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 by James L. Hammons
   7 //
   8
   9 #include "eeprom.h"
  10
  11 #define eeprom_LOG
  12
  13 static uint16 eeprom_ram[64];
  14
  15 //
  16 // Private function prototypes
  17 //
  18
  19 void EEPROMSave(void);
  20 void eeprom_set_di(uint32 state);
  21 void eeprom_set_cs(uint32 state);
  22 uint32 eeprom_get_do(void);
  23
  24 #define EE_STATE_START                  1
  25 #define EE_STATE_OP_A                   2
  26 #define EE_STATE_OP_B                   3
  27 #define EE_STATE_0                              4
  28 #define EE_STATE_1                              5
  29 #define EE_STATE_2                              6
  30 #define EE_STATE_3                              7
  31 #define EE_STATE_0_0                    8
  32 #define EE_READ_ADDRESS                 9
  33 #define EE_STATE_0_0_0                  10
  34 #define EE_STATE_0_0_1                  11
  35 #define EE_STATE_0_0_2                  12
  36 #define EE_STATE_0_0_3                  13
  37 #define EE_STATE_0_0_1_0                14
  38 #define EE_READ_DATA                    15
  39 #define EE_STATE_BUSY                   16
  40 #define EE_STATE_1_0                    17
  41 #define EE_STATE_1_1                    18
  42 #define EE_STATE_2_0                    19
  43 #define EE_STATE_3_0                    20
  44
  45 // External global variables
  46
  47 extern char jaguar_boot_dir[1024];
  48
  49 // Local global variables
  50
  51 uint16 jerry_ee_state = EE_STATE_START;
  52 uint16 jerry_ee_op = 0;
  53 uint16 jerry_ee_rstate = 0;
  54 uint16 jerry_ee_address_data = 0;
  55 uint16 jerry_ee_address_cnt = 6;
  56 uint16 jerry_ee_data = 0;
  57 uint16 jerry_ee_data_cnt = 16;
  58 uint16 jerry_writes_enabled = 0;
  59 uint16 jerry_ee_direct_jump = 0;
  60 FILE * jerry_ee_fp;
  61 static char eeprom_filename[1024];
  62 static bool foundEEPROM = false;
  63
  64 void eeprom_init(void)
  65 {
  66         sprintf(eeprom_filename, "%s/%s%08X.eep", jaguar_boot_dir, jaguar_eeproms_path, (unsigned int)jaguar_mainRom_crc32);
  67         jerry_ee_fp = fopen(eeprom_filename, "rb");
  68         if (jerry_ee_fp)
  69         {
  70                 fread(eeprom_ram, 1, 128, jerry_ee_fp);
  71                 fclose(jerry_ee_fp);
  72                 WriteLog("EEPROM: Loaded from %s\n", eeprom_filename);
  73                 foundEEPROM = true;
  74         }
  75         else
  76         {
  77                 WriteLog("EEPROM: Creating %s\n", eeprom_filename);
  78                 jerry_ee_fp = fopen(eeprom_filename, "wb");
  79                 if (jerry_ee_fp == NULL)
  80                         WriteLog("EEPROM: Could not open/create %s\n", eeprom_filename);
  81         }
  82 }
  83
  84 void eeprom_reset(void)
  85 {
  86         if (!foundEEPROM)
  87                 memset(eeprom_ram, 0xFF, 64 * sizeof(uint16));
  88 }
  89
  90 void eeprom_done(void)
  91 {
  92 //Actually, is this necessary now that we write the file immediately?
  93         EEPROMSave();
  94 }
  95
  96 void EEPROMSave(void)
  97 {
  98         jerry_ee_fp = fopen(eeprom_filename, "wb");
  99         fwrite(eeprom_ram, 1, 128, jerry_ee_fp);
 100         fclose(jerry_ee_fp);
 101 }
 102
 103 uint8 eeprom_byte_read(uint32 offset)
 104 {
 105         switch (offset)
 106         {
 107         case 0xF14001:
 108                 return eeprom_get_do();
 109         case 0xF14801:
 110                 break;
 111         case 0xF15001:
 112                 eeprom_set_cs(1);
 113                 break;
 114 //      default: WriteLog("eeprom: unmapped 0x%.8x\n",offset); break;
 115         }
 116
 117         return 0x00;
 118 }
 119
 120 uint16 eeprom_word_read(uint32 offset)
 121 {
 122         return ((uint16)eeprom_byte_read(offset+0) << 8) | eeprom_byte_read(offset+1);
 123 }
 124
 125 void eeprom_byte_write(uint32 offset, uint8 data)
 126 {
 127         switch (offset)
 128         {
 129         case 0xF14001:
 130                 break;
 131         case 0xF14801:
 132                 eeprom_set_di(data & 0x01);
 133                 break;
 134         case 0xF15001:
 135                 eeprom_set_cs(1);
 136                 break;
 137 //      default: WriteLog("eeprom: unmapped 0x%.8x\n",offset); break;
 138         }
 139 }
 140
 141 void eeprom_word_write(uint32 offset, uint16 data)
 142 {
 143         eeprom_byte_write(offset+0, (data >> 8) & 0xFF);
 144         eeprom_byte_write(offset+1, data & 0xFF);
 145 }
 146
 147 void eeprom_set_di(uint32 data)
 148 {
 149 //      WriteLog("eeprom: di=%i\n",data);
 150 //      WriteLog("eeprom: state %i\n",jerry_ee_state);
 151         switch (jerry_ee_state)
 152         {
 153         case EE_STATE_START:
 154                 jerry_ee_state = EE_STATE_OP_A;
 155                 break;
 156         case EE_STATE_OP_A:
 157                 jerry_ee_op = (data << 1);
 158                 jerry_ee_state = EE_STATE_OP_B;
 159                 break;
 160         case EE_STATE_OP_B:
 161                 jerry_ee_op |= data;
 162                 jerry_ee_direct_jump = 0;
 163 //              WriteLog("eeprom: opcode %i\n",jerry_ee_op);
 164                 switch (jerry_ee_op)
 165                 {
 166                 case 0: jerry_ee_state = EE_STATE_0; break;
 167                 case 1: jerry_ee_state = EE_STATE_1; break;
 168                 case 2: jerry_ee_state = EE_STATE_2; break;
 169                 case 3: jerry_ee_state = EE_STATE_3; break;
 170                 }
 171                 eeprom_set_di(data);
 172                 break;
 173         case EE_STATE_0:
 174                 jerry_ee_rstate = EE_STATE_0_0;
 175                 jerry_ee_state = EE_READ_ADDRESS;
 176                 jerry_ee_direct_jump = 1;
 177                 jerry_ee_address_cnt = 6;
 178                 jerry_ee_address_data = 0;
 179                 break;
 180         case EE_STATE_0_0:
 181                 switch ((jerry_ee_address_data >> 4) & 0x03)
 182                 {
 183                 case 0: jerry_ee_state=EE_STATE_0_0_0; break;
 184                 case 1: jerry_ee_state=EE_STATE_0_0_1; break;
 185                 case 2: jerry_ee_state=EE_STATE_0_0_2; break;
 186                 case 3: jerry_ee_state=EE_STATE_0_0_3; break;
 187                 }
 188                 eeprom_set_di(data);
 189                 break;
 190         case EE_STATE_0_0_0:
 191                 // writes disable
 192                 // WriteLog("eeprom: read only\n");
 193                 jerry_writes_enabled = 0;
 194                 jerry_ee_state = EE_STATE_START;
 195                 break;
 196         case EE_STATE_0_0_1:
 197                 // writes all
 198                 jerry_ee_rstate = EE_STATE_0_0_1_0;
 199                 jerry_ee_state = EE_READ_DATA;
 200                 jerry_ee_data_cnt = 16;
 201                 jerry_ee_data = 0;
 202                 jerry_ee_direct_jump = 1;
 203                 break;
 204         case EE_STATE_0_0_1_0:
 205                 // WriteLog("eeprom: filling eeprom with 0x%.4x\n",data);
 206                 if (jerry_writes_enabled)
 207                         for(int i=0; i<64; i++)
 208                                 eeprom_ram[i] = jerry_ee_data;
 209                 EEPROMSave();   // Save it NOW!
 210                 //else
 211                 //      WriteLog("eeprom: not writing because read only\n");
 212                 jerry_ee_state = EE_STATE_BUSY;
 213                 break;
 214         case EE_STATE_0_0_2:
 215                 // erase all
 216                 //WriteLog("eeprom: erasing eeprom\n");
 217                 if (jerry_writes_enabled)
 218                         for(int i=0; i<64; i++)
 219                                 eeprom_ram[i] = 0xFFFF;
 220
 221                 jerry_ee_state=EE_STATE_BUSY;
 222                 break;
 223         case EE_STATE_0_0_3:
 224                 // writes enable
 225                 //WriteLog("eeprom: read/write\n");
 226                 jerry_writes_enabled = 1;
 227                 jerry_ee_state = EE_STATE_START;
 228                 break;
 229         case EE_STATE_1:
 230                 jerry_ee_rstate = EE_STATE_1_0;
 231                 jerry_ee_state = EE_READ_ADDRESS;
 232                 jerry_ee_address_cnt = 6;
 233                 jerry_ee_address_data = 0;
 234                 jerry_ee_direct_jump = 1;
 235                 break;
 236         case EE_STATE_1_0:
 237                 jerry_ee_rstate = EE_STATE_1_1;
 238                 jerry_ee_state = EE_READ_DATA;
 239                 jerry_ee_data_cnt = 16;
 240                 jerry_ee_data = 0;
 241                 jerry_ee_direct_jump = 1;
 242                 break;
 243         case EE_STATE_1_1:
 244                 //WriteLog("eeprom: writing 0x%.4x at 0x%.2x\n",jerry_ee_data,jerry_ee_address_data);
 245                 if (jerry_writes_enabled)
 246                         eeprom_ram[jerry_ee_address_data] = jerry_ee_data;
 247                 EEPROMSave();   // Save it NOW!
 248                 jerry_ee_state = EE_STATE_BUSY;
 249                 break;
 250         case EE_STATE_2:
 251                 jerry_ee_rstate = EE_STATE_2_0;
 252                 jerry_ee_state = EE_READ_ADDRESS;
 253                 jerry_ee_address_cnt = 6;
 254                 jerry_ee_address_data = 0;
 255                 jerry_ee_data_cnt = 16;
 256                 jerry_ee_data = 0;
 257                 break;
 258         case EE_STATE_3:
 259                 jerry_ee_rstate = EE_STATE_3_0;
 260                 jerry_ee_state = EE_READ_ADDRESS;
 261                 jerry_ee_address_cnt = 6;
 262                 jerry_ee_address_data = 0;
 263                 jerry_ee_direct_jump = 1;
 264                 break;
 265         case EE_STATE_3_0:
 266                 //WriteLog("eeprom: erasing 0x%.2x\n",jerry_ee_address_data);
 267                 if (jerry_writes_enabled)
 268                         eeprom_ram[jerry_ee_address_data] = 0xFFFF;
 269                 jerry_ee_state = EE_STATE_BUSY;
 270                 break;
 271         case EE_READ_DATA:
 272                 //WriteLog("eeprom:\t\t\t%i bit %i\n",data,jerry_ee_data_cnt-1);
 273                 jerry_ee_data <<= 1;
 274                 jerry_ee_data |= data;
 275                 jerry_ee_data_cnt--;
 276                 if (!jerry_ee_data_cnt)
 277                 {
 278                         jerry_ee_state = jerry_ee_rstate;
 279                         if (jerry_ee_direct_jump)
 280                                 eeprom_set_di(data);
 281                 }
 282                 break;
 283         case EE_READ_ADDRESS:
 284                 jerry_ee_address_data <<= 1;
 285                 jerry_ee_address_data |= data;
 286                 jerry_ee_address_cnt--;
 287 //              WriteLog("eeprom:\t%i bits remaining\n",jerry_ee_address_cnt);
 288                 if (!jerry_ee_address_cnt)
 289                 {
 290                         jerry_ee_state = jerry_ee_rstate;
 291                         //WriteLog("eeprom:\t\tread address 0x%.2x\n",jerry_ee_address_data);
 292                         if (jerry_ee_direct_jump)
 293                                 eeprom_set_di(data);
 294                 }
 295                 break;
 296         default:
 297                 jerry_ee_state = EE_STATE_OP_A;
 298         }
 299 }
 300
 301 void eeprom_set_cs(uint32 state)
 302 {
 303 //      WriteLog("eeprom: cs=%i\n",state);
 304         jerry_ee_state = EE_STATE_START;
 305         jerry_ee_op = 0;
 306         jerry_ee_rstate = 0;
 307         jerry_ee_address_data = 0;
 308         jerry_ee_address_cnt = 6;
 309         jerry_ee_data = 0;
 310         jerry_ee_data_cnt = 16;
 311         jerry_writes_enabled = 1;
 312 }
 313
 314 uint32 eeprom_get_do(void)
 315 {
 316         uint16 data = 1;
 317
 318         switch (jerry_ee_state)
 319         {
 320         case EE_STATE_START:
 321                 data = 1;
 322                 break;
 323         case EE_STATE_BUSY:
 324                 jerry_ee_state = EE_STATE_START;
 325                 data = 0;
 326                 break;
 327         case EE_STATE_2_0:
 328                 jerry_ee_data_cnt--;
 329                 data = (eeprom_ram[jerry_ee_address_data] & (1 << jerry_ee_data_cnt)) >> jerry_ee_data_cnt;
 330                 if (!jerry_ee_data_cnt)
 331                 {
 332                         //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());
 333                         jerry_ee_state = EE_STATE_START;
 334                 }
 335                 break;
 336         }
 337
 338 //      WriteLog("eeprom: do=%i\n",data);
 339         return data;
 340 }