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     if (!EmulatorInitialize())
 105     {
 106         wprintf(L"FATAL: Failed to initialize the CPU emulator\n");
 107         goto Cleanup;
 108     }
 109
 110     /* Initialize the performance counter (needed for hardware timers) */
 111     if (!QueryPerformanceFrequency(&Frequency))
 112     {
 113         wprintf(L"FATAL: Performance counter not available\n");
 114         goto Cleanup;
 115     }
 116
 117     /* Initialize the system BIOS */
 118     if (!BiosInitialize())
 119     {
 120         wprintf(L"FATAL: Failed to initialize the VDM BIOS.\n");
 121         goto Cleanup;
 122     }
 123
 124     /* Initialize the PC Speaker */
 125     SpeakerInitialize();
 126
 127     /* Initialize the VDM DOS kernel */
 128     if (!DosInitialize())
 129     {
 130         wprintf(L"FATAL: Failed to initialize the VDM DOS kernel.\n");
 131         goto Cleanup;
 132     }
 133
 134     /* Start the process from the command line */
 135     if (!DosCreateProcess(CommandLine, 0))
 136     {
 137         DisplayMessage(L"Could not start program: %S", CommandLine);
 138         return -1;
 139     }
 140
 141     /* Find the starting performance and tick count */
 142     StartTickCount = GetTickCount();
 143     QueryPerformanceCounter(&StartPerfCount);
 144
 145     /* Set the last timer ticks to the current time */
 146     LastTimerTick = LastRtcTick = StartPerfCount;
 147
 148     /* Main loop */
 149     while (VdmRunning)
 150     {
 151         DWORD PitResolution = PitGetResolution();
 152         DWORD RtcFrequency = RtcGetTicksPerSecond();
 153
 154         /* Get the current number of ticks */
 155         CurrentTickCount = GetTickCount();
 156
 157         if ((PitResolution <= 1000) && (RtcFrequency <= 1000))
 158         {
 159             /* Calculate the approximate performance counter value instead */
 160             Counter.QuadPart = StartPerfCount.QuadPart
 161                                + (CurrentTickCount - StartTickCount)
 162                                * (Frequency.QuadPart / 1000);
 163         }
 164         else
 165         {
 166             /* Get the current performance counter value */
 167             QueryPerformanceCounter(&Counter);
 168         }
 169
 170         /* Get the number of PIT ticks that have passed */
 171         TimerTicks = ((Counter.QuadPart - LastTimerTick.QuadPart)
 172                      * PIT_BASE_FREQUENCY) / Frequency.QuadPart;
 173
 174         /* Update the PIT */
 175         if (TimerTicks > 0)
 176         {
 177             PitDecrementCount(TimerTicks);
 178             LastTimerTick = Counter;
 179         }
 180
 181         /* Check for RTC update */
 182         if ((CurrentTickCount - LastClockUpdate) >= 1000)
 183         {
 184             RtcTimeUpdate();
 185             LastClockUpdate = CurrentTickCount;
 186         }
 187
 188         /* Check for RTC periodic tick */
 189         if ((Counter.QuadPart - LastRtcTick.QuadPart)
 190             >= (Frequency.QuadPart / (LONGLONG)RtcFrequency))
 191         {
 192             RtcPeriodicTick();
 193             LastRtcTick = Counter;
 194         }
 195
 196         /* Check for vertical retrace */
 197         if ((CurrentTickCount - LastVerticalRefresh) >= 16)
 198         {
 199             VgaRefreshDisplay();
 200             LastVerticalRefresh = CurrentTickCount;
 201         }
 202
 203         /* Horizontal retrace occurs as fast as possible */
 204         VgaHorizontalRetrace();
 205
 206         /* Continue CPU emulation */
 207         for (i = 0; (i < STEPS_PER_CYCLE) && VdmRunning; i++)
 208         {
 209             EmulatorStep();
 210             Cycles++;
 211         }
 212
 213         if ((CurrentTickCount - LastCyclePrintout) >= 1000)
 214         {
 215             DPRINT1("NTVDM: %lu Instructions Per Second\n", Cycles);
 216             LastCyclePrintout = CurrentTickCount;
 217             Cycles = 0;
 218         }
 219     }
 220
 221     /* Perform another screen refresh */
 222     VgaRefreshDisplay();
 223
 224 Cleanup:
 225     SpeakerCleanup();
 226     BiosCleanup();
 227     EmulatorCleanup();
 228
 229     return 0;
 230 }
 231
 232 /* EOF */