fceux/boards/mmc1.c

/* FCE Ultra - NES/Famicom Emulator
 *
 * Copyright notice for this file:
 *  Copyright (C) 1998 BERO
 *  Copyright (C) 2002 Xodnizel
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "mapinc.h"

static void GenMMC1Power(void);
static void GenMMC1Init(CartInfo *info, int prg, int chr, int wram, int battery);

static uint8 DRegs[4];
static uint8 Buffer,BufferShift;

static int mmc1opts;

static void (*MMC1CHRHook4)(uint32 A, uint8 V);
static void (*MMC1PRGHook16)(uint32 A, uint8 V);

static uint8 *WRAM=NULL;
static uint8 *CHRRAM=NULL;
static int is155;

static DECLFW(MBWRAM)
{
  if(!(DRegs[3]&0x10)||is155)
    Page[A>>11][A]=V;     // WRAM is enabled.
}

static DECLFR(MAWRAM)
{
  if((DRegs[3]&0x10)&&!is155)
    return X.DB;          // WRAM is disabled
  return(Page[A>>11][A]);
}

static void MMC1CHR(void)
{
  if(mmc1opts&4)
  {
    if(DRegs[0]&0x10)
      setprg8r(0x10,0x6000,(DRegs[1]>>4)&1);
    else
      setprg8r(0x10,0x6000,(DRegs[1]>>3)&1);
  }
  if(MMC1CHRHook4)
  {
    if(DRegs[0]&0x10)
    {
      MMC1CHRHook4(0x0000,DRegs[1]);
      MMC1CHRHook4(0x1000,DRegs[2]);
    }
    else
    {
      MMC1CHRHook4(0x0000,(DRegs[1]&0xFE));
      MMC1CHRHook4(0x1000,DRegs[1]|1);
    }
  }
  else
  {
    if(DRegs[0]&0x10)
    {
      setchr4(0x0000,DRegs[1]);
      setchr4(0x1000,DRegs[2]);
    }
    else
      setchr8(DRegs[1]>>1);
  }
}

static void MMC1PRG(void)
{
  uint8 offs=DRegs[1]&0x10;
  if(MMC1PRGHook16)
  {
    switch(DRegs[0]&0xC)
    {
      case 0xC: MMC1PRGHook16(0x8000,(DRegs[3]+offs));
                MMC1PRGHook16(0xC000,0xF+offs);
                break;
      case 0x8: MMC1PRGHook16(0xC000,(DRegs[3]+offs));
                MMC1PRGHook16(0x8000,offs);
                break;
      case 0x0:
      case 0x4:
                MMC1PRGHook16(0x8000,((DRegs[3]&~1)+offs));
                MMC1PRGHook16(0xc000,((DRegs[3]&~1)+offs+1));
                break;
    }
  }
  else switch(DRegs[0]&0xC)
  {
    case 0xC: setprg16(0x8000,(DRegs[3]+offs));
              setprg16(0xC000,0xF+offs);
              break;
    case 0x8: setprg16(0xC000,(DRegs[3]+offs));
              setprg16(0x8000,offs);
              break;
    case 0x0:
    case 0x4:
              setprg16(0x8000,((DRegs[3]&~1)+offs));
              setprg16(0xc000,((DRegs[3]&~1)+offs+1));
              break;
  }
}

static void MMC1MIRROR(void)
{
  switch(DRegs[0]&3)
  {
    case 2: setmirror(MI_V); break;
    case 3: setmirror(MI_H); break;
    case 0: setmirror(MI_0); break;
    case 1: setmirror(MI_1); break;
  }
}

static uint64 lreset;
static DECLFW(MMC1_write)
{
  int n=(A>>13)-4;
  //FCEU_DispMessage("%016x",timestampbase+timestamp);
  //printf("$%04x:$%02x, $%04x\n",A,V,X.PC);
  //DumpMem("out",0xe000,0xffff);

  /* The MMC1 is busy so ignore the write. */
  /* As of version FCE Ultra 0.81, the timestamp is only
     increased before each instruction is executed(in other words
     precision isn't that great), but this should still work to
     deal with 2 writes in a row from a single RMW instruction. */
  if((timestampbase+timestamp)<(lreset+2)) return;
  if(V&0x80)
  {
    DRegs[0]|=0xC;
    BufferShift=Buffer=0;
    MMC1PRG();
    lreset=timestampbase+timestamp;
    return;
  }
  Buffer|=(V&1)<<(BufferShift++);
  if(BufferShift==5)
  {
    DRegs[n] = Buffer;
    BufferShift = Buffer = 0;
    switch(n)
    {
      case 0: MMC1MIRROR(); MMC1CHR(); MMC1PRG(); break;
      case 1: MMC1CHR(); MMC1PRG(); break;
      case 2: MMC1CHR(); break;
      case 3: MMC1PRG(); break;
    }
  }
}

static void MMC1_Restore(int version)
{
  MMC1MIRROR();
  MMC1CHR();
  MMC1PRG();
  lreset=0;        /* timestamp(base) is not stored in save states. */
}

static void MMC1CMReset(void)
{
  int i;
  for(i=0;i<4;i++)
     DRegs[i]=0;
  Buffer = BufferShift = 0;
  DRegs[0]=0x1F;
  DRegs[1]=0;
  DRegs[2]=0;                  // Should this be something other than 0?
  DRegs[3]=0;

  MMC1MIRROR();
  MMC1CHR();
  MMC1PRG();
}

static int DetectMMC1WRAMSize(uint32 crc32)
{
  switch(crc32)
  {
    case 0xc6182024:       /* Romance of the 3 Kingdoms */
    case 0x2225c20f:       /* Genghis Khan */
    case 0x4642dda6:       /* Nobunaga's Ambition */
    case 0x29449ba9:       /* ""        "" (J) */
    case 0x2b11e0b0:       /* ""        "" (J) */
    case 0xb8747abf:       /* Best Play Pro Yakyuu Special (J) */
    case 0xc9556b36:       /* Final Fantasy I & II (J) [!] */
         FCEU_printf(" >8KB external WRAM present.  Use UNIF if you hack the ROM image.\n");
         return(16);
         break;
    default:return(8);
  }
}

static uint32 NWCIRQCount;
static uint8 NWCRec;
#define NWCDIP 0xE

static void FP_FASTAPASS(1) NWCIRQHook(int a)
{
  if(!(NWCRec&0x10))
  {
    NWCIRQCount+=a;
    if((NWCIRQCount|(NWCDIP<<25))>=0x3e000000)
    {
      NWCIRQCount=0;
      X6502_IRQBegin(FCEU_IQEXT);
    }
  }
}

static void NWCCHRHook(uint32 A, uint8 V)
{
  if((V&0x10)) // && !(NWCRec&0x10))
  {
    NWCIRQCount=0;
    X6502_IRQEnd(FCEU_IQEXT);
  }
  NWCRec=V;
  if(V&0x08)
    MMC1PRG();
  else
    setprg32(0x8000,(V>>1)&3);
}

static void NWCPRGHook(uint32 A, uint8 V)
{
  if(NWCRec&0x8)
    setprg16(A,8|(V&0x7));
  else
    setprg32(0x8000,(NWCRec>>1)&3);
}

static void NWCPower(void)
{
  GenMMC1Power();
  setchr8r(0,0);
}

void Mapper105_Init(CartInfo *info)
{
  GenMMC1Init(info, 256, 256, 8, 0);
  MMC1CHRHook4=NWCCHRHook;
  MMC1PRGHook16=NWCPRGHook;
  MapIRQHook=NWCIRQHook;
  info->Power=NWCPower;
}

static void GenMMC1Power(void)
{
  lreset=0;
  if(mmc1opts&1)
  {
    FCEU_CheatAddRAM(8,0x6000,WRAM);
    if(mmc1opts&4)
      FCEU_dwmemset(WRAM,0,8192)
    else if(!(mmc1opts&2))
      FCEU_dwmemset(WRAM,0,8192);
  }
  SetWriteHandler(0x8000,0xFFFF,MMC1_write);
  SetReadHandler(0x8000,0xFFFF,CartBR);

  if(mmc1opts&1)
  {
    SetReadHandler(0x6000,0x7FFF,MAWRAM);
    SetWriteHandler(0x6000,0x7FFF,MBWRAM);
    setprg8r(0x10,0x6000,0);
  }

  MMC1CMReset();
}

static void GenMMC1Close(void)
{
  if(CHRRAM)
    FCEU_gfree(CHRRAM);
  if(WRAM)
    FCEU_gfree(WRAM);
  CHRRAM=WRAM=NULL;
}

static void GenMMC1Init(CartInfo *info, int prg, int chr, int wram, int battery)
{
  is155=0;

  info->Close=GenMMC1Close;
  MMC1PRGHook16=MMC1CHRHook4=0;
  mmc1opts=0;
  PRGmask16[0]&=(prg>>14)-1;
  CHRmask4[0]&=(chr>>12)-1;
  CHRmask8[0]&=(chr>>13)-1;

  if(wram)
  {
    WRAM=(uint8*)FCEU_gmalloc(wram*1024);
    mmc1opts|=1;
    if(wram>8) mmc1opts|=4;
    SetupCartPRGMapping(0x10,WRAM,wram*1024,1);
    AddExState(WRAM, wram*1024, 0, "WRAM");
    if(battery)
    {
      mmc1opts|=2;
      info->SaveGame[0]=WRAM+((mmc1opts&4)?8192:0);
      info->SaveGameLen[0]=8192;
    }
  }
  if(!chr)
  {
    CHRRAM=(uint8*)FCEU_gmalloc(8192);
    SetupCartCHRMapping(0, CHRRAM, 8192, 1);
    AddExState(CHRRAM, 8192, 0, "CHRR");
  }
  AddExState(DRegs, 4, 0, "DREG");

  info->Power=GenMMC1Power;
  GameStateRestore=MMC1_Restore;
  AddExState(&lreset, 8, 1, "LRST");
}

void Mapper1_Init(CartInfo *info)
{
  int ws=DetectMMC1WRAMSize(info->CRC32);
  GenMMC1Init(info, 512, 256, ws, info->battery);
}

/* Same as mapper 1, without respect for WRAM enable bit. */
void Mapper155_Init(CartInfo *info)
{
  GenMMC1Init(info,512,256,8,info->battery);
  is155=1;
}

void SAROM_Init(CartInfo *info)
{
  GenMMC1Init(info, 128, 64, 8, info->battery);
}

void SBROM_Init(CartInfo *info)
{
  GenMMC1Init(info, 128, 64, 0, 0);
}

void SCROM_Init(CartInfo *info)
{
  GenMMC1Init(info, 128, 128, 0, 0);
}

void SEROM_Init(CartInfo *info)
{
  GenMMC1Init(info, 32, 64, 0, 0);
}

void SGROM_Init(CartInfo *info)
{
  GenMMC1Init(info, 256, 0, 0, 0);
}

void SKROM_Init(CartInfo *info)
{
  GenMMC1Init(info, 256, 64, 8, info->battery);
}

void SLROM_Init(CartInfo *info)
{
  GenMMC1Init(info, 256, 128, 0, 0);
}

void SL1ROM_Init(CartInfo *info)
{
  GenMMC1Init(info, 128, 128, 0, 0);
}

/* Begin unknown - may be wrong - perhaps they use different MMC1s from the
   similarly functioning boards?
*/

void SL2ROM_Init(CartInfo *info)
{
  GenMMC1Init(info, 256, 256, 0, 0);
}

void SFROM_Init(CartInfo *info)
{
  GenMMC1Init(info, 256, 256, 0, 0);
}

void SHROM_Init(CartInfo *info)
{
  GenMMC1Init(info, 256, 256, 0, 0);
}

/* End unknown  */
/*              */
/*              */

void SNROM_Init(CartInfo *info)
{
  GenMMC1Init(info, 256, 0, 8, info->battery);
}

void SOROM_Init(CartInfo *info)
{
  GenMMC1Init(info, 256, 0, 16, info->battery);
}