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 #define NDEBUG
  12
  13 #include "ntvdm.h"
  14 #include "emulator.h"
  15 #include "bios.h"
  16 #include "vga.h"
  17 #include "dos.h"
  18 #include "timer.h"
  19 #include "pic.h"
  20 #include "ps2.h"
  21
  22 /*
  23  * Activate this line if you want to be able to test NTVDM with:
  24  * ntvdm.exe <program>
  25  */
  26 #define TESTING
  27
  28 /* PUBLIC VARIABLES ***********************************************************/
  29
  30 BOOLEAN VdmRunning = TRUE;
  31 LPVOID BaseAddress = NULL;
  32 LPCWSTR ExceptionName[] =
  33 {
  34     L"Division By Zero",
  35     L"Debug",
  36     L"Unexpected Error",
  37     L"Breakpoint",
  38     L"Integer Overflow",
  39     L"Bound Range Exceeded",
  40     L"Invalid Opcode",
  41     L"FPU Not Available"
  42 };
  43
  44 /* PUBLIC FUNCTIONS ***********************************************************/
  45
  46 VOID DisplayMessage(LPCWSTR Format, ...)
  47 {
  48     WCHAR Buffer[256];
  49     va_list Parameters;
  50
  51     va_start(Parameters, Format);
  52     _vsnwprintf(Buffer, 256, Format, Parameters);
  53     MessageBoxW(NULL, Buffer, L"NTVDM Subsystem", MB_OK);
  54     va_end(Parameters);
  55 }
  56
  57 BOOL WINAPI ConsoleCtrlHandler(DWORD ControlType)
  58 {
  59     switch (ControlType)
  60     {
  61         case CTRL_C_EVENT:
  62         case CTRL_BREAK_EVENT:
  63         {
  64             /* Perform interrupt 0x23 */
  65             EmulatorInterrupt(0x23);
  66             break;
  67         }
  68         default:
  69         {
  70             /* Stop the VDM if the user logs out or closes the console */
  71             VdmRunning = FALSE;
  72         }
  73     }
  74     return TRUE;
  75 }
  76
  77 INT wmain(INT argc, WCHAR *argv[])
  78 {
  79     INT i;
  80     CHAR CommandLine[128];
  81     DWORD CurrentTickCount;
  82     DWORD LastTickCount = GetTickCount();
  83     DWORD Cycles = 0;
  84     DWORD LastCyclePrintout = GetTickCount();
  85     DWORD LastVerticalRefresh = GetTickCount();
  86     LARGE_INTEGER Frequency, LastTimerTick, Counter;
  87     LONGLONG TimerTicks;
  88
  89     /* Set the handler routine */
  90     SetConsoleCtrlHandler(ConsoleCtrlHandler, TRUE);
  91
  92 #ifndef TESTING
  93     UNREFERENCED_PARAMETER(argc);
  94     UNREFERENCED_PARAMETER(argv);
  95
  96     /* The DOS command line must be ASCII */
  97     WideCharToMultiByte(CP_ACP, 0, GetCommandLine(), -1, CommandLine, 128, NULL, NULL);
  98 #else
  99     if (argc == 2 && argv[1] != NULL)
 100     {
 101         WideCharToMultiByte(CP_ACP, 0, argv[1], -1, CommandLine, 128, NULL, NULL);
 102     }
 103     else
 104     {
 105         wprintf(L"\nReactOS Virtual DOS Machine\n\n"
 106                 L"Usage: NTVDM <executable>\n");
 107         return 0;
 108     }
 109 #endif
 110
 111     if (!EmulatorInitialize())
 112     {
 113         wprintf(L"FATAL: Failed to initialize the CPU emulator\n");
 114         goto Cleanup;
 115     }
 116
 117     /* Initialize the performance counter (needed for hardware timers) */
 118     if (!QueryPerformanceFrequency(&Frequency))
 119     {
 120         wprintf(L"FATAL: Performance counter not available\n");
 121         goto Cleanup;
 122     }
 123
 124     /* Initialize the system BIOS */
 125     if (!BiosInitialize())
 126     {
 127         wprintf(L"FATAL: Failed to initialize the VDM BIOS.\n");
 128         goto Cleanup;
 129     }
 130
 131     /* Initialize the VDM DOS kernel */
 132     if (!DosInitialize())
 133     {
 134         wprintf(L"FATAL: Failed to initialize the VDM DOS kernel.\n");
 135         goto Cleanup;
 136     }
 137
 138     /* Start the process from the command line */
 139     if (!DosCreateProcess(CommandLine, 0))
 140     {
 141         DisplayMessage(L"Could not start program: %S", CommandLine);
 142         return -1;
 143     }
 144
 145     /* Set the last timer tick to the current time */
 146     QueryPerformanceCounter(&LastTimerTick);
 147
 148     /* Main loop */
 149     while (VdmRunning)
 150     {
 151         /* Get the current number of ticks */
 152         CurrentTickCount = GetTickCount();
 153
 154         /* Get the current performance counter value */
 155         QueryPerformanceCounter(&Counter);
 156
 157         /* Get the number of PIT ticks that have passed */
 158         TimerTicks = ((Counter.QuadPart - LastTimerTick.QuadPart)
 159                      * PIT_BASE_FREQUENCY) / Frequency.QuadPart;
 160
 161         /* Update the PIT */
 162         for (i = 0; i < TimerTicks; i++) PitDecrementCount();
 163         LastTimerTick = Counter;
 164
 165         /* Check for console input events every millisecond */
 166         if (CurrentTickCount != LastTickCount)
 167         {
 168             CheckForInputEvents();
 169             LastTickCount = CurrentTickCount;
 170         }
 171
 172         /* Check for vertical retrace */
 173         if ((CurrentTickCount - LastVerticalRefresh) >= 16)
 174         {
 175             VgaRefreshDisplay();
 176             LastVerticalRefresh = CurrentTickCount;
 177         }
 178
 179         /* Horizontal retrace occurs as fast as possible */
 180         VgaHorizontalRetrace();
 181
 182         /* Continue CPU emulation */
 183         for (i = 0; (i < STEPS_PER_CYCLE) && VdmRunning; i++)
 184         {
 185             EmulatorStep();
 186             Cycles++;
 187         }
 188
 189         if ((CurrentTickCount - LastCyclePrintout) >= 1000)
 190         {
 191             DPRINT1("NTVDM: %lu Instructions Per Second\n", Cycles);
 192             LastCyclePrintout = CurrentTickCount;
 193             Cycles = 0;
 194         }
 195     }
 196
 197     /* Perform another screen refresh */
 198     VgaRefreshDisplay();
 199
 200 Cleanup:
 201     BiosCleanup();
 202     EmulatorCleanup();
 203
 204     return 0;
 205 }
 206
 207 /* EOF */