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     EmulatorTerminate();
 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         EmulatorTerminate();
 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 EmulatorTerminate(VOID)
 223 {
 224     /* Stop the VDM */
 225     VdmRunning = FALSE;
 226 }
 227
 228 VOID EmulatorInterrupt(BYTE Number)
 229 {
 230     /* Call the Fast486 API */
 231     Fast486Interrupt(&EmulatorContext, Number);
 232 }
 233
 234 VOID EmulatorInterruptSignal(VOID)
 235 {
 236     /* Call the Fast486 API */
 237     Fast486InterruptSignal(&EmulatorContext);
 238 }
 239
 240 VOID EmulatorSetA20(BOOLEAN Enabled)
 241 {
 242     A20Line = Enabled;
 243 }
 244
 245 static VOID WINAPI EmulatorDebugBreakBop(LPWORD Stack)
 246 {
 247     DPRINT1("NTVDM: BOP_DEBUGGER\n");
 248     DebugBreak();
 249 }
 250
 251 static VOID WINAPI EmulatorUnsimulateBop(LPWORD Stack)
 252 {
 253     EmulatorUnsimulate();
 254 }
 255
 256 static BYTE WINAPI Port61hRead(ULONG Port)
 257 {
 258     return Port61hState;
 259 }
 260
 261 static VOID WINAPI Port61hWrite(ULONG Port, BYTE Data)
 262 {
 263     // BOOLEAN SpeakerChange = FALSE;
 264     BYTE OldPort61hState = Port61hState;
 265
 266     /* Only the four lowest bytes can be written */
 267     Port61hState = (Port61hState & 0xF0) | (Data & 0x0F);
 268
 269     if ((OldPort61hState ^ Port61hState) & 0x01)
 270     {
 271         DPRINT("PIT 2 Gate %s\n", Port61hState & 0x01 ? "on" : "off");
 272         // SpeakerChange = TRUE;
 273     }
 274
 275     PitSetGate(2, !!(Port61hState & 0x01));
 276
 277     if ((OldPort61hState ^ Port61hState) & 0x02)
 278     {
 279         /* There were some change for the speaker... */
 280         DPRINT("Speaker %s\n", Port61hState & 0x02 ? "on" : "off");
 281         // SpeakerChange = TRUE;
 282     }
 283     // if (SpeakerChange) SpeakerChange();
 284     SpeakerChange();
 285 }
 286
 287 static VOID WINAPI PitChan0Out(LPVOID Param, BOOLEAN State)
 288 {
 289     if (State)
 290     {
 291         DPRINT("PicInterruptRequest\n");
 292         PicInterruptRequest(0); // Raise IRQ 0
 293     }
 294     // else < Lower IRQ 0 >
 295 }
 296
 297 static VOID WINAPI PitChan1Out(LPVOID Param, BOOLEAN State)
 298 {
 299 #if 0
 300     if (State)
 301     {
 302         /* Set bit 4 of Port 61h */
 303         Port61hState |= 1 << 4;
 304     }
 305     else
 306     {
 307         /* Clear bit 4 of Port 61h */
 308         Port61hState &= ~(1 << 4);
 309     }
 310 #else
 311     Port61hState = (Port61hState & 0xEF) | (State << 4);
 312 #endif
 313 }
 314
 315 static VOID WINAPI PitChan2Out(LPVOID Param, BOOLEAN State)
 316 {
 317     // BYTE OldPort61hState = Port61hState;
 318
 319 #if 0
 320     if (State)
 321     {
 322         /* Set bit 5 of Port 61h */
 323         Port61hState |= 1 << 5;
 324     }
 325     else
 326     {
 327         /* Clear bit 5 of Port 61h */
 328         Port61hState &= ~(1 << 5);
 329     }
 330 #else
 331     Port61hState = (Port61hState & 0xDF) | (State << 5);
 332 #endif
 333     DPRINT("Speaker PIT out\n");
 334     // if ((OldPort61hState ^ Port61hState) & 0x20)
 335         // SpeakerChange();
 336 }
 337
 338 /* PUBLIC FUNCTIONS ***********************************************************/
 339
 340 DWORD WINAPI PumpConsoleInput(LPVOID Parameter);
 341
 342 BOOLEAN EmulatorInitialize(HANDLE ConsoleInput, HANDLE ConsoleOutput)
 343 {
 344     /* Allocate memory for the 16-bit address space */
 345     BaseAddress = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, MAX_ADDRESS);
 346     if (BaseAddress == NULL)
 347     {
 348         wprintf(L"FATAL: Failed to allocate VDM memory.\n");
 349         return FALSE;
 350     }
 351
 352     /* Initialize I/O ports */
 353     /* Initialize RAM */
 354
 355     /* Initialize the internal clock */
 356     if (!ClockInitialize())
 357     {
 358         wprintf(L"FATAL: Failed to initialize the clock\n");
 359         return FALSE;
 360     }
 361
 362     /* Initialize the CPU */
 363     Fast486Initialize(&EmulatorContext,
 364                       EmulatorReadMemory,
 365                       EmulatorWriteMemory,
 366                       EmulatorReadIo,
 367                       EmulatorWriteIo,
 368                       NULL,
 369                       EmulatorBiosOperation,
 370                       EmulatorIntAcknowledge,
 371                       NULL /* TODO: Use a TLB */);
 372
 373     /* Initialize DMA */
 374
 375     /* Initialize the PIC, the PIT, the CMOS and the PC Speaker */
 376     PicInitialize();
 377     PitInitialize();
 378     CmosInitialize();
 379     SpeakerInitialize();
 380
 381     /* Set output functions */
 382     PitSetOutFunction(0, NULL, PitChan0Out);
 383     PitSetOutFunction(1, NULL, PitChan1Out);
 384     PitSetOutFunction(2, NULL, PitChan2Out);
 385
 386     /* Register the I/O Ports */
 387     RegisterIoPort(CONTROL_SYSTEM_PORT61H, Port61hRead, Port61hWrite);
 388
 389     /* Set the console input mode */
 390     // FIXME: Activate ENABLE_WINDOW_INPUT when we will want to perform actions
 391     // upon console window events (screen buffer resize, ...).
 392     SetConsoleMode(ConsoleInput, ENABLE_PROCESSED_INPUT /* | ENABLE_WINDOW_INPUT */);
 393     // SetConsoleMode(ConsoleOutput, ENABLE_PROCESSED_OUTPUT | ENABLE_WRAP_AT_EOL_OUTPUT);
 394
 395     /* Initialize the PS2 port */
 396     PS2Initialize(ConsoleInput);
 397
 398     /* Start the input thread */
 399     InputThread = CreateThread(NULL, 0, &PumpConsoleInput, ConsoleInput, 0, NULL);
 400     // if (InputThread == NULL) return FALSE;
 401
 402     /* Initialize the VGA */
 403     // if (!VgaInitialize(ConsoleOutput)) return FALSE;
 404     VgaInitialize(ConsoleOutput);
 405
 406     /* Initialize the software callback system and register the emulator BOPs */
 407     InitializeCallbacks();
 408     RegisterBop(BOP_DEBUGGER  , EmulatorDebugBreakBop);
 409     RegisterBop(BOP_UNSIMULATE, EmulatorUnsimulateBop);
 410
 411     /* Initialize VDD support */
 412     VDDSupInitialize();
 413
 414     return TRUE;
 415 }
 416
 417 VOID EmulatorCleanup(VOID)
 418 {
 419     VgaCleanup();
 420
 421     /* Close the input thread handle */
 422     if (InputThread != NULL) CloseHandle(InputThread);
 423     InputThread = NULL;
 424
 425     PS2Cleanup();
 426
 427     SpeakerCleanup();
 428     CmosCleanup();
 429     // PitCleanup();
 430     // PicCleanup();
 431
 432     // Fast486Cleanup();
 433
 434     /* Free the memory allocated for the 16-bit address space */
 435     if (BaseAddress != NULL) HeapFree(GetProcessHeap(), 0, BaseAddress);
 436 }
 437
 438
 439
 440 VOID
 441 WINAPI
 442 VDDSimulate16(VOID)
 443 {
 444     EmulatorSimulate();
 445 }
 446
 447 VOID
 448 WINAPI
 449 VDDTerminateVDM(VOID)
 450 {
 451     /* Stop the VDM */
 452     EmulatorTerminate();
 453 }
 454
 455 PBYTE
 456 WINAPI
 457 Sim32pGetVDMPointer(IN ULONG   Address,
 458                     IN BOOLEAN ProtectedMode)
 459 {
 460     // FIXME
 461     UNREFERENCED_PARAMETER(ProtectedMode);
 462
 463     /*
 464      * HIWORD(Address) == Segment  (if ProtectedMode == FALSE)
 465      *                 or Selector (if ProtectedMode == TRUE )
 466      * LOWORD(Address) == Offset
 467      */
 468     return (PBYTE)FAR_POINTER(Address);
 469 }
 470
 471 PBYTE
 472 WINAPI
 473 MGetVdmPointer(IN ULONG   Address,
 474                IN ULONG   Size,
 475                IN BOOLEAN ProtectedMode)
 476 {
 477     UNREFERENCED_PARAMETER(Size);
 478     return Sim32pGetVDMPointer(Address, ProtectedMode);
 479 }
 480
 481 PVOID
 482 WINAPI
 483 VdmMapFlat(IN USHORT   Segment,
 484            IN ULONG    Offset,
 485            IN VDM_MODE Mode)
 486 {
 487     // FIXME
 488     UNREFERENCED_PARAMETER(Mode);
 489
 490     return SEG_OFF_TO_PTR(Segment, Offset);
 491 }
 492
 493 BOOL
 494 WINAPI
 495 VdmFlushCache(IN USHORT   Segment,
 496               IN ULONG    Offset,
 497               IN ULONG    Size,
 498               IN VDM_MODE Mode)
 499 {
 500     // FIXME
 501     UNIMPLEMENTED;
 502     return TRUE;
 503 }
 504
 505 BOOL
 506 WINAPI
 507 VdmUnmapFlat(IN USHORT   Segment,
 508              IN ULONG    Offset,
 509              IN PVOID    Buffer,
 510              IN VDM_MODE Mode)
 511 {
 512     // FIXME
 513     UNIMPLEMENTED;
 514     return TRUE;
 515 }
 516
 517 /* EOF */