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     BOOLEAN PrintUsage = TRUE;
  59     CHAR CommandLine[128];
  60     DWORD CurrentTickCount, LastTickCount = 0, Cycles = 0, LastCyclePrintout = 0;
  61     LARGE_INTEGER Frequency, LastTimerTick, Counter;
  62     LONGLONG TimerTicks;
  63
  64     /* Set the handler routine */
  65     SetConsoleCtrlHandler(ConsoleCtrlHandler, TRUE);
  66
  67     /* Parse the command line arguments */
  68     for (i = 1; i < argc; i++)
  69     {
  70         if (argv[i][0] != L'-' && argv[i][0] != L'/') continue;
  71
  72         switch (argv[i][1])
  73         {
  74             case L'f':
  75             case L'F':
  76             {
  77                 if (argv[i+1] != NULL)
  78                 {
  79                     /* The DOS command line must be ASCII */
  80                     WideCharToMultiByte(CP_ACP, 0, argv[i+1], -1, CommandLine, 128, NULL, NULL);
  81
  82                     /* This is the only mandatory parameter */
  83                     PrintUsage = FALSE;
  84                 }
  85                 break;
  86             }
  87             default:
  88             {
  89                 wprintf(L"Unknown option: %s", argv[i]);
  90             }
  91         }
  92     }
  93
  94     if (PrintUsage)
  95     {
  96         wprintf(L"ReactOS Virtual DOS Machine\n\n");
  97         wprintf(L"Usage: NTVDM /F <PROGRAM>\n");
  98         return 0;
  99     }
 100
 101     if (!EmulatorInitialize()) return 1;
 102
 103     /* Initialize the performance counter (needed for hardware timers) */
 104     if (!QueryPerformanceFrequency(&Frequency))
 105     {
 106         wprintf(L"FATAL: Performance counter not available\n");
 107         goto Cleanup;
 108     }
 109
 110     /* Initialize the system BIOS */
 111     if (!BiosInitialize())
 112     {
 113         wprintf(L"FATAL: Failed to initialize the VDM BIOS.\n");
 114         goto Cleanup;
 115     }
 116
 117     /* Initialize the VDM DOS kernel */
 118     if (!DosInitialize())
 119     {
 120         wprintf(L"FATAL: Failed to initialize the VDM DOS kernel.\n");
 121         goto Cleanup;
 122     }
 123
 124     /* Start the process from the command line */
 125     if (!DosCreateProcess(CommandLine, 0))
 126     {
 127         DisplayMessage(L"Could not start program: %S", CommandLine);
 128         return -1;
 129     }
 130
 131     /* Set the last timer tick to the current time */
 132     QueryPerformanceCounter(&LastTimerTick);
 133
 134     /* Main loop */
 135     while (VdmRunning)
 136     {
 137         /* Get the current number of ticks */
 138         CurrentTickCount = GetTickCount();
 139
 140         /* Get the current performance counter value */
 141         QueryPerformanceCounter(&Counter);
 142
 143         /* Get the number of PIT ticks that have passed */
 144         TimerTicks = ((Counter.QuadPart - LastTimerTick.QuadPart)
 145                      * PIT_BASE_FREQUENCY) / Frequency.QuadPart;
 146
 147         /* Update the PIT */
 148         for (i = 0; i < TimerTicks; i++) PitDecrementCount();
 149         LastTimerTick = Counter;
 150
 151         /* Check for console input events every millisecond */
 152         if (CurrentTickCount != LastTickCount)
 153         {
 154             CheckForInputEvents();
 155             LastTickCount = CurrentTickCount;
 156         }
 157
 158         /* Continue CPU emulation */
 159         for (i = 0; i < STEPS_PER_CYCLE; i++) EmulatorStep();
 160
 161         Cycles += STEPS_PER_CYCLE;
 162         if ((CurrentTickCount - LastCyclePrintout) >= 1000)
 163         {
 164             DPRINT1("NTVDM: %d Instructions Per Second\n", Cycles);
 165             LastCyclePrintout = CurrentTickCount;
 166             Cycles = 0;
 167         }
 168     }
 169
 170 Cleanup:
 171     EmulatorCleanup();
 172
 173     return 0;
 174 }
 175
 176 /* EOF */