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     DWORD CurrentTickCount;
  74     DWORD Cycles = 0;
  75     DWORD LastCyclePrintout = GetTickCount();
  76     DWORD LastVerticalRefresh = GetTickCount();
  77     DWORD LastClockUpdate = GetTickCount();
  78     LARGE_INTEGER Frequency, LastTimerTick, LastRtcTick, Counter;
  79     LONGLONG TimerTicks;
  80     LARGE_INTEGER StartPerfCount;
  81     DWORD StartTickCount;
  82
  83     /* Set the handler routine */
  84     SetConsoleCtrlHandler(ConsoleCtrlHandler, TRUE);
  85
  86 #ifndef TESTING
  87     UNREFERENCED_PARAMETER(argc);
  88     UNREFERENCED_PARAMETER(argv);
  89
  90     /* The DOS command line must be ASCII */
  91     WideCharToMultiByte(CP_ACP, 0, GetCommandLine(), -1, CommandLine, sizeof(CommandLine), NULL, NULL);
  92 #else
  93     if (argc == 2 && argv[1] != NULL)
  94     {
  95         WideCharToMultiByte(CP_ACP, 0, argv[1], -1, CommandLine, sizeof(CommandLine), NULL, NULL);
  96     }
  97     else
  98     {
  99         wprintf(L"\nReactOS Virtual DOS Machine\n\n"
 100                 L"Usage: NTVDM <executable>\n");
 101         return 0;
 102     }
 103 #endif
 104
 105     DPRINT1("\n\n\nNTVDM - Starting '%s'...\n\n\n", CommandLine);
 106
 107     if (!EmulatorInitialize())
 108     {
 109         wprintf(L"FATAL: Failed to initialize the CPU emulator\n");
 110         goto Cleanup;
 111     }
 112
 113     /* Initialize the performance counter (needed for hardware timers) */
 114     if (!QueryPerformanceFrequency(&Frequency))
 115     {
 116         wprintf(L"FATAL: Performance counter not available\n");
 117         goto Cleanup;
 118     }
 119
 120     /* Initialize the CMOS */
 121     if (!CmosInitialize())
 122     {
 123         wprintf(L"FATAL: Failed to initialize the VDM CMOS.\n");
 124         goto Cleanup;
 125     }
 126
 127     /* Initialize the system BIOS */
 128     if (!BiosInitialize())
 129     {
 130         wprintf(L"FATAL: Failed to initialize the VDM BIOS.\n");
 131         goto Cleanup;
 132     }
 133
 134     /* Initialize the PC Speaker */
 135     SpeakerInitialize();
 136
 137     /* Initialize the VDM DOS kernel */
 138     if (!DosInitialize())
 139     {
 140         wprintf(L"FATAL: Failed to initialize the VDM DOS kernel.\n");
 141         goto Cleanup;
 142     }
 143
 144     /* Start the process from the command line */
 145     if (!DosCreateProcess(CommandLine, 0))
 146     {
 147         DisplayMessage(L"Could not start program: %S", CommandLine);
 148         goto Cleanup;
 149     }
 150
 151     /* Find the starting performance and tick count */
 152     StartTickCount = GetTickCount();
 153     QueryPerformanceCounter(&StartPerfCount);
 154
 155     /* Set the last timer ticks to the current time */
 156     LastTimerTick = LastRtcTick = StartPerfCount;
 157
 158     /* Main loop */
 159     while (VdmRunning)
 160     {
 161         DWORD PitResolution = PitGetResolution();
 162         DWORD RtcFrequency = RtcGetTicksPerSecond();
 163
 164         /* Get the current number of ticks */
 165         CurrentTickCount = GetTickCount();
 166
 167         if ((PitResolution <= 1000) && (RtcFrequency <= 1000))
 168         {
 169             /* Calculate the approximate performance counter value instead */
 170             Counter.QuadPart = StartPerfCount.QuadPart
 171                                + (CurrentTickCount - StartTickCount)
 172                                * (Frequency.QuadPart / 1000);
 173         }
 174         else
 175         {
 176             /* Get the current performance counter value */
 177             QueryPerformanceCounter(&Counter);
 178         }
 179
 180         /* Get the number of PIT ticks that have passed */
 181         TimerTicks = ((Counter.QuadPart - LastTimerTick.QuadPart)
 182                      * PIT_BASE_FREQUENCY) / Frequency.QuadPart;
 183
 184         /* Update the PIT */
 185         if (TimerTicks > 0)
 186         {
 187             PitDecrementCount(TimerTicks);
 188             LastTimerTick = Counter;
 189         }
 190
 191         /* Check for RTC update */
 192         if ((CurrentTickCount - LastClockUpdate) >= 1000)
 193         {
 194             RtcTimeUpdate();
 195             LastClockUpdate = CurrentTickCount;
 196         }
 197
 198         /* Check for RTC periodic tick */
 199         if ((Counter.QuadPart - LastRtcTick.QuadPart)
 200             >= (Frequency.QuadPart / (LONGLONG)RtcFrequency))
 201         {
 202             RtcPeriodicTick();
 203             LastRtcTick = Counter;
 204         }
 205
 206         /* Check for vertical retrace */
 207         if ((CurrentTickCount - LastVerticalRefresh) >= 16)
 208         {
 209             VgaRefreshDisplay();
 210             LastVerticalRefresh = CurrentTickCount;
 211         }
 212
 213         /* Horizontal retrace occurs as fast as possible */
 214         VgaHorizontalRetrace();
 215
 216         /* Continue CPU emulation */
 217         for (i = 0; (i < STEPS_PER_CYCLE) && VdmRunning; i++)
 218         {
 219             EmulatorStep();
 220             Cycles++;
 221         }
 222
 223         if ((CurrentTickCount - LastCyclePrintout) >= 1000)
 224         {
 225             DPRINT1("NTVDM: %lu Instructions Per Second\n", Cycles);
 226             LastCyclePrintout = CurrentTickCount;
 227             Cycles = 0;
 228         }
 229     }
 230
 231     /* Perform another screen refresh */
 232     VgaRefreshDisplay();
 233
 234 Cleanup:
 235     SpeakerCleanup();
 236     BiosCleanup();
 237     CmosCleanup();
 238     EmulatorCleanup();
 239
 240     DPRINT1("\n\n\nNTVDM - Exiting...\n\n\n");
 241
 242     return 0;
 243 }
 244
 245 /* EOF */