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