/*
 * PicoDrive
 * (c) Copyright Dave, 2004
 * (C) notaz, 2006-2009
 *
 * This work is licensed under the terms of MAME license.
 * See COPYING file in the top-level directory.
 */

#include "pico_int.h"
#include "memory.h"

#ifdef USE_LIBRETRO_VFS
#include "file_stream_transforms.h"
#endif

/* context */
// Cyclone 68000
#ifdef EMU_C68K
struct Cyclone PicoCpuCM68k;
#endif
// MUSASHI 68000
#ifdef EMU_M68K
m68ki_cpu_core PicoCpuMM68k;
#endif
// FAME 68000
#ifdef EMU_F68K
M68K_CONTEXT PicoCpuFM68k;
#endif


static int do_ack(int level)
{
  struct PicoVideo *pv = &Pico.video;

  elprintf(EL_INTS, "%cack: @ %06x [%u], p=%02x",
    level == 6 ? 'v' : 'h', SekPc, SekCyclesDone(), pv->pending_ints);
  // the VDP doesn't look at the 68k level
  if (pv->pending_ints & pv->reg[1] & 0x20) {
    pv->pending_ints &= ~0x20;
    pv->status &= ~SR_F;
    return (pv->reg[0] & pv->pending_ints & 0x10) >> 2;
  }
  else if (pv->pending_ints & pv->reg[0] & 0x10)
    pv->pending_ints &= ~0x10;

  return 0;
}

/* callbacks */
#ifdef EMU_C68K
// interrupt acknowledgment
static int SekIntAck(int level)
{
  PicoCpuCM68k.irq = do_ack(level);
  return CYCLONE_INT_ACK_AUTOVECTOR;
}

static void SekResetAck(void)
{
  elprintf(EL_ANOMALY, "Reset encountered @ %06x", SekPc);
}

static int SekUnrecognizedOpcode()
{
  unsigned int pc;
  pc = SekPc;
  elprintf(EL_ANOMALY, "Unrecognized Opcode @ %06x", pc);
  // see if we are still in a mapped region
  pc &= 0x00ffffff;
  if (map_flag_set(m68k_read16_map[pc >> M68K_MEM_SHIFT])) {
    elprintf(EL_STATUS|EL_ANOMALY, "m68k crash @%06x", pc);
    PicoCpuCM68k.cycles = 0;
    PicoCpuCM68k.state_flags |= 1;
    return 1;
  }
  // happened once - may happen again
  SekFinishIdleDet();
#ifdef EMU_M68K // debugging cyclone
  {
    extern int have_illegal;
    have_illegal = 1;
  }
#endif
  return 0;
}
#endif


#ifdef EMU_M68K
static int SekIntAckM68K(int level)
{
  CPU_INT_LEVEL = do_ack(level) << 8;
  return M68K_INT_ACK_AUTOVECTOR;
}

static int SekTasCallback(void)
{
  return 0; // no writeback
}
#endif


#ifdef EMU_F68K
static void SekIntAckF68K(unsigned level)
{
  PicoCpuFM68k.interrupts[0] = do_ack(level);
}
#endif


PICO_INTERNAL void SekInit(void)
{
#ifdef EMU_C68K
  CycloneInit();
  memset(&PicoCpuCM68k,0,sizeof(PicoCpuCM68k));
  PicoCpuCM68k.IrqCallback=SekIntAck;
  PicoCpuCM68k.ResetCallback=SekResetAck;
  PicoCpuCM68k.UnrecognizedCallback=SekUnrecognizedOpcode;
  PicoCpuCM68k.flags=4;   // Z set
#endif
#ifdef EMU_M68K
  {
    void *oldcontext = m68ki_cpu_p;
    m68k_set_context(&PicoCpuMM68k);
    m68k_set_cpu_type(M68K_CPU_TYPE_68000);
    m68k_init();
    m68k_set_int_ack_callback(SekIntAckM68K);
    m68k_set_tas_instr_callback(SekTasCallback);
    //m68k_pulse_reset();
    m68k_set_context(oldcontext);
  }
#endif
#ifdef EMU_F68K
  memset(&PicoCpuFM68k, 0, sizeof(PicoCpuFM68k));
  fm68k_init();
  PicoCpuFM68k.iack_handler = SekIntAckF68K;
  PicoCpuFM68k.sr = 0x2704; // Z flag
#endif
}


// Reset the 68000:
PICO_INTERNAL int SekReset(void)
{
  if (Pico.rom==NULL) return 1;

#ifdef EMU_C68K
  CycloneReset(&PicoCpuCM68k);
#endif
#ifdef EMU_M68K
  m68k_set_context(&PicoCpuMM68k); // if we ever reset m68k, we always need it's context to be set
  m68ki_cpu.sp[0]=0;
  m68k_set_irq(0);
  m68k_pulse_reset();
  REG_USP = 0; // ?
#endif
#ifdef EMU_F68K
  fm68k_reset(&PicoCpuFM68k);
#endif

  return 0;
}

void SekStepM68k(void)
{
  Pico.t.m68c_aim = Pico.t.m68c_cnt + 1;
#if defined(EMU_CORE_DEBUG)
  Pico.t.m68c_cnt += CM_compareRun(1, 0);
#elif defined(EMU_C68K)
  PicoCpuCM68k.cycles=1;
  CycloneRun(&PicoCpuCM68k);
  Pico.t.m68c_cnt += 1 - PicoCpuCM68k.cycles;
#elif defined(EMU_M68K)
  Pico.t.m68c_cnt += m68k_execute(1);
#elif defined(EMU_F68K)
  Pico.t.m68c_cnt += fm68k_emulate(&PicoCpuFM68k, 1, 0);
#endif
}

PICO_INTERNAL void SekSetRealTAS(int use_real)
{
#ifdef EMU_C68K
  CycloneSetRealTAS(use_real);
#endif
#ifdef EMU_F68K
  // TODO
#endif
}

// Pack the cpu into a common format:
// XXX: rename
PICO_INTERNAL void SekPackCpu(unsigned char *cpu, int is_sub)
{
  unsigned int pc=0;

#if defined(EMU_C68K)
  struct Cyclone *context = is_sub ? &PicoCpuCS68k : &PicoCpuCM68k;
  memcpy(cpu,context->d,0x40);
  pc=context->pc-context->membase;
  *(unsigned int *)(cpu+0x44)=CycloneGetSr(context);
  *(unsigned int *)(cpu+0x48)=context->osp;
  cpu[0x4c] = context->irq;
  cpu[0x4d] = context->state_flags & 1;
#elif defined(EMU_M68K)
  void *oldcontext = m68ki_cpu_p;
  m68k_set_context(is_sub ? &PicoCpuMS68k : &PicoCpuMM68k);
  memcpy(cpu,m68ki_cpu_p->dar,0x40);
  pc=m68ki_cpu_p->pc;
  *(unsigned int  *)(cpu+0x44)=m68k_get_reg(NULL, M68K_REG_SR);
  *(unsigned int  *)(cpu+0x48)=m68ki_cpu_p->sp[m68ki_cpu_p->s_flag^SFLAG_SET];
  cpu[0x4c] = CPU_INT_LEVEL>>8;
  cpu[0x4d] = CPU_STOPPED;
  m68k_set_context(oldcontext);
#elif defined(EMU_F68K)
  M68K_CONTEXT *context = is_sub ? &PicoCpuFS68k : &PicoCpuFM68k;
  memcpy(cpu,context->dreg,0x40);
  pc=context->pc;
  *(unsigned int  *)(cpu+0x44)=context->sr;
  *(unsigned int  *)(cpu+0x48)=context->asp;
  cpu[0x4c] = context->interrupts[0];
  cpu[0x4d] = (context->execinfo & FM68K_HALTED) ? 1 : 0;
#endif

  *(unsigned int *)(cpu+0x40) = pc;
  *(unsigned int *)(cpu+0x50) =
    is_sub ? SekCycleCntS68k : Pico.t.m68c_cnt;
}

PICO_INTERNAL void SekUnpackCpu(const unsigned char *cpu, int is_sub)
{
#if defined(EMU_C68K)
  struct Cyclone *context = is_sub ? &PicoCpuCS68k : &PicoCpuCM68k;
  CycloneSetSr(context, *(unsigned int *)(cpu+0x44));
  context->osp=*(unsigned int *)(cpu+0x48);
  memcpy(context->d,cpu,0x40);
  context->membase = 0;
  context->pc = *(unsigned int *)(cpu+0x40);
  CycloneUnpack(context, NULL); // rebase PC
  context->irq = cpu[0x4c];
  context->state_flags = 0;
  if (cpu[0x4d])
    context->state_flags |= 1;
#elif defined(EMU_M68K)
  void *oldcontext = m68ki_cpu_p;
  m68k_set_context(is_sub ? &PicoCpuMS68k : &PicoCpuMM68k);
  m68k_set_reg(M68K_REG_SR, *(unsigned int *)(cpu+0x44));
  memcpy(m68ki_cpu_p->dar,cpu,0x40);
  m68ki_cpu_p->pc=*(unsigned int *)(cpu+0x40);
  m68ki_cpu_p->sp[m68ki_cpu_p->s_flag^SFLAG_SET]=*(unsigned int *)(cpu+0x48);
  CPU_INT_LEVEL = cpu[0x4c] << 8;
  CPU_STOPPED = cpu[0x4d];
  m68k_set_context(oldcontext);
#elif defined(EMU_F68K)
  M68K_CONTEXT *context = is_sub ? &PicoCpuFS68k : &PicoCpuFM68k;
  memcpy(context->dreg,cpu,0x40);
  context->pc =*(unsigned int *)(cpu+0x40);
  context->sr =*(unsigned int *)(cpu+0x44);
  context->asp=*(unsigned int *)(cpu+0x48);
  context->interrupts[0] = cpu[0x4c];
  context->execinfo &= ~FM68K_HALTED;
  if (cpu[0x4d]&1) context->execinfo |= FM68K_HALTED;
#endif
  if (is_sub)
    SekCycleCntS68k = *(unsigned int *)(cpu+0x50);
  else
    Pico.t.m68c_cnt = *(unsigned int *)(cpu+0x50);
}


/* idle loop detection, not to be used in CD mode */
#ifdef EMU_C68K
#include "cpu/cyclone/tools/idle.h"
#endif

static unsigned short **idledet_ptrs = NULL;
static int idledet_count = 0, idledet_bads = 0;
static int idledet_start_frame = 0;

#if 0
#define IDLE_STATS 1
unsigned int idlehit_addrs[128], idlehit_counts[128];

void SekRegisterIdleHit(unsigned int pc)
{
  int i;
  for (i = 0; i < 127 && idlehit_addrs[i]; i++) {
    if (idlehit_addrs[i] == pc) {
      idlehit_counts[i]++;
      return;
    }
  }
  idlehit_addrs[i] = pc;
  idlehit_counts[i] = 1;
  idlehit_addrs[i+1] = 0;
}
#endif

void SekInitIdleDet(void)
{
  unsigned short **tmp;
  tmp = realloc(idledet_ptrs, 0x200 * sizeof(tmp[0]));
  if (tmp == NULL) {
    free(idledet_ptrs);
    idledet_ptrs = NULL;
  }
  else
    idledet_ptrs = tmp;
  idledet_count = idledet_bads = 0;
  idledet_start_frame = Pico.m.frame_count + 360;
#ifdef IDLE_STATS
  idlehit_addrs[0] = 0;
#endif

#ifdef EMU_C68K
  CycloneInitIdle();
#endif
#ifdef EMU_F68K
  fm68k_idle_install();
#endif
}

int SekIsIdleReady(void)
{
	return (Pico.m.frame_count >= idledet_start_frame);
}

int SekIsIdleCode(unsigned short *dst, int bytes)
{
  // printf("SekIsIdleCode %04x %i\n", *dst, bytes);
  switch (bytes)
  {
    case 2:
      if ((*dst & 0xf000) != 0x6000)     // not another branch
        return 1;
      break;
    case 4:
      if ( (*dst & 0xff3f) == 0x4a38 || // tst.x ($xxxx.w); tas ($xxxx.w)
           (*dst & 0xc1ff) == 0x0038 || // move.x ($xxxx.w), dX
           (*dst & 0xf13f) == 0xb038)   // cmp.x ($xxxx.w), dX
        return 1;
      if (PicoIn.AHW & (PAHW_MCD|PAHW_32X))
        break;
      // with no addons, there should be no need to wait
      // for byte change anywhere
      if ( (*dst & 0xfff8) == 0x4a10 || // tst.b ($aX)
           (*dst & 0xfff8) == 0x4a28)   // tst.b ($xxxx,a0)
        return 1;
      break;
    case 6:
      if ( ((dst[1] & 0xe0) == 0xe0 && ( // RAM and
            *dst == 0x4a39 ||            //   tst.b ($xxxxxxxx)
            *dst == 0x4a79 ||            //   tst.w ($xxxxxxxx)
            *dst == 0x4ab9 ||            //   tst.l ($xxxxxxxx)
            (*dst & 0xc1ff) == 0x0039 || //   move.x ($xxxxxxxx), dX
            (*dst & 0xf13f) == 0xb039))||//   cmp.x ($xxxxxxxx), dX
            *dst == 0x0838 ||            // btst $X, ($xxxx.w) [6 byte op]
            (*dst & 0xffbf) == 0x0c38)   // cmpi.{b,w} $X, ($xxxx.w)
        return 1;
      break;
    case 8:
      if ( ((dst[2] & 0xe0) == 0xe0 && ( // RAM and
            *dst == 0x0839 ||            //   btst $X, ($xxxxxxxx.w) [8 byte op]
            (*dst & 0xffbf) == 0x0c39))||//   cmpi.{b,w} $X, ($xxxxxxxx)
            *dst == 0x0cb8)              // cmpi.l $X, ($xxxx.w)
        return 1;
      break;
    case 12:
      if (PicoIn.AHW & (PAHW_MCD|PAHW_32X))
        break;
      if ( (*dst & 0xf1f8) == 0x3010 && // move.w (aX), dX
            (dst[1]&0xf100) == 0x0000 && // arithmetic
            (dst[3]&0xf100) == 0x0000)   // arithmetic
        return 1;
      break;
  }

  return 0;
}

int SekRegisterIdlePatch(unsigned int pc, int oldop, int newop, void *ctx)
{
  int is_main68k = 1;
  u16 *target;
  uptr v;

#if   defined(EMU_C68K)
  struct Cyclone *cyc = ctx;
  is_main68k = cyc == &PicoCpuCM68k;
  pc -= cyc->membase;
#elif defined(EMU_F68K)
  is_main68k = ctx == &PicoCpuFM68k;
#endif
  pc &= ~0xff000000;
  if (!(newop&0x200))
  elprintf(EL_IDLE, "idle: patch %06x %04x %04x %c %c #%i", pc, oldop, newop,
    (newop&0x200)?'n':'y', is_main68k?'m':'s', idledet_count);

  // XXX: probably shouldn't patch RAM too
  v = m68k_read16_map[pc >> M68K_MEM_SHIFT];
  if (!(v & 0x80000000))
    target = (u16 *)((v << 1) + pc);
  else {
    if (++idledet_bads > 128)
      return 2; // remove detector
    return 1; // don't patch
  }

  if (idledet_count >= 0x200 && (idledet_count & 0x1ff) == 0) {
    unsigned short **tmp;
    tmp = realloc(idledet_ptrs, (idledet_count+0x200) * sizeof(tmp[0]));
    if (tmp == NULL)
      return 1;
    idledet_ptrs = tmp;
  }

  idledet_ptrs[idledet_count++] = target;

  return 0;
}

void SekFinishIdleDet(void)
{
  if (idledet_count < 0)
    return;
#ifdef EMU_C68K
  CycloneFinishIdle();
#endif
#ifdef EMU_F68K
  fm68k_idle_remove();
#endif
  while (idledet_count > 0)
  {
    unsigned short *op = idledet_ptrs[--idledet_count];
    if      ((*op & 0xfd00) == 0x7100)
      *op &= 0xff, *op |= 0x6600;
    else if ((*op & 0xfd00) == 0x7500)
      *op &= 0xff, *op |= 0x6700;
    else if ((*op & 0xfd00) == 0x7d00)
      *op &= 0xff, *op |= 0x6000;
    else
      elprintf(EL_STATUS|EL_IDLE, "idle: don't know how to restore %04x", *op);
  }
  idledet_count = -1;
}


#if defined(CPU_CMP_R) || defined(CPU_CMP_W)
#include "debug.h"

struct ref_68k {
  u32 dar[16];
  u32 pc;
  u32 sr;
  u32 cycles;
  u32 pc_prev;
};
struct ref_68k ref_68ks[2];
static int current_68k;

void SekTrace(int is_s68k)
{
  struct ref_68k *x68k = &ref_68ks[is_s68k];
  u32 pc = is_s68k ? SekPcS68k : SekPc;
  u32 sr = is_s68k ? SekSrS68k : SekSr;
  u32 cycles = is_s68k ? SekCycleCntS68k : Pico.t.m68c_cnt;
  u32 r;
  u8 cmd;
#ifdef CPU_CMP_W
  int i;

  if (is_s68k != current_68k) {
    current_68k = is_s68k;
    cmd = CTL_68K_SLAVE | current_68k;
    tl_write(&cmd, sizeof(cmd));
  }
  if (pc != x68k->pc) {
    x68k->pc = pc;
    tl_write_uint(CTL_68K_PC, x68k->pc);
  }
  if (sr != x68k->sr) {
    x68k->sr = sr;
    tl_write_uint(CTL_68K_SR, x68k->sr);
  }
  for (i = 0; i < 16; i++) {
    r = is_s68k ? SekDarS68k(i) : SekDar(i);
    if (r != x68k->dar[i]) {
      x68k->dar[i] = r;
      tl_write_uint(CTL_68K_R + i, r);
    }
  }
  tl_write_uint(CTL_68K_CYCLES, cycles);
#else
  int i, bad = 0;

  while (1)
  {
    int ret = tl_read(&cmd, sizeof(cmd));
    if (ret == 0) {
      elprintf(EL_STATUS, "EOF");
      exit(1);
    }
    switch (cmd) {
    case CTL_68K_SLAVE:
    case CTL_68K_SLAVE + 1:
      current_68k = cmd & 1;
      break;
    case CTL_68K_PC:
      tl_read_uint(&x68k->pc);
      break;
    case CTL_68K_SR:
      tl_read_uint(&x68k->sr);
      break;
    case CTL_68K_CYCLES:
      tl_read_uint(&x68k->cycles);
      goto breakloop;
    default:
      if (CTL_68K_R <= cmd && cmd < CTL_68K_R + 0x10)
        tl_read_uint(&x68k->dar[cmd - CTL_68K_R]);
      else
        elprintf(EL_STATUS, "invalid cmd: %02x", cmd);
    }
  }

breakloop:
  if (is_s68k != current_68k) {
		printf("bad 68k: %d %d\n", is_s68k, current_68k);
    bad = 1;
  }
  if (cycles != x68k->cycles) {
		printf("bad cycles: %u %u\n", cycles, x68k->cycles);
    bad = 1;
  }
  if ((pc ^ x68k->pc) & 0xffffff) {
		printf("bad PC: %08x %08x\n", pc, x68k->pc);
    bad = 1;
  }
  if (sr != x68k->sr) {
		printf("bad SR:  %03x %03x\n", sr, x68k->sr);
    bad = 1;
  }
  for (i = 0; i < 16; i++) {
    r = is_s68k ? SekDarS68k(i) : SekDar(i);
    if (r != x68k->dar[i]) {
		  printf("bad %c%d: %08x %08x\n", i < 8 ? 'D' : 'A', i & 7,
        r, x68k->dar[i]);
      bad = 1;
    }
  }
  if (bad) {
    for (i = 0; i < 8; i++)
			printf("D%d: %08x  A%d: %08x\n", i, x68k->dar[i],
        i, x68k->dar[i + 8]);
		printf("PC: %08x, %08x\n", x68k->pc, x68k->pc_prev);
		printf("SR: %04x\n", x68k->sr);

    PDebugDumpMem();
    exit(1);
  }
  x68k->pc_prev = x68k->pc;
#endif
}
#endif // CPU_CMP_*

#if defined(EMU_M68K) && M68K_INSTRUCTION_HOOK == OPT_SPECIFY_HANDLER
static unsigned char op_flags[0x400000/2] = { 0, };
static int atexit_set = 0;

static void make_idc(void)
{
  FILE *f = fopen("idc.idc", "w");
  int i;
  if (!f) return;
  fprintf(f, "#include <idc.idc>\nstatic main() {\n");
  for (i = 0; i < 0x400000/2; i++)
    if (op_flags[i] != 0)
      fprintf(f, "  MakeCode(0x%06x);\n", i*2);
  fprintf(f, "}\n");
  fclose(f);
}

void instruction_hook(void)
{
  if (!atexit_set) {
    atexit(make_idc);
    atexit_set = 1;
  }
  if (REG_PC < 0x400000)
    op_flags[REG_PC/2] = 1;
}
#endif

// vim:shiftwidth=2:ts=2:expandtab
