Shamusworld >> Repos - virtualjaguar/blob - src/eeprom.cpp

   1 //
   2 // EEPROM handler
   3 //
   4 // by Cal2
   5 // GCC/SDL port by Niels Wagenaar (Linux/WIN32) and Caz (BeOS)
   6 // Cleanups/enhancements by James L. Hammons
   7 //
   8
   9 #include "eeprom.h"
  10
  11 #include <string.h>                                                             // For memset
  12 #include <stdlib.h>
  13 #include "settings.h"
  14 #include "log.h"
  15 #include "jaguar.h"
  16
  17 #define eeprom_LOG
  18
  19 static uint16 eeprom_ram[64];
  20
  21 //
  22 // Private function prototypes
  23 //
  24
  25 void EEPROMSave(void);
  26 void eeprom_set_di(uint32 state);
  27 void eeprom_set_cs(uint32 state);
  28 uint32 eeprom_get_do(void);
  29
  30 enum { EE_STATE_START = 1, EE_STATE_OP_A, EE_STATE_OP_B, EE_STATE_0, EE_STATE_1,
  31         EE_STATE_2, EE_STATE_3, EE_STATE_0_0, EE_READ_ADDRESS, EE_STATE_0_0_0,
  32         EE_STATE_0_0_1, EE_STATE_0_0_2, EE_STATE_0_0_3, EE_STATE_0_0_1_0, EE_READ_DATA,
  33         EE_STATE_BUSY, EE_STATE_1_0, EE_STATE_1_1, EE_STATE_2_0, EE_STATE_3_0 };
  34
  35 // Local global variables
  36
  37 uint16 jerry_ee_state = EE_STATE_START;
  38 uint16 jerry_ee_op = 0;
  39 uint16 jerry_ee_rstate = 0;
  40 uint16 jerry_ee_address_data = 0;
  41 uint16 jerry_ee_address_cnt = 6;
  42 uint16 jerry_ee_data = 0;
  43 uint16 jerry_ee_data_cnt = 16;
  44 uint16 jerry_writes_enabled = 0;
  45 uint16 jerry_ee_direct_jump = 0;
  46 static char eeprom_filename[MAX_PATH];
  47 static bool foundEEPROM = false;
  48
  49 void eeprom_init(void)
  50 {
  51         sprintf(eeprom_filename, "%s%08X.eep", vjs.EEPROMPath, (unsigned int)jaguar_mainRom_crc32);
  52         FILE * jerry_ee_fp = fopen(eeprom_filename, "rb");
  53         if (jerry_ee_fp)
  54         {
  55                 fread(eeprom_ram, 1, 128, jerry_ee_fp);
  56                 fclose(jerry_ee_fp);
  57                 WriteLog("EEPROM: Loaded from %s\n", eeprom_filename);
  58                 foundEEPROM = true;
  59         }
  60         else
  61                 WriteLog("EEPROM: Could not open file \"%s\"!\n", eeprom_filename);
  62 }
  63
  64 void eeprom_reset(void)
  65 {
  66         if (!foundEEPROM)
  67                 memset(eeprom_ram, 0xFF, 64 * sizeof(uint16));
  68 }
  69
  70 void eeprom_done(void)
  71 {
  72 }
  73
  74 void EEPROMSave(void)
  75 {
  76         FILE * jerry_ee_fp = fopen(eeprom_filename, "wb");
  77
  78         if (jerry_ee_fp == NULL)
  79         {
  80                 WriteLog("EEPROM: Could not create file \"%s!\"\n", eeprom_filename);
  81                 return;
  82         }
  83
  84         fwrite(eeprom_ram, 1, 128, jerry_ee_fp);
  85         fclose(jerry_ee_fp);
  86 }
  87
  88 uint8 eeprom_byte_read(uint32 offset)
  89 {
  90         switch (offset)
  91         {
  92         case 0xF14001:
  93                 return eeprom_get_do();
  94         case 0xF14801:
  95                 break;
  96         case 0xF15001:
  97                 eeprom_set_cs(1);
  98                 break;
  99 //      default: WriteLog("eeprom: unmapped 0x%.8x\n",offset); break;
 100         }
 101
 102         return 0x00;
 103 }
 104
 105 uint16 eeprom_word_read(uint32 offset)
 106 {
 107         return ((uint16)eeprom_byte_read(offset+0) << 8) | eeprom_byte_read(offset+1);
 108 }
 109
 110 void eeprom_byte_write(uint32 offset, uint8 data)
 111 {
 112         switch (offset)
 113         {
 114         case 0xF14001:
 115                 break;
 116         case 0xF14801:
 117                 eeprom_set_di(data & 0x01);
 118                 break;
 119         case 0xF15001:
 120                 eeprom_set_cs(1);
 121                 break;
 122 //      default: WriteLog("eeprom: unmapped 0x%.8x\n",offset); break;
 123         }
 124 }
 125
 126 void eeprom_word_write(uint32 offset, uint16 data)
 127 {
 128         eeprom_byte_write(offset+0, (data >> 8) & 0xFF);
 129         eeprom_byte_write(offset+1, data & 0xFF);
 130 }
 131
 132 void eeprom_set_di(uint32 data)
 133 {
 134 //      WriteLog("eeprom: di=%i\n",data);
 135 //      WriteLog("eeprom: state %i\n",jerry_ee_state);
 136         switch (jerry_ee_state)
 137         {
 138         case EE_STATE_START:
 139                 jerry_ee_state = EE_STATE_OP_A;
 140                 break;
 141         case EE_STATE_OP_A:
 142                 jerry_ee_op = (data << 1);
 143                 jerry_ee_state = EE_STATE_OP_B;
 144                 break;
 145         case EE_STATE_OP_B:
 146                 jerry_ee_op |= data;
 147                 jerry_ee_direct_jump = 0;
 148 //              WriteLog("eeprom: opcode %i\n",jerry_ee_op);
 149                 switch (jerry_ee_op)
 150                 {
 151                 case 0: jerry_ee_state = EE_STATE_0; break;
 152                 case 1: jerry_ee_state = EE_STATE_1; break;
 153                 case 2: jerry_ee_state = EE_STATE_2; break;
 154                 case 3: jerry_ee_state = EE_STATE_3; break;
 155                 }
 156                 eeprom_set_di(data);
 157                 break;
 158         case EE_STATE_0:
 159                 jerry_ee_rstate = EE_STATE_0_0;
 160                 jerry_ee_state = EE_READ_ADDRESS;
 161                 jerry_ee_direct_jump = 1;
 162                 jerry_ee_address_cnt = 6;
 163                 jerry_ee_address_data = 0;
 164                 break;
 165         case EE_STATE_0_0:
 166                 switch ((jerry_ee_address_data >> 4) & 0x03)
 167                 {
 168                 case 0: jerry_ee_state=EE_STATE_0_0_0; break;
 169                 case 1: jerry_ee_state=EE_STATE_0_0_1; break;
 170                 case 2: jerry_ee_state=EE_STATE_0_0_2; break;
 171                 case 3: jerry_ee_state=EE_STATE_0_0_3; break;
 172                 }
 173                 eeprom_set_di(data);
 174                 break;
 175         case EE_STATE_0_0_0:
 176                 // writes disable
 177                 // WriteLog("eeprom: read only\n");
 178                 jerry_writes_enabled = 0;
 179                 jerry_ee_state = EE_STATE_START;
 180                 break;
 181         case EE_STATE_0_0_1:
 182                 // writes all
 183                 jerry_ee_rstate = EE_STATE_0_0_1_0;
 184                 jerry_ee_state = EE_READ_DATA;
 185                 jerry_ee_data_cnt = 16;
 186                 jerry_ee_data = 0;
 187                 jerry_ee_direct_jump = 1;
 188                 break;
 189         case EE_STATE_0_0_1_0:
 190                 // WriteLog("eeprom: filling eeprom with 0x%.4x\n",data);
 191                 if (jerry_writes_enabled)
 192                         for(int i=0; i<64; i++)
 193                                 eeprom_ram[i] = jerry_ee_data;
 194                 EEPROMSave();                                                           // Save it NOW!
 195                 //else
 196                 //      WriteLog("eeprom: not writing because read only\n");
 197                 jerry_ee_state = EE_STATE_BUSY;
 198                 break;
 199         case EE_STATE_0_0_2:
 200                 // erase all
 201                 //WriteLog("eeprom: erasing eeprom\n");
 202                 if (jerry_writes_enabled)
 203                         for(int i=0; i<64; i++)
 204                                 eeprom_ram[i] = 0xFFFF;
 205
 206                 jerry_ee_state = EE_STATE_BUSY;
 207                 break;
 208         case EE_STATE_0_0_3:
 209                 // writes enable
 210                 //WriteLog("eeprom: read/write\n");
 211                 jerry_writes_enabled = 1;
 212                 jerry_ee_state = EE_STATE_START;
 213                 break;
 214         case EE_STATE_1:
 215                 jerry_ee_rstate = EE_STATE_1_0;
 216                 jerry_ee_state = EE_READ_ADDRESS;
 217                 jerry_ee_address_cnt = 6;
 218                 jerry_ee_address_data = 0;
 219                 jerry_ee_direct_jump = 1;
 220                 break;
 221         case EE_STATE_1_0:
 222                 jerry_ee_rstate = EE_STATE_1_1;
 223                 jerry_ee_state = EE_READ_DATA;
 224                 jerry_ee_data_cnt = 16;
 225                 jerry_ee_data = 0;
 226                 jerry_ee_direct_jump = 1;
 227                 break;
 228         case EE_STATE_1_1:
 229                 //WriteLog("eeprom: writing 0x%.4x at 0x%.2x\n",jerry_ee_data,jerry_ee_address_data);
 230                 if (jerry_writes_enabled)
 231                         eeprom_ram[jerry_ee_address_data] = jerry_ee_data;
 232                 EEPROMSave();                                                           // Save it NOW!
 233                 jerry_ee_state = EE_STATE_BUSY;
 234                 break;
 235         case EE_STATE_2:
 236                 jerry_ee_rstate = EE_STATE_2_0;
 237                 jerry_ee_state = EE_READ_ADDRESS;
 238                 jerry_ee_address_cnt = 6;
 239                 jerry_ee_address_data = 0;
 240                 jerry_ee_data_cnt = 16;
 241                 jerry_ee_data = 0;
 242                 break;
 243         case EE_STATE_3:
 244                 jerry_ee_rstate = EE_STATE_3_0;
 245                 jerry_ee_state = EE_READ_ADDRESS;
 246                 jerry_ee_address_cnt = 6;
 247                 jerry_ee_address_data = 0;
 248                 jerry_ee_direct_jump = 1;
 249                 break;
 250         case EE_STATE_3_0:
 251                 //WriteLog("eeprom: erasing 0x%.2x\n",jerry_ee_address_data);
 252                 if (jerry_writes_enabled)
 253                         eeprom_ram[jerry_ee_address_data] = 0xFFFF;
 254                 jerry_ee_state = EE_STATE_BUSY;
 255                 break;
 256         case EE_READ_DATA:
 257                 //WriteLog("eeprom:\t\t\t%i bit %i\n",data,jerry_ee_data_cnt-1);
 258                 jerry_ee_data <<= 1;
 259                 jerry_ee_data |= data;
 260                 jerry_ee_data_cnt--;
 261                 if (!jerry_ee_data_cnt)
 262                 {
 263                         jerry_ee_state = jerry_ee_rstate;
 264                         if (jerry_ee_direct_jump)
 265                                 eeprom_set_di(data);
 266                 }
 267                 break;
 268         case EE_READ_ADDRESS:
 269                 jerry_ee_address_data <<= 1;
 270                 jerry_ee_address_data |= data;
 271                 jerry_ee_address_cnt--;
 272 //              WriteLog("eeprom:\t%i bits remaining\n",jerry_ee_address_cnt);
 273                 if (!jerry_ee_address_cnt)
 274                 {
 275                         jerry_ee_state = jerry_ee_rstate;
 276                         //WriteLog("eeprom:\t\tread address 0x%.2x\n",jerry_ee_address_data);
 277                         if (jerry_ee_direct_jump)
 278                                 eeprom_set_di(data);
 279                 }
 280                 break;
 281         default:
 282                 jerry_ee_state = EE_STATE_OP_A;
 283         }
 284 }
 285
 286 void eeprom_set_cs(uint32 state)
 287 {
 288 //      WriteLog("eeprom: cs=%i\n",state);
 289         jerry_ee_state = EE_STATE_START;
 290         jerry_ee_op = 0;
 291         jerry_ee_rstate = 0;
 292         jerry_ee_address_data = 0;
 293         jerry_ee_address_cnt = 6;
 294         jerry_ee_data = 0;
 295         jerry_ee_data_cnt = 16;
 296         jerry_writes_enabled = 1;
 297 }
 298
 299 uint32 eeprom_get_do(void)
 300 {
 301         uint16 data = 1;
 302
 303         switch (jerry_ee_state)
 304         {
 305         case EE_STATE_START:
 306                 data = 1;
 307                 break;
 308         case EE_STATE_BUSY:
 309                 jerry_ee_state = EE_STATE_START;
 310                 data = 0;
 311                 break;
 312         case EE_STATE_2_0:
 313                 jerry_ee_data_cnt--;
 314                 data = (eeprom_ram[jerry_ee_address_data] & (1 << jerry_ee_data_cnt)) >> jerry_ee_data_cnt;
 315                 if (!jerry_ee_data_cnt)
 316                 {
 317                         //WriteLog("eeprom: read 0x%.4x at 0x%.2x cpu %i pc=0x%.8x\n",eeprom_ram[jerry_ee_address_data],jerry_ee_address_data,jaguar_cpu_in_exec,s68000readPC());
 318                         jerry_ee_state = EE_STATE_START;
 319                 }
 320                 break;
 321         }
 322
 323 //      WriteLog("eeprom: do=%i\n",data);
 324         return data;
 325 }