../../Pico/cd/Pico.o ../../Pico/cd/Memory.o ../../Pico/cd/Sek.o ../../Pico/cd/LC89510.o \
 		../../Pico/cd/cd_sys.o ../../Pico/cd/cd_file.o ../../Pico/cd/gfx_cd.o \
-		../../Pico/cd/Area.o ../../Pico/cd/Misc.o ../../Pico/cd/pcm.o
+		../../Pico/cd/Area.o ../../Pico/cd/Misc.o ../../Pico/cd/pcm.o ../../Pico/cd/buffering.o
 # Pico - sound
 OBJS += ../../Pico/sound/sound.o ../../Pico/sound/sn76496.o ../../Pico/sound/ym2612.o ../../Pico/sound/mix.o
 # zlib

platform/readme.txt

@@ -3,43 +3,149 @@ About
 -----
 
 This version of PicoDrive is another enhanced version of Dave's
-Megadrive / Genesis emulator for Pocket PC. The original Dave's code was
+Megadrive / Genesis emulator for Pocket PC, which now can also emulate
-heavily modified (including Cyclone core), parts of it were rewritten in
+Sega/Mega CD. The original Dave's code was heavily modified (including
-asm, many features added, accuracy increased. This version is aimed at
+Cyclone core), parts of it were rewritten in asm, many features added,
-ARM-based handheld devices, so ports exist for GP2X handheld console,
+accuracy increased. Sega/Mega CD emulation is mostly based on Gens code.
-Symbian smartphones and PocketPC devices.
+This version is aimed at ARM-based handheld devices, so ports exist for
+GP2X handheld console, Symbian smartphones and other devices.
 
 
 How to make it run
 ------------------
 
-GP2X:
 Copy PicoDrive.gpe, code940.bin and mmuhack.o to any place in your filesystem
 (all 3 files must be in the same directory) and run PicoDrive.gpe.
-Then load a ROM and enjoy!
+Then load a ROM and enjoy! ROMs can be in .smd or .bin format and can be zipped.
 
-Symbian:
-Select PicoDrive from application (tools) menu and run it. That's it!
-
-All:
 If you have any problems (game does not boot, sound is glitchy, broken graphics),
 make sure you enable "Accurate timing", "Emulate Z80" and then disable
 "Fast renderer". This way you will get the best compatibility this emulator can
 provide.
 
 
+How to run Sega/Mega CD games
+-----------------------------
+
+To play any game, you need BIOS files. These files must be copied to the same
+directory as PicoDrive.gpe. Files can be named as follows:
+US: us_scd1_9210.bin us_scd2_9306.bin SegaCDBIOS9303.bin
+EU: eu_mcd1_9210.bin eu_mcd2_9303.bin eu_mcd2_9306.bin
+JP: jp_mcd1_9112.bin jp_mcd1_9111.bin
+these files can also be zipped.
+
+The game must be dumped to ISO format, but BIN can be used too. If you want
+CD music, you must use ISO+mp3 files. Audio from BIN files won't be read at
+all due to SD access issues. Also BIN files are usually larger, so it's better
+to use ISO. ISO+mp3 files can be named similarly as for other emus.
+Here are some examples:
+
+SonicCD.iso             data track
+SonicCD_02.mp3          audio track 1 (CD track 2)
+SonicCD_03.mp3
+...
+
+Sonic the Hedgehog CD (US) - Track 01.iso
+Sonic the Hedgehog CD (US) - Track 02.mp3
+Sonic the Hedgehog CD (US) - Track 03.mp3
+...
+
+ISO files can also be zipped (but not mp3 files, as they are already
+compressed). Note that this can cause very long loading times, which may
+take up to several minutes. File naming is similar as with uncompressed ISOs.
+Example:
+
+SonicCD.zip             data track
+SonicCD_02.mp3          audio track 1 (CD track 2)
+SonicCD_03.mp3
+...
+
+
 Configuration
 -------------
 
 See config.txt file.
 
 
+Other important stuff
+---------------------
+
+* When you use both GP2X CPUs, keep in mind that you can't overclock as high as
+  when using ARM920 only. For example my GP2X when run singlecore can reach
+  280MHz, but with both cores it's about 250MHz. When overclocked too much,
+  it may start hanging and producing random noise.
+* PicoDrive is not a mp3 player, so all mp3s MUST be encoded at 44.1kHz stereo.
+  Otherwise mp3s will play too fast or too slow.
+* Due to internal implementation mp3s must not be larger that ~15MB
+  (15548416 bytes). Larger mp3s will not be fully loaded.
+* Use lower bitrate for better performance (96 or 128kbps CBRs recommended).
+* RAM timings option is good for dualcore operation (it is disabled by
+  default because it doesn't work on every GP2X, so enable it in advanced
+  options).
+
+
+Cheat support
+-------------
+
+To use GG/patch codes, you must type them into your favorite text editor, one
+per line. Comments may follow code after a whitespace. Only GameGenie and
+Genecyst patch formats are supported.
+Examples:
+
+Genecyst patch (this example is for Sonic):
+
+00334A:0005 Start with five lives
+012D24:0001 Keep invincibility until end of stage
+009C76:5478 each ring worth 2
+009C76:5678 each ring worth 3
+...
+
+Game Genie patch (for Sonic 2):
+
+ACLA-ATD4 Hidden palace instead of death egg in level select
+...
+
+Both GG and patch codes can be mixed in one file.
+
+When the file is ready, name it just like your ROM file, but with additional
+.pat extension, making sure that case matches.
+
+Examples:
+
+ROM: Sonic.zip
+PATCH FILE: Sonic.zip.pat
+
+ROM: Sonic 2.bin
+PATCH FILE: Sonic 2.bin.pat
+
+Put the file into your ROMs directory. Then load the .pat file as you would
+a ROM. Then Cheat Menu Option should appear in main menu.
+
+
+What is emulated?
+-----------------
+
+Genesis/MegaDrive:
+main 68k @ 7.6MHz: yes, Cyclone core
+z80 @ 3.6MHz: yes, DrZ80 core
+VDP: yes, except some quirks not used by games
+YM2612 FM: yes, optimized MAME core
+SN76489 PSG: yes, MAME core
+
+Sega/Mega CD:
+another 68k @ 12.5MHz: yes, Cyclone too
+gfx scaling/rotation chip (custom ASIC): not yet (faked only)
+PCM sound source: yes
+CD-ROM controller: yes (mostly)
+bram (internal backup RAM): yes
+
+
 Problems / limitations
 ----------------------
 
-* 32x, Sega CD, SVP are not emulated.
+* 32x and SVP are not emulated.
 * Various VDP quirks (window bug, scroll size 2, etc.) are not emulated,
-  as very few games use this.
+  as very few games use this (if any at all).
 * Some games don't work or have glitches because of inaccurate timing and sync
   between the emulated chips.
 
@@ -67,13 +173,18 @@ MultiArcadeMachineEmulator (MAME) development
 Texas Instruments SN76489 / SN76496 programmable tone /noise generator
 Homepage: http://www.mame.net/
 
+Stephane Dallongeville
+Gens, MD/Mega CD/32X emulator. Most Sega CD code is based on this emu.
+
+Helix community
+Helix mp3 decoder
+
 
 Additional thanks
 -----------------
 
 * Charles MacDonald (http://cgfm2.emuviews.com/) for old but still very useful
   info about genesis hardware.
-* Stéphane Dallongeville for creating Gens and making it open-source.
 * Steve Snake for all that he has done for Genesis emulation scene.
 * Bart Trzynadlowski for his SSFII and 68000 docs.
 * Haze for his research (http://haze.mameworld.info).
@@ -100,6 +211,47 @@ Symbian:
 
 Changelog
 ---------
+1.2x
+  + ISO files now can be zipped. Note that this causes VERY long loading times.
+  + Added data pre-buffering support, this allows to reduce frequency of short pauses
+    in FMV games, but makes those pauses longer.
+  * Fixed PCM DMA transfers (intro FMV in Popful Mail).
+
+1.201
+  + Added basic cheat support (GameGenie and Genecyst patches).
+
+1.20
+  * Fixed a long-standing problem in audio mixing code which caused slight distortions
+    at lower sample rates.
+  * Changed the way 920 and 940 communicates (again), should be more reliable and give
+    slight performance increase.
+  * Some optimizations in audio mixing code.
+  * Some menu changes (background added, smaller font in ROM browser, savestate loader
+    now can select slots).
+  + 1M mode DMA transfers implemented (used by FMV games like Night Trap and Sewer Shark).
+  + Games now can run code from WORD RAM in 1M mode (fixes Adventures of Willy Beamish).
+  + "Cell arrange" address mapping is now emulated (Heart of the alien).
+  + "Color numeric operation" is now emulated (text in Lunar 2, Silpheed intro graphics).
+  + "Better sync" option added (prevents some games from hanging).
+
+1.14
+  + Region autodetection now can be customized.
+  * When CDDA music tracks changed, old buffer contents were incorrectly played. Fixed.
+  * BRAM is now automatically formatted (no need to enter BIOS menu and format any more).
+  * Games now can be reset, CDDA music no longer breaks after loading another ISO.
+  * Fixed a race condition between 920 and 940 which sometimes caused CDDA music not to play.
+  + Savestates implemented for Sega/Mega CD.
+  + PCM sound added.
+  * Some mixer code rewritten in asm. 22kHz and 11kHz sound rates are now supported in
+    Mega CD mode (but mp3s must still be 44kHz stereo).
+  + Timer emulation added.
+  * CDC DMA tansfers fixed. Snatcher and probably some more games now boot.
+  * 2M word RAM -> VDP transfers fixed, no more corruption in Ecco and some other games.
+
+1.10
+  + GP2X: Added experimental Sega CD support.
+  + GP2X: Added partial gmv movie playback support.
+
 0.964
   * GP2X: Fixed a sound buffer underflow issue on lower sample rate modes, which was
           happening for NTSC games and causing sound clicks.
@@ -299,3 +451,7 @@ INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
 POSSIBILITY OF SUCH DAMAGE. 
+
+SEGA/Genesis/MegaDrive/SEGA-CD/Mega-CD/32X are trademarks of
+Sega Enterprises Ltd.
+