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
  33 /* PUBLIC FUNCTIONS ***********************************************************/
  34
  35 VOID DisplayMessage(LPCWSTR Format, ...)
  36 {
  37     WCHAR Buffer[256];
  38     va_list Parameters;
  39
  40     va_start(Parameters, Format);
  41     _vsnwprintf(Buffer, 256, Format, Parameters);
  42     MessageBoxW(NULL, Buffer, L"NTVDM Subsystem", MB_OK);
  43     va_end(Parameters);
  44 }
  45
  46 BOOL WINAPI ConsoleCtrlHandler(DWORD ControlType)
  47 {
  48     switch (ControlType)
  49     {
  50         case CTRL_C_EVENT:
  51         case CTRL_BREAK_EVENT:
  52         {
  53             /* Perform interrupt 0x23 */
  54             EmulatorInterrupt(0x23);
  55             break;
  56         }
  57         default:
  58         {
  59             /* Stop the VDM if the user logs out or closes the console */
  60             VdmRunning = FALSE;
  61         }
  62     }
  63     return TRUE;
  64 }
  65
  66 INT wmain(INT argc, WCHAR *argv[])
  67 {
  68     INT i;
  69     CHAR CommandLine[DOS_CMDLINE_LENGTH];
  70     DWORD CurrentTickCount;
  71     DWORD Cycles = 0;
  72     DWORD LastCyclePrintout = GetTickCount();
  73     DWORD LastVerticalRefresh = GetTickCount();
  74     LARGE_INTEGER Frequency, LastTimerTick, Counter;
  75     LONGLONG TimerTicks;
  76     HANDLE InputThread = NULL;
  77
  78     /* Set the handler routine */
  79     SetConsoleCtrlHandler(ConsoleCtrlHandler, TRUE);
  80
  81 #ifndef TESTING
  82     UNREFERENCED_PARAMETER(argc);
  83     UNREFERENCED_PARAMETER(argv);
  84
  85     /* The DOS command line must be ASCII */
  86     WideCharToMultiByte(CP_ACP, 0, GetCommandLine(), -1, CommandLine, sizeof(CommandLine), NULL, NULL);
  87 #else
  88     if (argc == 2 && argv[1] != NULL)
  89     {
  90         WideCharToMultiByte(CP_ACP, 0, argv[1], -1, CommandLine, sizeof(CommandLine), NULL, NULL);
  91     }
  92     else
  93     {
  94         wprintf(L"\nReactOS Virtual DOS Machine\n\n"
  95                 L"Usage: NTVDM <executable>\n");
  96         return 0;
  97     }
  98 #endif
  99
 100     if (!EmulatorInitialize())
 101     {
 102         wprintf(L"FATAL: Failed to initialize the CPU emulator\n");
 103         goto Cleanup;
 104     }
 105
 106     /* Initialize the performance counter (needed for hardware timers) */
 107     if (!QueryPerformanceFrequency(&Frequency))
 108     {
 109         wprintf(L"FATAL: Performance counter not available\n");
 110         goto Cleanup;
 111     }
 112
 113     /* Initialize the system BIOS */
 114     if (!BiosInitialize())
 115     {
 116         wprintf(L"FATAL: Failed to initialize the VDM BIOS.\n");
 117         goto Cleanup;
 118     }
 119
 120     /* Initialize the VDM DOS kernel */
 121     if (!DosInitialize())
 122     {
 123         wprintf(L"FATAL: Failed to initialize the VDM DOS kernel.\n");
 124         goto Cleanup;
 125     }
 126
 127     /* Start the process from the command line */
 128     if (!DosCreateProcess(CommandLine, 0))
 129     {
 130         DisplayMessage(L"Could not start program: %S", CommandLine);
 131         return -1;
 132     }
 133
 134     /* Start the input thread */
 135     InputThread = CreateThread(NULL, 0, &InputThreadProc, NULL, 0, NULL);
 136
 137     /* Set the last timer tick to the current time */
 138     QueryPerformanceCounter(&LastTimerTick);
 139
 140     /* Main loop */
 141     while (VdmRunning)
 142     {
 143         /* Get the resolution of the system timer */
 144         DWORD TimerResolution = PitGetResolution();
 145
 146         /* Get the current number of ticks */
 147         CurrentTickCount = GetTickCount();
 148
 149         if (TimerResolution > 1000)
 150         {
 151             /* Get the current performance counter value */
 152             QueryPerformanceCounter(&Counter);
 153
 154             /* Get the number of PIT ticks that have passed */
 155             TimerTicks = ((Counter.QuadPart - LastTimerTick.QuadPart)
 156                          * PIT_BASE_FREQUENCY) / Frequency.QuadPart;
 157         }
 158         else
 159         {
 160             /* Use the standard tick count */
 161             Counter.QuadPart = CurrentTickCount;
 162
 163             /* Get the number of PIT ticks that have passed */
 164             TimerTicks = ((Counter.QuadPart - LastTimerTick.QuadPart)
 165                          * PIT_BASE_FREQUENCY) / 1000;
 166         }
 167
 168         /* Update the PIT */
 169         if (TimerTicks > 0)
 170         {
 171             for (i = 0; i < TimerTicks; i++) PitDecrementCount();
 172             LastTimerTick = Counter;
 173         }
 174
 175         /* Check for vertical retrace */
 176         if ((CurrentTickCount - LastVerticalRefresh) >= 16)
 177         {
 178             VgaRefreshDisplay();
 179             LastVerticalRefresh = CurrentTickCount;
 180         }
 181
 182         /* Horizontal retrace occurs as fast as possible */
 183         VgaHorizontalRetrace();
 184
 185         /* Continue CPU emulation */
 186         for (i = 0; (i < STEPS_PER_CYCLE) && VdmRunning; i++)
 187         {
 188             EmulatorStep();
 189             Cycles++;
 190         }
 191
 192         if ((CurrentTickCount - LastCyclePrintout) >= 1000)
 193         {
 194             DPRINT1("NTVDM: %lu Instructions Per Second\n", Cycles);
 195             LastCyclePrintout = CurrentTickCount;
 196             Cycles = 0;
 197         }
 198     }
 199
 200     /* Perform another screen refresh */
 201     VgaRefreshDisplay();
 202
 203 Cleanup:
 204     if (InputThread != NULL) CloseHandle(InputThread);
 205     BiosCleanup();
 206     EmulatorCleanup();
 207
 208     return 0;
 209 }
 210
 211 /* EOF */