picodrive/pico/pico.c

/*
 * PicoDrive
 * (c) Copyright Dave, 2004
 * (C) notaz, 2006-2010
 *
 * This work is licensed under the terms of MAME license.
 * See COPYING file in the top-level directory.
 */

#include "pico_int.h"
#include "sound/ym2612.h"

struct Pico Pico;
struct PicoMem PicoMem;
PicoInterface PicoIn;

void (*PicoResetHook)(void) = NULL;
void (*PicoLineHook)(void) = NULL;

// to be called once on emu init
void PicoInit(void)
{
  // Blank space for state:
  memset(&Pico,0,sizeof(Pico));
  memset(&PicoMem,0,sizeof(PicoMem));
  memset(&PicoIn.pad,0,sizeof(PicoIn.pad));
  memset(&PicoIn.padInt,0,sizeof(PicoIn.padInt));

  Pico.est.Pico = &Pico;
  Pico.est.PicoMem_vram = PicoMem.vram;
  Pico.est.PicoMem_cram = PicoMem.cram;
  Pico.est.PicoOpt = &PicoIn.opt;

  // Init CPUs:
  SekInit();
  z80_init(); // init even if we aren't going to use it

  PicoInitMCD();
  PicoSVPInit();
  Pico32xInit();
  PsndInit();

  PicoVideoInit();
  PicoDrawInit();
  PicoDraw2Init();
}

// to be called once on emu exit
void PicoExit(void)
{
  if (PicoIn.AHW & PAHW_MCD)
    PicoExitMCD();
  PicoCartUnload();
  z80_exit();
  PsndExit();

  free(Pico.sv.data);
  Pico.sv.data = NULL;
  Pico.sv.start = Pico.sv.end = 0;
  pevt_dump();
}

void PicoPower(void)
{
  Pico.m.frame_count = 0;
  Pico.t.m68c_cnt = Pico.t.m68c_aim = 0;

  // clear all memory of the emulated machine
  memset(&PicoMem,0,sizeof(PicoMem));

  memset(&Pico.video,0,sizeof(Pico.video));
  memset(&Pico.m,0,sizeof(Pico.m));
  memset(&Pico.t,0,sizeof(Pico.t));

  Pico.video.pending_ints=0;
  z80_reset();

  // my MD1 VA6 console has this in IO
  PicoMem.ioports[1] = PicoMem.ioports[2] = PicoMem.ioports[3] = 0xff;

  // default VDP register values (based on Fusion)
  Pico.video.reg[0] = Pico.video.reg[1] = 0x04;
  Pico.video.reg[0xc] = 0x81;
  Pico.video.reg[0xf] = 0x02;
  PicoVideoFIFOMode(0, 1);

  if (PicoIn.AHW & PAHW_MCD)
    PicoPowerMCD();

  if (PicoIn.opt & POPT_EN_32X)
    PicoPower32x();

  PicoReset();
}

PICO_INTERNAL void PicoDetectRegion(void)
{
  int support=0, hw=0, i;
  unsigned char pal=0;

  if (PicoIn.regionOverride)
  {
    support = PicoIn.regionOverride;
  }
  else
  {
    // Read cartridge region data:
    unsigned short *rd = (unsigned short *)(Pico.rom + 0x1f0);
    int region = (rd[0] << 16) | rd[1];

    for (i = 0; i < 4; i++)
    {
      int c;

      c = region >> (i<<3);
      c &= 0xff;
      if (c <= ' ') continue;

           if (c=='J')  support|=1;
      else if (c=='U')  support|=4;
      else if (c=='E')  support|=8;
      else if (c=='j') {support|=1; break; }
      else if (c=='u') {support|=4; break; }
      else if (c=='e') {support|=8; break; }
      else
      {
        // New style code:
        char s[2]={0,0};
        s[0]=(char)c;
        support|=strtol(s,NULL,16);
      }
    }
  }

  // auto detection order override
  if (PicoIn.autoRgnOrder) {
         if (((PicoIn.autoRgnOrder>>0)&0xf) & support) support = (PicoIn.autoRgnOrder>>0)&0xf;
    else if (((PicoIn.autoRgnOrder>>4)&0xf) & support) support = (PicoIn.autoRgnOrder>>4)&0xf;
    else if (((PicoIn.autoRgnOrder>>8)&0xf) & support) support = (PicoIn.autoRgnOrder>>8)&0xf;
  }

  // Try to pick the best hardware value for English/50hz:
       if (support&8) { hw=0xc0; pal=1; } // Europe
  else if (support&4)   hw=0x80;          // USA
  else if (support&2) { hw=0x40; pal=1; } // Japan PAL
  else if (support&1)   hw=0x00;          // Japan NTSC
  else hw=0x80; // USA

  Pico.m.hardware=(unsigned char)(hw|0x20); // No disk attached
  Pico.m.pal=pal;
}

int PicoReset(void)
{
  if (Pico.romsize <= 0)
    return 1;

#if defined(CPU_CMP_R) || defined(CPU_CMP_W) || defined(DRC_CMP)
  PicoIn.opt |= POPT_DIS_VDP_FIFO|POPT_DIS_IDLE_DET;
#endif

  /* must call now, so that banking is reset, and correct vectors get fetched */
  if (PicoResetHook)
    PicoResetHook();

  memset(&PicoIn.padInt, 0, sizeof(PicoIn.padInt));

  if (PicoIn.AHW & PAHW_SMS) {
    PicoResetMS();
    return 0;
  }

  SekReset();
  // ..but do not reset SekCycle* to not desync with addons

  // s68k doesn't have the TAS quirk, so we just globally set normal TAS handler in MCD mode (used by Batman games).
  SekSetRealTAS(PicoIn.AHW & PAHW_MCD);

  Pico.m.dirtyPal = 1;

  Pico.m.z80_bank68k = 0;
  Pico.m.z80_reset = 1;

  PicoDetectRegion();
  Pico.video.status = 0x3428 | Pico.m.pal; // 'always set' bits | vblank | collision | pal

  PsndReset(); // pal must be known here

  // create an empty "dma" to cause 68k exec start at random frame location
  PicoVideoFIFOWrite(rand() & 0x1fff, 0, 0, PVS_CPURD);

  SekFinishIdleDet();

  if (PicoIn.AHW & PAHW_MCD) {
    PicoResetMCD();
    return 0;
  }

  // reinit, so that checksum checks pass
  if (!(PicoIn.opt & POPT_DIS_IDLE_DET))
    SekInitIdleDet();

  if (PicoIn.opt & POPT_EN_32X)
    PicoReset32x();

  // reset sram state; enable sram access by default if it doesn't overlap with ROM
  Pico.m.sram_reg = 0;
  if ((Pico.sv.flags & SRF_EEPROM) || Pico.romsize <= Pico.sv.start)
    Pico.m.sram_reg |= SRR_MAPPED;

  if (Pico.sv.flags & SRF_ENABLED)
    elprintf(EL_STATUS, "sram: %06x - %06x; eeprom: %i", Pico.sv.start, Pico.sv.end,
      !!(Pico.sv.flags & SRF_EEPROM));

  return 0;
}

// flush config changes before emu loop starts
void PicoLoopPrepare(void)
{
  if (PicoIn.regionOverride)
    // force setting possibly changed..
    Pico.m.pal = (PicoIn.regionOverride == 2 || PicoIn.regionOverride == 8) ? 1 : 0;

  Pico.m.dirtyPal = 1;
  rendstatus_old = -1;
}

#include "pico_cmn.c"

/* sync z80 to 68k */
PICO_INTERNAL void PicoSyncZ80(unsigned int m68k_cycles_done)
{
  int m68k_cnt;
  int cnt;

  m68k_cnt = m68k_cycles_done - Pico.t.m68c_frame_start;
  Pico.t.z80c_aim = cycles_68k_to_z80(m68k_cnt);
  cnt = Pico.t.z80c_aim - Pico.t.z80c_cnt;

  pprof_start(z80);

  elprintf(EL_BUSREQ, "z80 sync %i (%u|%u -> %u|%u)", cnt,
    Pico.t.z80c_cnt, Pico.t.z80c_cnt * 15 / 7 / 488,
    Pico.t.z80c_aim, Pico.t.z80c_aim * 15 / 7 / 488);

  if (cnt > 0)
    Pico.t.z80c_cnt += z80_run(cnt);

  pprof_end(z80);
}


void PicoFrame(void)
{
  pprof_start(frame);

  Pico.m.frame_count++;

  if (PicoIn.AHW & PAHW_SMS) {
    PicoFrameMS();
    goto end;
  }

  if (PicoIn.AHW & PAHW_32X) {
    PicoFrame32x(); // also does MCD+32X
    goto end;
  }

  if (PicoIn.AHW & PAHW_MCD) {
    PicoFrameMCD();
    goto end;
  }

  //if(Pico.video.reg[12]&0x2) Pico.video.status ^= SR_ODD; // change odd bit in interlace mode

  PicoFrameStart();
  PicoFrameHints();

end:
  pprof_end(frame);
}

void PicoFrameDrawOnly(void)
{
  if (!(PicoIn.AHW & PAHW_SMS)) {
    PicoFrameStart();
    PicoDrawSync(Pico.m.pal?239:223, 0);
  } else {
    PicoFrameDrawOnlyMS();
  }
}

void PicoGetInternal(pint_t which, pint_ret_t *r)
{
  switch (which)
  {
    case PI_ROM:         r->vptr = Pico.rom; break;
    case PI_ISPAL:       r->vint = Pico.m.pal; break;
    case PI_IS40_CELL:   r->vint = Pico.video.reg[12]&1; break;
    case PI_IS240_LINES: r->vint = Pico.m.pal && (Pico.video.reg[1]&8); break;
  }
}

// vim:ts=2:sw=2:expandtab