drivers/dd/blue/blue.c

   1 /* $Id$
   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 STDCALL
  71 ScrCreate(PDEVICE_OBJECT DeviceObject,
  72           PIRP Irp)
  73 {
  74     PDEVICE_EXTENSION DeviceExtension;
  75     PHYSICAL_ADDRESS BaseAddress;
  76     NTSTATUS Status;
  77     unsigned int offset;
  78     BYTE data, value;
  79
  80     DeviceExtension = DeviceObject->DeviceExtension;
  81
  82     /* get pointer to video memory */
  83     BaseAddress.QuadPart = VIDMEM_BASE;
  84     DeviceExtension->VideoMemory =
  85         (PBYTE)MmMapIoSpace (BaseAddress, VIDMEM_SIZE, FALSE);
  86
  87     /* disable interrupts */
  88     __asm__("cli\n\t");
  89
  90     /* get current output position */
  91     WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_CURSORPOSLO);
  92     offset = READ_PORT_UCHAR (CRTC_DATA);
  93     WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_CURSORPOSHI);
  94     offset += (READ_PORT_UCHAR (CRTC_DATA) << 8);
  95
  96     /* switch blinking characters off */
  97     READ_PORT_UCHAR (ATTRC_INPST1);
  98     value = READ_PORT_UCHAR (ATTRC_WRITEREG);
  99     WRITE_PORT_UCHAR (ATTRC_WRITEREG, 0x10);
 100     data  = READ_PORT_UCHAR (ATTRC_READREG);
 101     data  = data & ~0x08;
 102     WRITE_PORT_UCHAR (ATTRC_WRITEREG, data);
 103     WRITE_PORT_UCHAR (ATTRC_WRITEREG, value);
 104     READ_PORT_UCHAR (ATTRC_INPST1);
 105
 106     /* read screen information from crt controller */
 107     WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_COLUMNS);
 108     DeviceExtension->Columns = READ_PORT_UCHAR (CRTC_DATA) + 1;
 109     WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_ROWS);
 110     DeviceExtension->Rows = READ_PORT_UCHAR (CRTC_DATA);
 111     WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_OVERFLOW);
 112     data = READ_PORT_UCHAR (CRTC_DATA);
 113     DeviceExtension->Rows |= (((data & 0x02) << 7) | ((data & 0x40) << 3));
 114     DeviceExtension->Rows++;
 115     WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_SCANLINES);
 116     DeviceExtension->ScanLines = (READ_PORT_UCHAR (CRTC_DATA) & 0x1F) + 1;
 117
 118     /* enable interrupts */
 119     __asm__("sti\n\t");
 120
 121     /* calculate number of text rows */
 122     DeviceExtension->Rows =
 123         DeviceExtension->Rows / DeviceExtension->ScanLines;
 124 #ifdef BOCHS_30ROWS
 125     DeviceExtension->Rows = 30;
 126 #endif
 127
 128     DPRINT ("%d Columns  %d Rows %d Scanlines\n",
 129             DeviceExtension->Columns,
 130             DeviceExtension->Rows,
 131             DeviceExtension->ScanLines);
 132
 133     DeviceExtension->CursorSize    = 5; /* FIXME: value correct?? */
 134     DeviceExtension->CursorVisible = TRUE;
 135
 136     /* more initialization */
 137     DeviceExtension->CharAttribute = 0x17;  /* light grey on blue */
 138     DeviceExtension->Mode = ENABLE_PROCESSED_OUTPUT |
 139                             ENABLE_WRAP_AT_EOL_OUTPUT;
 140
 141     /* show blinking cursor */
 142     __asm__("cli\n\t");
 143     WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_CURSORSTART);
 144     WRITE_PORT_UCHAR (CRTC_DATA, (DeviceExtension->ScanLines - 1) & 0x1F);
 145     WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_CURSOREND);
 146     data = READ_PORT_UCHAR (CRTC_DATA) & 0xE0;
 147     WRITE_PORT_UCHAR (CRTC_DATA,
 148                       data | ((DeviceExtension->ScanLines - 1) & 0x1F));
 149     __asm__("sti\n\t");
 150
 151     Status = STATUS_SUCCESS;
 152
 153     Irp->IoStatus.Status = Status;
 154     IoCompleteRequest (Irp, IO_NO_INCREMENT);
 155
 156     return (Status);
 157 }
 158
 159
 160 NTSTATUS STDCALL
 161 ScrWrite(PDEVICE_OBJECT DeviceObject,
 162          PIRP Irp)
 163 {
 164     PIO_STACK_LOCATION stk = IoGetCurrentIrpStackLocation (Irp);
 165     PDEVICE_EXTENSION DeviceExtension = DeviceObject->DeviceExtension;
 166     NTSTATUS Status;
 167     char *pch = Irp->UserBuffer;
 168     char *vidmem;
 169     int i, j, offset;
 170     int cursorx, cursory;
 171     int rows, columns;
 172     int processed = DeviceExtension->Mode & ENABLE_PROCESSED_OUTPUT;
 173
 174     vidmem  = DeviceExtension->VideoMemory;
 175     rows = DeviceExtension->Rows;
 176     columns = DeviceExtension->Columns;
 177
 178     WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_CURSORPOSHI);
 179     offset = READ_PORT_UCHAR (CRTC_DATA)<<8;
 180     WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_CURSORPOSLO);
 181     offset += READ_PORT_UCHAR (CRTC_DATA);
 182
 183     cursory = offset / columns;
 184     cursorx = offset % columns;
 185     if( processed == 0 )
 186        {
 187           /* raw output mode */
 188           memcpy( &vidmem[(cursorx * 2) + (cursory * columns * 2)], pch, stk->Parameters.Write.Length );
 189           offset += (stk->Parameters.Write.Length / 2);
 190        }
 191     else {
 192        for (i = 0; i < stk->Parameters.Write.Length; i++, pch++)
 193           {
 194              switch (*pch)
 195                 {
 196                 case '\b':
 197                    if (cursorx > 0)
 198                       {
 199                          cursorx--;
 200                       }
 201                    else if (cursory > 0)
 202                       {
 203                          cursorx = columns - 1;
 204                          cursory--;
 205                       }
 206                    vidmem[(cursorx * 2) + (cursory * columns * 2)] = ' ';
 207                    vidmem[(cursorx * 2) + (cursory * columns * 2) + 1] = (char) DeviceExtension->CharAttribute;
 208                    break;
 209
 210                 case '\n':
 211                    cursory++;
 212                    cursorx = 0;
 213                    break;
 214
 215                 case '\r':
 216                    cursorx = 0;
 217                    break;
 218
 219                 case '\t':
 220                    offset = TAB_WIDTH - (cursorx % TAB_WIDTH);
 221                    for (j = 0; j < offset; j++)
 222                       {
 223                          vidmem[(cursorx * 2) + (cursory * columns * 2)] = ' ';
 224                          cursorx++;
 225
 226                          if (cursorx >= columns)
 227                             {
 228                                cursory++;
 229                                cursorx = 0;
 230                             }
 231                       }
 232                    break;
 233
 234                 default:
 235                    vidmem[(cursorx * 2) + (cursory * columns * 2)] = *pch;
 236                    vidmem[(cursorx * 2) + (cursory * columns * 2) + 1] = (char) DeviceExtension->CharAttribute;
 237                    cursorx++;
 238                    if (cursorx >= columns)
 239                       {
 240                          cursory++;
 241                          cursorx = 0;
 242                       }
 243                    break;
 244                 }
 245              if (cursory >= rows)
 246                 {
 247                    unsigned short *LinePtr;
 248
 249                    memcpy (vidmem,
 250                            &vidmem[columns * 2],
 251                            columns * (rows - 1) * 2);
 252
 253                    LinePtr = (unsigned short *) &vidmem[columns * (rows - 1) * 2];
 254
 255                    for (j = 0; j < columns; j++)
 256                       {
 257                          LinePtr[j] = DeviceExtension->CharAttribute << 8;
 258                       }
 259                    cursory = rows - 1;
 260                    for (j = 0; j < columns; j++)
 261                       {
 262                          vidmem[(j * 2) + (cursory * columns * 2)] = ' ';
 263                          vidmem[(j * 2) + (cursory * columns * 2) + 1] = (char)DeviceExtension->CharAttribute;
 264                       }
 265                 }
 266           }
 267
 268        /* Set the cursor position */
 269        offset = (cursory * columns) + cursorx;
 270     }
 271     WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_CURSORPOSLO);
 272     WRITE_PORT_UCHAR (CRTC_DATA, offset);
 273     WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_CURSORPOSHI);
 274     offset >>= 8;
 275     WRITE_PORT_UCHAR (CRTC_DATA, offset);
 276
 277     Status = STATUS_SUCCESS;
 278
 279     Irp->IoStatus.Status = Status;
 280     IoCompleteRequest (Irp, IO_NO_INCREMENT);
 281
 282     return (Status);
 283 }
 284
 285
 286 NTSTATUS STDCALL
 287 ScrIoControl(PDEVICE_OBJECT DeviceObject,
 288              PIRP Irp)
 289 {
 290     PIO_STACK_LOCATION stk = IoGetCurrentIrpStackLocation (Irp);
 291     PDEVICE_EXTENSION DeviceExtension;
 292     NTSTATUS Status;
 293     DeviceExtension = DeviceObject->DeviceExtension;
 294     switch (stk->Parameters.DeviceIoControl.IoControlCode)
 295     {
 296         case IOCTL_CONSOLE_GET_SCREEN_BUFFER_INFO:
 297             {
 298                 PCONSOLE_SCREEN_BUFFER_INFO pcsbi = (PCONSOLE_SCREEN_BUFFER_INFO)Irp->AssociatedIrp.SystemBuffer;
 299                 int rows = DeviceExtension->Rows;
 300                 int columns = DeviceExtension->Columns;
 301                 unsigned int offset;
 302
 303                 /* read cursor position from crtc */
 304                 __asm__("cli\n\t");
 305                 WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_CURSORPOSLO);
 306                 offset = READ_PORT_UCHAR (CRTC_DATA);
 307                 WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_CURSORPOSHI);
 308                 offset += (READ_PORT_UCHAR (CRTC_DATA) << 8);
 309                 __asm__("sti\n\t");
 310
 311                 pcsbi->dwSize.X = columns;
 312                 pcsbi->dwSize.Y = rows;
 313
 314                 pcsbi->dwCursorPosition.X = (SHORT)(offset % columns);
 315                 pcsbi->dwCursorPosition.Y = (SHORT)(offset / columns);
 316
 317                 pcsbi->wAttributes = DeviceExtension->CharAttribute;
 318
 319                 pcsbi->srWindow.Left   = 0;
 320                 pcsbi->srWindow.Right  = columns - 1;
 321                 pcsbi->srWindow.Top    = 0;
 322                 pcsbi->srWindow.Bottom = rows - 1;
 323
 324                 pcsbi->dwMaximumWindowSize.X = columns;
 325                 pcsbi->dwMaximumWindowSize.Y = rows;
 326
 327                 Irp->IoStatus.Information = sizeof (CONSOLE_SCREEN_BUFFER_INFO);
 328                 Status = STATUS_SUCCESS;
 329             }
 330             break;
 331
 332         case IOCTL_CONSOLE_SET_SCREEN_BUFFER_INFO:
 333             {
 334                 PCONSOLE_SCREEN_BUFFER_INFO pcsbi = (PCONSOLE_SCREEN_BUFFER_INFO)Irp->AssociatedIrp.SystemBuffer;
 335                 unsigned int offset;
 336
 337                 DeviceExtension->CharAttribute = pcsbi->wAttributes;
 338                 offset = (pcsbi->dwCursorPosition.Y * DeviceExtension->Columns) +
 339                           pcsbi->dwCursorPosition.X;
 340
 341                 __asm__("cli\n\t");
 342                 WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_CURSORPOSLO);
 343                 WRITE_PORT_UCHAR (CRTC_DATA, offset);
 344                 WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_CURSORPOSHI);
 345                 WRITE_PORT_UCHAR (CRTC_DATA, offset>>8);
 346                 __asm__("sti\n\t");
 347
 348                 Irp->IoStatus.Information = 0;
 349                 Status = STATUS_SUCCESS;
 350             }
 351             break;
 352
 353         case IOCTL_CONSOLE_GET_CURSOR_INFO:
 354             {
 355                 PCONSOLE_CURSOR_INFO pcci = (PCONSOLE_CURSOR_INFO)Irp->AssociatedIrp.SystemBuffer;
 356
 357                 pcci->dwSize = DeviceExtension->CursorSize;
 358                 pcci->bVisible = DeviceExtension->CursorVisible;
 359
 360                 Irp->IoStatus.Information = sizeof (CONSOLE_CURSOR_INFO);
 361                 Status = STATUS_SUCCESS;
 362             }
 363             break;
 364
 365         case IOCTL_CONSOLE_SET_CURSOR_INFO:
 366             {
 367                 PCONSOLE_CURSOR_INFO pcci = (PCONSOLE_CURSOR_INFO)Irp->AssociatedIrp.SystemBuffer;
 368                 BYTE data, value;
 369                 DWORD size, height;
 370
 371                 DeviceExtension->CursorSize = pcci->dwSize;
 372                 DeviceExtension->CursorVisible = pcci->bVisible;
 373                 height = DeviceExtension->ScanLines;
 374                 data = (pcci->bVisible) ? 0x40 : 0x20;
 375
 376                 size = (pcci->dwSize * height) / 100;
 377                 if (size < 1)
 378                     size = 1;
 379
 380                 data |= (BYTE)(height - size);
 381
 382                 __asm__("cli\n\t");
 383                 WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_CURSORSTART);
 384                 WRITE_PORT_UCHAR (CRTC_DATA, data);
 385                 WRITE_PORT_UCHAR (CRTC_COMMAND, CRTC_CURSOREND);
 386                 value = READ_PORT_UCHAR (CRTC_DATA) & 0xE0;
 387                 WRITE_PORT_UCHAR (CRTC_DATA, value | (height - 1));
 388
 389                 __asm__("sti\n\t");
 390
 391                 Irp->IoStatus.Information = 0;
 392                 Status = STATUS_SUCCESS;
 393             }
 394             break;
 395
 396         case IOCTL_CONSOLE_GET_MODE:
 397             {
 398                 PCONSOLE_MODE pcm = (PCONSOLE_MODE)Irp->AssociatedIrp.SystemBuffer;
 399
 400                 pcm->dwMode = DeviceExtension->Mode;
 401
 402                 Irp->IoStatus.Information = sizeof(CONSOLE_MODE);
 403                 Status = STATUS_SUCCESS;
 404             }
 405             break;
 406
 407         case IOCTL_CONSOLE_SET_MODE:
 408             {
 409                 PCONSOLE_MODE pcm = (PCONSOLE_MODE)Irp->AssociatedIrp.SystemBuffer;
 410
 411                 DeviceExtension->Mode = pcm->dwMode;
 412
 413                 Irp->IoStatus.Information = 0;
 414                 Status = STATUS_SUCCESS;
 415             }
 416             break;
 417
 418         case IOCTL_CONSOLE_FILL_OUTPUT_ATTRIBUTE:
 419             {
 420                 POUTPUT_ATTRIBUTE Buf = (POUTPUT_ATTRIBUTE)Irp->AssociatedIrp.SystemBuffer;
 421                 char *vidmem;
 422                 int offset;
 423                 DWORD dwCount;
 424
 425                 vidmem = DeviceExtension->VideoMemory;
 426                 offset = (Buf->dwCoord.Y * DeviceExtension->Columns * 2) +
 427                          (Buf->dwCoord.X * 2) + 1;
 428
 429                 for (dwCount = 0; dwCount < Buf->nLength; dwCount++)
 430                 {
 431                     vidmem[offset + (dwCount * 2)] = (char) Buf->wAttribute;
 432                 }
 433
 434                 Buf->dwTransfered = Buf->nLength;
 435
 436                 Irp->IoStatus.Information = 0;
 437                 Status = STATUS_SUCCESS;
 438             }
 439             break;
 440
 441         case IOCTL_CONSOLE_READ_OUTPUT_ATTRIBUTE:
 442             {
 443                 POUTPUT_ATTRIBUTE Buf = (POUTPUT_ATTRIBUTE)Irp->AssociatedIrp.SystemBuffer;
 444                 PWORD pAttr = (PWORD)MmGetSystemAddressForMdl(Irp->MdlAddress);
 445                 char *vidmem;
 446                 int offset;
 447                 DWORD dwCount;
 448
 449                 vidmem = DeviceExtension->VideoMemory;
 450                 offset = (Buf->dwCoord.Y * DeviceExtension->Columns * 2) +
 451                          (Buf->dwCoord.X * 2) + 1;
 452
 453                 for (dwCount = 0; dwCount < stk->Parameters.Write.Length; dwCount++, pAttr++)
 454                 {
 455                     (char) *pAttr = vidmem[offset + (dwCount * 2)];
 456                 }
 457
 458                 Buf->dwTransfered = dwCount;
 459
 460                 Irp->IoStatus.Information = sizeof(OUTPUT_ATTRIBUTE);
 461                 Status = STATUS_SUCCESS;
 462             }
 463             break;
 464
 465         case IOCTL_CONSOLE_WRITE_OUTPUT_ATTRIBUTE:
 466             {
 467                 COORD *pCoord = (COORD *)MmGetSystemAddressForMdl(Irp->MdlAddress);
 468                 CHAR *pAttr = (CHAR *)(pCoord + 1);
 469                 char *vidmem;
 470                 int offset;
 471                 DWORD dwCount;
 472
 473                 vidmem = DeviceExtension->VideoMemory;
 474                 offset = (pCoord->Y * DeviceExtension->Columns * 2) +
 475                          (pCoord->X * 2) + 1;
 476
 477                 for (dwCount = 0; dwCount < (stk->Parameters.Write.Length - sizeof( COORD )); dwCount++, pAttr++)
 478                 {
 479                     vidmem[offset + (dwCount * 2)] = *pAttr;
 480                 }
 481                 Irp->IoStatus.Information = 0;
 482                 Status = STATUS_SUCCESS;
 483             }
 484             break;
 485
 486         case IOCTL_CONSOLE_SET_TEXT_ATTRIBUTE:
 487             DeviceExtension->CharAttribute = (WORD)*(PWORD)Irp->AssociatedIrp.SystemBuffer;
 488             Irp->IoStatus.Information = 0;
 489             Status = STATUS_SUCCESS;
 490             break;
 491
 492
 493         case IOCTL_CONSOLE_FILL_OUTPUT_CHARACTER:
 494             {
 495                 POUTPUT_CHARACTER Buf = (POUTPUT_CHARACTER)Irp->AssociatedIrp.SystemBuffer;
 496                 char *vidmem;
 497                 int offset;
 498                 DWORD dwCount;
 499
 500                 vidmem = DeviceExtension->VideoMemory;
 501                 offset = (Buf->dwCoord.Y * DeviceExtension->Columns * 2) +
 502                          (Buf->dwCoord.X * 2);
 503
 504                 CHECKPOINT
 505
 506                 for (dwCount = 0; dwCount < Buf->nLength; dwCount++)
 507                 {
 508                     vidmem[offset + (dwCount * 2)] = (char) Buf->cCharacter;
 509                 }
 510
 511                 Buf->dwTransfered = Buf->nLength;
 512
 513                 Irp->IoStatus.Information = 0;
 514                 Status = STATUS_SUCCESS;
 515             }
 516             break;
 517
 518         case IOCTL_CONSOLE_READ_OUTPUT_CHARACTER:
 519             {
 520                 POUTPUT_CHARACTER Buf = (POUTPUT_CHARACTER)Irp->AssociatedIrp.SystemBuffer;
 521                 LPSTR pChar = (LPSTR)MmGetSystemAddressForMdl(Irp->MdlAddress);
 522                 char *vidmem;
 523                 int offset;
 524                 DWORD dwCount;
 525
 526                 vidmem = DeviceExtension->VideoMemory;
 527                 offset = (Buf->dwCoord.Y * DeviceExtension->Columns * 2) +
 528                          (Buf->dwCoord.X * 2);
 529
 530                 for (dwCount = 0; dwCount < stk->Parameters.Write.Length; dwCount++, pChar++)
 531                 {
 532                     *pChar = vidmem[offset + (dwCount * 2)];
 533                 }
 534
 535                 Buf->dwTransfered = dwCount;
 536
 537                 Irp->IoStatus.Information = sizeof(OUTPUT_ATTRIBUTE);
 538                 Status = STATUS_SUCCESS;
 539             }
 540             break;
 541
 542         case IOCTL_CONSOLE_WRITE_OUTPUT_CHARACTER:
 543             {
 544                 COORD *pCoord;
 545                 LPSTR pChar;
 546                 char *vidmem;
 547                 int offset;
 548                 DWORD dwCount;
 549                 pCoord = (COORD *)MmGetSystemAddressForMdl(Irp->MdlAddress);
 550                 pChar = (CHAR *)(pCoord + 1);
 551                 vidmem = DeviceExtension->VideoMemory;
 552                 offset = (pCoord->Y * DeviceExtension->Columns * 2) +
 553                          (pCoord->X * 2);
 554
 555                 for (dwCount = 0; dwCount < (stk->Parameters.Write.Length - sizeof( COORD )); dwCount++, pChar++)
 556                 {
 557                     vidmem[offset + (dwCount * 2)] = *pChar;
 558                 }
 559
 560                 Irp->IoStatus.Information = 0;
 561                 Status = STATUS_SUCCESS;
 562             }
 563             break;
 564
 565
 566         default:
 567             Status = STATUS_NOT_IMPLEMENTED;
 568     }
 569
 570     Irp->IoStatus.Status = Status;
 571     IoCompleteRequest (Irp, IO_NO_INCREMENT);
 572
 573     return (Status);
 574 }
 575
 576
 577 NTSTATUS STDCALL
 578 ScrDispatch(PDEVICE_OBJECT DeviceObject,
 579             PIRP Irp)
 580 {
 581     PIO_STACK_LOCATION stk = IoGetCurrentIrpStackLocation(Irp);
 582     NTSTATUS Status;
 583
 584     switch (stk->MajorFunction)
 585     {
 586         case IRP_MJ_CLOSE:
 587             Status = STATUS_SUCCESS;
 588             break;
 589
 590         default:
 591             Status = STATUS_NOT_IMPLEMENTED;
 592             break;
 593     }
 594
 595
 596     Irp->IoStatus.Status = Status;
 597     IoCompleteRequest (Irp, IO_NO_INCREMENT);
 598
 599     return (Status);
 600 }
 601
 602
 603 /*
 604  * Module entry point
 605  */
 606 NTSTATUS STDCALL
 607 DriverEntry (PDRIVER_OBJECT DriverObject, PUNICODE_STRING RegistryPath)
 608 {
 609     PDEVICE_OBJECT DeviceObject;
 610     UNICODE_STRING DeviceName = UNICODE_STRING_INITIALIZER(L"\\Device\\BlueScreen");
 611     UNICODE_STRING SymlinkName = UNICODE_STRING_INITIALIZER(L"\\??\\BlueScreen");
 612
 613     DPRINT ("Screen Driver 0.0.6\n");
 614
 615     DriverObject->MajorFunction[IRP_MJ_CREATE] = ScrCreate;
 616     DriverObject->MajorFunction[IRP_MJ_CLOSE]  = ScrDispatch;
 617     DriverObject->MajorFunction[IRP_MJ_READ]   = ScrDispatch;
 618     DriverObject->MajorFunction[IRP_MJ_WRITE]  = ScrWrite;
 619     DriverObject->MajorFunction[IRP_MJ_DEVICE_CONTROL ] = ScrIoControl;
 620
 621     IoCreateDevice (DriverObject,
 622                     sizeof(DEVICE_EXTENSION),
 623                     &DeviceName,
 624                     FILE_DEVICE_SCREEN,
 625                     0,
 626                     TRUE,
 627                     &DeviceObject);
 628
 629     IoCreateSymbolicLink (&SymlinkName, &DeviceName);
 630
 631     return (STATUS_SUCCESS);
 632 }
 633
 634 /* EOF */