apps/plugins/rockboy/mem.c

   1
   2
   3 #include "rockmacros.h"
   4
   5 #include "defs.h"
   6 #include "hw.h"
   7 #include "regs.h"
   8 #include "mem.h"
   9 #include "rtc-gb.h"
  10 #include "lcd-gb.h"
  11 #include "lcdc.h"
  12 #include "sound.h"
  13
  14 struct mbc mbc IBSS_ATTR;
  15 struct rom rom IBSS_ATTR;
  16 struct ram ram;
  17
  18
  19 /*
  20  * In order to make reads and writes efficient, we keep tables
  21  * (indexed by the high nibble of the address) specifying which
  22  * regions can be read/written without a function call. For such
  23  * ranges, the pointer in the map table points to the base of the
  24  * region in host system memory. For ranges that require special
  25  * processing, the pointer is NULL.
  26  *
  27  * mem_updatemap is called whenever bank changes or other operations
  28  * make the old maps potentially invalid.
  29  */
  30
  31 void mem_updatemap(void)
  32 {
  33     int n;
  34     static byte **map;
  35
  36     map = mbc.rmap;
  37     map[0x0] = rom.bank[0];
  38     map[0x1] = rom.bank[0];
  39     map[0x2] = rom.bank[0];
  40     map[0x3] = rom.bank[0];
  41     if (mbc.rombank < mbc.romsize)
  42     {
  43         map[0x4] = rom.bank[mbc.rombank] - 0x4000;
  44         map[0x5] = rom.bank[mbc.rombank] - 0x4000;
  45         map[0x6] = rom.bank[mbc.rombank] - 0x4000;
  46         map[0x7] = rom.bank[mbc.rombank] - 0x4000;
  47     }
  48     else map[0x4] = map[0x5] = map[0x6] = map[0x7] = NULL;
  49         if (R_VBK & 1)
  50         {
  51                 map[0x8] = lcd.vbank[1] - 0x8000;
  52                 map[0x9] = lcd.vbank[1] - 0x8000;
  53         }
  54         else
  55         {
  56                 map[0x8] = lcd.vbank[0]/*[R_VBK & 1]*/ - 0x8000;
  57                 map[0x9] = lcd.vbank[0]/*[R_VBK & 1]*/ - 0x8000;
  58
  59         }
  60     if (mbc.enableram && !(rtc.sel&8))
  61     {
  62         map[0xA] = ram.sbank[mbc.rambank] - 0xA000;
  63         map[0xB] = ram.sbank[mbc.rambank] - 0xA000;
  64     }
  65     else map[0xA] = map[0xB] = NULL;
  66     map[0xC] = ram.ibank[0] - 0xC000;
  67     n = R_SVBK & 0x07;
  68     map[0xD] = ram.ibank[n?n:1] - 0xD000;
  69     map[0xE] = ram.ibank[0] - 0xE000;
  70     map[0xF] = NULL;
  71
  72     map = mbc.wmap;
  73     map[0x0] = map[0x1] = map[0x2] = map[0x3] = NULL;
  74     map[0x4] = map[0x5] = map[0x6] = map[0x7] = NULL;
  75     map[0x8] = map[0x9] = NULL;
  76     if (mbc.enableram && !(rtc.sel&8))
  77     {
  78         map[0xA] = ram.sbank[mbc.rambank] - 0xA000;
  79         map[0xB] = ram.sbank[mbc.rambank] - 0xA000;
  80     }
  81     else map[0xA] = map[0xB] = NULL;
  82     map[0xC] = ram.ibank[0] - 0xC000;
  83     n = R_SVBK & 0x07;
  84     map[0xD] = ram.ibank[n?n:1] - 0xD000;
  85     map[0xE] = ram.ibank[0] - 0xE000;
  86     map[0xF] = NULL;
  87 }
  88
  89
  90 /*
  91  * ioreg_write handles output to io registers in the FF00-FF7F,FFFF
  92  * range. It takes the register number (low byte of the address) and a
  93  * byte value to be written.
  94  */
  95
  96 static void ioreg_write(byte r, byte b) ICODE_ATTR;
  97 static void ioreg_write(byte r, byte b)
  98 {
  99     if (!hw.cgb)
 100     {
 101
 102         switch (r)
 103         {
 104         case RI_VBK:
 105         case RI_BCPS:
 106         case RI_OCPS:
 107         case RI_BCPD:
 108         case RI_OCPD:
 109         case RI_SVBK:
 110         case RI_KEY1:
 111         case RI_HDMA1:
 112         case RI_HDMA2:
 113         case RI_HDMA3:
 114         case RI_HDMA4:
 115         case RI_HDMA5:
 116             return;
 117         }
 118     }
 119     switch(r)
 120     {
 121     case RI_TIMA:
 122     case RI_TMA:
 123     case RI_TAC:
 124     case RI_SCY:
 125     case RI_SCX:
 126     case RI_WY:
 127     case RI_WX:
 128         REG(r) = b;
 129         break;
 130     case RI_BGP:
 131         if (R_BGP == b) break;
 132         pal_write_dmg(0, 0, b);
 133         pal_write_dmg(8, 1, b);
 134         R_BGP = b;
 135         break;
 136     case RI_OBP0:
 137         if (R_OBP0 == b) break;
 138         pal_write_dmg(64, 2, b);
 139         R_OBP0 = b;
 140         break;
 141     case RI_OBP1:
 142         if (R_OBP1 == b) break;
 143         pal_write_dmg(72, 3, b);
 144         R_OBP1 = b;
 145         break;
 146     case RI_IF:
 147     case RI_IE:
 148         REG(r) = b & 0x1F;
 149         break;
 150     case RI_P1:
 151         REG(r) = b;
 152         pad_refresh();
 153         break;
 154     case RI_SC:
 155         /* FIXME - this is a hack for stupid roms that probe serial */
 156         if ((b & 0x81) == 0x81)
 157         {
 158             R_SB = 0xff;
 159             hw_interrupt(IF_SERIAL, IF_SERIAL);
 160             hw_interrupt(0, IF_SERIAL);
 161         }
 162         R_SC = b; /* & 0x7f; */
 163         break;
 164     case RI_DIV:
 165         REG(r) = 0;
 166         break;
 167     case RI_LCDC:
 168         lcdc_change(b);
 169         break;
 170     case RI_STAT:
 171                 REG(r) = (REG(r) & 0x07) | (b & 0x78);
 172                 stat_trigger();
 173         break;
 174     case RI_LYC:
 175         REG(r) = b;
 176         stat_trigger();
 177         break;
 178     case RI_VBK:
 179         REG(r) = b | 0xFE;
 180         mem_updatemap();
 181         break;
 182     case RI_BCPS:
 183         R_BCPS = b & 0xBF;
 184         R_BCPD = lcd.pal[b & 0x3F];
 185         break;
 186     case RI_OCPS:
 187         R_OCPS = b & 0xBF;
 188         R_OCPD = lcd.pal[64 + (b & 0x3F)];
 189         break;
 190     case RI_BCPD:
 191         R_BCPD = b;
 192         pal_write(R_BCPS & 0x3F, b);
 193         if (R_BCPS & 0x80) R_BCPS = (R_BCPS+1) & 0xBF;
 194         break;
 195     case RI_OCPD:
 196         R_OCPD = b;
 197         pal_write(64 + (R_OCPS & 0x3F), b);
 198         if (R_OCPS & 0x80) R_OCPS = (R_OCPS+1) & 0xBF;
 199         break;
 200     case RI_SVBK:
 201         REG(r) = b & 0x07;
 202         mem_updatemap();
 203         break;
 204     case RI_DMA:
 205         hw_dma(b);
 206         break;
 207     case RI_KEY1:
 208         REG(r) = (REG(r) & 0x80) | (b & 0x01);
 209         break;
 210     case RI_HDMA1:
 211         REG(r) = b;
 212         break;
 213     case RI_HDMA2:
 214         REG(r) = b & 0xF0;
 215         break;
 216     case RI_HDMA3:
 217         REG(r) = b & 0x1F;
 218         break;
 219     case RI_HDMA4:
 220         REG(r) = b & 0xF0;
 221         break;
 222     case RI_HDMA5:
 223         hw_hdma_cmd(b);
 224         break;
 225     }
 226 }
 227
 228
 229 static byte ioreg_read(byte r)
 230 {
 231     switch(r)
 232     {
 233     case RI_SC:
 234         r = R_SC;
 235         R_SC &= 0x7f;
 236         return r;
 237     case RI_P1:
 238     case RI_SB:
 239     case RI_DIV:
 240     case RI_TIMA:
 241     case RI_TMA:
 242     case RI_TAC:
 243     case RI_LCDC:
 244     case RI_STAT:
 245     case RI_SCY:
 246     case RI_SCX:
 247     case RI_LY:
 248     case RI_LYC:
 249     case RI_BGP:
 250     case RI_OBP0:
 251     case RI_OBP1:
 252     case RI_WY:
 253     case RI_WX:
 254     case RI_IE:
 255     case RI_IF:
 256         return REG(r);
 257     case RI_VBK:
 258     case RI_BCPS:
 259     case RI_OCPS:
 260     case RI_BCPD:
 261     case RI_OCPD:
 262     case RI_SVBK:
 263     case RI_KEY1:
 264     case RI_HDMA1:
 265     case RI_HDMA2:
 266     case RI_HDMA3:
 267     case RI_HDMA4:
 268     case RI_HDMA5:
 269         if (hw.cgb) return REG(r);
 270     default:
 271         return 0xff;
 272     }
 273 }
 274
 275
 276
 277 /*
 278  * Memory bank controllers typically intercept write attempts to
 279  * 0000-7FFF, using the address and byte written as instructions to
 280  * change rom or sram banks, control special hardware, etc.
 281  *
 282  * mbc_write takes an address (which should be in the proper range)
 283  * and a byte value written to the address.
 284  */
 285
 286 static void mbc_write(int a, byte b) ICODE_ATTR;
 287 static void mbc_write(int a, byte b)
 288 {
 289     byte ha = (a>>12);
 290
 291     /* printf("mbc %d: rom bank %02X -[%04X:%02X]-> ", mbc.type, mbc.rombank, a, b); */
 292     switch (mbc.type)
 293     {
 294     case MBC_MBC1:
 295         switch (ha & 0xE)
 296         {
 297         case 0x0:
 298             mbc.enableram = ((b & 0x0F) == 0x0A);
 299             break;
 300         case 0x2:
 301             if ((b & 0x1F) == 0) b = 0x01;
 302             mbc.rombank = (mbc.rombank & 0x60) | (b & 0x1F);
 303             break;
 304         case 0x4:
 305             if (mbc.model)
 306             {
 307                 mbc.rambank = b & 0x03;
 308                 break;
 309             }
 310             mbc.rombank = (mbc.rombank & 0x1F) | ((int)(b&3)<<5);
 311             break;
 312         case 0x6:
 313             mbc.model = b & 0x1;
 314             break;
 315         }
 316         break;
 317     case MBC_MBC2: /* is this at all right? */
 318         if ((a & 0x0100) == 0x0000)
 319         {
 320             mbc.enableram = ((b & 0x0F) == 0x0A);
 321             break;
 322         }
 323         if ((a & 0xE100) == 0x2100)
 324         {
 325             mbc.rombank = b & 0x0F;
 326             break;
 327         }
 328         break;
 329     case MBC_MBC3:
 330         switch (ha & 0xE)
 331         {
 332         case 0x0:
 333             mbc.enableram = ((b & 0x0F) == 0x0A);
 334             break;
 335         case 0x2:
 336             if ((b & 0x7F) == 0) b = 0x01;
 337             mbc.rombank = b & 0x7F;
 338             break;
 339         case 0x4:
 340             rtc.sel = b & 0x0f;
 341             mbc.rambank = b & 0x03;
 342             break;
 343         case 0x6:
 344             rtc_latch(b);
 345             break;
 346         }
 347         break;
 348     case MBC_RUMBLE:
 349         switch (ha & 0xF)
 350         {
 351         case 0x4:
 352         case 0x5:
 353             /* FIXME - save high bit as rumble state */
 354             /* mask off high bit */
 355             b &= 0x7;
 356             break;
 357         }
 358         /* fall thru */
 359     case MBC_MBC5:
 360         switch (ha & 0xF)
 361         {
 362         case 0x0:
 363         case 0x1:
 364             mbc.enableram = ((b & 0x0F) == 0x0A);
 365             break;
 366         case 0x2:
 367             if ((b & 0xFF) == 0) b = 0x01;
 368             mbc.rombank = (mbc.rombank & 0x100) | (b & 0xFF);
 369             break;
 370         case 0x3:
 371             mbc.rombank = (mbc.rombank & 0xFF) | ((int)(b&1)<<8);
 372             break;
 373         case 0x4:
 374         case 0x5:
 375             mbc.rambank = b & 0x0f;
 376             break;
 377         }
 378         break;
 379     case MBC_HUC1: /* FIXME - this is all guesswork -- is it right??? */
 380         switch (ha & 0xE)
 381         {
 382         case 0x0:
 383             mbc.enableram = ((b & 0x0F) == 0x0A);
 384             break;
 385         case 0x2:
 386             if ((b & 0x1F) == 0) b = 0x01;
 387             mbc.rombank = (mbc.rombank & 0x60) | (b & 0x1F);
 388             break;
 389         case 0x4:
 390             if (mbc.model)
 391             {
 392                 mbc.rambank = b & 0x03;
 393                 break;
 394             }
 395             mbc.rombank = (mbc.rombank & 0x1F) | ((int)(b&3)<<5);
 396             break;
 397         case 0x6:
 398             mbc.model = b & 0x1;
 399             break;
 400         }
 401         break;
 402         case MBC_HUC3: /* FIXME - this is all guesswork -- is it right??? */
 403                 switch (ha & 0xE)
 404                 {
 405                 case 0x0:
 406                         mbc.enableram = ((b & 0x0F) == 0x0A);
 407                         break;
 408                 case 0x2:
 409                         if (!b) b = 1;
 410                         mbc.rombank = b;
 411                         break;
 412                 case 0x4:
 413                         if (mbc.model)
 414                         {
 415                                 mbc.rambank = b & 0x03;
 416                                 break;
 417                         }
 418                         break;
 419                 case 0x6:
 420                         mbc.model = b & 1;
 421                         break;
 422                 }
 423                 break;
 424         }
 425     mbc.rombank &= (mbc.romsize - 1);
 426     mbc.rambank &= (mbc.ramsize - 1);
 427     mem_updatemap();
 428 }
 429
 430
 431 /*
 432  * mem_write is the basic write function. Although it should only be
 433  * called when the write map contains a NULL for the requested address
 434  * region, it accepts writes to any address.
 435  */
 436
 437 void mem_write(int a, byte b)
 438 {
 439     int n;
 440     byte ha = (a>>12) & 0xE;
 441
 442     /* printf("write to 0x%04X: 0x%02X\n", a, b); */
 443     switch (ha)
 444     {
 445     case 0x0:
 446     case 0x2:
 447     case 0x4:
 448     case 0x6:
 449         mbc_write(a, b);
 450         break;
 451     case 0x8:
 452         /* if ((R_STAT & 0x03) == 0x03) break; */
 453         vram_write(a & 0x1FFF, b);
 454         break;
 455     case 0xA:
 456         if (!mbc.enableram) break;
 457         if (rtc.sel&8)
 458         {
 459             rtc_write(b);
 460             break;
 461         }
 462         ram.sbank[mbc.rambank][a & 0x1FFF] = b;
 463         break;
 464     case 0xC:
 465         if ((a & 0xF000) == 0xC000)
 466         {
 467             ram.ibank[0][a & 0x0FFF] = b;
 468             break;
 469         }
 470         n = R_SVBK & 0x07;
 471         ram.ibank[n?n:1][a & 0x0FFF] = b;
 472         break;
 473     case 0xE:
 474         if (a < 0xFE00)
 475         {
 476             mem_write(a & 0xDFFF, b);
 477             break;
 478         }
 479         if ((a & 0xFF00) == 0xFE00)
 480         {
 481             /* if (R_STAT & 0x02) break; */
 482             if (a < 0xFEA0) lcd.oam.mem[a & 0xFF] = b;
 483             break;
 484         }
 485         /* return writehi(a & 0xFF, b); */
 486         if (a >= 0xFF10 && a <= 0xFF3F)
 487         {
 488             if(options.sound)
 489                 sound_write(a & 0xFF, b);
 490             break;
 491         }
 492         if ((a & 0xFF80) == 0xFF80 && a != 0xFFFF)
 493         {
 494             ram.hi[a & 0xFF] = b;
 495             break;
 496         }
 497         ioreg_write(a & 0xFF, b);
 498     }
 499 }
 500
 501
 502 /*
 503  * mem_read is the basic read function...not useful for much anymore
 504  * with the read map, but it's still necessary for the final messy
 505  * region.
 506  */
 507
 508 byte mem_read(int a)
 509 {
 510     int n;
 511     byte ha = (a>>12) & 0xE;
 512
 513     /* printf("read %04x\n", a); */
 514     switch (ha)
 515     {
 516     case 0x0:
 517     case 0x2:
 518         return rom.bank[0][a];
 519     case 0x4:
 520     case 0x6:
 521         return rom.bank[mbc.rombank][a & 0x3FFF];
 522     case 0x8:
 523         /* if ((R_STAT & 0x03) == 0x03) return 0xFF; */
 524         return lcd.vbank[R_VBK&1][a & 0x1FFF];
 525         case 0xA:
 526                 if (!mbc.enableram)
 527                         return 0xFF;
 528                 if (rtc.sel&8)
 529                         return rtc.regs[rtc.sel&7];
 530                 return ram.sbank[mbc.rambank][a & 0x1FFF];
 531     case 0xC:
 532         if ((a & 0xF000) == 0xC000)
 533             return ram.ibank[0][a & 0x0FFF];
 534         n = R_SVBK & 0x07;
 535         return ram.ibank[n?n:1][a & 0x0FFF];
 536     case 0xE:
 537         if (a < 0xFE00) return mem_read(a & 0xDFFF);
 538         if ((a & 0xFF00) == 0xFE00)
 539         {
 540             /* if (R_STAT & 0x02) return 0xFF; */
 541             if (a < 0xFEA0) return lcd.oam.mem[a & 0xFF];
 542             return 0xFF;
 543         }
 544         /* return readhi(a & 0xFF); */
 545         if (a == 0xFFFF) return REG(0xFF);
 546         if (a >= 0xFF10 && a <= 0xFF3F)
 547         {
 548             if(options.sound)
 549                 return sound_read(a & 0xFF);
 550             else
 551                 return 1;
 552         }
 553         if ((a & 0xFF80) == 0xFF80)
 554             return ram.hi[a & 0xFF];
 555         return ioreg_read(a & 0xFF);
 556     }
 557     return 0xff; /* not reached */
 558 }
 559
 560 void mbc_reset(void)
 561 {
 562     mbc.rombank = 1;
 563     mbc.rambank = 0;
 564     mbc.enableram = 0;
 565     mem_updatemap();
 566 }