/* MusashiCPU <-> vamos memory interface
 *
 * written by Christian Vogelgsang <chris@vogelgsang.org>
 * under the GNU Public License V2
 */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "mem.h"

/* THOR: I need a *little* more memory than 16MB.
** This gives 256MB max.
*/
#define NUM_PAGES   4096

/* ----- Data ----- */
static uint8_t *ram_data;
static uint     ram_size;
static uint     ram_pages;

static read_func_t    r_func[NUM_PAGES][3];
static write_func_t   w_func[NUM_PAGES][3];
static void *         r_ctx[NUM_PAGES][3];
static void *         w_ctx[NUM_PAGES][3];

static invalid_func_t invalid_func;
static void *invalid_ctx;
static int mem_trace = 0;
static trace_func_t trace_func;
static void *trace_ctx;
static uint special_page = NUM_PAGES;

/* ----- RAW Access ----- */
extern uint8_t *mem_raw_ptr(void)
{
  return ram_data;
}

extern uint mem_raw_size(void)
{
  return ram_size;
}

/* ----- Default Funcs ----- */
static void default_invalid(int mode, int width, uint addr, void *ctx)
{
  printf("INVALID: %c(%d): %06x\n",(char)mode,width,addr);
}

static void default_trace(int mode, int width, uint addr, uint val, void *ctx)
{
  printf("%c(%d): %06x: %x\n",(char)mode,width,addr,val);
}

static uint r8_fail(uint addr, void *ctx)
{
  invalid_func('R', 0, addr, invalid_ctx);
  return 0;
}

static uint r16_fail(uint addr, void *ctx)
{
  invalid_func('R', 1, addr, invalid_ctx);
  return 0;
}

static uint r32_fail(uint addr, void *ctx)
{
  invalid_func('R', 2, addr, invalid_ctx);
  return 0;
}

static void w8_fail(uint addr, uint val, void *ctx)
{
  invalid_func('W', 0, addr, invalid_ctx);
}

static void w16_fail(uint addr, uint val, void *ctx)
{
  invalid_func('W', 1, addr, invalid_ctx);
}

static void w32_fail(uint addr, uint val, void *ctx)
{
  invalid_func('W', 2, addr, invalid_ctx);
}

/* ----- RAM access ----- */
static uint mem_r8_ram(uint addr, void *ctx)
{
  return ram_data[addr];
}

static uint mem_r16_ram(uint addr, void *ctx)
{
  return (ram_data[addr] << 8) | ram_data[addr+1];
}

static uint mem_r32_ram(uint addr, void *ctx)
{
  return (ram_data[addr] << 24) | (ram_data[addr+1] << 16) | (ram_data[addr+2] << 8) | (ram_data[addr+3]);
}

static void mem_w8_ram(uint addr, uint val, void *ctx)
{
  ram_data[addr] = val;
}

static void mem_w16_ram(uint addr, uint val, void *ctx)
{
  ram_data[addr] = val >> 8;
  ram_data[addr+1] = val & 0xff;
}

static void mem_w32_ram(uint addr, uint val, void *ctx)
{
  ram_data[addr]   = val >> 24;
  ram_data[addr+1] = (val >> 16) & 0xff;
  ram_data[addr+2] = (val >> 8) & 0xff;
  ram_data[addr+3] = val & 0xff;
}

/* ----- Musashi Interface ----- */

#include "m68kcpu.h"

unsigned int  m68k_read_memory_8(unsigned int address)
{
  uint page = address >> 16;
  if (page < NUM_PAGES) {
    uint val = r_func[page][0](address, r_ctx[page][0]);
    if(mem_trace) {
      trace_func('R',0,address,val,trace_ctx);
    }
    return val;
  } else {
    invalid_func('R',0,address,invalid_ctx);
    return 0;
  }
}

unsigned int  m68k_read_memory_16(unsigned int address)
{
  uint page = address >> 16;
  if (page < NUM_PAGES) {
    uint val = r_func[page][1](address, r_ctx[page][1]);
    if(mem_trace) {
      trace_func('R',1,address,val,trace_ctx);
    }
    return val;
  } else {
    invalid_func('R',1,address,invalid_ctx);
    return 0;
  }
}

unsigned int  m68k_read_memory_32(unsigned int address)
{
  uint page = address >> 16;
  if (page < NUM_PAGES) {
    uint val = r_func[page][2](address, r_ctx[page][2]);
    if(mem_trace) {
      trace_func('R',2,address,val,trace_ctx);
    }
    return val;
  } else {
    invalid_func('R',2,address,invalid_ctx);
    return 0;
  }
}

void m68k_write_memory_8(unsigned int address, unsigned int value)
{
  uint page = address >> 16;
  if (page < NUM_PAGES) {
    w_func[page][0](address, value, w_ctx[page][0]);
    if(mem_trace) {
      trace_func('W',0,address,value,trace_ctx);
    }
  } else {
    invalid_func('W',0,address,invalid_ctx);
  }
}

void m68k_write_memory_16(unsigned int address, unsigned int value)
{
  uint page = address >> 16;
  if (page < NUM_PAGES) {
    w_func[page][1](address, value, w_ctx[page][1]);
    if(mem_trace) {
      trace_func('W',1,address,value,trace_ctx);
    }
  } else {
    invalid_func('W',1,address,invalid_ctx);
  }
}

void m68k_write_memory_32(unsigned int address, unsigned int value)
{
  uint page = address >> 16;
  if (page < NUM_PAGES) {
    w_func[page][2](address, value, w_ctx[page][2]);
    if(mem_trace) {
      trace_func('W',2,address,value,trace_ctx);
    }
  } else {
    invalid_func('W',2,address,invalid_ctx);
  }
}

/* Disassemble support */

unsigned int m68k_read_disassembler_16 (unsigned int address)
{
  uint page = address >> 16;
  if (page < NUM_PAGES) {
    uint val = r_func[page][1](address, r_ctx[page][1]);
    return val;
  } else {
    return 0x0;
  }
}

unsigned int m68k_read_disassembler_32 (unsigned int address)
{
  uint page = address >> 16;
  if (page < NUM_PAGES) {
    uint val = r_func[page][2](address, r_ctx[page][1]);
    return val;
  } else {
    return 0x0;
  }
}

/* ----- API ----- */

int mem_init(uint ram_size_kib)
{
  int i;
  ram_pages = (ram_size_kib + 63) / 64;
  ram_size = ram_pages * 64 * 1024;
  ram_data = (uint8_t *)malloc(ram_size);
  memset(ram_data, 0, ram_size);

  for(i=0;i<NUM_PAGES;i++) {
    if(i < ram_pages) {
      r_func[i][0] = mem_r8_ram;
      r_func[i][1] = mem_r16_ram;
      r_func[i][2] = mem_r32_ram;
      w_func[i][0] = mem_w8_ram;
      w_func[i][1] = mem_w16_ram;
      w_func[i][2] = mem_w32_ram;
    } else {
      r_func[i][0] = r8_fail;
      r_func[i][1] = r16_fail;
      r_func[i][2] = r32_fail;
      w_func[i][0] = w8_fail;
      w_func[i][1] = w16_fail;
      w_func[i][2] = w32_fail;
    }
  }

  mem_trace = 0;
  trace_func = default_trace;
  invalid_func = default_invalid;

  return (ram_data != NULL);
}

void mem_free(void)
{
  free(ram_data);
  ram_data = NULL;
}

void mem_set_invalid_func(invalid_func_t func, void *ctx)
{
  if(func == NULL) {
    func = default_invalid;
    ctx = NULL;
  }
  invalid_func = func;
  invalid_ctx = ctx;
}

void mem_set_trace_mode(int on)
{
  mem_trace = on;
}

void mem_set_trace_func(trace_func_t func, void *ctx)
{
  if(func == NULL) {
    func = default_trace;
    ctx = NULL;
  }
  trace_func = func;
  trace_ctx = ctx;
}

uint mem_reserve_special_range(uint num_pages)
{
  uint begin_page = special_page - num_pages;
  if(begin_page < ram_pages) {
    return 0;
  }
  special_page = begin_page;
  return begin_page << 16;
}

void mem_set_special_range_read_func(uint page_addr, uint width, read_func_t func, void *ctx)
{
  uint page = page_addr >> 16;
  r_func[page][width] = func;
  r_ctx[page][width] = ctx;
}

void mem_set_special_range_write_func(uint page_addr, uint width, write_func_t func, void *ctx)
{
  uint page = page_addr >> 16;
  w_func[page][width] = func;
  w_ctx[page][width] = ctx;
}

/* RAM access */

int mem_ram_r8(uint addr, uint *val)
{
  if(addr < ram_size) {
    *val = ram_data[addr];
    return 0;
  } else {
    return 1;
  }
}

int mem_ram_r16(uint addr, uint *val)
{
  if(addr < (ram_size - 1)) {
    *val = (ram_data[addr] << 8) | ram_data[addr+1];
    return 0;
  } else {
    return 1;
  }
}

int mem_ram_r32(uint addr, uint *val)
{
  if(addr < (ram_size - 3)) {
    *val = (ram_data[addr] << 24) | (ram_data[addr+1] << 16) | (ram_data[addr+2] << 8) | (ram_data[addr+3]);
    return 0;
  } else {
    return 1;
  }
}

int mem_ram_w8(uint addr, uint val)
{
  if(addr < ram_size) {
    ram_data[addr] = (uint8_t)(val & 0xff);
    return 0;
  } else {
    return 1;
  }
}

int mem_ram_w16(uint addr, uint val)
{
  if(addr < (ram_size - 1)) {
    ram_data[addr] = val >> 8;
    ram_data[addr+1] = val & 0xff;
    return 0;
  } else {
    return 1;
  }
}

int mem_ram_w32(uint addr, uint val)
{
  if(addr < (ram_size - 3)) {
    ram_data[addr]   = val >> 24;
    ram_data[addr+1] = (val >> 16) & 0xff;
    ram_data[addr+2] = (val >> 8) & 0xff;
    ram_data[addr+3] = val & 0xff;
    return 0;
  } else {
    return 1;
  }
}