subsystems/ntvdm/emulator.c

   1 /*
   2  * COPYRIGHT:       GPL - See COPYING in the top level directory
   3  * PROJECT:         ReactOS Virtual DOS Machine
   4  * FILE:            emulator.c
   5  * PURPOSE:         Minimal x86 machine emulator for the VDM
   6  * PROGRAMMERS:     Aleksandar Andrejevic <theflash AT sdf DOT lonestar DOT org>
   7  */
   8
   9 /* INCLUDES *******************************************************************/
  10
  11 #define NDEBUG
  12
  13 #include "emulator.h"
  14 #include "callback.h"
  15
  16 #include "clock.h"
  17 #include "bios/rom.h"
  18 #include "hardware/cmos.h"
  19 #include "hardware/pic.h"
  20 #include "hardware/ps2.h"
  21 #include "hardware/speaker.h"
  22 #include "hardware/timer.h"
  23 #include "hardware/vga.h"
  24
  25 #include "bop.h"
  26 #include "vddsup.h"
  27 #include "io.h"
  28
  29 #include <isvbop.h>
  30
  31 /* PRIVATE VARIABLES **********************************************************/
  32
  33 FAST486_STATE EmulatorContext;
  34 BOOLEAN CpuSimulate = FALSE;
  35
  36 /* No more than 'MaxCpuCallLevel' recursive CPU calls are allowed */
  37 const static INT MaxCpuCallLevel = 32;
  38 static INT CpuCallLevel = 0;
  39
  40 LPVOID  BaseAddress = NULL;
  41 BOOLEAN VdmRunning  = TRUE;
  42
  43 static BOOLEAN A20Line   = FALSE;
  44 static BYTE Port61hState = 0x00;
  45
  46 static HANDLE InputThread = NULL;
  47
  48 LPCWSTR ExceptionName[] =
  49 {
  50     L"Division By Zero",
  51     L"Debug",
  52     L"Unexpected Error",
  53     L"Breakpoint",
  54     L"Integer Overflow",
  55     L"Bound Range Exceeded",
  56     L"Invalid Opcode",
  57     L"FPU Not Available"
  58 };
  59
  60 /* BOP Identifiers */
  61 #define BOP_DEBUGGER    0x56    // Break into the debugger from a 16-bit app
  62
  63 /* PRIVATE FUNCTIONS **********************************************************/
  64
  65 VOID WINAPI EmulatorReadMemory(PFAST486_STATE State, ULONG Address, PVOID Buffer, ULONG Size)
  66 {
  67     UNREFERENCED_PARAMETER(State);
  68
  69     // BIG HACK!!!! To make BIOS images working correctly,
  70     // until Aleksander rewrites memory management!!
  71     if (Address >= 0xFFFFFFF0) Address -= 0xFFF00000;
  72
  73     /* If the A20 line is disabled, mask bit 20 */
  74     if (!A20Line) Address &= ~(1 << 20);
  75
  76     /* Make sure the requested address is valid */
  77     if ((Address + Size) >= MAX_ADDRESS) return;
  78
  79     /*
  80      * Check if we are going to read the VGA memory and
  81      * copy it into the virtual address space if needed.
  82      */
  83     if (((Address + Size) >= VgaGetVideoBaseAddress())
  84         && (Address < VgaGetVideoLimitAddress()))
  85     {
  86         DWORD VgaAddress = max(Address, VgaGetVideoBaseAddress());
  87         DWORD ActualSize = min(Address + Size - 1, VgaGetVideoLimitAddress())
  88                            - VgaAddress + 1;
  89         LPBYTE DestBuffer = (LPBYTE)REAL_TO_PHYS(VgaAddress);
  90
  91         /* Read from the VGA memory */
  92         VgaReadMemory(VgaAddress, DestBuffer, ActualSize);
  93     }
  94
  95     /* Read the data from the virtual address space and store it in the buffer */
  96     RtlCopyMemory(Buffer, REAL_TO_PHYS(Address), Size);
  97 }
  98
  99 VOID WINAPI EmulatorWriteMemory(PFAST486_STATE State, ULONG Address, PVOID Buffer, ULONG Size)
 100 {
 101     UNREFERENCED_PARAMETER(State);
 102
 103     // BIG HACK!!!! To make BIOS images working correctly,
 104     // until Aleksander rewrites memory management!!
 105     if (Address >= 0xFFFFFFF0) Address -= 0xFFF00000;
 106
 107     /* If the A20 line is disabled, mask bit 20 */
 108     if (!A20Line) Address &= ~(1 << 20);
 109
 110     /* Make sure the requested address is valid */
 111     if ((Address + Size) >= MAX_ADDRESS) return;
 112
 113     /* Make sure we don't write to the ROM area */
 114     if ((Address + Size) >= ROM_AREA_START && (Address < ROM_AREA_END)) return;
 115
 116     /* Read the data from the buffer and store it in the virtual address space */
 117     RtlCopyMemory(REAL_TO_PHYS(Address), Buffer, Size);
 118
 119     /*
 120      * Check if we modified the VGA memory.
 121      */
 122     if (((Address + Size) >= VgaGetVideoBaseAddress())
 123         && (Address < VgaGetVideoLimitAddress()))
 124     {
 125         DWORD VgaAddress = max(Address, VgaGetVideoBaseAddress());
 126         DWORD ActualSize = min(Address + Size - 1, VgaGetVideoLimitAddress())
 127                            - VgaAddress + 1;
 128         LPBYTE SrcBuffer = (LPBYTE)REAL_TO_PHYS(VgaAddress);
 129
 130         /* Write to the VGA memory */
 131         VgaWriteMemory(VgaAddress, SrcBuffer, ActualSize);
 132     }
 133 }
 134
 135 UCHAR WINAPI EmulatorIntAcknowledge(PFAST486_STATE State)
 136 {
 137     UNREFERENCED_PARAMETER(State);
 138
 139     /* Get the interrupt number from the PIC */
 140     return PicGetInterrupt();
 141 }
 142
 143 VOID EmulatorException(BYTE ExceptionNumber, LPWORD Stack)
 144 {
 145     WORD CodeSegment, InstructionPointer;
 146     PBYTE Opcode;
 147
 148     ASSERT(ExceptionNumber < 8);
 149
 150     /* Get the CS:IP */
 151     InstructionPointer = Stack[STACK_IP];
 152     CodeSegment = Stack[STACK_CS];
 153     Opcode = (PBYTE)SEG_OFF_TO_PTR(CodeSegment, InstructionPointer);
 154
 155     /* Display a message to the user */
 156     DisplayMessage(L"Exception: %s occured at %04X:%04X\n"
 157                    L"Opcode: %02X %02X %02X %02X %02X %02X %02X %02X %02X %02X",
 158                    ExceptionName[ExceptionNumber],
 159                    CodeSegment,
 160                    InstructionPointer,
 161                    Opcode[0],
 162                    Opcode[1],
 163                    Opcode[2],
 164                    Opcode[3],
 165                    Opcode[4],
 166                    Opcode[5],
 167                    Opcode[6],
 168                    Opcode[7],
 169                    Opcode[8],
 170                    Opcode[9]);
 171
 172     /* Stop the VDM */
 173     VdmRunning = FALSE;
 174     return;
 175 }
 176
 177 // FIXME: This function assumes 16-bit mode!!!
 178 VOID EmulatorExecute(WORD Segment, WORD Offset)
 179 {
 180     /* Tell Fast486 to move the instruction pointer */
 181     Fast486ExecuteAt(&EmulatorContext, Segment, Offset);
 182 }
 183
 184 VOID EmulatorStep(VOID)
 185 {
 186     /* Dump the state for debugging purposes */
 187     // Fast486DumpState(&EmulatorContext);
 188
 189     /* Execute the next instruction */
 190     Fast486StepInto(&EmulatorContext);
 191 }
 192
 193 VOID EmulatorSimulate(VOID)
 194 {
 195     if (CpuCallLevel > MaxCpuCallLevel)
 196     {
 197         DisplayMessage(L"Too many CPU levels of recursion (%d, expected maximum %d)",
 198                        CpuCallLevel, MaxCpuCallLevel);
 199
 200         /* Stop the VDM */
 201         VdmRunning = FALSE;
 202         return;
 203     }
 204     CpuCallLevel++;
 205
 206     CpuSimulate = TRUE;
 207     while (VdmRunning && CpuSimulate) ClockUpdate();
 208
 209     CpuCallLevel--;
 210     if (CpuCallLevel < 0) CpuCallLevel = 0;
 211
 212     /* This takes into account for reentrance */
 213     CpuSimulate = TRUE;
 214 }
 215
 216 VOID EmulatorUnsimulate(VOID)
 217 {
 218     /* Stop simulation */
 219     CpuSimulate = FALSE;
 220 }
 221
 222 VOID EmulatorInterrupt(BYTE Number)
 223 {
 224     /* Call the Fast486 API */
 225     Fast486Interrupt(&EmulatorContext, Number);
 226 }
 227
 228 VOID EmulatorInterruptSignal(VOID)
 229 {
 230     /* Call the Fast486 API */
 231     Fast486InterruptSignal(&EmulatorContext);
 232 }
 233
 234 VOID EmulatorSetA20(BOOLEAN Enabled)
 235 {
 236     A20Line = Enabled;
 237 }
 238
 239 VOID WINAPI EmulatorDebugBreakBop(LPWORD Stack)
 240 {
 241     DPRINT1("NTVDM: BOP_DEBUGGER\n");
 242     DebugBreak();
 243 }
 244
 245 VOID WINAPI EmulatorUnsimulateBop(LPWORD Stack)
 246 {
 247     EmulatorUnsimulate();
 248 }
 249
 250 static BYTE WINAPI Port61hRead(ULONG Port)
 251 {
 252     return Port61hState;
 253 }
 254
 255 static VOID WINAPI Port61hWrite(ULONG Port, BYTE Data)
 256 {
 257     // BOOLEAN SpeakerChange = FALSE;
 258     BYTE OldPort61hState = Port61hState;
 259
 260     /* Only the four lowest bytes can be written */
 261     Port61hState = (Port61hState & 0xF0) | (Data & 0x0F);
 262
 263     if ((OldPort61hState ^ Port61hState) & 0x01)
 264     {
 265         DPRINT("PIT 2 Gate %s\n", Port61hState & 0x01 ? "on" : "off");
 266         // SpeakerChange = TRUE;
 267     }
 268
 269     PitSetGate(2, !!(Port61hState & 0x01));
 270
 271     if ((OldPort61hState ^ Port61hState) & 0x02)
 272     {
 273         /* There were some change for the speaker... */
 274         DPRINT("Speaker %s\n", Port61hState & 0x02 ? "on" : "off");
 275         // SpeakerChange = TRUE;
 276     }
 277     // if (SpeakerChange) SpeakerChange();
 278     SpeakerChange();
 279 }
 280
 281 static VOID WINAPI PitChan0Out(LPVOID Param, BOOLEAN State)
 282 {
 283     if (State)
 284     {
 285         DPRINT("PicInterruptRequest\n");
 286         PicInterruptRequest(0); // Raise IRQ 0
 287     }
 288     // else < Lower IRQ 0 >
 289 }
 290
 291 static VOID WINAPI PitChan1Out(LPVOID Param, BOOLEAN State)
 292 {
 293 #if 0
 294     if (State)
 295     {
 296         /* Set bit 4 of Port 61h */
 297         Port61hState |= 1 << 4;
 298     }
 299     else
 300     {
 301         /* Clear bit 4 of Port 61h */
 302         Port61hState &= ~(1 << 4);
 303     }
 304 #else
 305     Port61hState = (Port61hState & 0xEF) | (State << 4);
 306 #endif
 307 }
 308
 309 static VOID WINAPI PitChan2Out(LPVOID Param, BOOLEAN State)
 310 {
 311     // BYTE OldPort61hState = Port61hState;
 312
 313 #if 0
 314     if (State)
 315     {
 316         /* Set bit 5 of Port 61h */
 317         Port61hState |= 1 << 5;
 318     }
 319     else
 320     {
 321         /* Clear bit 5 of Port 61h */
 322         Port61hState &= ~(1 << 5);
 323     }
 324 #else
 325     Port61hState = (Port61hState & 0xDF) | (State << 5);
 326 #endif
 327     DPRINT("Speaker PIT out\n");
 328     // if ((OldPort61hState ^ Port61hState) & 0x20)
 329         // SpeakerChange();
 330 }
 331
 332 /* PUBLIC FUNCTIONS ***********************************************************/
 333
 334 DWORD WINAPI PumpConsoleInput(LPVOID Parameter);
 335
 336 BOOLEAN EmulatorInitialize(HANDLE ConsoleInput, HANDLE ConsoleOutput)
 337 {
 338     /* Allocate memory for the 16-bit address space */
 339     BaseAddress = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, MAX_ADDRESS);
 340     if (BaseAddress == NULL)
 341     {
 342         wprintf(L"FATAL: Failed to allocate VDM memory.\n");
 343         return FALSE;
 344     }
 345
 346     /* Initialize I/O ports */
 347     /* Initialize RAM */
 348
 349     /* Initialize the internal clock */
 350     if (!ClockInitialize())
 351     {
 352         wprintf(L"FATAL: Failed to initialize the clock\n");
 353         return FALSE;
 354     }
 355
 356     /* Initialize the CPU */
 357     Fast486Initialize(&EmulatorContext,
 358                       EmulatorReadMemory,
 359                       EmulatorWriteMemory,
 360                       EmulatorReadIo,
 361                       EmulatorWriteIo,
 362                       NULL,
 363                       EmulatorBiosOperation,
 364                       EmulatorIntAcknowledge,
 365                       NULL /* TODO: Use a TLB */);
 366
 367     /* Initialize DMA */
 368
 369     /* Initialize the PIC, the PIT, the CMOS and the PC Speaker */
 370     PicInitialize();
 371     PitInitialize();
 372     CmosInitialize();
 373     SpeakerInitialize();
 374
 375     /* Set output functions */
 376     PitSetOutFunction(0, NULL, PitChan0Out);
 377     PitSetOutFunction(1, NULL, PitChan1Out);
 378     PitSetOutFunction(2, NULL, PitChan2Out);
 379
 380     /* Register the I/O Ports */
 381     RegisterIoPort(CONTROL_SYSTEM_PORT61H, Port61hRead, Port61hWrite);
 382
 383     /* Initialize the PS2 port */
 384     PS2Initialize(ConsoleInput);
 385
 386     /* Set the console input mode */
 387     // SetConsoleMode(ConsoleInput, ENABLE_MOUSE_INPUT | ENABLE_PROCESSED_INPUT);
 388
 389     /* Start the input thread */
 390     InputThread = CreateThread(NULL, 0, &PumpConsoleInput, ConsoleInput, 0, NULL);
 391     // if (InputThread == NULL) return FALSE;
 392
 393     /* Initialize the VGA */
 394     // if (!VgaInitialize(ConsoleOutput)) return FALSE;
 395     VgaInitialize(ConsoleOutput);
 396
 397     /* Initialize the software callback system and register the emulator BOPs */
 398     InitializeCallbacks();
 399     RegisterBop(BOP_DEBUGGER  , EmulatorDebugBreakBop);
 400     RegisterBop(BOP_UNSIMULATE, EmulatorUnsimulateBop);
 401
 402     /* Initialize VDD support */
 403     VDDSupInitialize();
 404
 405     return TRUE;
 406 }
 407
 408 VOID EmulatorCleanup(VOID)
 409 {
 410     // VgaCleanup();
 411
 412     /* Close the input thread handle */
 413     if (InputThread != NULL) CloseHandle(InputThread);
 414     InputThread = NULL;
 415
 416     PS2Cleanup();
 417
 418     SpeakerCleanup();
 419     CmosCleanup();
 420     // PitCleanup();
 421     // PicCleanup();
 422
 423     // Fast486Cleanup();
 424
 425     /* Free the memory allocated for the 16-bit address space */
 426     if (BaseAddress != NULL) HeapFree(GetProcessHeap(), 0, BaseAddress);
 427 }
 428
 429
 430
 431 VOID
 432 WINAPI
 433 VDDSimulate16(VOID)
 434 {
 435     EmulatorSimulate();
 436 }
 437
 438 VOID
 439 WINAPI
 440 VDDTerminateVDM(VOID)
 441 {
 442     /* Stop the VDM */
 443     VdmRunning = FALSE;
 444 }
 445
 446 PBYTE
 447 WINAPI
 448 Sim32pGetVDMPointer(IN ULONG   Address,
 449                     IN BOOLEAN ProtectedMode)
 450 {
 451     // FIXME
 452     UNREFERENCED_PARAMETER(ProtectedMode);
 453
 454     /*
 455      * HIWORD(Address) == Segment  (if ProtectedMode == FALSE)
 456      *                 or Selector (if ProtectedMode == TRUE )
 457      * LOWORD(Address) == Offset
 458      */
 459     return (PBYTE)FAR_POINTER(Address);
 460 }
 461
 462 PBYTE
 463 WINAPI
 464 MGetVdmPointer(IN ULONG   Address,
 465                IN ULONG   Size,
 466                IN BOOLEAN ProtectedMode)
 467 {
 468     UNREFERENCED_PARAMETER(Size);
 469     return Sim32pGetVDMPointer(Address, ProtectedMode);
 470 }
 471
 472 PVOID
 473 WINAPI
 474 VdmMapFlat(IN USHORT   Segment,
 475            IN ULONG    Offset,
 476            IN VDM_MODE Mode)
 477 {
 478     // FIXME
 479     UNREFERENCED_PARAMETER(Mode);
 480
 481     return SEG_OFF_TO_PTR(Segment, Offset);
 482 }
 483
 484 BOOL
 485 WINAPI
 486 VdmFlushCache(IN USHORT   Segment,
 487               IN ULONG    Offset,
 488               IN ULONG    Size,
 489               IN VDM_MODE Mode)
 490 {
 491     // FIXME
 492     UNIMPLEMENTED;
 493     return TRUE;
 494 }
 495
 496 BOOL
 497 WINAPI
 498 VdmUnmapFlat(IN USHORT   Segment,
 499              IN ULONG    Offset,
 500              IN PVOID    Buffer,
 501              IN VDM_MODE Mode)
 502 {
 503     // FIXME
 504     UNIMPLEMENTED;
 505     return TRUE;
 506 }
 507
 508 /* EOF */