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