reactos/drivers/dd/blue/blue.c

   1 /* $Id: blue.c,v 1.29 2001/01/31 02:24:46 phreak Exp $
   2  *
   3  * COPYRIGHT:            See COPYING in the top level directory
   4  * PROJECT:              ReactOS kernel
   5  * FILE:                 services/dd/blue/blue.c
   6  * PURPOSE:              Console (blue screen) device driver
   7  * PROGRAMMER:           Eric Kohl (ekohl@abo.rhein-zeitung.de)
   8  * UPDATE HISTORY:
   9  *                       ??? Created
  10  */
  11
  12 /* INCLUDES ******************************************************************/
  13
  14 #include <ddk/ntddk.h>
  15 #include <ddk/ntddblue.h>
  16 #include <string.h>
  17 #include <defines.h>
  18
  19 #define NDEBUG
  20 #include <debug.h>
  21
  22
  23 /* DEFINITIONS ***************************************************************/
  24
  25 #define VIDMEM_BASE        0xb8000
  26 #define VIDMEM_SIZE        0x2000
  27
  28 #define CRTC_COMMAND       ((PUCHAR)0x3d4)
  29 #define CRTC_DATA          ((PUCHAR)0x3d5)
  30
  31 #define CRTC_COLUMNS       0x01
  32 #define CRTC_OVERFLOW      0x07
  33 #define CRTC_ROWS          0x12
  34 #define CRTC_SCANLINES     0x09
  35 #define CRTC_CURSORSTART   0x0a
  36 #define CRTC_CURSOREND     0x0b
  37 #define CRTC_CURSORPOSHI   0x0e
  38 #define CRTC_CURSORPOSLO   0x0f
  39
  40 #define ATTRC_WRITEREG     ((PUCHAR)0x3c0)
  41 #define ATTRC_READREG      ((PUCHAR)0x3c1)
  42 #define ATTRC_INPST1       ((PUCHAR)0x3da)
  43
  44 #define TAB_WIDTH          8
  45
  46
  47 /* NOTES ******************************************************************/
  48 /*
  49  *  [[character][attribute]][[character][attribute]]....
  50  */
  51
  52
  53 /* TYPEDEFS ***************************************************************/
  54
  55 typedef struct _DEVICE_EXTENSION
  56 {
  57     PBYTE VideoMemory;    /* Pointer to video memory */
  58     DWORD CursorSize;
  59     BOOL  CursorVisible;
  60     WORD  CharAttribute;
  61     DWORD Mode;
  62     BYTE  ScanLines;      /* Height of a text line */
  63     WORD  Rows;           /* Number of rows        */
  64     WORD  Columns;        /* Number of columns     */
  65 } DEVICE_EXTENSION, *PDEVICE_EXTENSION;
  66
  67
  68 /* FUNCTIONS **************************************************************/
  69
  70 NTSTATUS
  71 STDCALL ScrCreate (PDEVICE_OBJECT DeviceObject, PIRP Irp)
  72 {
  73     PDEVICE_EXTENSION DeviceExtension;
  74     PHYSICAL_ADDRESS BaseAddress;
  75     NTSTATUS Status;
  76     unsigned int offset;
  77     BYTE data, value;
  78
  79     DeviceExtension = DeviceObject->DeviceExtension;
  80
  81     /* get pointer to video memory */
  82     BaseAddress.QuadPart = VIDMEM_BASE;
  83     DeviceExtension->VideoMemory =
  84         (PBYTE)MmMapIoSpace (BaseAddress, VIDMEM_SIZE, FALSE);
  85
  86     /* disable interrupts */
  87     __asm__("cli\n\t");
  88
  89     /* get current output position */
  90     WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_CURSORPOSLO);
  91     offset = READ_PORT_UCHAR (CRTC_DATA);
  92     WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_CURSORPOSHI);
  93     offset += (READ_PORT_UCHAR (CRTC_DATA) << 8);
  94
  95     /* switch blinking characters off */
  96     READ_PORT_UCHAR (ATTRC_INPST1);
  97     value = READ_PORT_UCHAR (ATTRC_WRITEREG);
  98     WRITE_PORT_UCHAR (ATTRC_WRITEREG, 0x10);
  99     data  = READ_PORT_UCHAR (ATTRC_READREG);
 100     data  = data & ~0x08;
 101     WRITE_PORT_UCHAR (ATTRC_WRITEREG, data);
 102     WRITE_PORT_UCHAR (ATTRC_WRITEREG, value);
 103     READ_PORT_UCHAR (ATTRC_INPST1);
 104
 105     /* read screen information from crt controller */
 106     WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_COLUMNS);
 107     DeviceExtension->Columns = READ_PORT_UCHAR (CRTC_DATA) + 1;
 108     WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_ROWS);
 109     DeviceExtension->Rows = READ_PORT_UCHAR (CRTC_DATA);
 110     WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_OVERFLOW);
 111     data = READ_PORT_UCHAR (CRTC_DATA);
 112     DeviceExtension->Rows |= (((data & 0x02) << 7) | ((data & 0x40) << 3));
 113     DeviceExtension->Rows++;
 114     WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_SCANLINES);
 115     DeviceExtension->ScanLines = (READ_PORT_UCHAR (CRTC_DATA) & 0x1F) + 1;
 116
 117     /* enable interrupts */
 118     __asm__("sti\n\t");
 119
 120     /* calculate number of text rows */
 121     DeviceExtension->Rows =
 122         DeviceExtension->Rows / DeviceExtension->ScanLines;
 123 #ifdef BOCHS_30ROWS
 124     DeviceExtension->Rows = 30;
 125 #endif
 126
 127     DPRINT ("%d Columns  %d Rows %d Scanlines\n",
 128             DeviceExtension->Columns,
 129             DeviceExtension->Rows,
 130             DeviceExtension->ScanLines);
 131
 132     DeviceExtension->CursorSize    = 5; /* FIXME: value correct?? */
 133     DeviceExtension->CursorVisible = TRUE;
 134
 135     /* more initialization */
 136     DeviceExtension->CharAttribute = 0x17;  /* light grey on blue */
 137     DeviceExtension->Mode = ENABLE_PROCESSED_OUTPUT |
 138                             ENABLE_WRAP_AT_EOL_OUTPUT;
 139
 140     /* show blinking cursor */
 141     __asm__("cli\n\t");
 142     WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_CURSORSTART);
 143     WRITE_PORT_UCHAR (CRTC_DATA, (DeviceExtension->ScanLines - 1) & 0x1F);
 144     WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_CURSOREND);
 145     data = READ_PORT_UCHAR (CRTC_DATA) & 0xE0;
 146     WRITE_PORT_UCHAR (CRTC_DATA,
 147                       data | ((DeviceExtension->ScanLines - 1) & 0x1F));
 148     __asm__("sti\n\t");
 149
 150     Status = STATUS_SUCCESS;
 151
 152     Irp->IoStatus.Status = Status;
 153     IoCompleteRequest (Irp, IO_NO_INCREMENT);
 154
 155     return (Status);
 156 }
 157
 158
 159 NTSTATUS
 160 STDCALL ScrWrite (PDEVICE_OBJECT DeviceObject, PIRP Irp)
 161 {
 162     PIO_STACK_LOCATION stk = IoGetCurrentIrpStackLocation (Irp);
 163     PDEVICE_EXTENSION DeviceExtension = DeviceObject->DeviceExtension;
 164     NTSTATUS Status;
 165     char *pch = Irp->UserBuffer;
 166     char *vidmem;
 167     int i, j, offset;
 168     int cursorx, cursory;
 169     int rows, columns;
 170     int processed = DeviceExtension->Mode & ENABLE_PROCESSED_OUTPUT;
 171
 172     vidmem  = DeviceExtension->VideoMemory;
 173     rows = DeviceExtension->Rows;
 174     columns = DeviceExtension->Columns;
 175
 176     WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_CURSORPOSHI);
 177     offset = READ_PORT_UCHAR (CRTC_DATA)<<8;
 178     WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_CURSORPOSLO);
 179     offset += READ_PORT_UCHAR (CRTC_DATA);
 180
 181     cursory = offset / columns;
 182     cursorx = offset % columns;
 183     if( processed == 0 )
 184        {
 185           /* raw output mode */
 186           memcpy( &vidmem[(cursorx * 2) + (cursory * columns * 2)], pch, stk->Parameters.Write.Length );
 187           offset += (stk->Parameters.Write.Length / 2);
 188        }
 189     else {
 190        for (i = 0; i < stk->Parameters.Write.Length; i++, pch++)
 191           {
 192              switch (*pch)
 193                 {
 194                 case '\b':
 195                    if (cursorx > 0)
 196                       {
 197                          cursorx--;
 198                       }
 199                    else if (cursory > 0)
 200                       {
 201                          cursorx = columns - 1;
 202                          cursory--;
 203                       }
 204                    vidmem[(cursorx * 2) + (cursory * columns * 2)] = ' ';
 205                    vidmem[(cursorx * 2) + (cursory * columns * 2) + 1] = (char) DeviceExtension->CharAttribute;
 206                    break;
 207
 208                 case '\n':
 209                    cursory++;
 210                    cursorx = 0;
 211                    break;
 212
 213                 case '\r':
 214                    break;
 215
 216                 case '\t':
 217                    offset = TAB_WIDTH - (cursorx % TAB_WIDTH);
 218                    for (j = 0; j < offset; j++)
 219                       {
 220                          vidmem[(cursorx * 2) + (cursory * columns * 2)] = ' ';
 221                          cursorx++;
 222
 223                          if (cursorx >= columns)
 224                             {
 225                                cursory++;
 226                                cursorx = 0;
 227                             }
 228                       }
 229                    break;
 230
 231                 default:
 232                    vidmem[(cursorx * 2) + (cursory * columns * 2)] = *pch;
 233                    vidmem[(cursorx * 2) + (cursory * columns * 2) + 1] = (char) DeviceExtension->CharAttribute;
 234                    cursorx++;
 235                    if (cursorx >= columns)
 236                       {
 237                          cursory++;
 238                          cursorx = 0;
 239                       }
 240                    break;
 241                 }
 242              if (cursory >= rows)
 243                 {
 244                    unsigned short *LinePtr;
 245
 246                    memcpy (vidmem,
 247                            &vidmem[columns * 2],
 248                            columns * (rows - 1) * 2);
 249
 250                    LinePtr = (unsigned short *) &vidmem[columns * (rows - 1) * 2];
 251
 252                    for (j = 0; j < columns; j++)
 253                       {
 254                          LinePtr[j] = DeviceExtension->CharAttribute << 8;
 255                       }
 256                    cursory = rows - 1;
 257                    for (j = 0; j < columns; j++)
 258                       {
 259                          vidmem[(j * 2) + (cursory * columns * 2)] = ' ';
 260                          vidmem[(j * 2) + (cursory * columns * 2) + 1] = (char)DeviceExtension->CharAttribute;
 261                       }
 262                 }
 263           }
 264
 265        /* Set the cursor position */
 266        offset = (cursory * columns) + cursorx;
 267     }
 268     WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_CURSORPOSLO);
 269     WRITE_PORT_UCHAR (CRTC_DATA, offset);
 270     WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_CURSORPOSHI);
 271     offset >>= 8;
 272     WRITE_PORT_UCHAR (CRTC_DATA, offset);
 273
 274     Status = STATUS_SUCCESS;
 275
 276     Irp->IoStatus.Status = Status;
 277     IoCompleteRequest (Irp, IO_NO_INCREMENT);
 278
 279     return (Status);
 280 }
 281
 282
 283 NTSTATUS
 284 STDCALL ScrIoControl (PDEVICE_OBJECT DeviceObject, PIRP Irp)
 285 {
 286     PIO_STACK_LOCATION stk = IoGetCurrentIrpStackLocation (Irp);
 287     PDEVICE_EXTENSION DeviceExtension;
 288     NTSTATUS Status;
 289     DeviceExtension = DeviceObject->DeviceExtension;
 290     switch (stk->Parameters.DeviceIoControl.IoControlCode)
 291     {
 292         case IOCTL_CONSOLE_GET_SCREEN_BUFFER_INFO:
 293             {
 294                 PCONSOLE_SCREEN_BUFFER_INFO pcsbi = (PCONSOLE_SCREEN_BUFFER_INFO)Irp->AssociatedIrp.SystemBuffer;
 295                 int rows = DeviceExtension->Rows;
 296                 int columns = DeviceExtension->Columns;
 297                 unsigned int offset;
 298
 299                 /* read cursor position from crtc */
 300                 __asm__("cli\n\t");
 301                 WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_CURSORPOSLO);
 302                 offset = READ_PORT_UCHAR (CRTC_DATA);
 303                 WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_CURSORPOSHI);
 304                 offset += (READ_PORT_UCHAR (CRTC_DATA) << 8);
 305                 __asm__("sti\n\t");
 306
 307                 pcsbi->dwSize.X = columns;
 308                 pcsbi->dwSize.Y = rows;
 309
 310                 pcsbi->dwCursorPosition.X = (SHORT)(offset % columns);
 311                 pcsbi->dwCursorPosition.Y = (SHORT)(offset / columns);
 312
 313                 pcsbi->wAttributes = DeviceExtension->CharAttribute;
 314
 315                 pcsbi->srWindow.Left   = 0;
 316                 pcsbi->srWindow.Right  = columns - 1;
 317                 pcsbi->srWindow.Top    = 0;
 318                 pcsbi->srWindow.Bottom = rows - 1;
 319
 320                 pcsbi->dwMaximumWindowSize.X = columns;
 321                 pcsbi->dwMaximumWindowSize.Y = rows;
 322
 323                 Irp->IoStatus.Information = sizeof (CONSOLE_SCREEN_BUFFER_INFO);
 324                 Status = STATUS_SUCCESS;
 325             }
 326             break;
 327
 328         case IOCTL_CONSOLE_SET_SCREEN_BUFFER_INFO:
 329             {
 330                 PCONSOLE_SCREEN_BUFFER_INFO pcsbi = (PCONSOLE_SCREEN_BUFFER_INFO)Irp->AssociatedIrp.SystemBuffer;
 331                 unsigned int offset;
 332
 333                 DeviceExtension->CharAttribute = pcsbi->wAttributes;
 334                 offset = (pcsbi->dwCursorPosition.Y * DeviceExtension->Columns) +
 335                           pcsbi->dwCursorPosition.X;
 336
 337                 __asm__("cli\n\t");
 338                 WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_CURSORPOSLO);
 339                 WRITE_PORT_UCHAR (CRTC_DATA, offset);
 340                 WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_CURSORPOSHI);
 341                 WRITE_PORT_UCHAR (CRTC_DATA, offset>>8);
 342                 __asm__("sti\n\t");
 343
 344                 Irp->IoStatus.Information = 0;
 345                 Status = STATUS_SUCCESS;
 346             }
 347             break;
 348
 349         case IOCTL_CONSOLE_GET_CURSOR_INFO:
 350             {
 351                 PCONSOLE_CURSOR_INFO pcci = (PCONSOLE_CURSOR_INFO)Irp->AssociatedIrp.SystemBuffer;
 352
 353                 pcci->dwSize = DeviceExtension->CursorSize;
 354                 pcci->bVisible = DeviceExtension->CursorVisible;
 355
 356                 Irp->IoStatus.Information = sizeof (CONSOLE_CURSOR_INFO);
 357                 Status = STATUS_SUCCESS;
 358             }
 359             break;
 360
 361         case IOCTL_CONSOLE_SET_CURSOR_INFO:
 362             {
 363                 PCONSOLE_CURSOR_INFO pcci = (PCONSOLE_CURSOR_INFO)Irp->AssociatedIrp.SystemBuffer;
 364                 BYTE data, value;
 365                 DWORD size, height;
 366
 367                 DeviceExtension->CursorSize = pcci->dwSize;
 368                 DeviceExtension->CursorVisible = pcci->bVisible;
 369                 height = DeviceExtension->ScanLines;
 370                 data = (pcci->bVisible) ? 0x40 : 0x20;
 371
 372                 size = (pcci->dwSize * height) / 100;
 373                 if (size < 1)
 374                     size = 1;
 375
 376                 data |= (BYTE)(height - size);
 377
 378                 __asm__("cli\n\t");
 379                 WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_CURSORSTART);
 380                 WRITE_PORT_UCHAR (CRTC_DATA, data);
 381                 WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_CURSOREND);
 382                 value = READ_PORT_UCHAR (CRTC_DATA) & 0xE0;
 383                 WRITE_PORT_UCHAR (CRTC_DATA, value | (height - 1));
 384
 385                 __asm__("sti\n\t");
 386
 387                 Irp->IoStatus.Information = 0;
 388                 Status = STATUS_SUCCESS;
 389             }
 390             break;
 391
 392         case IOCTL_CONSOLE_GET_MODE:
 393             {
 394                 PCONSOLE_MODE pcm = (PCONSOLE_MODE)Irp->AssociatedIrp.SystemBuffer;
 395
 396                 pcm->dwMode = DeviceExtension->Mode;
 397
 398                 Irp->IoStatus.Information = sizeof(CONSOLE_MODE);
 399                 Status = STATUS_SUCCESS;
 400             }
 401             break;
 402
 403         case IOCTL_CONSOLE_SET_MODE:
 404             {
 405                 PCONSOLE_MODE pcm = (PCONSOLE_MODE)Irp->AssociatedIrp.SystemBuffer;
 406
 407                 DeviceExtension->Mode = pcm->dwMode;
 408
 409                 Irp->IoStatus.Information = 0;
 410                 Status = STATUS_SUCCESS;
 411             }
 412             break;
 413
 414         case IOCTL_CONSOLE_FILL_OUTPUT_ATTRIBUTE:
 415             {
 416                 POUTPUT_ATTRIBUTE Buf = (POUTPUT_ATTRIBUTE)Irp->AssociatedIrp.SystemBuffer;
 417                 char *vidmem;
 418                 int offset;
 419                 DWORD dwCount;
 420
 421                 vidmem = DeviceExtension->VideoMemory;
 422                 offset = (Buf->dwCoord.Y * DeviceExtension->Columns * 2) +
 423                          (Buf->dwCoord.X * 2) + 1;
 424
 425                 for (dwCount = 0; dwCount < Buf->nLength; dwCount++)
 426                 {
 427                     vidmem[offset + (dwCount * 2)] = (char) Buf->wAttribute;
 428                 }
 429
 430                 Buf->dwTransfered = Buf->nLength;
 431
 432                 Irp->IoStatus.Information = 0;
 433                 Status = STATUS_SUCCESS;
 434             }
 435             break;
 436
 437         case IOCTL_CONSOLE_READ_OUTPUT_ATTRIBUTE:
 438             {
 439                 POUTPUT_ATTRIBUTE Buf = (POUTPUT_ATTRIBUTE)Irp->AssociatedIrp.SystemBuffer;
 440                 PWORD pAttr = (PWORD)MmGetSystemAddressForMdl(Irp->MdlAddress);
 441                 char *vidmem;
 442                 int offset;
 443                 DWORD dwCount;
 444
 445                 vidmem = DeviceExtension->VideoMemory;
 446                 offset = (Buf->dwCoord.Y * DeviceExtension->Columns * 2) +
 447                          (Buf->dwCoord.X * 2) + 1;
 448
 449                 for (dwCount = 0; dwCount < stk->Parameters.Write.Length; dwCount++, pAttr++)
 450                 {
 451                     (char) *pAttr = vidmem[offset + (dwCount * 2)];
 452                 }
 453
 454                 Buf->dwTransfered = dwCount;
 455
 456                 Irp->IoStatus.Information = sizeof(OUTPUT_ATTRIBUTE);
 457                 Status = STATUS_SUCCESS;
 458             }
 459             break;
 460
 461         case IOCTL_CONSOLE_WRITE_OUTPUT_ATTRIBUTE:
 462             {
 463                 COORD *pCoord = (COORD *)MmGetSystemAddressForMdl(Irp->MdlAddress);
 464                 CHAR *pAttr = (CHAR *)(pCoord + 1);
 465                 char *vidmem;
 466                 int offset;
 467                 DWORD dwCount;
 468
 469                 vidmem = DeviceExtension->VideoMemory;
 470                 offset = (pCoord->Y * DeviceExtension->Columns * 2) +
 471                          (pCoord->X * 2) + 1;
 472
 473                 for (dwCount = 0; dwCount < (stk->Parameters.Write.Length - sizeof( COORD )); dwCount++, pAttr++)
 474                 {
 475                     vidmem[offset + (dwCount * 2)] = *pAttr;
 476                 }
 477                 Irp->IoStatus.Information = 0;
 478                 Status = STATUS_SUCCESS;
 479             }
 480             break;
 481
 482         case IOCTL_CONSOLE_SET_TEXT_ATTRIBUTE:
 483             DeviceExtension->CharAttribute = (WORD)*(PWORD)Irp->AssociatedIrp.SystemBuffer;
 484             Irp->IoStatus.Information = 0;
 485             Status = STATUS_SUCCESS;
 486             break;
 487
 488
 489         case IOCTL_CONSOLE_FILL_OUTPUT_CHARACTER:
 490             {
 491                 POUTPUT_CHARACTER Buf = (POUTPUT_CHARACTER)Irp->AssociatedIrp.SystemBuffer;
 492                 char *vidmem;
 493                 int offset;
 494                 DWORD dwCount;
 495
 496                 vidmem = DeviceExtension->VideoMemory;
 497                 offset = (Buf->dwCoord.Y * DeviceExtension->Columns * 2) +
 498                          (Buf->dwCoord.X * 2);
 499
 500                 CHECKPOINT
 501
 502                 for (dwCount = 0; dwCount < Buf->nLength; dwCount++)
 503                 {
 504                     vidmem[offset + (dwCount * 2)] = (char) Buf->cCharacter;
 505                 }
 506
 507                 Buf->dwTransfered = Buf->nLength;
 508
 509                 Irp->IoStatus.Information = 0;
 510                 Status = STATUS_SUCCESS;
 511             }
 512             break;
 513
 514         case IOCTL_CONSOLE_READ_OUTPUT_CHARACTER:
 515             {
 516                 POUTPUT_CHARACTER Buf = (POUTPUT_CHARACTER)Irp->AssociatedIrp.SystemBuffer;
 517                 LPSTR pChar = (LPSTR)MmGetSystemAddressForMdl(Irp->MdlAddress);
 518                 char *vidmem;
 519                 int offset;
 520                 DWORD dwCount;
 521
 522                 vidmem = DeviceExtension->VideoMemory;
 523                 offset = (Buf->dwCoord.Y * DeviceExtension->Columns * 2) +
 524                          (Buf->dwCoord.X * 2);
 525
 526                 for (dwCount = 0; dwCount < stk->Parameters.Write.Length; dwCount++, pChar++)
 527                 {
 528                     *pChar = vidmem[offset + (dwCount * 2)];
 529                 }
 530
 531                 Buf->dwTransfered = dwCount;
 532
 533                 Irp->IoStatus.Information = sizeof(OUTPUT_ATTRIBUTE);
 534                 Status = STATUS_SUCCESS;
 535             }
 536             break;
 537
 538         case IOCTL_CONSOLE_WRITE_OUTPUT_CHARACTER:
 539             {
 540                 COORD *pCoord;
 541                 LPSTR pChar;
 542                 char *vidmem;
 543                 int offset;
 544                 DWORD dwCount;
 545                 pCoord = (COORD *)MmGetSystemAddressForMdl(Irp->MdlAddress);
 546                 pChar = (CHAR *)(pCoord + 1);
 547                 vidmem = DeviceExtension->VideoMemory;
 548                 offset = (pCoord->Y * DeviceExtension->Columns * 2) +
 549                          (pCoord->X * 2);
 550
 551                 for (dwCount = 0; dwCount < (stk->Parameters.Write.Length - sizeof( COORD )); dwCount++, pChar++)
 552                 {
 553                     vidmem[offset + (dwCount * 2)] = *pChar;
 554                 }
 555
 556                 Irp->IoStatus.Information = 0;
 557                 Status = STATUS_SUCCESS;
 558             }
 559             break;
 560
 561
 562         default:
 563             Status = STATUS_NOT_IMPLEMENTED;
 564     }
 565
 566     Irp->IoStatus.Status = Status;
 567     IoCompleteRequest (Irp, IO_NO_INCREMENT);
 568
 569     return (Status);
 570 }
 571
 572
 573 NTSTATUS
 574 STDCALL ScrDispatch (PDEVICE_OBJECT DeviceObject, PIRP Irp)
 575 {
 576     PIO_STACK_LOCATION stk = IoGetCurrentIrpStackLocation(Irp);
 577     NTSTATUS Status;
 578
 579     switch (stk->MajorFunction)
 580     {
 581         case IRP_MJ_CLOSE:
 582             Status = STATUS_SUCCESS;
 583             break;
 584
 585         default:
 586             Status = STATUS_NOT_IMPLEMENTED;
 587             break;
 588     }
 589
 590
 591     Irp->IoStatus.Status = Status;
 592     IoCompleteRequest (Irp, IO_NO_INCREMENT);
 593
 594     return (Status);
 595 }
 596
 597
 598 /*
 599  * Module entry point
 600  */
 601 NTSTATUS
 602 STDCALL
 603 DriverEntry (PDRIVER_OBJECT DriverObject, PUNICODE_STRING RegistryPath)
 604 {
 605     PDEVICE_OBJECT DeviceObject;
 606     UNICODE_STRING DeviceName;
 607     UNICODE_STRING SymlinkName;
 608
 609     DbgPrint ("Screen Driver 0.0.6\n");
 610
 611     DriverObject->MajorFunction[IRP_MJ_CREATE] = ScrCreate;
 612     DriverObject->MajorFunction[IRP_MJ_CLOSE]  = ScrDispatch;
 613     DriverObject->MajorFunction[IRP_MJ_READ]   = ScrDispatch;
 614     DriverObject->MajorFunction[IRP_MJ_WRITE]  = ScrWrite;
 615     DriverObject->MajorFunction[IRP_MJ_DEVICE_CONTROL ] = ScrIoControl;
 616
 617     RtlInitUnicodeString (&DeviceName, L"\\Device\\BlueScreen");
 618     IoCreateDevice (DriverObject,
 619                     sizeof(DEVICE_EXTENSION),
 620                     &DeviceName,
 621                     FILE_DEVICE_SCREEN,
 622                     0,
 623                     TRUE,
 624                     &DeviceObject);
 625
 626     RtlInitUnicodeString (&SymlinkName, L"\\??\\BlueScreen");
 627     IoCreateSymbolicLink (&SymlinkName, &DeviceName);
 628
 629     return (STATUS_SUCCESS);
 630 }
 631
 632 /* EOF */