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