dlls/winedos/dosvm.c

   1 /*
   2  * DOS Virtual Machine
   3  *
   4  * Copyright 1998 Ove Kåven
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library 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 GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  *
  20  * Note: This code hasn't been completely cleaned up yet.
  21  */
  22
  23 #include "config.h"
  24 #include "wine/port.h"
  25
  26 #include <stdarg.h>
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30 #include <errno.h>
  31 #include <fcntl.h>
  32 #include <signal.h>
  33 #ifdef HAVE_UNISTD_H
  34 # include <unistd.h>
  35 #endif
  36 #ifdef HAVE_SYS_TIME_H
  37 # include <sys/time.h>
  38 #endif
  39 #include <sys/types.h>
  40
  41 #include "wine/winbase16.h"
  42 #include "wine/exception.h"
  43 #include "windef.h"
  44 #include "winbase.h"
  45 #include "wingdi.h"
  46 #include "winuser.h"
  47 #include "wownt32.h"
  48 #include "winnt.h"
  49 #include "wincon.h"
  50
  51 #include "thread.h"
  52 #include "dosexe.h"
  53 #include "dosvm.h"
  54 #include "wine/debug.h"
  55 #include "excpt.h"
  56
  57 WINE_DEFAULT_DEBUG_CHANNEL(int);
  58 WINE_DECLARE_DEBUG_CHANNEL(module);
  59 #ifdef MZ_SUPPORTED
  60 WINE_DECLARE_DEBUG_CHANNEL(relay);
  61 #endif
  62
  63 WORD DOSVM_psp = 0;
  64 WORD DOSVM_retval = 0;
  65
  66 #ifdef HAVE_SYS_MMAN_H
  67 # include <sys/mman.h>
  68 #endif
  69
  70
  71 typedef struct _DOSEVENT {
  72   int irq,priority;
  73   DOSRELAY relay;
  74   void *data;
  75   struct _DOSEVENT *next;
  76 } DOSEVENT, *LPDOSEVENT;
  77
  78 static struct _DOSEVENT *pending_event, *current_event;
  79 static HANDLE event_notifier;
  80
  81 static CRITICAL_SECTION qcrit;
  82 static CRITICAL_SECTION_DEBUG critsect_debug =
  83 {
  84     0, 0, &qcrit,
  85     { &critsect_debug.ProcessLocksList, &critsect_debug.ProcessLocksList },
  86       0, 0, { (DWORD_PTR)(__FILE__ ": qcrit") }
  87 };
  88 static CRITICAL_SECTION qcrit = { &critsect_debug, -1, 0, 0, 0, 0 };
  89
  90
  91 /***********************************************************************
  92  *              DOSVM_HasPendingEvents
  93  *
  94  * Return true if there are pending events that are not
  95  * blocked by currently active event.
  96  */
  97 static BOOL DOSVM_HasPendingEvents( void )
  98 {
  99     if (!pending_event)
 100         return FALSE;
 101
 102     if (!current_event)
 103         return TRUE;
 104
 105     if (pending_event->priority < current_event->priority)
 106         return TRUE;
 107
 108     return FALSE;
 109 }
 110
 111
 112 /***********************************************************************
 113  *              DOSVM_SendOneEvent
 114  *
 115  * Process single pending event.
 116  *
 117  * This function should be called with queue critical section locked.
 118  * The function temporarily releases the critical section if it is
 119  * possible that internal interrupt handler or user procedure will
 120  * be called. This is because we may otherwise get a deadlock if
 121  * another thread is waiting for the same critical section.
 122  */
 123 static void DOSVM_SendOneEvent( CONTEXT86 *context )
 124 {
 125     LPDOSEVENT event = pending_event;
 126
 127     /* Remove from pending events list. */
 128     pending_event = event->next;
 129
 130     /* Process active event. */
 131     if (event->irq >= 0)
 132     {
 133         BYTE intnum = (event->irq < 8) ?
 134             (event->irq + 8) : (event->irq - 8 + 0x70);
 135
 136         /* Event is an IRQ, move it to current events list. */
 137         event->next = current_event;
 138         current_event = event;
 139
 140         TRACE( "Dispatching IRQ %d.\n", event->irq );
 141
 142         if (ISV86(context))
 143         {
 144             /*
 145              * Note that if DOSVM_HardwareInterruptRM calls an internal
 146              * interrupt directly, current_event might be cleared
 147              * (and event freed) in this call.
 148              */
 149             LeaveCriticalSection(&qcrit);
 150             DOSVM_HardwareInterruptRM( context, intnum );
 151             EnterCriticalSection(&qcrit);
 152         }
 153         else
 154         {
 155             /*
 156              * This routine only modifies current context so it is
 157              * not necessary to release critical section.
 158              */
 159             DOSVM_HardwareInterruptPM( context, intnum );
 160         }
 161     }
 162     else
 163     {
 164         /* Callback event. */
 165         TRACE( "Dispatching callback event.\n" );
 166
 167         if (ISV86(context))
 168         {
 169             /*
 170              * Call relay immediately in real mode.
 171              */
 172             LeaveCriticalSection(&qcrit);
 173             (*event->relay)( context, event->data );
 174             EnterCriticalSection(&qcrit);
 175         }
 176         else
 177         {
 178             /*
 179              * Force return to relay code. We do not want to
 180              * call relay directly because we may be inside a signal handler.
 181              */
 182             DOSVM_BuildCallFrame( context, event->relay, event->data );
 183         }
 184
 185         free(event);
 186     }
 187 }
 188
 189
 190 /***********************************************************************
 191  *              DOSVM_SendQueuedEvents
 192  *
 193  * As long as context instruction pointer stays unmodified,
 194  * process all pending events that are not blocked by currently
 195  * active event.
 196  *
 197  * This routine assumes that caller has already cleared TEB.vm86_pending
 198  * and checked that interrupts are enabled.
 199  */
 200 void DOSVM_SendQueuedEvents( CONTEXT86 *context )
 201 {
 202     DWORD old_cs = context->SegCs;
 203     DWORD old_ip = context->Eip;
 204
 205     EnterCriticalSection(&qcrit);
 206
 207     TRACE( "Called in %s mode %s events pending (time=%d)\n",
 208            ISV86(context) ? "real" : "protected",
 209            DOSVM_HasPendingEvents() ? "with" : "without",
 210            GetTickCount() );
 211     TRACE( "cs:ip=%04x:%08x, ss:sp=%04x:%08x\n",
 212            context->SegCs, context->Eip, context->SegSs, context->Esp);
 213
 214     while (context->SegCs == old_cs &&
 215            context->Eip == old_ip &&
 216            DOSVM_HasPendingEvents())
 217     {
 218         DOSVM_SendOneEvent(context);
 219
 220         /*
 221          * Event handling may have turned pending events flag on.
 222          * We disable it here because this prevents some
 223          * unnecessary calls to this function.
 224          */
 225         NtCurrentTeb()->vm86_pending = 0;
 226     }
 227
 228 #ifdef MZ_SUPPORTED
 229
 230     if (DOSVM_HasPendingEvents())
 231     {
 232         /*
 233          * Interrupts disabled, but there are still
 234          * pending events, make sure that pending flag is turned on.
 235          */
 236         TRACE( "Another event is pending, setting VIP flag.\n" );
 237         NtCurrentTeb()->vm86_pending |= VIP_MASK;
 238     }
 239
 240 #else
 241
 242     FIXME("No DOS .exe file support on this platform (yet)\n");
 243
 244 #endif /* MZ_SUPPORTED */
 245
 246     LeaveCriticalSection(&qcrit);
 247 }
 248
 249
 250 #ifdef MZ_SUPPORTED
 251 /***********************************************************************
 252  *              QueueEvent (WINEDOS.@)
 253  */
 254 void WINAPI DOSVM_QueueEvent( INT irq, INT priority, DOSRELAY relay, LPVOID data)
 255 {
 256   LPDOSEVENT event, cur, prev;
 257   BOOL       old_pending;
 258
 259   if (MZ_Current()) {
 260     event = malloc(sizeof(DOSEVENT));
 261     if (!event) {
 262       ERR("out of memory allocating event entry\n");
 263       return;
 264     }
 265     event->irq = irq; event->priority = priority;
 266     event->relay = relay; event->data = data;
 267
 268     EnterCriticalSection(&qcrit);
 269     old_pending = DOSVM_HasPendingEvents();
 270
 271     /* insert event into linked list, in order *after*
 272      * all earlier events of higher or equal priority */
 273     cur = pending_event; prev = NULL;
 274     while (cur && cur->priority<=priority) {
 275       prev = cur;
 276       cur = cur->next;
 277     }
 278     event->next = cur;
 279     if (prev) prev->next = event;
 280     else pending_event = event;
 281
 282     if (!old_pending && DOSVM_HasPendingEvents()) {
 283       TRACE("new event queued, signalling (time=%d)\n", GetTickCount());
 284
 285       /* Alert VM86 thread about the new event. */
 286       kill(dosvm_pid,SIGUSR2);
 287
 288       /* Wake up DOSVM_Wait so that it can serve pending events. */
 289       SetEvent(event_notifier);
 290     } else {
 291       TRACE("new event queued (time=%d)\n", GetTickCount());
 292     }
 293
 294     LeaveCriticalSection(&qcrit);
 295   } else {
 296     /* DOS subsystem not running */
 297     /* (this probably means that we're running a win16 app
 298      *  which uses DPMI to thunk down to DOS services) */
 299     if (irq<0) {
 300       /* callback event, perform it with dummy context */
 301       CONTEXT86 context;
 302       memset(&context,0,sizeof(context));
 303       (*relay)(&context,data);
 304     } else {
 305       ERR("IRQ without DOS task: should not happen\n");
 306     }
 307   }
 308 }
 309
 310 static void DOSVM_ProcessConsole(void)
 311 {
 312   INPUT_RECORD msg;
 313   DWORD res;
 314   BYTE scan, ascii;
 315
 316   if (ReadConsoleInputA(GetStdHandle(STD_INPUT_HANDLE),&msg,1,&res)) {
 317     switch (msg.EventType) {
 318     case KEY_EVENT:
 319       scan = msg.Event.KeyEvent.wVirtualScanCode;
 320       ascii = msg.Event.KeyEvent.uChar.AsciiChar;
 321       TRACE("scan %02x, ascii %02x\n", scan, ascii);
 322
 323       /* set the "break" (release) flag if key released */
 324       if (!msg.Event.KeyEvent.bKeyDown) scan |= 0x80;
 325
 326       /* check whether extended bit is set,
 327        * and if so, queue the extension prefix */
 328       if (msg.Event.KeyEvent.dwControlKeyState & ENHANCED_KEY) {
 329         DOSVM_Int09SendScan(0xE0,0);
 330       }
 331       DOSVM_Int09SendScan(scan, ascii);
 332       break;
 333     case MOUSE_EVENT:
 334       DOSVM_Int33Console(&msg.Event.MouseEvent);
 335       break;
 336     case WINDOW_BUFFER_SIZE_EVENT:
 337       FIXME("unhandled WINDOW_BUFFER_SIZE_EVENT.\n");
 338       break;
 339     case MENU_EVENT:
 340       FIXME("unhandled MENU_EVENT.\n");
 341       break;
 342     case FOCUS_EVENT:
 343       FIXME("unhandled FOCUS_EVENT.\n");
 344       break;
 345     default:
 346       FIXME("unknown console event: %d\n", msg.EventType);
 347     }
 348   }
 349 }
 350
 351 static void DOSVM_ProcessMessage(MSG *msg)
 352 {
 353   BYTE scan = 0;
 354
 355   TRACE("got message %04x, wparam=%08lx, lparam=%08lx\n",msg->message,msg->wParam,msg->lParam);
 356   if ((msg->message>=WM_MOUSEFIRST)&&
 357       (msg->message<=WM_MOUSELAST)) {
 358     DOSVM_Int33Message(msg->message,msg->wParam,msg->lParam);
 359   } else {
 360     switch (msg->message) {
 361     case WM_KEYUP:
 362       scan = 0x80;
 363     case WM_KEYDOWN:
 364       scan |= (msg->lParam >> 16) & 0x7f;
 365
 366       /* check whether extended bit is set,
 367        * and if so, queue the extension prefix */
 368       if (msg->lParam & 0x1000000) {
 369         /* FIXME: some keys (function keys) have
 370          * extended bit set even when they shouldn't,
 371          * should check for them */
 372         DOSVM_Int09SendScan(0xE0,0);
 373       }
 374       DOSVM_Int09SendScan(scan,0);
 375       break;
 376     }
 377   }
 378 }
 379
 380
 381 /***********************************************************************
 382  *              DOSVM_Wait
 383  *
 384  * Wait for asynchronous events. This routine temporarily enables
 385  * interrupts and waits until some asynchronous event has been
 386  * processed.
 387  */
 388 void WINAPI DOSVM_Wait( CONTEXT86 *waitctx )
 389 {
 390     if (DOSVM_HasPendingEvents())
 391     {
 392         CONTEXT86 context = *waitctx;
 393
 394         /*
 395          * If DOSVM_Wait is called from protected mode we emulate
 396          * interrupt reflection and convert context into real mode context.
 397          * This is actually the correct thing to do as long as DOSVM_Wait
 398          * is only called from those interrupt functions that DPMI reflects
 399          * to real mode.
 400          *
 401          * FIXME: Need to think about where to place real mode stack.
 402          * FIXME: If DOSVM_Wait calls are nested stack gets corrupted.
 403          *        Can this really happen?
 404          */
 405         if (!ISV86(&context))
 406         {
 407             context.EFlags |= V86_FLAG;
 408             context.SegSs = 0xffff;
 409             context.Esp = 0;
 410         }
 411
 412         context.EFlags |= VIF_MASK;
 413         context.SegCs = 0;
 414         context.Eip = 0;
 415
 416         DOSVM_SendQueuedEvents(&context);
 417
 418         if(context.SegCs || context.Eip)
 419             DPMI_CallRMProc( &context, NULL, 0, TRUE );
 420     }
 421     else
 422     {
 423         HANDLE objs[2];
 424         int    objc = DOSVM_IsWin16() ? 2 : 1;
 425         DWORD  waitret;
 426
 427         objs[0] = event_notifier;
 428         objs[1] = GetStdHandle(STD_INPUT_HANDLE);
 429
 430         waitret = MsgWaitForMultipleObjects( objc, objs, FALSE,
 431                                              INFINITE, QS_ALLINPUT );
 432
 433         if (waitret == WAIT_OBJECT_0)
 434         {
 435             /*
 436              * New pending event has been queued, we ignore it
 437              * here because it will be processed on next call to
 438              * DOSVM_Wait.
 439              */
 440         }
 441         else if (objc == 2 && waitret == WAIT_OBJECT_0 + 1)
 442         {
 443             DOSVM_ProcessConsole();
 444         }
 445         else if (waitret == WAIT_OBJECT_0 + objc)
 446         {
 447             MSG msg;
 448             while (PeekMessageA(&msg,0,0,0,PM_REMOVE|PM_NOYIELD))
 449             {
 450                 /* got a message */
 451                 DOSVM_ProcessMessage(&msg);
 452                 /* we don't need a TranslateMessage here */
 453                 DispatchMessageA(&msg);
 454             }
 455         }
 456         else
 457         {
 458             ERR_(module)( "dosvm wait error=%d\n", GetLastError() );
 459         }
 460     }
 461 }
 462
 463
 464 DWORD WINAPI DOSVM_Loop( HANDLE hThread )
 465 {
 466   HANDLE objs[2];
 467   MSG msg;
 468   DWORD waitret;
 469
 470   objs[0] = GetStdHandle(STD_INPUT_HANDLE);
 471   objs[1] = hThread;
 472
 473   for(;;) {
 474       TRACE_(int)("waiting for action\n");
 475       waitret = MsgWaitForMultipleObjects(2, objs, FALSE, INFINITE, QS_ALLINPUT);
 476       if (waitret == WAIT_OBJECT_0) {
 477           DOSVM_ProcessConsole();
 478       }
 479       else if (waitret == WAIT_OBJECT_0 + 1) {
 480          DWORD rv;
 481          if(!GetExitCodeThread(hThread, &rv)) {
 482              ERR("Failed to get thread exit code!\n");
 483              rv = 0;
 484          }
 485          return rv;
 486       }
 487       else if (waitret == WAIT_OBJECT_0 + 2) {
 488           while (PeekMessageA(&msg,0,0,0,PM_REMOVE)) {
 489               if (msg.hwnd) {
 490                   /* it's a window message */
 491                   DOSVM_ProcessMessage(&msg);
 492                   DispatchMessageA(&msg);
 493               } else {
 494                   /* it's a thread message */
 495                   switch (msg.message) {
 496                   case WM_QUIT:
 497                       /* stop this madness!! */
 498                       return 0;
 499                   case WM_USER:
 500                       /* run passed procedure in this thread */
 501                       /* (sort of like APC, but we signal the completion) */
 502                       {
 503                           DOS_SPC *spc = (DOS_SPC *)msg.lParam;
 504                           TRACE_(int)("calling %p with arg %08lx\n", spc->proc, spc->arg);
 505                           (spc->proc)(spc->arg);
 506                           TRACE_(int)("done, signalling event %lx\n", msg.wParam);
 507                           SetEvent( (HANDLE)msg.wParam );
 508                       }
 509                       break;
 510                   default:
 511                       DispatchMessageA(&msg);
 512                   }
 513               }
 514           }
 515       }
 516       else
 517       {
 518           ERR_(int)("MsgWaitForMultipleObjects returned unexpected value.\n");
 519           return 0;
 520       }
 521   }
 522 }
 523
 524 static LONG WINAPI exception_handler(EXCEPTION_POINTERS *eptr)
 525 {
 526   EXCEPTION_RECORD *rec = eptr->ExceptionRecord;
 527   CONTEXT *context = eptr->ContextRecord;
 528   int arg = rec->ExceptionInformation[0];
 529   BOOL ret;
 530
 531   switch(rec->ExceptionCode) {
 532   case EXCEPTION_VM86_INTx:
 533     TRACE_(relay)("Call DOS int 0x%02x ret=%04x:%04x\n"
 534                   " eax=%08x ebx=%08x ecx=%08x edx=%08x esi=%08x edi=%08x\n"
 535                   " ebp=%08x esp=%08x ds=%04x es=%04x fs=%04x gs=%04x flags=%08x\n",
 536                   arg, context->SegCs, context->Eip,
 537                   context->Eax, context->Ebx, context->Ecx, context->Edx, context->Esi, context->Edi,
 538                   context->Ebp, context->Esp, context->SegDs, context->SegEs, context->SegFs, context->SegGs,
 539                   context->EFlags );
 540     ret = DOSVM_EmulateInterruptRM( context, arg );
 541     TRACE_(relay)("Ret  DOS int 0x%02x ret=%04x:%04x\n"
 542                   " eax=%08x ebx=%08x ecx=%08x edx=%08x esi=%08x edi=%08x\n"
 543                   " ebp=%08x esp=%08x ds=%04x es=%04x fs=%04x gs=%04x flags=%08x\n",
 544                   arg, context->SegCs, context->Eip,
 545                   context->Eax, context->Ebx, context->Ecx, context->Edx, context->Esi, context->Edi,
 546                   context->Ebp, context->Esp, context->SegDs, context->SegEs,
 547                   context->SegFs, context->SegGs, context->EFlags );
 548     return ret ? EXCEPTION_CONTINUE_EXECUTION : EXCEPTION_EXECUTE_HANDLER;
 549
 550   case EXCEPTION_VM86_STI:
 551   /* case EXCEPTION_VM86_PICRETURN: */
 552     if (!ISV86(context))
 553       ERR( "Protected mode STI caught by real mode handler!\n" );
 554     DOSVM_SendQueuedEvents(context);
 555     return EXCEPTION_CONTINUE_EXECUTION;
 556
 557   case EXCEPTION_SINGLE_STEP:
 558     ret = DOSVM_EmulateInterruptRM( context, 1 );
 559     return ret ? EXCEPTION_CONTINUE_EXECUTION : EXCEPTION_EXECUTE_HANDLER;
 560
 561   case EXCEPTION_BREAKPOINT:
 562     ret = DOSVM_EmulateInterruptRM( context, 3 );
 563     return ret ? EXCEPTION_CONTINUE_EXECUTION : EXCEPTION_EXECUTE_HANDLER;
 564
 565   }
 566   return EXCEPTION_CONTINUE_SEARCH;
 567 }
 568
 569 int WINAPI DOSVM_Enter( CONTEXT86 *context )
 570 {
 571   if (!ISV86(context))
 572       ERR( "Called with protected mode context!\n" );
 573
 574   __TRY
 575   {
 576       WOWCallback16Ex( 0, WCB16_REGS, 0, NULL, (DWORD *)context );
 577       TRACE_(module)( "vm86 returned: %s\n", strerror(errno) );
 578   }
 579   __EXCEPT(exception_handler)
 580   {
 581     TRACE_(module)( "leaving vm86 mode\n" );
 582   }
 583   __ENDTRY
 584
 585   return 0;
 586 }
 587
 588 /***********************************************************************
 589  *              OutPIC (WINEDOS.@)
 590  */
 591 void WINAPI DOSVM_PIC_ioport_out( WORD port, BYTE val)
 592 {
 593     if (port != 0x20)
 594     {
 595         FIXME( "Unsupported PIC port %04x\n", port );
 596     }
 597     else if (val == 0x20 || (val >= 0x60 && val <= 0x67))
 598     {
 599         EnterCriticalSection(&qcrit);
 600
 601         if (!current_event)
 602         {
 603             WARN( "%s without active IRQ\n",
 604                   val == 0x20 ? "EOI" : "Specific EOI" );
 605         }
 606         else if (val != 0x20 && val - 0x60 != current_event->irq)
 607         {
 608             WARN( "Specific EOI but current IRQ %d is not %d\n",
 609                   current_event->irq, val - 0x60 );
 610         }
 611         else
 612         {
 613             LPDOSEVENT event = current_event;
 614
 615             TRACE( "Received %s for current IRQ %d, clearing event\n",
 616                    val == 0x20 ? "EOI" : "Specific EOI", event->irq );
 617
 618             current_event = event->next;
 619             if (event->relay)
 620                 (*event->relay)(NULL,event->data);
 621             free(event);
 622
 623             if (DOSVM_HasPendingEvents())
 624             {
 625                 TRACE( "Another event pending, setting pending flag\n" );
 626                 NtCurrentTeb()->vm86_pending |= VIP_MASK;
 627             }
 628         }
 629
 630         LeaveCriticalSection(&qcrit);
 631     }
 632     else
 633     {
 634         FIXME( "Unrecognized PIC command %02x\n", val );
 635     }
 636 }
 637
 638 #else /* !MZ_SUPPORTED */
 639
 640 /***********************************************************************
 641  *              Enter (WINEDOS.@)
 642  */
 643 INT WINAPI DOSVM_Enter( CONTEXT86 *context )
 644 {
 645  ERR_(module)("DOS realmode not supported on this architecture!\n");
 646  return -1;
 647 }
 648
 649 /***********************************************************************
 650  *              Wait (WINEDOS.@)
 651  */
 652 void WINAPI DOSVM_Wait( CONTEXT86 *waitctx ) { }
 653
 654 /***********************************************************************
 655  *              OutPIC (WINEDOS.@)
 656  */
 657 void WINAPI DOSVM_PIC_ioport_out( WORD port, BYTE val) {}
 658
 659 /***********************************************************************
 660  *              QueueEvent (WINEDOS.@)
 661  */
 662 void WINAPI DOSVM_QueueEvent( INT irq, INT priority, DOSRELAY relay, LPVOID data)
 663 {
 664   if (irq<0) {
 665     /* callback event, perform it with dummy context */
 666     CONTEXT86 context;
 667     memset(&context,0,sizeof(context));
 668     (*relay)(&context,data);
 669   } else {
 670     ERR("IRQ without DOS task: should not happen\n");
 671   }
 672 }
 673
 674 #endif /* MZ_SUPPORTED */
 675
 676
 677 /**********************************************************************
 678  *         DOSVM_AcknowledgeIRQ
 679  *
 680  * This routine should be called by all internal IRQ handlers.
 681  */
 682 void WINAPI DOSVM_AcknowledgeIRQ( CONTEXT86 *context )
 683 {
 684     /*
 685      * Send EOI to PIC.
 686      */
 687     DOSVM_PIC_ioport_out( 0x20, 0x20 );
 688
 689     /*
 690      * Protected mode IRQ handlers are supposed
 691      * to turn VIF flag on before they return.
 692      */
 693     if (!ISV86(context))
 694         NtCurrentTeb()->dpmi_vif = 1;
 695 }
 696
 697
 698 /**********************************************************************
 699  *          DllMain  (DOSVM.0)
 700  */
 701 BOOL WINAPI DllMain( HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved )
 702 {
 703     TRACE_(module)("(%p,%d,%p)\n", hinstDLL, fdwReason, lpvReserved);
 704
 705     if (fdwReason == DLL_PROCESS_ATTACH)
 706     {
 707         DisableThreadLibraryCalls(hinstDLL);
 708         if (!DOSMEM_InitDosMemory()) return FALSE;
 709         DOSVM_InitSegments();
 710
 711         event_notifier = CreateEventW(NULL, FALSE, FALSE, NULL);
 712         if(!event_notifier)
 713           ERR("Failed to create event object!\n");
 714     }
 715     return TRUE;
 716 }