reactos/ntoskrnl/ke/i386/v86m.c

   1 /* $Id$
   2  *
   3  * COPYRIGHT:       See COPYING in the top level directory
   4  * PROJECT:         ReactOS kernel
   5  * FILE:            ntoskrnl/ke/i386/v86m.c
   6  * PURPOSE:         Support for v86 mode
   7  *
   8  * PROGRAMMERS:     David Welch (welch@cwcom.net)
   9  */
  10
  11 /* INCLUDES *****************************************************************/
  12
  13 #include <ntoskrnl.h>
  14 #define NDEBUG
  15 #include <internal/debug.h>
  16
  17 /* GLOBALS *******************************************************************/
  18
  19 #define IOPL_FLAG          ((1 << 12) | (1 << 13))
  20 #define INTERRUPT_FLAG     (1 << 9)
  21 #define TRAP_FLAG          (1 << 8)
  22 #define DIRECTION_FLAG     (1 << 10)
  23
  24 #define VALID_FLAGS         (0xDFF)
  25
  26 /* FUNCTIONS *****************************************************************/
  27
  28 ULONG
  29 KeV86GPF(PKV86M_TRAP_FRAME VTf, PKTRAP_FRAME Tf)
  30 {
  31   PUCHAR ip;
  32   PUSHORT sp;
  33   PULONG dsp;
  34   BOOL BigDataPrefix = FALSE;
  35   BOOL BigAddressPrefix = FALSE;
  36   BOOL RepPrefix = FALSE;
  37   ULONG i = 0;
  38   BOOL Exit = FALSE;
  39
  40   ip = (PUCHAR)((Tf->Cs & 0xFFFF) * 16 + (Tf->Eip & 0xFFFF));
  41   sp = (PUSHORT)((Tf->Ss & 0xFFFF) * 16 + (Tf->Esp & 0xFFFF));
  42   dsp = (PULONG)sp;
  43
  44   DPRINT("KeV86GPF handling %x at %x:%x ss:sp %x:%x Flags %x\n",
  45          ip[0], Tf->Cs, Tf->Eip, Tf->Ss, Tf->Esp, VTf->regs->Flags);
  46
  47   while (!Exit)
  48     {
  49       switch (ip[i])
  50         {
  51           /* 32-bit data prefix */
  52         case 0x66:
  53           BigDataPrefix = TRUE;
  54           i++;
  55           Tf->Eip++;
  56           break;
  57
  58           /* 32-bit address prefix */
  59         case 0x67:
  60           BigAddressPrefix = TRUE;
  61           i++;
  62           Tf->Eip++;
  63           break;
  64
  65           /* rep prefix */
  66         case 0xFC:
  67           RepPrefix = TRUE;
  68           i++;
  69           Tf->Eip++;
  70           break;
  71
  72           /* sti */
  73         case 0xFB:
  74           if (BigDataPrefix || BigAddressPrefix || RepPrefix)
  75             {
  76               *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
  77               return(1);
  78             }
  79           if (VTf->regs->Flags & KV86M_EMULATE_CLI_STI)
  80             {
  81               Tf->Eip++;
  82               VTf->regs->Vif = 1;
  83               return(0);
  84             }
  85           Exit = TRUE;
  86           break;
  87
  88           /* cli */
  89         case 0xFA:
  90           if (BigDataPrefix || BigAddressPrefix || RepPrefix)
  91             {
  92               *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
  93               return(1);
  94             }
  95           if (VTf->regs->Flags & KV86M_EMULATE_CLI_STI)
  96             {
  97               Tf->Eip++;
  98               VTf->regs->Vif = 0;
  99               return(0);
 100             }
 101           Exit = TRUE;
 102           break;
 103
 104           /* pushf */
 105         case 0x9C:
 106           if (RepPrefix)
 107             {
 108               *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
 109               return(1);
 110             }
 111           if (VTf->regs->Flags & KV86M_EMULATE_CLI_STI)
 112             {
 113               Tf->Eip++;
 114               if (!BigAddressPrefix)
 115                 {
 116                   Tf->Esp = Tf->Esp - 2;
 117                   sp = sp - 1;
 118                   sp[0] = (USHORT)(Tf->Eflags & 0xFFFF);
 119                   if (VTf->regs->Vif == 1)
 120                     {
 121                       sp[0] = (USHORT)(sp[0] | INTERRUPT_FLAG);
 122                     }
 123                   else
 124                     {
 125                       sp[0] = (USHORT)(sp[0] & (~INTERRUPT_FLAG));
 126                     }
 127                 }
 128               else
 129                 {
 130                   Tf->Esp = Tf->Esp - 4;
 131                   dsp = dsp - 1;
 132                   dsp[0] = Tf->Eflags;
 133                   dsp[0] = dsp[0] & VALID_FLAGS;
 134                   if (VTf->regs->Vif == 1)
 135                     {
 136                       dsp[0] = dsp[0] | INTERRUPT_FLAG;
 137                     }
 138                   else
 139                     {
 140                       dsp[0] = dsp[0] & (~INTERRUPT_FLAG);
 141                     }
 142                 }
 143               return(0);
 144             }
 145           Exit = TRUE;
 146           break;
 147
 148           /* popf */
 149         case 0x9D:
 150           if (RepPrefix)
 151             {
 152               *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
 153               return(1);
 154             }
 155           if (VTf->regs->Flags & KV86M_EMULATE_CLI_STI)
 156             {
 157               Tf->Eip++;
 158               if (!BigAddressPrefix)
 159                 {
 160                   Tf->Eflags = Tf->Eflags & (~0xFFFF);
 161                   Tf->Eflags = Tf->Eflags | (sp[0] & VALID_FLAGS);
 162                   if (Tf->Eflags & INTERRUPT_FLAG)
 163                     {
 164                       VTf->regs->Vif = 1;
 165                     }
 166                   else
 167                     {
 168                       VTf->regs->Vif = 0;
 169                     }
 170                   Tf->Eflags = Tf->Eflags | INTERRUPT_FLAG;
 171                   Tf->Esp = Tf->Esp + 2;
 172                 }
 173               else
 174                 {
 175                   Tf->Eflags = Tf->Eflags | (dsp[0] & VALID_FLAGS);
 176                   if (dsp[0] & INTERRUPT_FLAG)
 177                     {
 178                       VTf->regs->Vif = 1;
 179                     }
 180                   else
 181                     {
 182                       VTf->regs->Vif = 0;
 183                     }
 184                   Tf->Eflags = Tf->Eflags | INTERRUPT_FLAG;
 185                   Tf->Esp = Tf->Esp + 2;
 186                 }
 187               return(0);
 188             }
 189           Exit = TRUE;
 190           break;
 191
 192       /* iret */
 193         case 0xCF:
 194           if (RepPrefix)
 195             {
 196               *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
 197               return(1);
 198             }
 199           if (VTf->regs->Flags & KV86M_EMULATE_CLI_STI)
 200             {
 201               Tf->Eip = sp[0];
 202               Tf->Cs = sp[1];
 203               Tf->Eflags = Tf->Eflags & (~0xFFFF);
 204               Tf->Eflags = Tf->Eflags | sp[2];
 205               if (Tf->Eflags & INTERRUPT_FLAG)
 206                 {
 207                   VTf->regs->Vif = 1;
 208                 }
 209               else
 210                 {
 211                   VTf->regs->Vif = 0;
 212                 }
 213               Tf->Eflags = Tf->Eflags & (~INTERRUPT_FLAG);
 214               Tf->Esp = Tf->Esp + 6;
 215               return(0);
 216             }
 217           Exit = TRUE;
 218           break;
 219
 220           /* out imm8, al */
 221         case 0xE6:
 222           if (RepPrefix)
 223             {
 224               *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
 225               return(1);
 226             }
 227           if (VTf->regs->Flags & KV86M_ALLOW_IO_PORT_ACCESS)
 228             {
 229               DPRINT("outb %d, %x\n", (ULONG)ip[i + 1], Tf->Eax & 0xFF);
 230               WRITE_PORT_UCHAR((PUCHAR)(ULONG)ip[i + 1],
 231                                (UCHAR)(Tf->Eax & 0xFF));
 232               Tf->Eip = Tf->Eip + 2;
 233               return(0);
 234             }
 235           Exit = TRUE;
 236           break;
 237
 238           /* out imm8, ax */
 239         case 0xE7:
 240           if (RepPrefix)
 241             {
 242               *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
 243               return(1);
 244             }
 245           if (VTf->regs->Flags & KV86M_ALLOW_IO_PORT_ACCESS)
 246             {
 247               if (!BigDataPrefix)
 248                 {
 249                   DPRINT("outw %d, %x\n", (ULONG)ip[i + 1], Tf->Eax & 0xFFFF);
 250                   WRITE_PORT_USHORT((PUSHORT)(ULONG)ip[1], (USHORT)(Tf->Eax & 0xFFFF));
 251                 }
 252               else
 253                 {
 254                   DPRINT("outl %d, %x\n", (ULONG)ip[i + 1], Tf->Eax);
 255                   WRITE_PORT_ULONG((PULONG)(ULONG)ip[1], Tf->Eax);
 256                 }
 257               Tf->Eip = Tf->Eip + 2;
 258               return(0);
 259             }
 260           Exit = TRUE;
 261           break;
 262
 263           /* out dx, al */
 264         case 0xEE:
 265           if (RepPrefix)
 266             {
 267               *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
 268               return(1);
 269             }
 270           if (VTf->regs->Flags & KV86M_ALLOW_IO_PORT_ACCESS)
 271             {
 272               DPRINT("outb %d, %x\n", Tf->Edx & 0xFFFF, Tf->Eax & 0xFF);
 273               WRITE_PORT_UCHAR((PUCHAR)(Tf->Edx & 0xFFFF), (UCHAR)(Tf->Eax & 0xFF));
 274               Tf->Eip = Tf->Eip + 1;
 275               return(0);
 276             }
 277           Exit = TRUE;
 278           break;
 279
 280           /* out dx, ax */
 281         case 0xEF:
 282           if (RepPrefix)
 283             {
 284               *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
 285               return(1);
 286             }
 287           if (VTf->regs->Flags & KV86M_ALLOW_IO_PORT_ACCESS)
 288             {
 289               if (!BigDataPrefix)
 290                 {
 291                   DPRINT("outw %d, %x\n", Tf->Edx & 0xFFFF, Tf->Eax & 0xFFFF);
 292                   WRITE_PORT_USHORT((PUSHORT)(Tf->Edx & 0xFFFF),
 293                                     (USHORT)(Tf->Eax & 0xFFFF));
 294                 }
 295               else
 296                 {
 297                   DPRINT("outl %d, %x\n", Tf->Edx & 0xFFFF, Tf->Eax);
 298                   WRITE_PORT_ULONG((PULONG)(Tf->Edx & 0xFFFF),
 299                                    Tf->Eax);
 300                 }
 301               Tf->Eip = Tf->Eip + 1;
 302               return(0);
 303             }
 304           Exit = TRUE;
 305           break;
 306
 307           /* in al, imm8 */
 308         case 0xE4:
 309           if (RepPrefix)
 310             {
 311               *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
 312               return(1);
 313             }
 314           if (VTf->regs->Flags & KV86M_ALLOW_IO_PORT_ACCESS)
 315             {
 316               UCHAR v;
 317
 318               v = READ_PORT_UCHAR((PUCHAR)(ULONG)ip[1]);
 319               DPRINT("inb %d\t%X\n", (ULONG)ip[1], v);
 320               Tf->Eax = Tf->Eax & (~0xFF);
 321               Tf->Eax = Tf->Eax | v;
 322               Tf->Eip = Tf->Eip + 2;
 323               return(0);
 324             }
 325           Exit = TRUE;
 326           break;
 327
 328           /* in ax, imm8 */
 329         case 0xE5:
 330           if (RepPrefix)
 331             {
 332               *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
 333               return(1);
 334             }
 335           if (VTf->regs->Flags & KV86M_ALLOW_IO_PORT_ACCESS)
 336             {
 337               if (!BigDataPrefix)
 338                 {
 339                   USHORT v;
 340                   v = READ_PORT_USHORT((PUSHORT)(ULONG)ip[1]);
 341                   DPRINT("inw %d\t%X\n", (ULONG)ip[1], v);
 342                   Tf->Eax = Tf->Eax & (~0xFFFF);
 343                   Tf->Eax = Tf->Eax | v;
 344                 }
 345               else
 346                 {
 347                   ULONG v;
 348                   v = READ_PORT_ULONG((PULONG)(ULONG)ip[1]);
 349                   DPRINT("inl %d\t%X\n", (ULONG)ip[1], v);
 350                   Tf->Eax = v;
 351                 }
 352               Tf->Eip = Tf->Eip + 2;
 353               return(0);
 354             }
 355           Exit = TRUE;
 356           break;
 357
 358           /* in al, dx */
 359         case 0xEC:
 360           if (RepPrefix)
 361             {
 362               *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
 363               return(1);
 364             }
 365           if (VTf->regs->Flags & KV86M_ALLOW_IO_PORT_ACCESS)
 366             {
 367               UCHAR v;
 368
 369               v = READ_PORT_UCHAR((PUCHAR)(Tf->Edx & 0xFFFF));
 370               DPRINT("inb %d\t%X\n", Tf->Edx & 0xFFFF, v);
 371               Tf->Eax = Tf->Eax & (~0xFF);
 372               Tf->Eax = Tf->Eax | v;
 373               Tf->Eip = Tf->Eip + 1;
 374               return(0);
 375             }
 376           Exit = TRUE;
 377           break;
 378
 379           /* in ax, dx */
 380         case 0xED:
 381           if (RepPrefix)
 382             {
 383               *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
 384               return(1);
 385             }
 386           if (VTf->regs->Flags & KV86M_ALLOW_IO_PORT_ACCESS)
 387             {
 388               if (!BigDataPrefix)
 389                 {
 390                   USHORT v;
 391
 392                   v = READ_PORT_USHORT((PUSHORT)(Tf->Edx & 0xFFFF));
 393                   DPRINT("inw %d\t%X\n", Tf->Edx & 0xFFFF, v);
 394                   Tf->Eax = Tf->Eax & (~0xFFFF);
 395                   Tf->Eax = Tf->Eax | v;
 396                 }
 397               else
 398                 {
 399                   ULONG v;
 400
 401                   v = READ_PORT_ULONG((PULONG)(Tf->Edx & 0xFFFF));
 402                   DPRINT("inl %d\t%X\n", Tf->Edx & 0xFFFF, v);
 403                   Tf->Eax = v;
 404                 }
 405               Tf->Eip = Tf->Eip + 1;
 406               return(0);
 407             }
 408           Exit = TRUE;
 409           break;
 410
 411       /* outsb */
 412         case 0x6E:
 413           if (VTf->regs->Flags & KV86M_ALLOW_IO_PORT_ACCESS)
 414             {
 415               ULONG Count;
 416               PUCHAR Port;
 417               PUCHAR Buffer;
 418               ULONG Offset;
 419
 420               Count = 1;
 421               if (RepPrefix)
 422                 {
 423                   Count = Tf->Ecx;
 424                   if (!BigAddressPrefix)
 425                     {
 426                       Count = Count & 0xFFFF;
 427                     }
 428                 }
 429
 430               Port = (PUCHAR)(Tf->Edx & 0xFFFF);
 431               Offset = Tf->Edi;
 432               if (!BigAddressPrefix)
 433                 {
 434                   Offset = Offset & 0xFFFF;
 435                 }
 436               Buffer = (PUCHAR)((Tf->Es * 16) + Offset);
 437               for (; Count > 0; Count--)
 438                 {
 439                   WRITE_PORT_UCHAR(Port, *Buffer);
 440                   if (Tf->Eflags & DIRECTION_FLAG)
 441                     {
 442                       Buffer++;
 443                     }
 444                   else
 445                     {
 446                       Buffer--;
 447                     }
 448                 }
 449               Tf->Eip++;
 450               return(0);
 451             }
 452           Exit = TRUE;
 453           break;
 454
 455           /* insw/insd */
 456         case 0x6F:
 457           if (VTf->regs->Flags & KV86M_ALLOW_IO_PORT_ACCESS)
 458             {
 459               ULONG Count;
 460               PUCHAR Port;
 461               PUSHORT BufferS = NULL;
 462               PULONG BufferL = NULL;
 463               ULONG Offset;
 464
 465               Count = 1;
 466               if (RepPrefix)
 467                 {
 468                   Count = Tf->Ecx;
 469                   if (!BigAddressPrefix)
 470                     {
 471                       Count = Count & 0xFFFF;
 472                     }
 473                 }
 474
 475               Port = (PUCHAR)(Tf->Edx & 0xFFFF);
 476               Offset = Tf->Edi;
 477               if (!BigAddressPrefix)
 478                 {
 479                   Offset = Offset & 0xFFFF;
 480                 }
 481               if (BigDataPrefix)
 482                 {
 483                   BufferL = (PULONG)((Tf->Es * 16) + Offset);
 484                 }
 485               else
 486                 {
 487                   BufferS = (PUSHORT)((Tf->Es * 16) + Offset);
 488                 }
 489               for (; Count > 0; Count--)
 490                 {
 491                   if (BigDataPrefix)
 492                     {
 493                       WRITE_PORT_ULONG((PULONG)Port, *BufferL);
 494                     }
 495                   else
 496                     {
 497                       WRITE_PORT_USHORT((PUSHORT)Port, *BufferS);
 498                     }
 499                   if (Tf->Eflags & DIRECTION_FLAG)
 500                     {
 501                       if (BigDataPrefix)
 502                         {
 503                           BufferL++;
 504                         }
 505                       else
 506                         {
 507                           BufferS++;
 508                         }
 509                     }
 510                   else
 511                     {
 512                       if (BigDataPrefix)
 513                         {
 514                           BufferL--;
 515                         }
 516                       else
 517                         {
 518                           BufferS--;
 519                         }
 520                     }
 521                 }
 522               Tf->Eip++;
 523               return(0);
 524             }
 525           Exit = TRUE;
 526           break;
 527
 528       /* insb */
 529         case 0x6C:
 530           if (VTf->regs->Flags & KV86M_ALLOW_IO_PORT_ACCESS)
 531             {
 532               ULONG Count;
 533               PUCHAR Port;
 534               PUCHAR Buffer;
 535               ULONG Offset;
 536
 537               Count = 1;
 538               if (RepPrefix)
 539                 {
 540                   Count = Tf->Ecx;
 541                   if (!BigAddressPrefix)
 542                     {
 543                       Count = Count & 0xFFFF;
 544                     }
 545                 }
 546
 547               Port = (PUCHAR)(Tf->Edx & 0xFFFF);
 548               Offset = Tf->Edi;
 549               if (!BigAddressPrefix)
 550                 {
 551                   Offset = Offset & 0xFFFF;
 552                 }
 553               Buffer = (PUCHAR)((Tf->Es * 16) + Offset);
 554               for (; Count > 0; Count--)
 555                 {
 556                   *Buffer = READ_PORT_UCHAR(Port);
 557                   if (Tf->Eflags & DIRECTION_FLAG)
 558                     {
 559                       Buffer++;
 560                     }
 561                   else
 562                     {
 563                       Buffer--;
 564                     }
 565                 }
 566               Tf->Eip++;
 567               return(0);
 568             }
 569           Exit = TRUE;
 570           break;
 571
 572           /* insw/insd */
 573         case 0x6D:
 574           if (VTf->regs->Flags & KV86M_ALLOW_IO_PORT_ACCESS)
 575             {
 576               ULONG Count;
 577               PUCHAR Port;
 578               PUSHORT BufferS = NULL;
 579               PULONG BufferL = NULL;
 580               ULONG Offset;
 581
 582               Count = 1;
 583               if (RepPrefix)
 584                 {
 585                   Count = Tf->Ecx;
 586                   if (!BigAddressPrefix)
 587                     {
 588                       Count = Count & 0xFFFF;
 589                     }
 590                 }
 591
 592               Port = (PUCHAR)(Tf->Edx & 0xFFFF);
 593               Offset = Tf->Edi;
 594               if (!BigAddressPrefix)
 595                 {
 596                   Offset = Offset & 0xFFFF;
 597                 }
 598               if (BigDataPrefix)
 599                 {
 600                   BufferL = (PULONG)((Tf->Es * 16) + Offset);
 601                 }
 602               else
 603                 {
 604                   BufferS = (PUSHORT)((Tf->Es * 16) + Offset);
 605                 }
 606               for (; Count > 0; Count--)
 607                 {
 608                   if (BigDataPrefix)
 609                     {
 610                       *BufferL = READ_PORT_ULONG((PULONG)Port);
 611                     }
 612                   else
 613                     {
 614                       *BufferS = READ_PORT_USHORT((PUSHORT)Port);
 615                     }
 616                   if (Tf->Eflags & DIRECTION_FLAG)
 617                     {
 618                       if (BigDataPrefix)
 619                         {
 620                           BufferL++;
 621                         }
 622                       else
 623                         {
 624                           BufferS++;
 625                         }
 626                     }
 627                   else
 628                     {
 629                       if (BigDataPrefix)
 630                         {
 631                           BufferL--;
 632                         }
 633                       else
 634                         {
 635                           BufferS--;
 636                         }
 637                     }
 638                 }
 639               Tf->Eip++;
 640               return(0);
 641             }
 642           Exit = TRUE;
 643           break;
 644
 645           /* Int nn */
 646         case 0xCD:
 647           {
 648             unsigned int inum;
 649             unsigned int entry;
 650
 651             inum = ip[1];
 652             entry = ((unsigned int *)0)[inum];
 653
 654             Tf->Esp = Tf->Esp - 6;
 655             sp = sp - 3;
 656
 657             sp[0] = (USHORT)((Tf->Eip & 0xFFFF) + 2);
 658             sp[1] = (USHORT)(Tf->Cs & 0xFFFF);
 659             sp[2] = (USHORT)(Tf->Eflags & 0xFFFF);
 660             if (VTf->regs->Vif == 1)
 661               {
 662                 sp[2] = (USHORT)(sp[2] | INTERRUPT_FLAG);
 663               }
 664             DPRINT("sp[0] %x sp[1] %x sp[2] %x\n", sp[0], sp[1], sp[2]);
 665             Tf->Eip = entry & 0xFFFF;
 666             Tf->Cs = entry >> 16;
 667             Tf->Eflags = Tf->Eflags & (~TRAP_FLAG);
 668
 669             return(0);
 670           }
 671         }
 672
 673       /* FIXME: Also emulate ins and outs */
 674       /* FIXME: Handle opcode prefixes */
 675       /* FIXME: Don't allow the BIOS to write to sensitive I/O ports */
 676     }
 677
 678   DPRINT1("V86GPF unhandled (was %x)\n", ip[i]);
 679   *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
 680   return(1);
 681 }
 682
 683 ULONG
 684 KeV86Exception(ULONG ExceptionNr, PKTRAP_FRAME Tf, ULONG address)
 685 {
 686   PUCHAR Ip;
 687   PKV86M_TRAP_FRAME VTf;
 688
 689   VTf = (PKV86M_TRAP_FRAME)Tf;
 690
 691   if(KeGetCurrentProcess()->NtVdmFlag)
 692   {
 693     VTf->regs->PStatus = (PNTSTATUS) ExceptionNr;
 694     if(ExceptionNr != 14) return 1;
 695   }
 696
 697   /*
 698    * Check if we have reached the recovery instruction
 699    */
 700   Ip = (PUCHAR)((Tf->Cs & 0xFFFF) * 16 + (Tf->Eip & 0xFFFF));
 701   if (ExceptionNr != 14)
 702     {
 703       DPRINT("ExceptionNr %d Ip[0] %x Ip[1] %x Ip[2] %x Ip[3] %x Tf->Cs %x "
 704              "Tf->Eip %x\n", ExceptionNr, Ip[0], Ip[1], Ip[2], Ip[3], Tf->Cs,
 705              Tf->Eip);
 706       DPRINT("VTf %x VTf->regs %x\n", VTf, VTf->regs);
 707     }
 708   if (ExceptionNr == 6 &&
 709       memcmp(Ip, VTf->regs->RecoveryInstruction, 4) == 0 &&
 710       (Tf->Cs * 16 + Tf->Eip) == VTf->regs->RecoveryAddress)
 711     {
 712       *VTf->regs->PStatus = STATUS_SUCCESS;
 713       return(1);
 714     }
 715
 716   /*
 717    * Handle the exceptions
 718    */
 719   switch (ExceptionNr)
 720     {
 721       /* Divide error */
 722     case 0:
 723       *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
 724       return(1);
 725
 726       /* Single step */
 727     case 1:
 728       *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
 729       return(1);
 730
 731       /* NMI */
 732     case 2:
 733       *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
 734       return(1);
 735
 736       /* Breakpoint */
 737     case 3:
 738       *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
 739       return(1);
 740
 741       /* Overflow */
 742     case 4:
 743       *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
 744       return(1);
 745
 746       /* Array bounds check */
 747     case 5:
 748       *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
 749       return(1);
 750
 751       /* Invalid opcode */
 752     case 6:
 753       *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
 754       return(1);
 755
 756       /* Device not available */
 757     case 7:
 758       *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
 759       return(1);
 760
 761       /* Double fault */
 762     case 8:
 763       *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
 764       return(1);
 765
 766       /* Intel reserved */
 767     case 9:
 768       *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
 769       return(1);
 770
 771       /* Invalid TSS */
 772     case 10:
 773       *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
 774       return(1);
 775
 776       /* Segment not present */
 777     case 11:
 778       *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;;
 779       return(1);
 780
 781       /* Stack fault */
 782     case 12:
 783       *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
 784       return(1);
 785
 786       /* General protection fault */
 787     case 13:
 788       return(KeV86GPF(VTf, Tf));
 789
 790       /* Page fault */
 791     case 14:
 792       {
 793         NTSTATUS Status;
 794
 795         Status = MmPageFault(USER_CS,
 796                              &Tf->Eip,
 797                              NULL,
 798                              address,
 799                              Tf->ErrorCode);
 800         if (!NT_SUCCESS(Status))
 801           {
 802             if(KeGetCurrentProcess()->NtVdmFlag)
 803             {
 804               VTf->regs->PStatus = (PNTSTATUS) STATUS_NONCONTINUABLE_EXCEPTION;
 805               return 1;
 806             }
 807
 808             DPRINT("V86Exception, halting due to page fault\n");
 809             *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
 810             return(1);
 811           }
 812         return(0);
 813       }
 814
 815       /* Intel reserved */
 816     case 15:
 817     case 16:
 818       *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
 819       return(1);
 820
 821       /* Alignment check */
 822     case 17:
 823       *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
 824       return(1);
 825
 826     default:
 827       *VTf->regs->PStatus = STATUS_NONCONTINUABLE_EXCEPTION;
 828       return(1);
 829     }
 830 }
 831
 832
 833