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 L. Hammons
   7 //
   8
   9 #include "eeprom.h"
  10
  11 #include <stdlib.h>
  12 #include <string.h>                                                             // For memset
  13 #include "jaguar.h"
  14 #include "log.h"
  15 #include "settings.h"
  16
  17 #define eeprom_LOG
  18
  19 static uint16 eeprom_ram[64];
  20
  21 //
  22 // Private function prototypes
  23 //
  24
  25 static void EEPROMSave(void);
  26 static void eeprom_set_di(uint32 state);
  27 static void eeprom_set_cs(uint32 state);
  28 static 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 static uint16 jerry_ee_state = EE_STATE_START;
  38 static uint16 jerry_ee_op = 0;
  39 static uint16 jerry_ee_rstate = 0;
  40 static uint16 jerry_ee_address_data = 0;
  41 static uint16 jerry_ee_address_cnt = 6;
  42 static uint16 jerry_ee_data = 0;
  43 static uint16 jerry_ee_data_cnt = 16;
  44 static uint16 jerry_writes_enabled = 0;
  45 static uint16 jerry_ee_direct_jump = 0;
  46 static char eeprom_filename[MAX_PATH];
  47 static bool foundEEPROM = false;
  48
  49 void EepromInit(void)
  50 {
  51         sprintf(eeprom_filename, "%s%08X.eep", vjs.EEPROMPath, (unsigned int)jaguarMainROMCRC32);
  52         FILE * fp = fopen(eeprom_filename, "rb");
  53
  54         if (fp)
  55         {
  56                 fread(eeprom_ram, 1, 128, fp);
  57                 fclose(fp);
  58                 WriteLog("EEPROM: Loaded from %s\n", eeprom_filename);
  59                 foundEEPROM = true;
  60         }
  61         else
  62                 WriteLog("EEPROM: Could not open file \"%s\"!\n", eeprom_filename);
  63 }
  64
  65 void EepromReset(void)
  66 {
  67         if (!foundEEPROM)
  68                 memset(eeprom_ram, 0xFF, 64 * sizeof(uint16));
  69 }
  70
  71 void EepromDone(void)
  72 {
  73         WriteLog("EEPROM: Done.\n");
  74 }
  75
  76 static void EEPROMSave(void)
  77 {
  78         FILE * fp = fopen(eeprom_filename, "wb");
  79
  80         if (fp == NULL)
  81         {
  82                 WriteLog("EEPROM: Could not create file \"%s!\"\n", eeprom_filename);
  83                 return;
  84         }
  85
  86         fwrite(eeprom_ram, 1, 128, fp);
  87         fclose(fp);
  88 }
  89
  90 uint8 EepromReadByte(uint32 offset)
  91 {
  92         switch (offset)
  93         {
  94         case 0xF14001:
  95                 return eeprom_get_do();
  96         case 0xF14801:
  97                 break;
  98         case 0xF15001:
  99                 eeprom_set_cs(1);
 100                 break;
 101 //      default: WriteLog("EEPROM: unmapped 0x%.8x\n", offset); break;
 102         }
 103
 104         return 0x00;
 105 }
 106
 107 uint16 EepromReadWord(uint32 offset)
 108 {
 109         return ((uint16)EepromReadByte(offset + 0) << 8) | EepromReadByte(offset + 1);
 110 }
 111
 112 void EepromWriteByte(uint32 offset, uint8 data)
 113 {
 114         switch (offset)
 115         {
 116         case 0xF14001:
 117                 break;
 118         case 0xF14801:
 119                 eeprom_set_di(data & 0x01);
 120                 break;
 121         case 0xF15001:
 122                 eeprom_set_cs(1);
 123                 break;
 124 //      default: WriteLog("eeprom: unmapped 0x%.8x\n",offset); break;
 125         }
 126 }
 127
 128 void EepromWriteWord(uint32 offset, uint16 data)
 129 {
 130         EepromWriteByte(offset + 0, (data >> 8) & 0xFF);
 131         EepromWriteByte(offset + 1, data & 0xFF);
 132 }
 133
 134 static void eeprom_set_di(uint32 data)
 135 {
 136 //      WriteLog("eeprom: di=%i\n",data);
 137 //      WriteLog("eeprom: state %i\n",jerry_ee_state);
 138         switch (jerry_ee_state)
 139         {
 140         case EE_STATE_START:
 141                 jerry_ee_state = EE_STATE_OP_A;
 142                 break;
 143         case EE_STATE_OP_A:
 144                 jerry_ee_op = (data << 1);
 145                 jerry_ee_state = EE_STATE_OP_B;
 146                 break;
 147         case EE_STATE_OP_B:
 148                 jerry_ee_op |= data;
 149                 jerry_ee_direct_jump = 0;
 150 //              WriteLog("eeprom: opcode %i\n",jerry_ee_op);
 151                 switch (jerry_ee_op)
 152                 {
 153                 case 0: jerry_ee_state = EE_STATE_0; break;
 154                 case 1: jerry_ee_state = EE_STATE_1; break;
 155                 case 2: jerry_ee_state = EE_STATE_2; break;
 156                 case 3: jerry_ee_state = EE_STATE_3; break;
 157                 }
 158                 eeprom_set_di(data);
 159                 break;
 160         case EE_STATE_0:
 161                 jerry_ee_rstate = EE_STATE_0_0;
 162                 jerry_ee_state = EE_READ_ADDRESS;
 163                 jerry_ee_direct_jump = 1;
 164                 jerry_ee_address_cnt = 6;
 165                 jerry_ee_address_data = 0;
 166                 break;
 167         case EE_STATE_0_0:
 168                 switch ((jerry_ee_address_data >> 4) & 0x03)
 169                 {
 170                 case 0: jerry_ee_state=EE_STATE_0_0_0; break;
 171                 case 1: jerry_ee_state=EE_STATE_0_0_1; break;
 172                 case 2: jerry_ee_state=EE_STATE_0_0_2; break;
 173                 case 3: jerry_ee_state=EE_STATE_0_0_3; break;
 174                 }
 175                 eeprom_set_di(data);
 176                 break;
 177         case EE_STATE_0_0_0:
 178                 // writes disable
 179                 // WriteLog("eeprom: read only\n");
 180                 jerry_writes_enabled = 0;
 181                 jerry_ee_state = EE_STATE_START;
 182                 break;
 183         case EE_STATE_0_0_1:
 184                 // writes all
 185                 jerry_ee_rstate = EE_STATE_0_0_1_0;
 186                 jerry_ee_state = EE_READ_DATA;
 187                 jerry_ee_data_cnt = 16;
 188                 jerry_ee_data = 0;
 189                 jerry_ee_direct_jump = 1;
 190                 break;
 191         case EE_STATE_0_0_1_0:
 192                 // WriteLog("eeprom: filling eeprom with 0x%.4x\n",data);
 193                 if (jerry_writes_enabled)
 194                         for(int i=0; i<64; i++)
 195                                 eeprom_ram[i] = jerry_ee_data;
 196                 EEPROMSave();                                                           // Save it NOW!
 197                 //else
 198                 //      WriteLog("eeprom: not writing because read only\n");
 199                 jerry_ee_state = EE_STATE_BUSY;
 200                 break;
 201         case EE_STATE_0_0_2:
 202                 // erase all
 203                 //WriteLog("eeprom: erasing eeprom\n");
 204                 if (jerry_writes_enabled)
 205                         for(int i=0; i<64; i++)
 206                                 eeprom_ram[i] = 0xFFFF;
 207
 208                 jerry_ee_state = EE_STATE_BUSY;
 209                 break;
 210         case EE_STATE_0_0_3:
 211                 // writes enable
 212                 //WriteLog("eeprom: read/write\n");
 213                 jerry_writes_enabled = 1;
 214                 jerry_ee_state = EE_STATE_START;
 215                 break;
 216         case EE_STATE_1:
 217                 jerry_ee_rstate = EE_STATE_1_0;
 218                 jerry_ee_state = EE_READ_ADDRESS;
 219                 jerry_ee_address_cnt = 6;
 220                 jerry_ee_address_data = 0;
 221                 jerry_ee_direct_jump = 1;
 222                 break;
 223         case EE_STATE_1_0:
 224                 jerry_ee_rstate = EE_STATE_1_1;
 225                 jerry_ee_state = EE_READ_DATA;
 226                 jerry_ee_data_cnt = 16;
 227                 jerry_ee_data = 0;
 228                 jerry_ee_direct_jump = 1;
 229                 break;
 230         case EE_STATE_1_1:
 231                 //WriteLog("eeprom: writing 0x%.4x at 0x%.2x\n",jerry_ee_data,jerry_ee_address_data);
 232                 if (jerry_writes_enabled)
 233                         eeprom_ram[jerry_ee_address_data] = jerry_ee_data;
 234                 EEPROMSave();                                                           // Save it NOW!
 235                 jerry_ee_state = EE_STATE_BUSY;
 236                 break;
 237         case EE_STATE_2:
 238                 jerry_ee_rstate = EE_STATE_2_0;
 239                 jerry_ee_state = EE_READ_ADDRESS;
 240                 jerry_ee_address_cnt = 6;
 241                 jerry_ee_address_data = 0;
 242                 jerry_ee_data_cnt = 16;
 243                 jerry_ee_data = 0;
 244                 break;
 245         case EE_STATE_3:
 246                 jerry_ee_rstate = EE_STATE_3_0;
 247                 jerry_ee_state = EE_READ_ADDRESS;
 248                 jerry_ee_address_cnt = 6;
 249                 jerry_ee_address_data = 0;
 250                 jerry_ee_direct_jump = 1;
 251                 break;
 252         case EE_STATE_3_0:
 253                 //WriteLog("eeprom: erasing 0x%.2x\n",jerry_ee_address_data);
 254                 if (jerry_writes_enabled)
 255                         eeprom_ram[jerry_ee_address_data] = 0xFFFF;
 256                 jerry_ee_state = EE_STATE_BUSY;
 257                 break;
 258         case EE_READ_DATA:
 259                 //WriteLog("eeprom:\t\t\t%i bit %i\n",data,jerry_ee_data_cnt-1);
 260                 jerry_ee_data <<= 1;
 261                 jerry_ee_data |= data;
 262                 jerry_ee_data_cnt--;
 263                 if (!jerry_ee_data_cnt)
 264                 {
 265                         jerry_ee_state = jerry_ee_rstate;
 266                         if (jerry_ee_direct_jump)
 267                                 eeprom_set_di(data);
 268                 }
 269                 break;
 270         case EE_READ_ADDRESS:
 271                 jerry_ee_address_data <<= 1;
 272                 jerry_ee_address_data |= data;
 273                 jerry_ee_address_cnt--;
 274 //              WriteLog("eeprom:\t%i bits remaining\n",jerry_ee_address_cnt);
 275                 if (!jerry_ee_address_cnt)
 276                 {
 277                         jerry_ee_state = jerry_ee_rstate;
 278                         //WriteLog("eeprom:\t\tread address 0x%.2x\n",jerry_ee_address_data);
 279                         if (jerry_ee_direct_jump)
 280                                 eeprom_set_di(data);
 281                 }
 282                 break;
 283         default:
 284                 jerry_ee_state = EE_STATE_OP_A;
 285         }
 286 }
 287
 288 static void eeprom_set_cs(uint32 state)
 289 {
 290 //      WriteLog("eeprom: cs=%i\n",state);
 291         jerry_ee_state = EE_STATE_START;
 292         jerry_ee_op = 0;
 293         jerry_ee_rstate = 0;
 294         jerry_ee_address_data = 0;
 295         jerry_ee_address_cnt = 6;
 296         jerry_ee_data = 0;
 297         jerry_ee_data_cnt = 16;
 298         jerry_writes_enabled = 1;
 299 }
 300
 301 static uint32 eeprom_get_do(void)
 302 {
 303         uint16 data = 1;
 304
 305         switch (jerry_ee_state)
 306         {
 307         case EE_STATE_START:
 308                 data = 1;
 309                 break;
 310         case EE_STATE_BUSY:
 311                 jerry_ee_state = EE_STATE_START;
 312                 data = 0;
 313                 break;
 314         case EE_STATE_2_0:
 315                 jerry_ee_data_cnt--;
 316                 data = (eeprom_ram[jerry_ee_address_data] & (1 << jerry_ee_data_cnt)) >> jerry_ee_data_cnt;
 317                 if (!jerry_ee_data_cnt)
 318                 {
 319                         //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());
 320                         jerry_ee_state = EE_STATE_START;
 321                 }
 322                 break;
 323         }
 324
 325 //      WriteLog("eeprom: do=%i\n",data);
 326         return data;
 327 }