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 /* INCLUDES *******************************************************************/
  10
  11 #include "ntvdm.h"
  12 #include "emulator.h"
  13 #include "bios.h"
  14 #include "dos.h"
  15 #include "timer.h"
  16 #include "pic.h"
  17 #include "ps2.h"
  18
  19 /* PUBLIC VARIABLES ***********************************************************/
  20
  21 BOOLEAN VdmRunning = TRUE;
  22 LPVOID BaseAddress = NULL;
  23 LPCWSTR ExceptionName[] =
  24 {
  25     L"Division By Zero",
  26     L"Debug",
  27     L"Unexpected Error",
  28     L"Breakpoint",
  29     L"Integer Overflow",
  30     L"Bound Range Exceeded",
  31     L"Invalid Opcode",
  32     L"FPU Not Available"
  33 };
  34
  35 /* PUBLIC FUNCTIONS ***********************************************************/
  36
  37 VOID DisplayMessage(LPCWSTR Format, ...)
  38 {
  39     WCHAR Buffer[256];
  40     va_list Parameters;
  41
  42     va_start(Parameters, Format);
  43     _vsnwprintf(Buffer, 256, Format, Parameters);
  44     MessageBox(NULL, Buffer, L"NTVDM Subsystem", MB_OK);
  45     va_end(Parameters);
  46 }
  47
  48 BOOL WINAPI ConsoleCtrlHandler(DWORD ControlType)
  49 {
  50     switch (ControlType)
  51     {
  52         case CTRL_C_EVENT:
  53         case CTRL_BREAK_EVENT:
  54         {
  55             /* Perform interrupt 0x23 */
  56             EmulatorInterrupt(0x23);
  57             break;
  58         }
  59         default:
  60         {
  61             /* Stop the VDM if the user logs out or closes the console */
  62             VdmRunning = FALSE;
  63         }
  64     }
  65     return TRUE;
  66 }
  67
  68 INT wmain(INT argc, WCHAR *argv[])
  69 {
  70     INT i;
  71     CHAR CommandLine[128];
  72     DWORD CurrentTickCount;
  73     DWORD LastTickCount = GetTickCount();
  74     DWORD Cycles = 0;
  75     DWORD LastCyclePrintout = GetTickCount();
  76     DWORD LastVerticalRefresh = GetTickCount();
  77     LARGE_INTEGER Frequency, LastTimerTick, Counter;
  78     LONGLONG TimerTicks;
  79
  80     /* Set the handler routine */
  81     SetConsoleCtrlHandler(ConsoleCtrlHandler, TRUE);
  82
  83     /* The DOS command line must be ASCII */
  84     WideCharToMultiByte(CP_ACP, 0, GetCommandLine(), -1, CommandLine, 128, NULL, NULL);
  85
  86     if (!EmulatorInitialize())
  87     {
  88         wprintf(L"FATAL: Failed to initialize the CPU emulator\n");
  89         goto Cleanup;
  90     }
  91
  92     /* Initialize the performance counter (needed for hardware timers) */
  93     if (!QueryPerformanceFrequency(&Frequency))
  94     {
  95         wprintf(L"FATAL: Performance counter not available\n");
  96         goto Cleanup;
  97     }
  98
  99     /* Initialize the system BIOS */
 100     if (!BiosInitialize())
 101     {
 102         wprintf(L"FATAL: Failed to initialize the VDM BIOS.\n");
 103         goto Cleanup;
 104     }
 105
 106     /* Initialize the VDM DOS kernel */
 107     if (!DosInitialize())
 108     {
 109         wprintf(L"FATAL: Failed to initialize the VDM DOS kernel.\n");
 110         goto Cleanup;
 111     }
 112
 113     /* Start the process from the command line */
 114     if (!DosCreateProcess(CommandLine, 0))
 115     {
 116         DisplayMessage(L"Could not start program: %S", CommandLine);
 117         return -1;
 118     }
 119
 120     /* Set the last timer tick to the current time */
 121     QueryPerformanceCounter(&LastTimerTick);
 122
 123     /* Main loop */
 124     while (VdmRunning)
 125     {
 126         /* Get the current number of ticks */
 127         CurrentTickCount = GetTickCount();
 128
 129         /* Get the current performance counter value */
 130         QueryPerformanceCounter(&Counter);
 131
 132         /* Get the number of PIT ticks that have passed */
 133         TimerTicks = ((Counter.QuadPart - LastTimerTick.QuadPart)
 134                      * PIT_BASE_FREQUENCY) / Frequency.QuadPart;
 135
 136         /* Update the PIT */
 137         for (i = 0; i < TimerTicks; i++) PitDecrementCount();
 138         LastTimerTick = Counter;
 139
 140         /* Check for console input events every millisecond */
 141         if (CurrentTickCount != LastTickCount)
 142         {
 143             CheckForInputEvents();
 144             LastTickCount = CurrentTickCount;
 145         }
 146
 147         /* Check for vertical refresh */
 148         if ((CurrentTickCount - LastVerticalRefresh) >= 16)
 149         {
 150             BiosVerticalRefresh();
 151             LastVerticalRefresh = CurrentTickCount;
 152         }
 153
 154         /* Continue CPU emulation */
 155         for (i = 0; (i < STEPS_PER_CYCLE) && VdmRunning; i++)
 156         {
 157             EmulatorStep();
 158             Cycles++;
 159         }
 160
 161         if ((CurrentTickCount - LastCyclePrintout) >= 1000)
 162         {
 163             DPRINT1("NTVDM: %d Instructions Per Second\n", Cycles);
 164             LastCyclePrintout = CurrentTickCount;
 165             Cycles = 0;
 166         }
 167     }
 168
 169 Cleanup:
 170     BiosCleanup();
 171     EmulatorCleanup();
 172
 173     return 0;
 174 }
 175
 176 /* EOF */