git.gag.com Git - fw/sdcc/blob - as/z80/z80mch.c

   1 /* z80mch.c
   2
   3    Copyright (C) 1989-1995 Alan R. Baldwin
   4    721 Berkeley St., Kent, Ohio 44240
   5
   6 This program is free software; you can redistribute it and/or modify it
   7 under the terms of the GNU General Public License as published by the
   8 Free Software Foundation; either version 3, or (at your option) any
   9 later version.
  10
  11 This program is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with this program.  If not, see <http://www.gnu.org/licenses/>. */
  18
  19 /*
  20  * Extensions: P. Felber
  21  */
  22
  23 #include <stdio.h>
  24 #include <setjmp.h>
  25 #include "asm.h"
  26 #include "z80.h"
  27
  28 char    imtab[3] = { 0x46, 0x56, 0x5E };
  29 #ifndef GAMEBOY
  30 int     hd64;
  31 #endif /* GAMEBOY */
  32
  33 /*
  34  * Process a machine op.
  35  */
  36 VOID
  37 machine(mp)
  38 struct mne *mp;
  39 {
  40         register int op, t1, t2;
  41         struct expr e1, e2;
  42         int rf, v1, v2;
  43
  44         clrexpr(&e1);
  45         clrexpr(&e2);
  46         op = mp->m_valu;
  47         rf = mp->m_type;
  48 #ifndef GAMEBOY
  49         if (!hd64 && rf>X_HD64)
  50                 rf = 0;
  51 #endif /* GAMEBOY */
  52         switch (rf) {
  53
  54         case S_INH1:
  55                 outab(op);
  56                 break;
  57
  58 #ifndef GAMEBOY
  59         case S_INH2:
  60                 outab(0xED);
  61                 outab(op);
  62                 break;
  63 #endif /* GAMEBOY */
  64
  65         case S_RET:
  66                 if (more()) {
  67                         if ((v1 = admode(CND)) != 0) {
  68                                 outab(op | v1<<3);
  69                         } else {
  70                                 qerr();
  71                         }
  72                 } else {
  73                         outab(0xC9);
  74                 }
  75                 break;
  76
  77         case S_PUSH:
  78                 if (admode(R16X)) {
  79                         outab(op+0x30);
  80                         break;
  81                 } else
  82                 if ((v1 = admode(R16)) != 0 && (v1 &= 0xFF) != SP) {
  83                         if (v1 != gixiy(v1)) {
  84                                 outab(op+0x20);
  85                                 break;
  86                         }
  87                         outab(op | v1<<4);
  88                         break;
  89                 }
  90                 aerr();
  91                 break;
  92
  93         case S_RST:
  94                 v1 = absexpr();
  95                 if (v1 & ~0x38) {
  96                         aerr();
  97                         v1 = 0;
  98                 }
  99                 outab(op|v1);
 100                 break;
 101
 102         case S_IM:
 103                 expr(&e1, 0);
 104                 abscheck(&e1);
 105                 if (e1.e_addr > 2) {
 106                         aerr();
 107                         e1.e_addr = 0;
 108                 }
 109                 outab(op);
 110                 outab(imtab[e1.e_addr]);
 111                 break;
 112
 113         case S_BIT:
 114                 expr(&e1, 0);
 115                 t1 = 0;
 116                 v1 = e1.e_addr;
 117                 if (v1 > 7) {
 118                         ++t1;
 119                         v1 &= 0x07;
 120                 }
 121                 op |= (v1<<3);
 122                 comma();
 123                 addr(&e2);
 124                 abscheck(&e1);
 125                 if (genop(0xCB, op, &e2, 0) || t1)
 126                         aerr();
 127                 break;
 128
 129         case S_RL:
 130                 t1 = 0;
 131                 t2 = addr(&e2);
 132                 if (more()) {
 133                         if ((t2 != S_R8) || (e2.e_addr != A))
 134                                 ++t1;
 135                         comma();
 136                         t2 = addr(&e2);
 137                 }
 138                 if (genop(0xCB, op, &e2, 0) || t1)
 139                         aerr();
 140                 break;
 141
 142         case S_AND:
 143         case S_SUB:
 144                 t1 = 0;
 145                 t2 = addr(&e2);
 146                 if (more()) {
 147                         if ((t2 != S_R8) || (e2.e_addr != A))
 148                                 ++t1;
 149                         comma();
 150                         t2 = addr(&e2);
 151                 }
 152                 if (genop(0, op, &e2, 1) || t1)
 153                         aerr();
 154                 break;
 155
 156         case S_ADD:
 157         case S_ADC:
 158         case S_SBC:
 159                 t1 = addr(&e1);
 160                 t2 = 0;
 161                 if (more()) {
 162                         comma();
 163                         t2 = addr(&e2);
 164                 }
 165                 if (t2 == 0) {
 166                         if (genop(0, op, &e1, 1))
 167                                 aerr();
 168                         break;
 169                 }
 170                 if ((t1 == S_R8) && (e1.e_addr == A)) {
 171                         if (genop(0, op, &e2, 1))
 172                                 aerr();
 173                         break;
 174                 }
 175                 if ((t1 == S_R16) && (t2 == S_R16)) {
 176 #ifndef GAMEBOY
 177                         if (rf == S_ADD)
 178                                 op = 0x09;
 179                         if (rf == S_ADC)
 180                                 op = 0x4A;
 181                         if (rf == S_SBC)
 182                                 op = 0x42;
 183                         v1 = e1.e_addr;
 184                         v2 = e2.e_addr;
 185                         if ((v1 == HL) && (v2 <= SP)) {
 186                                 if (rf != S_ADD)
 187                                         outab(0xED);
 188                                 outab(op | (v2<<4));
 189                                 break;
 190                         }
 191                         if (rf != S_ADD) {
 192                                 aerr();
 193                                 break;
 194                         }
 195                         if ((v1 == IX) && (v2 != HL) && (v2 != IY)) {
 196                                 if (v2 == IX)
 197                                         v2 = HL;
 198                                 outab(0xDD);
 199                                 outab(op | (v2<<4));
 200                                 break;
 201                         }
 202                         if ((v1 == IY) && (v2 != HL) && (v2 != IX)) {
 203                                 if (v2 == IY)
 204                                         v2 = HL;
 205                                 outab(0xFD);
 206                                 outab(op | (v2<<4));
 207                                 break;
 208                         }
 209                 }
 210 #else /* GAMEBOY */
 211                         v1 = e1.e_addr;
 212                         v2 = e2.e_addr;
 213                         if ((v1 == HL) && (v2 <= SP) && (rf == S_ADD)) {
 214                                 outab(0x09 | (v2<<4));
 215                                 break;
 216                         }
 217                 }
 218                 /*
 219                  * 0xE8 : ADD SP,#n
 220                  */
 221                 if ((rf == S_ADD) && (t1 == S_R16) && (e1.e_addr == SP) && (t2 == S_IMMED)) {
 222                         outab(0xE8);
 223                         outrb(&e2,0);
 224                         break;
 225                 }
 226 #endif /* GAMEBOY */
 227                 aerr();
 228                 break;
 229
 230         case S_LD:
 231                 t1 = addr(&e1);
 232                 comma();
 233                 t2 = addr(&e2);
 234                 if (t1 == S_R8) {
 235                         v1 = op | e1.e_addr<<3;
 236                         if (genop(0, v1, &e2, 0) == 0)
 237                                 break;
 238                         if (t2 == S_IMMED) {
 239                                 outab(e1.e_addr<<3 | 0x06);
 240                                 outrb(&e2,0);
 241                                 break;
 242                         }
 243                 }
 244                 v1 = e1.e_addr;
 245                 v2 = e2.e_addr;
 246                 if ((t1 == S_R16) && (t2 == S_IMMED)) {
 247                         v1 = gixiy(v1);
 248                         outab(0x01|v1<<4);
 249                         outrw(&e2, 0);
 250                         break;
 251                 }
 252 #ifndef GAMEBOY
 253                 if ((t1 == S_R16) && (t2 == S_INDM)) {
 254                         if (gixiy(v1) == HL) {
 255                                 outab(0x2A);
 256                         } else {
 257                                 outab(0xED);
 258                                 outab(0x4B | v1<<4);
 259                         }
 260                         outrw(&e2, 0);
 261                         break;
 262                 }
 263                 if ((t1 == S_INDM) && (t2 == S_R16)) {
 264                         if (gixiy(v2) == HL) {
 265                                 outab(0x22);
 266                         } else {
 267                                 outab(0xED);
 268                                 outab(0x43 | v2<<4);
 269                         }
 270                         outrw(&e1, 0);
 271                         break;
 272                 }
 273                 if ((t1 == S_R8) && (v1 == A) && (t2 == S_INDM)) {
 274                         outab(0x3A);
 275                         outrw(&e2, 0);
 276                         break;
 277                 }
 278                 if ((t1 == S_INDM) && (t2 == S_R8) && (v2 == A)) {
 279                         outab(0x32);
 280                         outrw(&e1, 0);
 281                         break;
 282                 }
 283 #endif /* GAMEBOY */
 284                 if ((t2 == S_R8) && (gixiy(t1) == S_IDHL)) {
 285                         outab(0x70|v2);
 286                         if (t1 != S_IDHL)
 287                                 outrb(&e1, 0);
 288                         break;
 289                 }
 290                 if ((t2 == S_IMMED) && (gixiy(t1) == S_IDHL)) {
 291                         outab(0x36);
 292                         if (t1 != S_IDHL)
 293                                 outrb(&e1, 0);
 294                         outrb(&e2, 0);
 295                         break;
 296                 }
 297 #ifndef GAMEBOY
 298                 if ((t1 == S_R8X) && (t2 == S_R8) && (v2 == A)) {
 299                         outab(0xED);
 300                         outab(v1);
 301                         break;
 302                 }
 303                 if ((t1 == S_R8) && (v1 == A) && (t2 == S_R8X)) {
 304                         outab(0xED);
 305                         outab(v2|0x10);
 306                         break;
 307                 }
 308 #endif /* GAMEBOY */
 309                 if ((t1 == S_R16) && (v1 == SP)) {
 310                         if ((t2 == S_R16) && (gixiy(v2) == HL)) {
 311                                 outab(0xF9);
 312                                 break;
 313                         }
 314                 }
 315                 if ((t1 == S_R8) && (v1 == A)) {
 316                         if ((t2 == S_IDBC) || (t2 == S_IDDE)) {
 317                                 outab(0x0A | (t2-S_INDR)<<4);
 318                                 break;
 319                         }
 320                 }
 321                 if ((t2 == S_R8) && (v2 == A)) {
 322                         if ((t1 == S_IDBC) || (t1 == S_IDDE)) {
 323                                 outab(0x02 | (t1-S_INDR)<<4);
 324                                 break;
 325                         }
 326                 }
 327 #ifdef GAMEBOY
 328                 /*
 329                  * 0x08 : LD (nn),SP
 330                  */
 331                 if ((t1 == S_INDM) && (t2 == S_R16) && (v2 == SP)) {
 332                         outab(0x08);
 333                         outrw(&e1, 0);
 334                         break;
 335                 }
 336                 /*
 337                  * 0xEA : LD (nn),A
 338                  * 0xFA : LD A,(nn)
 339                  */
 340                 if ((t1 == S_INDM) && (t2 == S_R8) && (v2 == A)) {
 341                         outab(0xEA);
 342                         outrw(&e1, 0);
 343                         break;
 344                 }
 345                 if ((t2 == S_INDM) && (t1 == S_R8) && (v1 == A)) {
 346                         outab(0xFA);
 347                         outrw(&e2, 0);
 348                         break;
 349                 }
 350                 /*
 351                  * 0x32 : LD (HL-),A
 352                  * 0x3A : LD A,(HL-)
 353                  */
 354                 if ((t1 == S_R8) && (v1 == A) && (t2 == S_IDHLD)) {
 355                         outab(0x3A);
 356                         break;
 357                 }
 358                 if ((t2 == S_R8) && (v2 == A) && (t1 == S_IDHLD)) {
 359                         outab(0x32);
 360                         break;
 361                 }
 362                 /*
 363                  * 0x22 : LD (HL+),A
 364                  * 0x2A : LD A,(HL+)
 365                  */
 366                 if ((t1 == S_R8) && (v1 == A) && (t2 == S_IDHLI)) {
 367                         outab(0x2A);
 368                         break;
 369                 }
 370                 if ((t2 == S_R8) && (v2 == A) && (t1 == S_IDHLI)) {
 371                         outab(0x22);
 372                         break;
 373                 }
 374 #endif /* GAMEBOY */
 375                 aerr();
 376                 break;
 377
 378
 379 #ifdef GAMEBOY
 380         case S_STOP:    /* 0x10 */
 381                 /*
 382                  * 0x10 : STOP
 383                  */
 384                 outab(op);
 385                 outab(0x00);
 386                 break;
 387
 388
 389         case S_LDH:     /* 0xE0 */
 390                 /*
 391                  * 0xE0 : LDH (n),A = LD ($FF00+n),A
 392                  * 0xE2 : LDH (C),A = LD ($FF00+C),A
 393                  * 0xF0 : LDH A,(n) = LD A,($FF00+n)
 394                  * 0xF2 : LDH A,(C) = LD A,($FF00+C)
 395                  */
 396                 t1 = addr(&e1);
 397                 comma();
 398                 t2 = addr(&e2);
 399                 if ((t1 == S_INDM) && (t2 == S_R8) && (e2.e_addr == A)) {
 400                         outab(0xE0);
 401                         outrb(&e1, 0);
 402                         break;
 403                 }
 404                 if ((t1 == S_IDC) && (t2 == S_R8) && (e2.e_addr == A)) {
 405                         outab(0xE2);
 406                         break;
 407                 }
 408                 if ((t2 == S_INDM) && (t1 == S_R8) && (e1.e_addr == A)) {
 409                         outab(0xF0);
 410                         outrb(&e2, 0);
 411                         break;
 412                 }
 413                 if ((t2 == S_IDC) && (t1 == S_R8) && (e1.e_addr == A)) {
 414                         outab(0xF2);
 415                         break;
 416                 }
 417                 aerr();
 418                 break;
 419
 420
 421         case S_LDA:     /* 0xE8 */
 422                 /*
 423                  * 0xE8 : LDA SP,#n(SP)
 424                  * 0xF8 : LDA HL,#n(SP)
 425                  */
 426                 t1 = addr(&e1);
 427                 comma();
 428                 t2 = addr(&e2);
 429                 if ((t1 == S_R16) && (e1.e_addr == SP) && (t2 == S_INDR+SP)) {
 430                         outab(0xE8);
 431                         outrb(&e2,0);
 432                         break;
 433                 }
 434                 if ((t1 == S_R16) && (e1.e_addr == HL) && (t2 == S_INDR+SP)) {
 435                         outab(0xF8);
 436                         outrb(&e2,0);
 437                         break;
 438                 }
 439                 aerr();
 440                 break;
 441
 442
 443         case S_LDHL:    /* 0xF8 */
 444                 /*
 445                  * 0xF8 : LDHL SP,#n
 446                  */
 447                 t1 = addr(&e1);
 448                 comma();
 449                 t2 = addr(&e2);
 450                 if ((t1 == S_R16) && (e1.e_addr == SP) && (t2 == S_IMMED)) {
 451                         outab(0xF8);
 452                         outrb(&e2,0);
 453                         break;
 454                 }
 455                 aerr();
 456                 break;
 457 #endif /* GAMEBOY */
 458
 459
 460 #ifndef GAMEBOY
 461         case S_EX:
 462                 t1 = addr(&e1);
 463                 comma();
 464                 t2 = addr(&e2);
 465                 if (t2 == S_R16) {
 466                         v1 = e1.e_addr;
 467                         v2 = e2.e_addr;
 468                         if ((t1 == S_IDSP) && (v1 == 0)) {
 469                                 if (gixiy(v2) == HL) {
 470                                         outab(op);
 471                                         break;
 472                                 }
 473                         }
 474                         if (t1 == S_R16) {
 475                                 if ((v1 == DE) && (v2 == HL)) {
 476                                         outab(0xEB);
 477                                         break;
 478                                 }
 479                         }
 480                 }
 481                 if ((t1 == S_R16X) && (t2 == S_R16X)) {
 482                         outab(0x08);
 483                         break;
 484                 }
 485                 aerr();
 486                 break;
 487
 488         case S_IN:
 489         case S_OUT:
 490                 if (rf == S_IN) {
 491                         t1 = addr(&e1);
 492                         comma();
 493                         t2 = addr(&e2);
 494                 } else {
 495                         t2 = addr(&e2);
 496                         comma();
 497                         t1 = addr(&e1);
 498                 }
 499                 v1 = e1.e_addr;
 500                 v2 = e2.e_addr;
 501                 if (t1 == S_R8) {
 502                         if ((v1 == A) && (t2 == S_INDM)) {
 503                                 outab(op);
 504                                 outab(v2);
 505                                 break;
 506                         }
 507                         if (t2 == S_IDC) {
 508                                 outab(0xED);
 509                                 outab(((rf == S_IN) ? 0x40 : 0x41) + (v1<<3));
 510                                 break;
 511                         }
 512                 }
 513                 aerr();
 514                 break;
 515 #endif /* GAMEBOY */
 516
 517         case S_DEC:
 518         case S_INC:
 519                 t1 = addr(&e1);
 520                 v1 = e1.e_addr;
 521                 if (t1 == S_R8) {
 522                         outab(op|(v1<<3));
 523                         break;
 524                 }
 525                 if (t1 == S_IDHL) {
 526                         outab(op|0x30);
 527                         break;
 528                 }
 529                 if (t1 != gixiy(t1)) {
 530                         outab(op|0x30);
 531                         outrb(&e1,0);
 532                         break;
 533                 }
 534                 if (t1 == S_R16) {
 535                         v1 = gixiy(v1);
 536                         if (rf == S_INC) {
 537                                 outab(0x03|(v1<<4));
 538                                 break;
 539                         }
 540                         if (rf == S_DEC) {
 541                                 outab(0x0B|(v1<<4));
 542                                 break;
 543                         }
 544                 }
 545                 aerr();
 546                 break;
 547
 548 #ifndef GAMEBOY
 549         case S_DJNZ:
 550         case S_JR:
 551                 if ((v1 = admode(CND)) != 0 && rf != S_DJNZ) {
 552                         if ((v1 &= 0xFF) <= 0x18 && v1 != PO && v1 != PE && v1 != P && v1 != M) {
 553                                 op += (v1+1)<<3;
 554                         } else {
 555                                 aerr();
 556                         }
 557                         comma();
 558                 }
 559 #else /* GAMEBOY */
 560         case S_JR:
 561                 if ((v1 = admode(CND)) != 0) {
 562                         if ((v1 &= 0xFF) <= 0x18) {
 563                                 op += (v1+1)<<3;
 564                         } else {
 565                                 aerr();
 566                         }
 567                         comma();
 568                 }
 569 #endif /* GAMEBOY */
 570                 expr(&e2, 0);
 571                 outab(op);
 572                 if (e2.e_base.e_ap == NULL || e2.e_base.e_ap == dot.s_area) {
 573                         v2 = e2.e_addr - dot.s_addr - 1;
 574                         if (pass == 2 && ((v2 < -128) || (v2 > 127)))
 575                                 aerr();
 576                         outab(v2);
 577                 } else {
 578                         outrb(&e2, R_PCR);
 579                 }
 580                 if (e2.e_mode != S_USER)
 581                         rerr();
 582                 break;
 583
 584         case S_CALL:
 585                 if ((v1 = admode(CND)) != 0) {
 586                         op |= (v1&0xFF)<<3;
 587                         comma();
 588                 } else {
 589                         op = 0xCD;
 590                 }
 591                 expr(&e1, 0);
 592                 outab(op);
 593                 outrw(&e1, 0);
 594                 break;
 595
 596         case S_JP:
 597                 if ((v1 = admode(CND)) != 0) {
 598                         op |= (v1&0xFF)<<3;
 599                         comma();
 600                         expr(&e1, 0);
 601                         outab(op);
 602                         outrw(&e1, 0);
 603                         break;
 604                 }
 605                 t1 = addr(&e1);
 606                 if (t1 == S_USER) {
 607                         outab(0xC3);
 608                         outrw(&e1, 0);
 609                         break;
 610                 }
 611                 if ((e1.e_addr == 0) && (gixiy(t1) == S_IDHL)) {
 612                         outab(0xE9);
 613                         break;
 614                 }
 615                 aerr();
 616                 break;
 617
 618 #ifndef GAMEBOY
 619         case X_HD64:
 620                 ++hd64;
 621                 break;
 622
 623         case X_INH2:
 624                 outab(0xED);
 625                 outab(op);
 626                 break;
 627
 628         case X_IN:
 629         case X_OUT:
 630                 if (rf == X_IN) {
 631                         t1 = addr(&e1);
 632                         comma();
 633                         t2 = addr(&e2);
 634                 } else {
 635                         t2 = addr(&e2);
 636                         comma();
 637                         t1 = addr(&e1);
 638                 }
 639                 if ((t1 == S_R8) && (t2 == S_INDM)) {
 640                         outab(0xED);
 641                         outab(op | e1.e_addr<<3);
 642                         outrb(&e2, 0);
 643                         break;
 644                 }
 645                 aerr();
 646                 break;
 647
 648         case X_MLT:
 649                 t1 = addr(&e1);
 650                 if ((t1 == S_R16) && ((v1 = e1.e_addr) <= SP)) {
 651                         outab(0xED);
 652                         outab(op | v1<<4);
 653                         break;
 654                 }
 655                 aerr();
 656                 break;
 657
 658         case X_TST:
 659                 t1 = addr(&e1);
 660                 if (t1 == S_R8) {
 661                         outab(0xED);
 662                         outab(op | e1.e_addr<<3);
 663                         break;
 664                 }
 665                 if (t1 == S_IDHL) {
 666                         outab(0xED);
 667                         outab(0x34);
 668                         break;
 669                 }
 670                 if (t1 == S_IMMED) {
 671                         outab(0xED);
 672                         outab(0x64);
 673                         outrb(&e1, 0);
 674                         break;
 675                 }
 676                 aerr();
 677                 break;
 678
 679         case X_TSTIO:
 680                 t1 = addr(&e1);
 681                 if (t1 == S_IMMED) {
 682                         outab(0xED);
 683                         outab(op);
 684                         outrb(&e1, 0);
 685                         break;
 686                 }
 687                 aerr();
 688                 break;
 689 #endif /* GAMEBOY */
 690
 691         default:
 692                 err('o');
 693         }
 694 }
 695
 696 /*
 697  * general addressing evaluation
 698  * return(0) if general addressing mode output, else
 699  * return(esp->e_mode)
 700  */
 701 int
 702 genop(pop, op, esp, f)
 703 register int pop, op;
 704 register struct expr *esp;
 705 int f;
 706 {
 707         register int t1;
 708         if ((t1 = esp->e_mode) == S_R8) {
 709                 if (pop)
 710                         outab(pop);
 711                 outab(op|esp->e_addr);
 712                 return(0);
 713         }
 714         if (t1 == S_IDHL) {
 715                 if (pop)
 716                         outab(pop);
 717                 outab(op|0x06);
 718                 return(0);
 719         }
 720         if (gixiy(t1) == S_IDHL) {
 721                 if (pop) {
 722                         outab(pop);
 723                         outrb(esp,0);
 724                         outab(op|0x06);
 725                 } else {
 726                         outab(op|0x06);
 727                         outrb(esp,0);
 728                 }
 729                 return(0);
 730         }
 731         if ((t1 == S_IMMED) && (f)) {
 732                 if (pop)
 733                         outab(pop);
 734                 outab(op|0x46);
 735                 outrb(esp,0);
 736                 return(0);
 737         }
 738         return(t1);
 739 }
 740
 741 /*
 742  * IX and IY prebyte check
 743  */
 744 int
 745 gixiy(v)
 746 int v;
 747 {
 748 #ifndef GAMEBOY
 749         if (v == IX) {
 750                 v = HL;
 751                 outab(0xDD);
 752         } else if (v == IY) {
 753                 v = HL;
 754                 outab(0xFD);
 755         } else if (v == S_IDIX) {
 756                 v = S_IDHL;
 757                 outab(0xDD);
 758         } else if (v == S_IDIY) {
 759                 v = S_IDHL;
 760                 outab(0xFD);
 761         }
 762 #endif /* GAMEBOY */
 763         return(v);
 764 }
 765
 766 /*
 767  * The next character must be a
 768  * comma.
 769  */
 770 int
 771 comma()
 772 {
 773         if (getnb() != ',')
 774                 qerr();
 775         return(1);
 776 }
 777
 778 /*
 779  * Machine dependent initialization
 780  */
 781 VOID
 782 minit()
 783 {
 784 #ifndef GAMEBOY
 785         hd64 = 0;
 786 #endif /* GAMEBOY */
 787 }