subsystems/ntvdm/ntvdm.c

   1 /*
   2  * COPYRIGHT:       GPL - See COPYING in the top level directory
   3  * PROJECT:         ReactOS Virtual DOS Machine
   4  * FILE:            ntvdm.c
   5  * PURPOSE:         Virtual DOS Machine
   6  * PROGRAMMERS:     Aleksandar Andrejevic <theflash AT sdf DOT lonestar DOT org>
   7  */
   8
   9 #include "ntvdm.h"
  10
  11 BOOLEAN VdmRunning = TRUE;
  12 LPVOID BaseAddress = NULL;
  13 LPCWSTR ExceptionName[] =
  14 {
  15     L"Division By Zero",
  16     L"Debug",
  17     L"Unexpected Error",
  18     L"Breakpoint",
  19     L"Integer Overflow",
  20     L"Bound Range Exceeded",
  21     L"Invalid Opcode",
  22     L"FPU Not Available"
  23 };
  24
  25 VOID DisplayMessage(LPCWSTR Format, ...)
  26 {
  27     WCHAR Buffer[256];
  28     va_list Parameters;
  29
  30     va_start(Parameters, Format);
  31     _vsnwprintf(Buffer, 256, Format, Parameters);
  32     MessageBox(NULL, Buffer, L"NTVDM Subsystem", MB_OK);
  33     va_end(Parameters);
  34 }
  35
  36 BOOL WINAPI ConsoleCtrlHandler(DWORD ControlType)
  37 {
  38     switch (ControlType)
  39     {
  40         case CTRL_C_EVENT:
  41         case CTRL_BREAK_EVENT:
  42         {
  43             /* Perform interrupt 0x23 */
  44             EmulatorInterrupt(0x23);
  45         }
  46         default:
  47         {
  48             /* Stop the VDM if the user logs out or closes the console */
  49             VdmRunning = FALSE;
  50         }
  51     }
  52     return TRUE;
  53 }
  54
  55 INT wmain(INT argc, WCHAR *argv[])
  56 {
  57     INT i;
  58     CHAR CommandLine[128];
  59     DWORD CurrentTickCount, LastTickCount = 0, Cycles = 0, LastCyclePrintout = 0;
  60     LARGE_INTEGER Frequency, LastTimerTick, Counter;
  61     LONGLONG TimerTicks;
  62
  63     /* Set the handler routine */
  64     SetConsoleCtrlHandler(ConsoleCtrlHandler, TRUE);
  65
  66     /* The DOS command line must be ASCII */
  67     WideCharToMultiByte(CP_ACP, 0, GetCommandLine(), -1, CommandLine, 128, NULL, NULL);
  68
  69     if (!EmulatorInitialize()) return 1;
  70
  71     /* Initialize the performance counter (needed for hardware timers) */
  72     if (!QueryPerformanceFrequency(&Frequency))
  73     {
  74         wprintf(L"FATAL: Performance counter not available\n");
  75         goto Cleanup;
  76     }
  77
  78     /* Initialize the system BIOS */
  79     if (!BiosInitialize())
  80     {
  81         wprintf(L"FATAL: Failed to initialize the VDM BIOS.\n");
  82         goto Cleanup;
  83     }
  84
  85     /* Initialize the VDM DOS kernel */
  86     if (!DosInitialize())
  87     {
  88         wprintf(L"FATAL: Failed to initialize the VDM DOS kernel.\n");
  89         goto Cleanup;
  90     }
  91
  92     /* Start the process from the command line */
  93     if (!DosCreateProcess(CommandLine, 0))
  94     {
  95         DisplayMessage(L"Could not start program: %S", CommandLine);
  96         return -1;
  97     }
  98
  99     /* Set the last timer tick to the current time */
 100     QueryPerformanceCounter(&LastTimerTick);
 101
 102     /* Main loop */
 103     while (VdmRunning)
 104     {
 105         /* Get the current number of ticks */
 106         CurrentTickCount = GetTickCount();
 107
 108         /* Get the current performance counter value */
 109         QueryPerformanceCounter(&Counter);
 110
 111         /* Get the number of PIT ticks that have passed */
 112         TimerTicks = ((Counter.QuadPart - LastTimerTick.QuadPart)
 113                      * PIT_BASE_FREQUENCY) / Frequency.QuadPart;
 114
 115         /* Update the PIT */
 116         for (i = 0; i < TimerTicks; i++) PitDecrementCount();
 117         LastTimerTick = Counter;
 118
 119         /* Check for console input events every millisecond */
 120         if (CurrentTickCount != LastTickCount)
 121         {
 122             CheckForInputEvents();
 123             LastTickCount = CurrentTickCount;
 124         }
 125
 126         /* Continue CPU emulation */
 127         for (i = 0; i < STEPS_PER_CYCLE; i++) EmulatorStep();
 128
 129         Cycles += STEPS_PER_CYCLE;
 130         if ((CurrentTickCount - LastCyclePrintout) >= 1000)
 131         {
 132             DPRINT1("NTVDM: %d Instructions Per Second\n", Cycles);
 133             LastCyclePrintout = CurrentTickCount;
 134             Cycles = 0;
 135         }
 136     }
 137
 138 Cleanup:
 139     EmulatorCleanup();
 140
 141     return 0;
 142 }
 143
 144 /* EOF */