/**
 * Mupen64 - flashram.c
 * Copyright (C) 2002 Hacktarux
 *
 * Mupen64 homepage: http://mupen64.emulation64.com
 * email address: hacktarux@yahoo.fr
 * 
 * If you want to contribute to the project please contact
 * me first (maybe someone is already making what you are
 * planning to do).
 *
 *
 * This program is free software; you can redistribute it and/
 * or modify it under the terms of the GNU General Public Li-
 * cence as published by the Free Software Foundation; either
 * version 2 of the Licence, or any later version.
 *
 * This program is distributed in the hope that it will be use-
 * ful, but WITHOUT ANY WARRANTY; without even the implied war-
 * ranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public Licence for more details.
 *
 * You should have received a copy of the GNU General Public
 * Licence along with this program; if not, write to the Free
 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139,
 * USA.
 *
**/

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

#include "../r4300/r4300.h"
#include "../main/main.h"
#include "../main/guifuncs.h"
#include "memory.h"

int use_flashram;

typedef enum flashram_mode
{
   NOPES_MODE = 0,
   ERASE_MODE,
   WRITE_MODE,
   READ_MODE,
   STATUS_MODE
} Flashram_mode;

static int mode;
static unsigned long long status;
static unsigned char flashram[0x20000];
static unsigned int erase_offset, write_pointer;

void save_flashram_infos(char *buf)
{
   memcpy(buf+0 , &use_flashram , 4);
   memcpy(buf+4 , &mode         , 4);
   memcpy(buf+8 , &status       , 8);
   memcpy(buf+16, &erase_offset , 4);
   memcpy(buf+20, &write_pointer, 4);
}

void load_flashram_infos(char *buf)
{
   memcpy(&use_flashram , buf+0 , 4);
   memcpy(&mode         , buf+4 , 4);
   memcpy(&status       , buf+8 , 8);
   memcpy(&erase_offset , buf+16, 4);
   memcpy(&write_pointer, buf+20, 4);
}

void init_flashram()
{
   mode = NOPES_MODE;
   status = 0;
}

unsigned int flashram_status()
{
   return (status >> 32);
}

void flashram_command(unsigned int command)
{
   switch(command & 0xff000000)
     {
      case 0x4b000000:
    erase_offset = (command & 0xffff) * 128;
    break;
      case 0x78000000:
    mode = ERASE_MODE;
    status = 0x1111800800c20000LL;
    break;
      case 0xa5000000:
    erase_offset = (command & 0xffff) * 128;
    status = 0x1111800400c20000LL;
    break;
      case 0xb4000000:
    mode = WRITE_MODE;
    break;
      case 0xd2000000:  // execute
    switch (mode)
      {
       case NOPES_MODE:
         break;
       case ERASE_MODE:
           {
          char *filename;
          FILE *f;
          int i;
          filename = malloc(strlen(get_savespath())+
                    strlen(ROM_SETTINGS.goodname)+4+1);
          strcpy(filename, get_savespath());
          strcat(filename, ROM_SETTINGS.goodname);
          strcat(filename, ".fla");
          f = fopen(filename, "rb");
          if (f)
            {
               fread(flashram, 1, 0x20000, f);
               fclose(f);
            }
          else for (i=0; i<0x20000; i++) flashram[i] = 0xff;
          for (i=erase_offset; i<(erase_offset+128); i++)
            flashram[i^S8] = 0xff;
          f = fopen(filename, "wb");
          if (f == NULL)
          {
            printf("Warning: couldn't open flashram file '%s' for erasing.\n", filename);
          }
          else
          {
            fwrite(flashram, 1, 0x20000, f);
            fclose(f);
          }
          free(filename);
         }
         break;
       case WRITE_MODE:
           {
          char *filename;
          FILE *f;
          int i;
          filename = malloc(strlen(get_savespath())+
                    strlen(ROM_SETTINGS.goodname)+4+1);
          strcpy(filename, get_savespath());
          strcat(filename, ROM_SETTINGS.goodname);
          strcat(filename, ".fla");
          f = fopen(filename, "rb");
          if (f)
            {
               fread(flashram, 1, 0x20000, f);
               fclose(f);
            }
          else for (i=0; i<0x20000; i++) flashram[i] = 0xff;
          for (i=0; i<128; i++)
            flashram[(erase_offset+i)^S8]=
            ((unsigned char*)rdram)[(write_pointer+i)^S8];
          f = fopen(filename, "wb");
          if (f == NULL)
          {
            printf("Warning: couldn't open flashram file '%s' for writing.\n", filename);
          }
          else
          {
            fwrite(flashram, 1, 0x20000, f);
            fclose(f);
          }
          free(filename);
         }
         break;
       case STATUS_MODE:
         break;
       default:
         printf("unknown flashram command with mode:%x\n", (int)mode);
         stop=1;
      }
    mode = NOPES_MODE;
    break;
      case 0xe1000000:
    mode = STATUS_MODE;
    status = 0x1111800100c20000LL;
    break;
      case 0xf0000000:
    mode = READ_MODE;
    status = 0x11118004f0000000LL;
    break;
      default:
    printf("unknown flashram command:%x\n", (int)command);
    //stop=1;
     }
}

void dma_read_flashram()
{
   int i;
   char *filename;
   FILE *f;
   
   switch(mode)
     {
      case STATUS_MODE:
    rdram[pi_register.pi_dram_addr_reg/4] = (unsigned int)(status >> 32);
    rdram[pi_register.pi_dram_addr_reg/4+1] = (unsigned int)(status);
    break;
      case READ_MODE:
    filename = malloc(strlen(get_savespath())+
              strlen(ROM_SETTINGS.goodname)+4+1);
    strcpy(filename, get_savespath());
    strcat(filename, ROM_SETTINGS.goodname);
    strcat(filename, ".fla");
    f = fopen(filename, "rb");
    if (f)
      {
         fread(flashram, 1, 0x20000, f);
         fclose(f);
      }
    else for (i=0; i<0x20000; i++) flashram[i] = 0xff;
    free(filename);
    for (i=0; i<(pi_register.pi_wr_len_reg & 0x0FFFFFF)+1; i++)
      ((unsigned char*)rdram)[(pi_register.pi_dram_addr_reg+i)^S8]=
      flashram[(((pi_register.pi_cart_addr_reg-0x08000000)&0xFFFF)*2+i)^S8];
    break;
      default:  
    printf("unknown dma_read_flashram:%x\n", mode);
    stop=1;
     }
}

void dma_write_flashram()
{
   switch(mode)
     {
      case WRITE_MODE:
    write_pointer = pi_register.pi_dram_addr_reg;
    break;
      default:
    printf("unknown dma_read_flashram:%x\n", mode);
    stop=1;
     }
}