usr.bin/doscmd/trap.c

   1 /*
   2  * Copyright (c) 1992, 1993, 1996
   3  *      Berkeley Software Design, Inc.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by Berkeley Software
  16  *      Design, Inc.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND
  19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED.  IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  *
  30  *      BSDI trap.c,v 2.3 1996/04/08 19:33:08 bostic Exp
  31  *
  32  * $FreeBSD: src/usr.bin/doscmd/trap.c,v 1.7.2.1 2002/04/25 11:04:51 tg Exp $
  33  * $DragonFly: src/usr.bin/doscmd/trap.c,v 1.3 2004/01/21 21:48:21 rob Exp $
  34  */
  35
  36 #include <machine/trap.h>
  37
  38 #include "doscmd.h"
  39 #include "trap.h"
  40 #include "tty.h"
  41 #include "video.h"
  42
  43 /*
  44 ** When the emulator is very busy, it's often common for
  45 ** SIGALRM to be missed, leading to missed screen updates.
  46 **
  47 ** We update this counter every time a DOS interrupt is processed and
  48 ** if it hits a certain threshold, force an update.
  49 **
  50 ** When updates occur, the counter is zeroed.
  51 */
  52 static int      update_counter = 0;
  53 #define         BUSY_UPDATES    2000
  54
  55 /*
  56 ** handle interrupts passed to us by the kernel
  57 */
  58 void
  59 fake_int(regcontext_t *REGS, int intnum)
  60 {
  61     if (R_CS == 0xF000 || (ivec[intnum] >> 16) == 0xF000) {
  62         if (R_CS != 0xF000)
  63             intnum = ((u_char *)VECPTR(ivec[intnum]))[1];
  64         debug(D_ITRAPS | intnum, "INT %02x:%02x %04x:%04x/%08lx\n",
  65               intnum, R_AH, R_CS, R_IP, ivec[intnum]);
  66         switch (intnum) {
  67         case 0x2f:                      /* multiplex interrupt */
  68             int2f((regcontext_t *)&REGS->sc);
  69             break;
  70         case 0xff:                      /* doscmd special */
  71             emuint(REGS);
  72             break;
  73         default:                        /* should not get here */
  74             if (vflag) dump_regs(REGS);
  75             fatal("no interrupt set up for 0x%02x\n", intnum);
  76         }
  77         return;
  78     }
  79
  80     /* user_int: */
  81     debug(D_TRAPS | intnum,
  82           "INT %02x:%02x [%04lx:%04lx] %04x %04x %04x %04x from %04x:%04x\n",
  83           intnum, R_AH, ivec[intnum] >> 16, ivec[intnum] & 0xffff,
  84           R_AX, R_BX, R_CX, R_DX, R_CS, R_IP);
  85
  86 #if 0
  87     if ((intnum == 0x13) && (*(u_char *)VECPTR(ivec[intnum]) != 0xf4)) {
  88 #if 1
  89         char *addr; /*= (char *)VECPTR(ivec[intnum]);*/
  90         int i, l, j;
  91         char buf[100];
  92
  93         R_CS = 0x2c7;
  94         R_IP = 0x14f9;
  95         addr = (char *)MAKEPTR(R_CS, R_IP);
  96
  97         printf("\n");
  98         for (i = 0; i < 100; i++) {
  99             l = i386dis(R_CS, R_IP, addr, buf, 0);
 100             printf("%04x:%04x  %s\t;",R_CS,R_IP,buf);
 101             for (j = 0; j < l; j++)
 102                 printf(" %02x", (u_char)addr[j]);
 103             printf("\n");
 104             R_IP += l;
 105             addr += l;
 106         }
 107         exit (0);
 108 #else
 109         tmode = 1;
 110 #endif
 111     }
 112 #endif
 113
 114     if (intnum == 0)
 115         dump_regs(REGS);
 116
 117     if (ivec[intnum] == 0) {            /* uninitialised interrupt? */
 118         if (vflag) dump_regs(REGS);
 119         fatal("Call to uninitialised interrupt 0x%02x\n", intnum);
 120     }
 121
 122     /*
 123      * This is really ugly, but when DOS boots, it seems to loop
 124      * for a while on INT 16:11 INT 21:3E INT 2A:82
 125      * INT 21:3E is a close(), which seems like something one would
 126      * not sit on for ever, so we will allow it to reset our POLL count.
 127      */
 128     if (intnum == 0x21 && R_AX == 0x3E)
 129         reset_poll();
 130
 131     /* stack for and call the interrupt in vm86 space */
 132     PUSH((R_FLAGS & ~PSL_I) | (R_EFLAGS & PSL_VIF ? PSL_I : 0), REGS);
 133     PUSH(R_CS, REGS);
 134     PUSH(R_IP, REGS);
 135     R_EFLAGS &= ~PSL_VIF;               /* disable interrupts */
 136     PUTVEC(R_CS, R_IP, ivec[intnum]);
 137 }
 138
 139 /* make this read a little more intuitively */
 140 #define ipadvance(c,n)  SET16(c->sc_eip, GET16(c->sc_eip) + n)  /* move %ip along */
 141
 142 #ifdef USE_VM86
 143 /* entry from NetBSD-style vm86 */
 144 void
 145 sigurg(struct sigframe *sf)
 146 {
 147 #define sc      (&sf->sf_sc)
 148     int intnum;
 149     u_char *addr;
 150     int rep;
 151     int port;
 152     callback_t func;
 153
 154 #if 0
 155     printf("ivec08 = %08x\n", ivec[0x08]);
 156 #endif
 157
 158     if (tmode)
 159         resettrace(sc);
 160
 161     switch (VM86_TYPE(sf->sf_code)) {
 162     case VM86_INTx:
 163         intnum = VM86_ARG(sf->sf_code);
 164         switch (intnum) {
 165         case 0x2f:
 166             switch (GET8H(sc->sc_eax)) {
 167             case 0x11:
 168                 debug (D_TRAPS|0x2f, "INT 2F:%04x\n", GET16(sc->sc_eax));
 169                 if (int2f_11(sc)) {
 170                     /* Skip over int 2f:11 */
 171                     goto out;
 172                 }
 173                 break;
 174             case 0x43:
 175                 debug (D_TRAPS|0x2f, "INT 2F:%04x\n", GET16(sc->sc_eax));
 176                 if (int2f_43(sc)) {
 177                     /* Skip over int 2f:43 */
 178                     goto out;
 179                 }
 180                 break;
 181             }
 182             break;
 183         }
 184         fake_int(sc, intnum);
 185         break;
 186     case VM86_UNKNOWN:
 187         /*XXXXX failed vector also gets here without IP adjust*/
 188
 189         addr = (u_char *)MAKEPTR(sc->sc_cs, sc->sc_eip);
 190         rep = 1;
 191
 192         debug (D_TRAPS2, "%04x:%04x [%02x]", GET16(sc->sc_cs),
 193             GET16(sc->sc_eip), addr[0]);
 194         switch (addr[0]) {
 195         case TRACETRAP:
 196             ipadvance(sc,1);
 197             fake_int(sc, 3);
 198             break;
 199         case INd:
 200             port = addr[1];
 201             ipadvance(sc,2);
 202             inb(sc, port);
 203             break;
 204         case OUTd:
 205             port = addr[1];
 206             ipadvance(sc,2);
 207             outb(sc, port);
 208             break;
 209         case INdX:
 210             port = addr[1];
 211             ipadvance(sc,2);
 212             inx(sc, port);
 213             break;
 214         case OUTdX:
 215             port = addr[1];
 216             ipadvance(sc,2);
 217             outx(sc, port);
 218             break;
 219         case IN:
 220             ipadvance(sc,1);
 221             inb(sc, GET16(sc->sc_edx));
 222             break;
 223         case INX:
 224             ipadvance(sc,1);
 225             inx(sc, GET16(sc->sc_edx));
 226             break;
 227         case OUT:
 228             ipadvance(sc,1);
 229             outb(sc, GET16(sc->sc_edx));
 230             break;
 231         case OUTX:
 232             ipadvance(sc,1);
 233             outx(sc, GET16(sc->sc_edx));
 234             break;
 235         case OUTSB:
 236             ipadvance(sc,1);
 237             while (rep-- > 0)
 238                 outsb(sc, GET16(sc->sc_edx));
 239             break;
 240         case OUTSW:
 241             ipadvance(sc,1);
 242             while (rep-- > 0)
 243                 outsx(sc, GET16(sc->sc_edx));
 244             break;
 245         case INSB:
 246             ipadvance(sc,1);
 247             while (rep-- > 0)
 248                 insb(sc, GET16(sc->sc_edx));
 249             break;
 250         case INSW:
 251             ipadvance(sc,1);
 252             while (rep-- > 0)
 253                 insx(sc, GET16(sc->sc_edx));
 254             break;
 255         case LOCK:
 256             debug(D_TRAPS2, "lock\n");
 257             ipadvance(sc,1);
 258             break;
 259         case HLT:       /* BIOS entry points populated with HLT */
 260             func = find_callback(GETVEC(sc->sc_cs, sc->sc_eip));
 261             if (func) {
 262                 ipadvance(sc,);
 263                 SET16(sc->sc_eip, GET16(sc->sc_eip) + 1);
 264                 func(sc);
 265                 break;
 266             }
 267         default:
 268             dump_regs(sc);
 269             fatal("unsupported instruction\n");
 270         }
 271                 break;
 272         default:
 273                 dump_regs(sc);
 274                 printf("code = %04x\n", sf->sf_code);
 275                 fatal("unrecognized vm86 trap\n");
 276         }
 277
 278 out:
 279         if (tmode)
 280                 tracetrap(sc);
 281 #undef  sc
 282 #undef  ipadvance
 283 }
 284
 285 #else /* USE_VM86 */
 286
 287 /* entry from FreeBSD, BSD/OS vm86 */
 288 void
 289 sigbus(struct sigframe *sf)
 290 {
 291     u_char              *addr;
 292     int                 tempflags,okflags;
 293     int                 intnum;
 294     int                 port;
 295     callback_t          func;
 296     regcontext_t        *REGS = (regcontext_t *)(&sf->sf_uc.uc_mcontext);
 297
 298     if (!(R_EFLAGS && PSL_VM))
 299         fatal("SIGBUS in the emulator\n");
 300
 301     if ((int)sf->sf_siginfo != 0) {
 302         switch (sf->sf_uc.uc_mcontext.mc_trapno) {
 303         case T_PAGEFLT:
 304             debug(D_TRAPS2, "Page fault, trying to access 0x%x\n",
 305                   sf->sf_addr);
 306             /* nothing but accesses to video memory can fault for now */
 307             if (vmem_pageflt(sf) == 0)
 308                 goto out;
 309             /* FALLTHROUGH */
 310         default:
 311             dump_regs(REGS);
 312             fatal("SIGBUS code %d, trapno: %d, err: %d\n",
 313                   (int)sf->sf_siginfo, sf->sf_uc.uc_mcontext.mc_trapno,
 314                   sf->sf_uc.uc_mcontext.mc_err);
 315             /* NOTREACHED */
 316         }
 317     }
 318
 319     addr = (u_char *)MAKEPTR(R_CS, R_IP);
 320
 321     if (tmode)
 322         resettrace(REGS);
 323
 324     if ((R_EFLAGS & (PSL_VIP | PSL_VIF)) == (PSL_VIP | PSL_VIF)) {
 325         resume_interrupt();
 326         goto out;
 327     }
 328
 329 /*    printf("%p\n", addr); fflush(stdout); */
 330     debug (D_TRAPS2, "%04x:%04x [%02x %02x %02x] ", R_CS, R_IP,
 331         (int)addr[0], (int)addr[1], (int)addr[2]);
 332 #if 0
 333     if ((int)addr[0] == 0x67) {
 334         int i;
 335         printf("HERE\n"); fflush(stdout);
 336         printf("addr: %p\n", REGS); fflush(stdout);
 337         for (i = 0; i < 21 * 4; i++) {
 338             printf("%d: %x\n", i, ((u_char *)REGS)[i]);
 339             fflush(stdout);
 340         }
 341         printf("Trapno, error: %p %p\n", REGS->sc.sc_trapno, REGS->sc.sc_err);
 342         fflush(stdout);
 343         dump_regs(REGS);
 344     }
 345 #endif
 346
 347         switch (addr[0]) {              /* what was that again dear? */
 348
 349         case CLI:
 350             debug (D_TRAPS2, "cli\n");
 351             R_IP++;
 352             R_EFLAGS &= ~PSL_VIP;
 353             break;
 354
 355         case STI:
 356             debug (D_TRAPS2, "sti\n");
 357             R_IP++;
 358             R_EFLAGS |= PSL_VIP;
 359 #if 0
 360             if (update_counter++ > BUSY_UPDATES)
 361                 sigalrm(sf);
 362 #endif
 363             break;
 364
 365         case PUSHF:
 366             debug (D_TRAPS2, "pushf <- 0x%lx\n", R_EFLAGS);
 367             R_IP++;
 368             PUSH((R_FLAGS & ~PSL_I) | (R_EFLAGS & PSL_VIF ? PSL_I : 0),
 369                 REGS);
 370             break;
 371
 372         case IRET:
 373             R_IP = POP(REGS);           /* get new cs:ip off the stack */
 374             R_CS = POP(REGS);
 375             debug (D_TRAPS2, "iret to %04x:%04x ", R_CS, R_IP);
 376             /* FALLTHROUGH */           /* 'safe' flag pop operation */
 377
 378         case POPF:
 379 /* XXX */
 380             fatal("popf/iret in emulator");
 381
 382             if (addr[0] == POPF)
 383                 R_IP++;
 384             /* get flags from stack */
 385             tempflags = POP(REGS);
 386             /* flags we consider OK */
 387             okflags =  (PSL_ALLCC | PSL_T | PSL_D | PSL_V);
 388             /* keep state of non-OK flags */
 389             R_FLAGS = ((R_FLAGS & ~okflags) |
 390                        /* pop state of OK flags */
 391                        (tempflags & okflags));
 392
 393             /* restore pseudo PSL_I flag */
 394             IntState = tempflags & PSL_I;
 395             debug(D_TRAPS2, "popf -> 0x%lx\n", R_EFLAGS);
 396             break;
 397
 398         case TRACETRAP:
 399             debug(D_TRAPS2, "ttrap\n");
 400             R_IP++;
 401             fake_int(REGS, 3);
 402             break;
 403
 404         case INTn:
 405             intnum = addr[1];
 406             R_IP += 2;                  /* nobody else will do it for us */
 407             switch (intnum) {
 408             case 0x2f:
 409                 switch (R_AH) {         /* function number */
 410                 case 0x11:
 411                     debug (D_TRAPS|0x2f, "INT 2F:%04x\n", R_AX);
 412                     if (int2f_11(REGS)) {
 413                         /* Skip over int 2f:11 */
 414                         goto out;
 415                     }
 416                     break;
 417                 case 0x43:
 418                     debug (D_TRAPS|0x2f, "INT 2F:%04x\n", R_AX);
 419                     if (int2f_43(REGS)) {
 420                         /* Skip over int 2f:43 */
 421                         goto out;
 422                     }
 423                     break;
 424                 }
 425                 break;
 426             }
 427             fake_int(REGS, intnum);
 428             break;
 429
 430         case INd:               /* XXX implement in/out */
 431             R_IP += 2;
 432             port = addr[1];
 433             inb(REGS, port);
 434             break;
 435         case IN:
 436             R_IP++;
 437             inb(REGS,R_DX);
 438             break;
 439         case INX:
 440             R_IP++;
 441             inx(REGS,R_DX);
 442             break;
 443         case INdX:
 444             R_IP += 2;
 445             port = addr[1];
 446             inx(REGS, port);
 447             break;
 448         case INSB:
 449             R_IP++;
 450             printf("(missed) INSB <- 0x%02x\n",R_DX);
 451             break;
 452         case INSW:
 453             R_IP++;
 454             printf("(missed) INSW <- 0x%02x\n",R_DX);
 455             break;
 456
 457         case OUTd:
 458             R_IP += 2;
 459             port = addr[1];
 460             outb(REGS, port);
 461             break;
 462         case OUTdX:
 463             R_IP += 2;
 464             port = addr[1];
 465             outx(REGS, port);
 466             break;
 467         case OUT:
 468             R_IP++;
 469             outb(REGS, R_DX);
 470             break;
 471         case OUTX:
 472             R_IP++;
 473             outx(REGS, R_DX);
 474             break;
 475         case OUTSB:
 476             R_IP++;
 477             printf("(missed) OUTSB -> 0x%02x\n",R_DX);
 478             break;
 479         case OUTSW:
 480             R_IP++;
 481             printf("(missed) OUTSW -> 0x%02x\n",R_DX);
 482 /* tmode = 1; */
 483             break;
 484
 485         case LOCK:
 486             debug(D_TRAPS2, "lock\n");
 487             R_IP++;
 488             break;
 489
 490         case HLT:       /* BIOS entry points populated with HLT */
 491             func = find_callback(MAKEVEC(R_CS, R_IP));
 492             if (func) {
 493                 R_IP++;                                 /* pass HLT opcode */
 494                 func(REGS);
 495 /*              dump_regs(REGS); */
 496 #if 0
 497                 update_counter += 5;
 498                 if (update_counter > BUSY_UPDATES)
 499                     sigalrm(sf);
 500 #endif
 501                 break;
 502             }
 503 /*            if (R_EFLAGS & PSL_VIF) { */
 504                 R_IP++;
 505                 tty_pause();
 506                 goto out;
 507 /*            } */
 508             /* FALLTHRU */
 509
 510         default:
 511             dump_regs(REGS);
 512             fatal("unsupported instruction\n");
 513         }
 514
 515 out:
 516         if (tmode)
 517             tracetrap(REGS);
 518 }
 519 #endif /* USE_VM86 */
 520
 521 void
 522 sigtrace(struct sigframe *sf)
 523 {
 524     int                 x;
 525     regcontext_t        *REGS = (regcontext_t *)(&sf->sf_uc.uc_mcontext);
 526
 527     if (R_EFLAGS & PSL_VM) {
 528         debug(D_ALWAYS, "Currently in DOS\n");
 529         dump_regs(REGS);
 530         for (x = 0; x < 16; ++x)
 531             debug(D_ALWAYS, " %02x", *(unsigned char *)x);
 532         putc('\n', debugf);
 533     } else {
 534         debug(D_ALWAYS, "Currently in the emulator\n");
 535         sigalrm(sf);
 536     }
 537 }
 538
 539 void
 540 sigtrap(struct sigframe *sf)
 541 {
 542     int                 intnum;
 543     int                 trapno;
 544     regcontext_t        *REGS = (regcontext_t *)(&sf->sf_uc.uc_mcontext);
 545
 546     if ((R_EFLAGS & PSL_VM) == 0) {
 547         dump_regs(REGS);
 548         fatal("%04x:%08x Sigtrap in protected mode\n", R_CS, R_IP);
 549     }
 550
 551     if (tmode)
 552         if (resettrace(REGS))
 553             goto doh;
 554
 555 #if defined (__FreeBSD__) || defined (__DragonFly__)
 556     trapno = (int)sf->sf_siginfo;                       /* XXX GROSTIC HACK ALERT */
 557 #else
 558     trapno = sc->sc_trapno;
 559 #endif
 560     if (trapno == T_BPTFLT)
 561         intnum = 3;
 562     else
 563         intnum = 1;
 564
 565     PUSH((R_FLAGS & ~PSL_I) | (R_EFLAGS & PSL_VIF ? PSL_I : 0), REGS);
 566     PUSH(R_CS, REGS);
 567     PUSH(R_IP, REGS);
 568     R_FLAGS &= ~PSL_T;
 569     PUTVEC(R_CS, R_IP, ivec[intnum]);
 570
 571 doh:
 572     if (tmode)
 573         tracetrap(REGS);
 574 }
 575
 576 void
 577 breakpoint(struct sigframe *sf)
 578 {
 579     regcontext_t        *REGS = (regcontext_t *)(&sf->sf_uc.uc_mcontext);
 580
 581     if (R_EFLAGS & PSL_VM)
 582         printf("doscmd ");
 583     printf("breakpoint: %04x\n", *(u_short *)0x8e64);
 584
 585     __asm__ volatile("mov 0, %eax");
 586     __asm__ volatile(".byte 0x0f");             /* MOV DR6,EAX */
 587     __asm__ volatile(".byte 0x21");
 588     __asm__ volatile(".byte 0x1b");
 589 }
 590
 591 /*
 592 ** periodic updates
 593 */
 594 void
 595 sigalrm(struct sigframe *sf)
 596 {
 597     regcontext_t        *REGS = (regcontext_t *)(&sf->sf_uc.uc_mcontext);
 598
 599     if (tmode)
 600         resettrace(REGS);
 601
 602     update_counter = 0;                 /* remember we've updated */
 603     video_update((regcontext_t *)&REGS->sc);
 604     hardint(0x00);
 605
 606     if (tmode)
 607         tracetrap(REGS);
 608 }
 609
 610 void
 611 sigill(struct sigframe *sf)
 612 {
 613     regcontext_t        *REGS = (regcontext_t *)(&sf->sf_uc.uc_mcontext);
 614
 615     fprintf(stderr, "Signal %d from DOS program\n", sf->sf_signum);
 616     dump_regs(REGS);
 617     fatal("%04x:%04x Illegal instruction\n", R_CS, R_IP);
 618
 619 }
 620
 621 void
 622 sigfpe(struct sigframe *sf)
 623 {
 624     regcontext_t        *REGS = (regcontext_t *)(&sf->sf_uc.uc_mcontext);
 625
 626     if (R_EFLAGS & PSL_VM) {
 627         dump_regs(REGS);
 628         debug(D_ALWAYS, "DOS program caused floating point fault\n");
 629 /*XXX Look into that !! */
 630         fake_int(REGS, 0);      /* call handler XXX rather bogus, eh? */
 631         return;
 632     }
 633     dump_regs(REGS);
 634     fatal("%04x:%04x Floating point fault in emulator.\n", R_CS, R_IP);
 635 }