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 "cmos.h"
  16 #include "bios.h"
  17 #include "speaker.h"
  18 #include "vga.h"
  19 #include "dos.h"
  20 #include "timer.h"
  21 #include "pic.h"
  22 #include "ps2.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     DPRINT1("\n\nNTVDM Subsystem\n%S\n\n", Buffer);
  45     MessageBoxW(NULL, Buffer, L"NTVDM Subsystem", MB_OK);
  46     va_end(Parameters);
  47 }
  48
  49 BOOL WINAPI ConsoleCtrlHandler(DWORD ControlType)
  50 {
  51     switch (ControlType)
  52     {
  53         case CTRL_C_EVENT:
  54         case CTRL_BREAK_EVENT:
  55         {
  56             /* Perform interrupt 0x23 */
  57             EmulatorInterrupt(0x23);
  58             break;
  59         }
  60         default:
  61         {
  62             /* Stop the VDM if the user logs out or closes the console */
  63             VdmRunning = FALSE;
  64         }
  65     }
  66     return TRUE;
  67 }
  68
  69 INT wmain(INT argc, WCHAR *argv[])
  70 {
  71     INT i;
  72     CHAR CommandLine[DOS_CMDLINE_LENGTH];
  73     LARGE_INTEGER StartPerfCount;
  74     LARGE_INTEGER Frequency, LastTimerTick, LastRtcTick, Counter;
  75     LONGLONG TimerTicks;
  76     DWORD StartTickCount, CurrentTickCount;
  77     DWORD LastClockUpdate;
  78     DWORD LastVerticalRefresh;
  79     DWORD LastCyclePrintout;
  80     DWORD Cycles = 0;
  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 CMOS */
 120     if (!CmosInitialize())
 121     {
 122         wprintf(L"FATAL: Failed to initialize the VDM CMOS.\n");
 123         goto Cleanup;
 124     }
 125
 126     /* Initialize the system BIOS */
 127     if (!BiosInitialize())
 128     {
 129         wprintf(L"FATAL: Failed to initialize the VDM BIOS.\n");
 130         goto Cleanup;
 131     }
 132
 133     /* Initialize the PC Speaker */
 134     SpeakerInitialize();
 135
 136     /* Initialize the VDM DOS kernel */
 137     if (!DosInitialize())
 138     {
 139         wprintf(L"FATAL: Failed to initialize the VDM DOS kernel.\n");
 140         goto Cleanup;
 141     }
 142
 143     /* Start the process from the command line */
 144     if (!DosCreateProcess(CommandLine, 0))
 145     {
 146         DisplayMessage(L"Could not start program: %S", CommandLine);
 147         goto Cleanup;
 148     }
 149
 150     /* Find the starting performance and tick count */
 151     StartTickCount = GetTickCount();
 152     QueryPerformanceCounter(&StartPerfCount);
 153
 154     /* Set the different last counts to the starting count */
 155     LastClockUpdate = LastVerticalRefresh = LastCyclePrintout = StartTickCount;
 156
 157     /* Set the last timer ticks to the current time */
 158     LastTimerTick = LastRtcTick = StartPerfCount;
 159
 160     /* Main loop */
 161     while (VdmRunning)
 162     {
 163         DWORD PitResolution = PitGetResolution();
 164         DWORD RtcFrequency = RtcGetTicksPerSecond();
 165
 166         /* Get the current number of ticks */
 167         CurrentTickCount = GetTickCount();
 168
 169         if ((PitResolution <= 1000) && (RtcFrequency <= 1000))
 170         {
 171             /* Calculate the approximate performance counter value instead */
 172             Counter.QuadPart = StartPerfCount.QuadPart
 173                                + (CurrentTickCount - StartTickCount)
 174                                * (Frequency.QuadPart / 1000);
 175         }
 176         else
 177         {
 178             /* Get the current performance counter value */
 179             QueryPerformanceCounter(&Counter);
 180         }
 181
 182         /* Get the number of PIT ticks that have passed */
 183         TimerTicks = ((Counter.QuadPart - LastTimerTick.QuadPart)
 184                      * PIT_BASE_FREQUENCY) / Frequency.QuadPart;
 185
 186         /* Update the PIT */
 187         if (TimerTicks > 0)
 188         {
 189             PitDecrementCount(TimerTicks);
 190             LastTimerTick = Counter;
 191         }
 192
 193         /* Check for RTC update */
 194         if ((CurrentTickCount - LastClockUpdate) >= 1000)
 195         {
 196             RtcTimeUpdate();
 197             LastClockUpdate = CurrentTickCount;
 198         }
 199
 200         /* Check for RTC periodic tick */
 201         if ((Counter.QuadPart - LastRtcTick.QuadPart)
 202             >= (Frequency.QuadPart / (LONGLONG)RtcFrequency))
 203         {
 204             RtcPeriodicTick();
 205             LastRtcTick = Counter;
 206         }
 207
 208         /* Check for vertical retrace */
 209         if ((CurrentTickCount - LastVerticalRefresh) >= 16)
 210         {
 211             VgaRefreshDisplay();
 212             LastVerticalRefresh = CurrentTickCount;
 213         }
 214
 215         /* Horizontal retrace occurs as fast as possible */
 216         VgaHorizontalRetrace();
 217
 218         /* Continue CPU emulation */
 219         for (i = 0; (i < STEPS_PER_CYCLE) && VdmRunning; i++)
 220         {
 221             EmulatorStep();
 222             Cycles++;
 223         }
 224
 225         if ((CurrentTickCount - LastCyclePrintout) >= 1000)
 226         {
 227             DPRINT1("NTVDM: %lu Instructions Per Second\n", Cycles);
 228             LastCyclePrintout = CurrentTickCount;
 229             Cycles = 0;
 230         }
 231     }
 232
 233     /* Perform another screen refresh */
 234     VgaRefreshDisplay();
 235
 236 Cleanup:
 237     SpeakerCleanup();
 238     BiosCleanup();
 239     CmosCleanup();
 240     EmulatorCleanup();
 241
 242     DPRINT1("\n\n\nNTVDM - Exiting...\n\n\n");
 243
 244     return 0;
 245 }
 246
 247 /* EOF */