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 "speaker.h"
  17 #include "vga.h"
  18 #include "dos.h"
  19 #include "timer.h"
  20 #include "pic.h"
  21 #include "ps2.h"
  22 #include "cmos.h"
  23
  24 /*
  25  * Activate this line if you want to be able to test NTVDM with:
  26  * ntvdm.exe <program>
  27  */
  28 #define TESTING
  29
  30 /* PUBLIC VARIABLES ***********************************************************/
  31
  32 BOOLEAN VdmRunning = TRUE;
  33 LPVOID BaseAddress = NULL;
  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     MessageBoxW(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[DOS_CMDLINE_LENGTH];
  72     DWORD CurrentTickCount;
  73     DWORD Cycles = 0;
  74     DWORD LastCyclePrintout = GetTickCount();
  75     DWORD LastVerticalRefresh = GetTickCount();
  76     DWORD LastClockUpdate = GetTickCount();
  77     LARGE_INTEGER Frequency, LastTimerTick, LastRtcTick, Counter;
  78     LONGLONG TimerTicks;
  79     LARGE_INTEGER StartPerfCount;
  80     DWORD StartTickCount;
  81
  82     /* Set the handler routine */
  83     SetConsoleCtrlHandler(ConsoleCtrlHandler, TRUE);
  84
  85 #ifndef TESTING
  86     UNREFERENCED_PARAMETER(argc);
  87     UNREFERENCED_PARAMETER(argv);
  88
  89     /* The DOS command line must be ASCII */
  90     WideCharToMultiByte(CP_ACP, 0, GetCommandLine(), -1, CommandLine, sizeof(CommandLine), NULL, NULL);
  91 #else
  92     if (argc == 2 && argv[1] != NULL)
  93     {
  94         WideCharToMultiByte(CP_ACP, 0, argv[1], -1, CommandLine, sizeof(CommandLine), NULL, NULL);
  95     }
  96     else
  97     {
  98         wprintf(L"\nReactOS Virtual DOS Machine\n\n"
  99                 L"Usage: NTVDM <executable>\n");
 100         return 0;
 101     }
 102 #endif
 103
 104     DPRINT1("\n\n\nNTVDM - Starting '%s'...\n\n\n", CommandLine);
 105
 106     if (!EmulatorInitialize())
 107     {
 108         wprintf(L"FATAL: Failed to initialize the CPU emulator\n");
 109         goto Cleanup;
 110     }
 111
 112     /* Initialize the performance counter (needed for hardware timers) */
 113     if (!QueryPerformanceFrequency(&Frequency))
 114     {
 115         wprintf(L"FATAL: Performance counter not available\n");
 116         goto Cleanup;
 117     }
 118
 119     /* Initialize the system BIOS */
 120     if (!BiosInitialize())
 121     {
 122         wprintf(L"FATAL: Failed to initialize the VDM BIOS.\n");
 123         goto Cleanup;
 124     }
 125
 126     /* Initialize the PC Speaker */
 127     SpeakerInitialize();
 128
 129     /* Initialize the VDM DOS kernel */
 130     if (!DosInitialize())
 131     {
 132         wprintf(L"FATAL: Failed to initialize the VDM DOS kernel.\n");
 133         goto Cleanup;
 134     }
 135
 136     /* Start the process from the command line */
 137     if (!DosCreateProcess(CommandLine, 0))
 138     {
 139         DisplayMessage(L"Could not start program: %S", CommandLine);
 140         goto Cleanup;
 141     }
 142
 143     /* Find the starting performance and tick count */
 144     StartTickCount = GetTickCount();
 145     QueryPerformanceCounter(&StartPerfCount);
 146
 147     /* Set the last timer ticks to the current time */
 148     LastTimerTick = LastRtcTick = StartPerfCount;
 149
 150     /* Main loop */
 151     while (VdmRunning)
 152     {
 153         DWORD PitResolution = PitGetResolution();
 154         DWORD RtcFrequency = RtcGetTicksPerSecond();
 155
 156         /* Get the current number of ticks */
 157         CurrentTickCount = GetTickCount();
 158
 159         if ((PitResolution <= 1000) && (RtcFrequency <= 1000))
 160         {
 161             /* Calculate the approximate performance counter value instead */
 162             Counter.QuadPart = StartPerfCount.QuadPart
 163                                + (CurrentTickCount - StartTickCount)
 164                                * (Frequency.QuadPart / 1000);
 165         }
 166         else
 167         {
 168             /* Get the current performance counter value */
 169             QueryPerformanceCounter(&Counter);
 170         }
 171
 172         /* Get the number of PIT ticks that have passed */
 173         TimerTicks = ((Counter.QuadPart - LastTimerTick.QuadPart)
 174                      * PIT_BASE_FREQUENCY) / Frequency.QuadPart;
 175
 176         /* Update the PIT */
 177         if (TimerTicks > 0)
 178         {
 179             PitDecrementCount(TimerTicks);
 180             LastTimerTick = Counter;
 181         }
 182
 183         /* Check for RTC update */
 184         if ((CurrentTickCount - LastClockUpdate) >= 1000)
 185         {
 186             RtcTimeUpdate();
 187             LastClockUpdate = CurrentTickCount;
 188         }
 189
 190         /* Check for RTC periodic tick */
 191         if ((Counter.QuadPart - LastRtcTick.QuadPart)
 192             >= (Frequency.QuadPart / (LONGLONG)RtcFrequency))
 193         {
 194             RtcPeriodicTick();
 195             LastRtcTick = Counter;
 196         }
 197
 198         /* Check for vertical retrace */
 199         if ((CurrentTickCount - LastVerticalRefresh) >= 16)
 200         {
 201             VgaRefreshDisplay();
 202             LastVerticalRefresh = CurrentTickCount;
 203         }
 204
 205         /* Horizontal retrace occurs as fast as possible */
 206         VgaHorizontalRetrace();
 207
 208         /* Continue CPU emulation */
 209         for (i = 0; (i < STEPS_PER_CYCLE) && VdmRunning; i++)
 210         {
 211             EmulatorStep();
 212             Cycles++;
 213         }
 214
 215         if ((CurrentTickCount - LastCyclePrintout) >= 1000)
 216         {
 217             DPRINT1("NTVDM: %lu Instructions Per Second\n", Cycles);
 218             LastCyclePrintout = CurrentTickCount;
 219             Cycles = 0;
 220         }
 221     }
 222
 223     /* Perform another screen refresh */
 224     VgaRefreshDisplay();
 225
 226 Cleanup:
 227     SpeakerCleanup();
 228     BiosCleanup();
 229     EmulatorCleanup();
 230
 231     DPRINT1("\n\n\nNTVDM - Exiting...\n\n\n");
 232
 233     return 0;
 234 }
 235
 236 /* EOF */