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

   1 //
   2 // Jaguar EEPROM handler
   3 //
   4 // by Cal2
   5 // GCC/SDL port by Niels Wagenaar (Linux/WIN32) and Caz (BeOS)
   6 // Cleanups/enhancements by James Hammons
   7 // (C) 2010 Underground Software
   8 //
   9 // JLH = James Hammons <jlhamm@acm.org>
  10 //
  11 // Who  When        What
  12 // ---  ----------  -------------------------------------------------------------
  13 // JLH  01/16/2010  Created this log ;-)
  14 //
  15
  16 #include "eeprom.h"
  17
  18 #include <stdlib.h>
  19 #include <string.h>                                                             // For memset
  20 #include "jaguar.h"
  21 #include "log.h"
  22 #include "settings.h"
  23
  24 #define eeprom_LOG
  25
  26 static uint16 eeprom_ram[64];
  27
  28 //
  29 // Private function prototypes
  30 //
  31
  32 static void EEPROMSave(void);
  33 static void eeprom_set_di(uint32 state);
  34 static void eeprom_set_cs(uint32 state);
  35 static uint32 eeprom_get_do(void);
  36
  37 enum { EE_STATE_START = 1, EE_STATE_OP_A, EE_STATE_OP_B, EE_STATE_0, EE_STATE_1,
  38         EE_STATE_2, EE_STATE_3, EE_STATE_0_0, EE_READ_ADDRESS, EE_STATE_0_0_0,
  39         EE_STATE_0_0_1, EE_STATE_0_0_2, EE_STATE_0_0_3, EE_STATE_0_0_1_0, EE_READ_DATA,
  40         EE_STATE_BUSY, EE_STATE_1_0, EE_STATE_1_1, EE_STATE_2_0, EE_STATE_3_0 };
  41
  42 // Local global variables
  43
  44 static uint16 jerry_ee_state = EE_STATE_START;
  45 static uint16 jerry_ee_op = 0;
  46 static uint16 jerry_ee_rstate = 0;
  47 static uint16 jerry_ee_address_data = 0;
  48 static uint16 jerry_ee_address_cnt = 6;
  49 static uint16 jerry_ee_data = 0;
  50 static uint16 jerry_ee_data_cnt = 16;
  51 static uint16 jerry_writes_enabled = 0;
  52 static uint16 jerry_ee_direct_jump = 0;
  53 static char eeprom_filename[MAX_PATH];
  54 static bool foundEEPROM = false;
  55
  56 void EepromInit(void)
  57 {
  58         sprintf(eeprom_filename, "%s%08X.eep", vjs.EEPROMPath, (unsigned int)jaguarMainROMCRC32);
  59         FILE * fp = fopen(eeprom_filename, "rb");
  60
  61         if (fp)
  62         {
  63                 fread(eeprom_ram, 1, 128, fp);
  64                 fclose(fp);
  65                 WriteLog("EEPROM: Loaded from %s\n", eeprom_filename);
  66                 foundEEPROM = true;
  67         }
  68         else
  69                 WriteLog("EEPROM: Could not open file \"%s\"!\n", eeprom_filename);
  70 }
  71
  72 void EepromReset(void)
  73 {
  74         if (!foundEEPROM)
  75                 memset(eeprom_ram, 0xFF, 64 * sizeof(uint16));
  76 }
  77
  78 void EepromDone(void)
  79 {
  80         WriteLog("EEPROM: Done.\n");
  81 }
  82
  83 static void EEPROMSave(void)
  84 {
  85         FILE * fp = fopen(eeprom_filename, "wb");
  86
  87         if (fp == NULL)
  88         {
  89                 WriteLog("EEPROM: Could not create file \"%s!\"\n", eeprom_filename);
  90                 return;
  91         }
  92
  93         fwrite(eeprom_ram, 1, 128, fp);
  94         fclose(fp);
  95 }
  96
  97 uint8 EepromReadByte(uint32 offset)
  98 {
  99         switch (offset)
 100         {
 101         case 0xF14001:
 102                 return eeprom_get_do();
 103         case 0xF14801:
 104                 break;
 105         case 0xF15001:
 106                 eeprom_set_cs(1);
 107                 break;
 108 //      default: WriteLog("EEPROM: unmapped 0x%.8x\n", offset); break;
 109         }
 110
 111         return 0x00;
 112 }
 113
 114 uint16 EepromReadWord(uint32 offset)
 115 {
 116         return ((uint16)EepromReadByte(offset + 0) << 8) | EepromReadByte(offset + 1);
 117 }
 118
 119 void EepromWriteByte(uint32 offset, uint8 data)
 120 {
 121         switch (offset)
 122         {
 123         case 0xF14001:
 124                 break;
 125         case 0xF14801:
 126                 eeprom_set_di(data & 0x01);
 127                 break;
 128         case 0xF15001:
 129                 eeprom_set_cs(1);
 130                 break;
 131 //      default: WriteLog("eeprom: unmapped 0x%.8x\n",offset); break;
 132         }
 133 }
 134
 135 void EepromWriteWord(uint32 offset, uint16 data)
 136 {
 137         EepromWriteByte(offset + 0, (data >> 8) & 0xFF);
 138         EepromWriteByte(offset + 1, data & 0xFF);
 139 }
 140
 141 static void eeprom_set_di(uint32 data)
 142 {
 143 //      WriteLog("eeprom: di=%i\n",data);
 144 //      WriteLog("eeprom: state %i\n",jerry_ee_state);
 145         switch (jerry_ee_state)
 146         {
 147         case EE_STATE_START:
 148                 jerry_ee_state = EE_STATE_OP_A;
 149                 break;
 150         case EE_STATE_OP_A:
 151                 jerry_ee_op = (data << 1);
 152                 jerry_ee_state = EE_STATE_OP_B;
 153                 break;
 154         case EE_STATE_OP_B:
 155                 jerry_ee_op |= data;
 156                 jerry_ee_direct_jump = 0;
 157 //              WriteLog("eeprom: opcode %i\n",jerry_ee_op);
 158                 switch (jerry_ee_op)
 159                 {
 160                 case 0: jerry_ee_state = EE_STATE_0; break;
 161                 case 1: jerry_ee_state = EE_STATE_1; break;
 162                 case 2: jerry_ee_state = EE_STATE_2; break;
 163                 case 3: jerry_ee_state = EE_STATE_3; break;
 164                 }
 165                 eeprom_set_di(data);
 166                 break;
 167         case EE_STATE_0:
 168                 jerry_ee_rstate = EE_STATE_0_0;
 169                 jerry_ee_state = EE_READ_ADDRESS;
 170                 jerry_ee_direct_jump = 1;
 171                 jerry_ee_address_cnt = 6;
 172                 jerry_ee_address_data = 0;
 173                 break;
 174         case EE_STATE_0_0:
 175                 switch ((jerry_ee_address_data >> 4) & 0x03)
 176                 {
 177                 case 0: jerry_ee_state=EE_STATE_0_0_0; break;
 178                 case 1: jerry_ee_state=EE_STATE_0_0_1; break;
 179                 case 2: jerry_ee_state=EE_STATE_0_0_2; break;
 180                 case 3: jerry_ee_state=EE_STATE_0_0_3; break;
 181                 }
 182                 eeprom_set_di(data);
 183                 break;
 184         case EE_STATE_0_0_0:
 185                 // writes disable
 186                 // WriteLog("eeprom: read only\n");
 187                 jerry_writes_enabled = 0;
 188                 jerry_ee_state = EE_STATE_START;
 189                 break;
 190         case EE_STATE_0_0_1:
 191                 // writes all
 192                 jerry_ee_rstate = EE_STATE_0_0_1_0;
 193                 jerry_ee_state = EE_READ_DATA;
 194                 jerry_ee_data_cnt = 16;
 195                 jerry_ee_data = 0;
 196                 jerry_ee_direct_jump = 1;
 197                 break;
 198         case EE_STATE_0_0_1_0:
 199                 // WriteLog("eeprom: filling eeprom with 0x%.4x\n",data);
 200                 if (jerry_writes_enabled)
 201                         for(int i=0; i<64; i++)
 202                                 eeprom_ram[i] = jerry_ee_data;
 203
 204                 EEPROMSave();                                                           // Save it NOW!
 205                 //else
 206                 //      WriteLog("eeprom: not writing because read only\n");
 207                 jerry_ee_state = EE_STATE_BUSY;
 208                 break;
 209         case EE_STATE_0_0_2:
 210                 // erase all
 211                 //WriteLog("eeprom: erasing eeprom\n");
 212                 if (jerry_writes_enabled)
 213                         for(int i=0; i<64; i++)
 214                                 eeprom_ram[i] = 0xFFFF;
 215
 216                 jerry_ee_state = EE_STATE_BUSY;
 217                 break;
 218         case EE_STATE_0_0_3:
 219                 // writes enable
 220                 //WriteLog("eeprom: read/write\n");
 221                 jerry_writes_enabled = 1;
 222                 jerry_ee_state = EE_STATE_START;
 223                 break;
 224         case EE_STATE_1:
 225                 jerry_ee_rstate = EE_STATE_1_0;
 226                 jerry_ee_state = EE_READ_ADDRESS;
 227                 jerry_ee_address_cnt = 6;
 228                 jerry_ee_address_data = 0;
 229                 jerry_ee_direct_jump = 1;
 230                 break;
 231         case EE_STATE_1_0:
 232                 jerry_ee_rstate = EE_STATE_1_1;
 233                 jerry_ee_state = EE_READ_DATA;
 234                 jerry_ee_data_cnt = 16;
 235                 jerry_ee_data = 0;
 236                 jerry_ee_direct_jump = 1;
 237                 break;
 238         case EE_STATE_1_1:
 239                 //WriteLog("eeprom: writing 0x%.4x at 0x%.2x\n",jerry_ee_data,jerry_ee_address_data);
 240                 if (jerry_writes_enabled)
 241                         eeprom_ram[jerry_ee_address_data] = jerry_ee_data;
 242
 243                 EEPROMSave();                                                           // Save it NOW!
 244                 jerry_ee_state = EE_STATE_BUSY;
 245                 break;
 246         case EE_STATE_2:
 247                 jerry_ee_rstate = EE_STATE_2_0;
 248                 jerry_ee_state = EE_READ_ADDRESS;
 249                 jerry_ee_address_cnt = 6;
 250                 jerry_ee_address_data = 0;
 251                 jerry_ee_data_cnt = 16;
 252                 jerry_ee_data = 0;
 253                 break;
 254         case EE_STATE_3:
 255                 jerry_ee_rstate = EE_STATE_3_0;
 256                 jerry_ee_state = EE_READ_ADDRESS;
 257                 jerry_ee_address_cnt = 6;
 258                 jerry_ee_address_data = 0;
 259                 jerry_ee_direct_jump = 1;
 260                 break;
 261         case EE_STATE_3_0:
 262                 //WriteLog("eeprom: erasing 0x%.2x\n",jerry_ee_address_data);
 263                 if (jerry_writes_enabled)
 264                         eeprom_ram[jerry_ee_address_data] = 0xFFFF;
 265
 266                 jerry_ee_state = EE_STATE_BUSY;
 267                 break;
 268         case EE_READ_DATA:
 269                 //WriteLog("eeprom:\t\t\t%i bit %i\n",data,jerry_ee_data_cnt-1);
 270                 jerry_ee_data <<= 1;
 271                 jerry_ee_data |= data;
 272                 jerry_ee_data_cnt--;
 273
 274                 if (!jerry_ee_data_cnt)
 275                 {
 276                         jerry_ee_state = jerry_ee_rstate;
 277
 278                         if (jerry_ee_direct_jump)
 279                                 eeprom_set_di(data);
 280                 }
 281                 break;
 282         case EE_READ_ADDRESS:
 283                 jerry_ee_address_data <<= 1;
 284                 jerry_ee_address_data |= data;
 285                 jerry_ee_address_cnt--;
 286 //              WriteLog("eeprom:\t%i bits remaining\n",jerry_ee_address_cnt);
 287
 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
 293                         if (jerry_ee_direct_jump)
 294                                 eeprom_set_di(data);
 295                 }
 296                 break;
 297         default:
 298                 jerry_ee_state = EE_STATE_OP_A;
 299         }
 300 }
 301
 302 static void eeprom_set_cs(uint32 state)
 303 {
 304 //      WriteLog("eeprom: cs=%i\n",state);
 305         jerry_ee_state = EE_STATE_START;
 306         jerry_ee_op = 0;
 307         jerry_ee_rstate = 0;
 308         jerry_ee_address_data = 0;
 309         jerry_ee_address_cnt = 6;
 310         jerry_ee_data = 0;
 311         jerry_ee_data_cnt = 16;
 312         jerry_writes_enabled = 1;
 313 }
 314
 315 static uint32 eeprom_get_do(void)
 316 {
 317         uint16 data = 1;
 318
 319         switch (jerry_ee_state)
 320         {
 321         case EE_STATE_START:
 322                 data = 1;
 323                 break;
 324         case EE_STATE_BUSY:
 325                 jerry_ee_state = EE_STATE_START;
 326                 data = 0;
 327                 break;
 328         case EE_STATE_2_0:
 329                 jerry_ee_data_cnt--;
 330                 data = (eeprom_ram[jerry_ee_address_data] & (1 << jerry_ee_data_cnt)) >> jerry_ee_data_cnt;
 331
 332                 if (!jerry_ee_data_cnt)
 333                 {
 334                         //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());
 335                         jerry_ee_state = EE_STATE_START;
 336                 }
 337                 break;
 338         }
 339
 340 //      WriteLog("eeprom: do=%i\n",data);
 341         return data;
 342 }