1 /* Copyright (c) 1982 Regents of the University of California */ 2 3 static char sccsid[] = "@(#)vax.c 1.5 01/25/83"; 4 5 /* 6 * Target machine dependent stuff. 7 */ 8 9 #include "defs.h" 10 #include "machine.h" 11 #include "process.h" 12 #include "events.h" 13 #include "main.h" 14 #include "symbols.h" 15 #include "source.h" 16 #include "mappings.h" 17 #include "object.h" 18 #include "ops.h" 19 #include <signal.h> 20 21 #ifndef public 22 typedef unsigned int Address; 23 typedef unsigned char Byte; 24 typedef unsigned int Word; 25 26 #define NREG 16 27 28 #define ARGP 12 29 #define FRP 13 30 #define STKP 14 31 #define PROGCTR 15 32 33 #define BITSPERBYTE 8 34 #define BITSPERWORD (BITSPERBYTE * sizeof(Word)) 35 36 #define nargspassed(frame) argn(0, frame) 37 38 #include "source.h" 39 #include "symbols.h" 40 41 Address pc; 42 Address prtaddr; 43 44 #endif 45 46 private Address printop(); 47 48 /* 49 * Decode and print the instructions within the given address range. 50 */ 51 52 public printinst(lowaddr, highaddr) 53 Address lowaddr; 54 Address highaddr; 55 { 56 register Address addr; 57 58 for (addr = lowaddr; addr <= highaddr; ) { 59 addr = printop(addr); 60 } 61 prtaddr = addr; 62 } 63 64 /* 65 * Another approach: print n instructions starting at the given address. 66 */ 67 68 public printninst(count, addr) 69 int count; 70 Address addr; 71 { 72 register Integer i; 73 register Address newaddr; 74 75 if (count <= 0) { 76 error("non-positive repetition count"); 77 } else { 78 newaddr = addr; 79 for (i = 0; i < count; i++) { 80 newaddr = printop(newaddr); 81 } 82 prtaddr = newaddr; 83 } 84 } 85 86 /* 87 * Hacked version of adb's VAX instruction decoder. 88 */ 89 90 private Address printop(addr) 91 Address addr; 92 { 93 Optab op; 94 VaxOpcode ins; 95 unsigned char mode; 96 int argtype, amode, argno, argval; 97 String reg; 98 Boolean indexf; 99 short offset; 100 101 argval = 0; 102 indexf = false; 103 printf("%08x ", addr); 104 iread(&ins, addr, sizeof(ins)); 105 addr += 1; 106 op = optab[ins]; 107 printf("%s", op.iname); 108 for (argno = 0; argno < op.numargs; argno++) { 109 if (indexf == true) { 110 indexf = false; 111 } else if (argno == 0) { 112 printf("\t"); 113 } else { 114 printf(","); 115 } 116 argtype = op.argtype[argno]; 117 if (is_branch_disp(argtype)) { 118 mode = 0xAF + (typelen(argtype) << 5); 119 } else { 120 iread(&mode, addr, sizeof(mode)); 121 addr += 1; 122 } 123 reg = regname[regnm(mode)]; 124 amode = addrmode(mode); 125 switch (amode) { 126 case LITSHORT: 127 case LITUPTO31: 128 case LITUPTO47: 129 case LITUPTO63: 130 if (typelen(argtype) == TYPF || typelen(argtype) ==TYPD) 131 printf("$%s", fltimm[mode]); 132 else 133 printf("$%x", mode); 134 argval = mode; 135 break; 136 137 case INDEX: 138 printf("[%s]", reg); 139 indexf = true; 140 argno--; 141 break; 142 143 case REG: 144 printf("%s", reg); 145 break; 146 147 case REGDEF: 148 printf("(%s)", reg); 149 break; 150 151 case AUTODEC: 152 printf("-(%s)", reg); 153 break; 154 155 case AUTOINC: 156 if (reg != regname[PROGCTR]) { 157 printf("(%s)+", reg); 158 } else { 159 printf("$"); 160 switch (typelen(argtype)) { 161 case TYPB: 162 argval = printdisp(addr, 1, reg, amode); 163 addr += 1; 164 break; 165 166 case TYPW: 167 argval = printdisp(addr, 2, reg, amode); 168 addr += 2; 169 break; 170 171 case TYPL: 172 argval = printdisp(addr, 4, reg, amode); 173 addr += 4; 174 break; 175 176 case TYPF: 177 iread(&argval, addr, sizeof(argval)); 178 printf("%06x", argval); 179 addr += 4; 180 break; 181 182 case TYPQ: 183 case TYPD: 184 iread(&argval, addr, sizeof(argval)); 185 printf("%06x", argval); 186 iread(&argval, addr+4, sizeof(argval)); 187 printf("%06x", argval); 188 addr += 8; 189 break; 190 } 191 } 192 break; 193 194 case AUTOINCDEF: 195 if (reg == regname[PROGCTR]) { 196 printf("*$"); 197 argval = printdisp(addr, 4, reg, amode); 198 addr += 4; 199 } else { 200 printf("*(%s)+", reg); 201 } 202 break; 203 204 case BYTEDISP: 205 argval = printdisp(addr, 1, reg, amode); 206 addr += 1; 207 break; 208 209 case BYTEDISPDEF: 210 printf("*"); 211 argval = printdisp(addr, 1, reg, amode); 212 addr += 1; 213 break; 214 215 case WORDDISP: 216 argval = printdisp(addr, 2, reg, amode); 217 addr += 2; 218 break; 219 220 case WORDDISPDEF: 221 printf("*"); 222 argval = printdisp(addr, 2, reg, amode); 223 addr += 2; 224 break; 225 226 case LONGDISP: 227 argval = printdisp(addr, 4, reg, amode); 228 addr += 4; 229 break; 230 231 case LONGDISPDEF: 232 printf("*"); 233 argval = printdisp(addr, 4, reg, amode); 234 addr += 4; 235 break; 236 } 237 } 238 if (ins == O_CASEB || ins == O_CASEW || ins == O_CASEL) { 239 for (argno = 0; argno <= argval; argno++) { 240 iread(&offset, addr, sizeof(offset)); 241 printf("\n\t\t%d", offset); 242 addr += 2; 243 } 244 } 245 printf("\n"); 246 return addr; 247 } 248 249 /* 250 * Print the displacement of an instruction that uses displacement 251 * addressing. 252 */ 253 254 private int printdisp(addr, nbytes, reg, mode) 255 Address addr; 256 int nbytes; 257 char *reg; 258 int mode; 259 { 260 char byte; 261 short hword; 262 int argval; 263 264 switch (nbytes) { 265 case 1: 266 iread(&byte, addr, sizeof(byte)); 267 argval = byte; 268 break; 269 270 case 2: 271 iread(&hword, addr, sizeof(hword)); 272 argval = hword; 273 break; 274 275 case 4: 276 iread(&argval, addr, sizeof(argval)); 277 break; 278 } 279 if (reg == regname[PROGCTR] && mode >= BYTEDISP) { 280 argval += addr + nbytes; 281 } 282 if (reg == regname[PROGCTR]) { 283 printf("%x", argval); 284 } else { 285 printf("%d(%s)", argval, reg); 286 } 287 return argval; 288 } 289 290 /* 291 * Print the contents of the addresses within the given range 292 * according to the given format. 293 */ 294 295 typedef struct { 296 String name; 297 String printfstring; 298 int length; 299 } Format; 300 301 private Format fmt[] = { 302 { "d", " %d", sizeof(short) }, 303 { "D", " %ld", sizeof(long) }, 304 { "o", " %o", sizeof(short) }, 305 { "O", " %lo", sizeof(long) }, 306 { "x", " %04x", sizeof(short) }, 307 { "X", " %08x", sizeof(long) }, 308 { "b", " \\%o", sizeof(char) }, 309 { "c", " '%c'", sizeof(char) }, 310 { "s", "%c", sizeof(char) }, 311 { "f", " %f", sizeof(double) }, 312 { "g", " %g", sizeof(double) }, 313 { nil, nil, 0 } 314 }; 315 316 public Address printdata(lowaddr, highaddr, format) 317 Address lowaddr; 318 Address highaddr; 319 String format; 320 { 321 register int n; 322 register Address addr; 323 register Format *f; 324 int value; 325 326 if (lowaddr > highaddr) { 327 error("first address larger than second"); 328 } 329 f = &fmt[0]; 330 while (f->name != nil and not streq(f->name, format)) { 331 ++f; 332 } 333 if (f->name == nil) { 334 error("bad print format \"%s\"", format); 335 } 336 n = 0; 337 value = 0; 338 for (addr = lowaddr; addr <= highaddr; addr += f->length) { 339 if (n == 0) { 340 printf("%08x: ", addr); 341 } 342 dread(&value, addr, f->length); 343 printf(f->printfstring, value); 344 ++n; 345 if (n >= (16 div f->length)) { 346 putchar('\n'); 347 n = 0; 348 } 349 } 350 if (n != 0) { 351 putchar('\n'); 352 } 353 prtaddr = addr; 354 return addr; 355 } 356 357 /* 358 * The other approach is to print n items starting with a given address. 359 */ 360 361 public printndata(count, startaddr, format) 362 int count; 363 Address startaddr; 364 String format; 365 { 366 register int i, n; 367 register Address addr; 368 register Format *f; 369 register Boolean isstring; 370 int value; 371 372 if (count <= 0) { 373 error("non-positive repetition count"); 374 } 375 f = &fmt[0]; 376 while (f->name != nil and not streq(f->name, format)) { 377 ++f; 378 } 379 if (f->name == nil) { 380 error("bad print format \"%s\"", format); 381 } 382 isstring = (Boolean) streq(f->name, "s"); 383 n = 0; 384 addr = startaddr; 385 value = 0; 386 for (i = 0; i < count; i++) { 387 if (n == 0) { 388 printf("%08x: ", addr); 389 } 390 if (isstring) { 391 putchar('"'); 392 dread(&value, addr, sizeof(char)); 393 while (value != '\0') { 394 printchar((char) value); 395 ++addr; 396 dread(&value, addr, sizeof(char)); 397 } 398 putchar('"'); 399 putchar('\n'); 400 n = 0; 401 addr += sizeof(String); 402 } else { 403 dread(&value, addr, f->length); 404 printf(f->printfstring, value); 405 ++n; 406 if (n >= (16 div f->length)) { 407 putchar('\n'); 408 n = 0; 409 } 410 addr += f->length; 411 } 412 } 413 if (n != 0) { 414 putchar('\n'); 415 } 416 prtaddr = addr; 417 } 418 419 /* 420 * Print out an execution time error. 421 * Assumes the source position of the error has been calculated. 422 * 423 * Have to check if the -r option was specified; if so then 424 * the object file information hasn't been read in yet. 425 */ 426 427 public printerror() 428 { 429 extern Integer sys_nsig; 430 extern String sys_siglist[]; 431 Integer err; 432 433 if (isfinished(process)) { 434 printf("\"%s\" exits with code %d\n", objname, exitcode(process)); 435 erecover(); 436 } 437 if (runfirst) { 438 fprintf(stderr, "Entering debugger ..."); 439 init(); 440 fprintf(stderr, " type 'help' for help\n"); 441 } 442 err = errnum(process); 443 if (err == SIGINT) { 444 printf("\n\ninterrupt "); 445 printloc(); 446 } else if (err == SIGTRAP) { 447 printf("\nerror "); 448 printloc(); 449 } else { 450 if (err < 0 or err > sys_nsig) { 451 printf("\nsignal %d ", err); 452 } else { 453 printf("\n%s ", sys_siglist[err]); 454 } 455 printloc(); 456 } 457 putchar('\n'); 458 if (curline > 0) { 459 printlines(curline, curline); 460 } else { 461 printinst(pc, pc); 462 } 463 erecover(); 464 } 465 466 private printloc() 467 { 468 if (curline > 0) { 469 if (nlhdr.nfiles > 1) { 470 printf("at line %d in file %s", curline, cursource); 471 } else { 472 printf("at line %d", curline); 473 } 474 } else { 475 printf("in "); 476 printname(stdout, curfunc); 477 printf(" at 0x%x", pc); 478 } 479 } 480 481 /* 482 * Note the termination of the program. We do this so as to avoid 483 * having the process exit, which would make the values of variables 484 * inaccessible. We do want to flush all output buffers here, 485 * otherwise it'll never get done. 486 */ 487 488 public endprogram() 489 { 490 Integer exitcode; 491 492 stepto(nextaddr(pc, true)); 493 printnews(); 494 exitcode = argn(1, nil); 495 printf("\nexecution completed, exit code is %d\n", exitcode); 496 getsrcpos(); 497 erecover(); 498 } 499 500 /* 501 * Single step the machine a source line (or instruction if "inst_tracing" 502 * is true). If "isnext" is true, skip over procedure calls. 503 */ 504 505 private Address getcall(); 506 507 public dostep(isnext) 508 Boolean isnext; 509 { 510 register Address addr; 511 register Lineno line; 512 String filename; 513 514 addr = nextaddr(pc, isnext); 515 if (not inst_tracing and nlhdr.nlines != 0) { 516 line = linelookup(addr); 517 while (line == 0) { 518 addr = nextaddr(addr, isnext); 519 line = linelookup(addr); 520 } 521 curline = line; 522 } else { 523 curline = 0; 524 } 525 stepto(addr); 526 filename = srcfilename(addr); 527 setsource(filename); 528 } 529 530 /* 531 * Compute the next address that will be executed from the given one. 532 * If "isnext" is true then consider a procedure call as straight line code. 533 * 534 * We must unfortunately do much of the same work that is necessary 535 * to print instructions. In addition we have to deal with branches. 536 * Unconditional branches we just follow, for conditional branches 537 * we continue execution to the current location and then single step 538 * the machine. We assume that the last argument in an instruction 539 * that branches is the branch address (or relative offset). 540 */ 541 542 public Address nextaddr(startaddr, isnext) 543 Address startaddr; 544 Boolean isnext; 545 { 546 register Address addr; 547 Optab op; 548 VaxOpcode ins; 549 unsigned char mode; 550 int argtype, amode, argno, argval; 551 String r; 552 Boolean indexf; 553 enum { KNOWN, SEQUENTIAL, BRANCH } addrstatus; 554 555 argval = 0; 556 indexf = false; 557 addr = startaddr; 558 iread(&ins, addr, sizeof(ins)); 559 switch (ins) { 560 case O_BRB: 561 case O_BRW: 562 case O_JMP: 563 addrstatus = BRANCH; 564 break; 565 566 case O_BSBB: 567 case O_BSBW: 568 case O_JSB: 569 case O_CALLG: 570 case O_CALLS: 571 if (isnext) { 572 addrstatus = SEQUENTIAL; 573 } else { 574 addrstatus = KNOWN; 575 stepto(addr); 576 pstep(process); 577 addr = reg(PROGCTR); 578 pc = addr; 579 callnews(/* iscall = */ true); 580 if (not isbperr()) { 581 printstatus(); 582 } else { 583 bpact(); 584 } 585 } 586 break; 587 588 case O_RSB: 589 case O_RET: 590 addrstatus = KNOWN; 591 callnews(/* iscall = */ false); 592 addr = return_addr(); 593 stepto(addr); 594 break; 595 596 case O_BNEQ: case O_BEQL: case O_BGTR: 597 case O_BLEQ: case O_BGEQ: case O_BLSS: 598 case O_BGTRU: case O_BLEQU: case O_BVC: 599 case O_BVS: case O_BCC: case O_BCS: 600 case O_CASEB: case O_CASEW: case O_CASEL: 601 case O_BBS: case O_BBC: case O_BBSS: case O_BBCS: 602 case O_BBSC: case O_BBCC: case O_BBSSI: 603 case O_BBCCI: case O_BLBS: case O_BLBC: 604 case O_ACBL: case O_AOBLSS: case O_AOBLEQ: 605 case O_SOBGEQ: case O_SOBGTR: 606 addrstatus = KNOWN; 607 stepto(addr); 608 pstep(process); 609 addr = reg(PROGCTR); 610 pc = addr; 611 if (not isbperr()) { 612 printstatus(); 613 } 614 break; 615 616 default: 617 addrstatus = SEQUENTIAL; 618 break; 619 } 620 if (addrstatus != KNOWN) { 621 addr += 1; 622 op = optab[ins]; 623 for (argno = 0; argno < op.numargs; argno++) { 624 if (indexf == true) { 625 indexf = false; 626 } 627 argtype = op.argtype[argno]; 628 if (is_branch_disp(argtype)) { 629 mode = 0xAF + (typelen(argtype) << 5); 630 } else { 631 iread(&mode, addr, sizeof(mode)); 632 addr += 1; 633 } 634 r = regname[regnm(mode)]; 635 amode = addrmode(mode); 636 switch (amode) { 637 case LITSHORT: 638 case LITUPTO31: 639 case LITUPTO47: 640 case LITUPTO63: 641 argval = mode; 642 break; 643 644 case INDEX: 645 indexf = true; 646 --argno; 647 break; 648 649 case REG: 650 case REGDEF: 651 case AUTODEC: 652 break; 653 654 case AUTOINC: 655 if (r == regname[PROGCTR]) { 656 switch (typelen(argtype)) { 657 case TYPB: 658 argval = getdisp(addr, 1, r, amode); 659 addr += 1; 660 break; 661 662 case TYPW: 663 argval = getdisp(addr, 2, r, amode); 664 addr += 2; 665 break; 666 667 case TYPL: 668 argval = getdisp(addr, 4, r, amode); 669 addr += 4; 670 break; 671 672 case TYPF: 673 iread(&argval, addr, sizeof(argval)); 674 addr += 4; 675 break; 676 677 case TYPQ: 678 case TYPD: 679 iread(&argval, addr+4, sizeof(argval)); 680 addr += 8; 681 break; 682 } 683 } 684 break; 685 686 case AUTOINCDEF: 687 if (r == regname[PROGCTR]) { 688 argval = getdisp(addr, 4, r, amode); 689 addr += 4; 690 } 691 break; 692 693 case BYTEDISP: 694 case BYTEDISPDEF: 695 argval = getdisp(addr, 1, r, amode); 696 addr += 1; 697 break; 698 699 case WORDDISP: 700 case WORDDISPDEF: 701 argval = getdisp(addr, 2, r, amode); 702 addr += 2; 703 break; 704 705 case LONGDISP: 706 case LONGDISPDEF: 707 argval = getdisp(addr, 4, r, amode); 708 addr += 4; 709 break; 710 } 711 } 712 if (ins == O_CALLS or ins == O_CALLG) { 713 argval += 2; 714 } 715 if (addrstatus == BRANCH) { 716 addr = argval; 717 } 718 } 719 return addr; 720 } 721 722 /* 723 * Get the displacement of an instruction that uses displacement addressing. 724 */ 725 726 private int getdisp(addr, nbytes, reg, mode) 727 Address addr; 728 int nbytes; 729 String reg; 730 int mode; 731 { 732 char byte; 733 short hword; 734 int argval; 735 736 switch (nbytes) { 737 case 1: 738 iread(&byte, addr, sizeof(byte)); 739 argval = byte; 740 break; 741 742 case 2: 743 iread(&hword, addr, sizeof(hword)); 744 argval = hword; 745 break; 746 747 case 4: 748 iread(&argval, addr, sizeof(argval)); 749 break; 750 } 751 if (reg == regname[PROGCTR] && mode >= BYTEDISP) { 752 argval += addr + nbytes; 753 } 754 return argval; 755 } 756 757 #define BP_OP O_BPT /* breakpoint trap */ 758 #define BP_ERRNO SIGTRAP /* signal received at a breakpoint */ 759 760 /* 761 * Setting a breakpoint at a location consists of saving 762 * the word at the location and poking a BP_OP there. 763 * 764 * We save the locations and words on a list for use in unsetting. 765 */ 766 767 typedef struct Savelist *Savelist; 768 769 struct Savelist { 770 Address location; 771 Byte save; 772 Byte refcount; 773 Savelist link; 774 }; 775 776 private Savelist savelist; 777 778 /* 779 * Set a breakpoint at the given address. Only save the word there 780 * if it's not already a breakpoint. 781 */ 782 783 public setbp(addr) 784 Address addr; 785 { 786 Byte w; 787 Byte save; 788 register Savelist newsave, s; 789 790 for (s = savelist; s != nil; s = s->link) { 791 if (s->location == addr) { 792 s->refcount++; 793 return; 794 } 795 } 796 iread(&save, addr, sizeof(addr)); 797 newsave = new(Savelist); 798 newsave->location = addr; 799 newsave->save = save; 800 newsave->refcount = 1; 801 newsave->link = savelist; 802 savelist = newsave; 803 w = BP_OP; 804 iwrite(&w, addr, sizeof(w)); 805 } 806 807 /* 808 * Unset a breakpoint; unfortunately we have to search the SAVELIST 809 * to find the saved value. The assumption is that the SAVELIST will 810 * usually be quite small. 811 */ 812 813 public unsetbp(addr) 814 Address addr; 815 { 816 register Savelist s, prev; 817 818 prev = nil; 819 for (s = savelist; s != nil; s = s->link) { 820 if (s->location == addr) { 821 iwrite(&s->save, addr, sizeof(s->save)); 822 s->refcount--; 823 if (s->refcount == 0) { 824 if (prev == nil) { 825 savelist = s->link; 826 } else { 827 prev->link = s->link; 828 } 829 dispose(s); 830 } 831 return; 832 } 833 prev = s; 834 } 835 panic("unsetbp: couldn't find address %d", addr); 836 } 837 838 /* 839 * Predicate to test if the reason the process stopped was because 840 * of a breakpoint. 841 */ 842 843 public Boolean isbperr() 844 { 845 return (Boolean) (not isfinished(process) and errnum(process) == SIGTRAP); 846 } 847 848 /* 849 * Enter a procedure by creating and executing a call instruction. 850 */ 851 852 #define CALLSIZE 7 /* size of call instruction */ 853 854 public beginproc(p, argc) 855 Symbol p; 856 Integer argc; 857 { 858 char save[CALLSIZE]; 859 struct { 860 VaxOpcode op; 861 unsigned char numargs; 862 unsigned char mode; 863 char addr[sizeof(long)]; /* unaligned long */ 864 } call; 865 long dest; 866 867 pc = 2; 868 iread(save, pc, sizeof(save)); 869 call.op = O_CALLS; 870 call.numargs = argc; 871 call.mode = 0xef; 872 dest = codeloc(p) - 2 - (pc + 7); 873 mov(&dest, call.addr, sizeof(call.addr)); 874 iwrite(&call, pc, sizeof(call)); 875 setreg(PROGCTR, pc); 876 pstep(process); 877 iwrite(save, pc, sizeof(save)); 878 pc = reg(PROGCTR); 879 if (not isbperr()) { 880 printstatus(); 881 } 882 } 883