MdeModulePkg/Universal/Acpi/BootGraphicsResourceTableDxe/BootGraphicsResourceTableDxe.c

   1 /** @file
   2   This module install ACPI Boot Graphics Resource Table (BGRT).
   3
   4   Copyright (c) 2011 - 2018, Intel Corporation. All rights reserved.<BR>
   5   Copyright (c) 2016, Microsoft Corporation<BR>
   6   SPDX-License-Identifier: BSD-2-Clause-Patent
   7 **/
   8
   9 #include <Uefi.h>
  10
  11 #include <IndustryStandard/Acpi.h>
  12
  13 #include <Protocol/AcpiTable.h>
  14 #include <Protocol/GraphicsOutput.h>
  15 #include <Protocol/BootLogo.h>
  16 #include <Protocol/BootLogo2.h>
  17
  18 #include <Guid/EventGroup.h>
  19
  20 #include <Library/BaseLib.h>
  21 #include <Library/BaseMemoryLib.h>
  22 #include <Library/MemoryAllocationLib.h>
  23 #include <Library/UefiBootServicesTableLib.h>
  24 #include <Library/DebugLib.h>
  25 #include <Library/PcdLib.h>
  26 #include <Library/SafeIntLib.h>
  27 #include <Library/BmpSupportLib.h>
  28
  29 /**
  30   Update information of logo image drawn on screen.
  31
  32   @param[in] This          The pointer to the Boot Logo protocol 2 instance.
  33   @param[in] BltBuffer     The BLT buffer for logo drawn on screen. If BltBuffer
  34                            is set to NULL, it indicates that logo image is no
  35                            longer on the screen.
  36   @param[in] DestinationX  X coordinate of destination for the BltBuffer.
  37   @param[in] DestinationY  Y coordinate of destination for the BltBuffer.
  38   @param[in] Width         Width of rectangle in BltBuffer in pixels.
  39   @param[in] Height        Hight of rectangle in BltBuffer in pixels.
  40
  41   @retval EFI_SUCCESS            The boot logo information was updated.
  42   @retval EFI_INVALID_PARAMETER  One of the parameters has an invalid value.
  43   @retval EFI_OUT_OF_RESOURCES   The logo information was not updated due to
  44                                  insufficient memory resources.
  45 **/
  46 EFI_STATUS
  47 EFIAPI
  48 SetBootLogo (
  49   IN EFI_BOOT_LOGO_PROTOCOL         *This,
  50   IN EFI_GRAPHICS_OUTPUT_BLT_PIXEL  *BltBuffer       OPTIONAL,
  51   IN UINTN                          DestinationX,
  52   IN UINTN                          DestinationY,
  53   IN UINTN                          Width,
  54   IN UINTN                          Height
  55   );
  56
  57 /**
  58   Update information of logo image drawn on screen.
  59
  60   @param[in] This          The pointer to the Boot Logo protocol 2 instance.
  61   @param[in] BltBuffer     The BLT buffer for logo drawn on screen. If BltBuffer
  62                            is set to NULL, it indicates that logo image is no
  63                            longer on the screen.
  64   @param[in] DestinationX  X coordinate of destination for the BltBuffer.
  65   @param[in] DestinationY  Y coordinate of destination for the BltBuffer.
  66   @param[in] Width         Width of rectangle in BltBuffer in pixels.
  67   @param[in] Height        Hight of rectangle in BltBuffer in pixels.
  68
  69   @retval EFI_SUCCESS            The boot logo information was updated.
  70   @retval EFI_INVALID_PARAMETER  One of the parameters has an invalid value.
  71   @retval EFI_OUT_OF_RESOURCES   The logo information was not updated due to
  72                                  insufficient memory resources.
  73 **/
  74 EFI_STATUS
  75 EFIAPI
  76 SetBootLogo2 (
  77   IN EDKII_BOOT_LOGO2_PROTOCOL      *This,
  78   IN EFI_GRAPHICS_OUTPUT_BLT_PIXEL  *BltBuffer       OPTIONAL,
  79   IN UINTN                          DestinationX,
  80   IN UINTN                          DestinationY,
  81   IN UINTN                          Width,
  82   IN UINTN                          Height
  83   );
  84
  85 /**
  86   Get the location of the boot logo on the screen.
  87
  88   @param[in]  This          The pointer to the Boot Logo Protocol 2 instance
  89   @param[out] BltBuffer     Returns pointer to the GOP BLT buffer that was
  90                             previously registered with SetBootLogo2(). The
  91                             buffer returned must not be modified or freed.
  92   @param[out] DestinationX  Returns the X start position of the GOP BLT buffer
  93                             that was previously registered with SetBootLogo2().
  94   @param[out] DestinationY  Returns the Y start position of the GOP BLT buffer
  95                             that was previously registered with SetBootLogo2().
  96   @param[out] Width         Returns the width of the GOP BLT buffer
  97                             that was previously registered with SetBootLogo2().
  98   @param[out] Height        Returns the height of the GOP BLT buffer
  99                             that was previously registered with SetBootLogo2().
 100
 101   @retval EFI_SUCCESS            The location of the boot logo was returned.
 102   @retval EFI_NOT_READY          The boot logo has not been set.
 103   @retval EFI_INVALID_PARAMETER  BltBuffer is NULL.
 104   @retval EFI_INVALID_PARAMETER  DestinationX is NULL.
 105   @retval EFI_INVALID_PARAMETER  DestinationY is NULL.
 106   @retval EFI_INVALID_PARAMETER  Width is NULL.
 107   @retval EFI_INVALID_PARAMETER  Height is NULL.
 108 **/
 109 EFI_STATUS
 110 EFIAPI
 111 GetBootLogo2 (
 112   IN  EDKII_BOOT_LOGO2_PROTOCOL      *This,
 113   OUT EFI_GRAPHICS_OUTPUT_BLT_PIXEL  **BltBuffer,
 114   OUT UINTN                          *DestinationX,
 115   OUT UINTN                          *DestinationY,
 116   OUT UINTN                          *Width,
 117   OUT UINTN                          *Height
 118   );
 119
 120 //
 121 // Boot Logo Protocol Handle
 122 //
 123 EFI_HANDLE  mBootLogoHandle = NULL;
 124
 125 //
 126 // Boot Logo Protocol Instance
 127 //
 128 EFI_BOOT_LOGO_PROTOCOL  mBootLogoProtocolTemplate = {
 129   SetBootLogo
 130 };
 131
 132 ///
 133 /// Boot Logo 2 Protocol instance
 134 ///
 135 EDKII_BOOT_LOGO2_PROTOCOL mBootLogo2ProtocolTemplate = {
 136   SetBootLogo2,
 137   GetBootLogo2
 138 };
 139
 140 EFI_EVENT                      mBootGraphicsReadyToBootEvent;
 141 UINTN                          mBootGraphicsResourceTableKey = 0;
 142 BOOLEAN                        mIsLogoValid = FALSE;
 143 EFI_GRAPHICS_OUTPUT_BLT_PIXEL  *mLogoBltBuffer = NULL;
 144 UINTN                          mLogoDestX  = 0;
 145 UINTN                          mLogoDestY  = 0;
 146 UINTN                          mLogoWidth  = 0;
 147 UINTN                          mLogoHeight = 0;
 148 BOOLEAN                        mAcpiBgrtInstalled     = FALSE;
 149 BOOLEAN                        mAcpiBgrtStatusChanged = FALSE;
 150 BOOLEAN                        mAcpiBgrtBufferChanged = FALSE;
 151
 152 //
 153 // ACPI Boot Graphics Resource Table template
 154 //
 155 EFI_ACPI_5_0_BOOT_GRAPHICS_RESOURCE_TABLE mBootGraphicsResourceTableTemplate = {
 156   {
 157     EFI_ACPI_5_0_BOOT_GRAPHICS_RESOURCE_TABLE_SIGNATURE,
 158     sizeof (EFI_ACPI_5_0_BOOT_GRAPHICS_RESOURCE_TABLE),
 159     EFI_ACPI_5_0_BOOT_GRAPHICS_RESOURCE_TABLE_REVISION,     // Revision
 160     0x00,  // Checksum will be updated at runtime
 161     //
 162     // It is expected that these values will be updated at EntryPoint.
 163     //
 164     {0x00},     // OEM ID is a 6 bytes long field
 165     0x00,       // OEM Table ID(8 bytes long)
 166     0x00,       // OEM Revision
 167     0x00,       // Creator ID
 168     0x00,       // Creator Revision
 169   },
 170   EFI_ACPI_5_0_BGRT_VERSION,         // Version
 171   EFI_ACPI_5_0_BGRT_STATUS_VALID,    // Status
 172   EFI_ACPI_5_0_BGRT_IMAGE_TYPE_BMP,  // Image Type
 173   0,                                 // Image Address
 174   0,                                 // Image Offset X
 175   0                                  // Image Offset Y
 176 };
 177
 178 /**
 179   Update information of logo image drawn on screen.
 180
 181   @param  This           The pointer to the Boot Logo protocol instance.
 182   @param  BltBuffer      The BLT buffer for logo drawn on screen. If BltBuffer
 183                          is set to NULL, it indicates that logo image is no
 184                          longer on the screen.
 185   @param  DestinationX   X coordinate of destination for the BltBuffer.
 186   @param  DestinationY   Y coordinate of destination for the BltBuffer.
 187   @param  Width          Width of rectangle in BltBuffer in pixels.
 188   @param  Height         Hight of rectangle in BltBuffer in pixels.
 189
 190   @retval EFI_SUCCESS             The boot logo information was updated.
 191   @retval EFI_INVALID_PARAMETER   One of the parameters has an invalid value.
 192   @retval EFI_OUT_OF_RESOURCES    The logo information was not updated due to
 193                                   insufficient memory resources.
 194
 195 **/
 196 EFI_STATUS
 197 EFIAPI
 198 SetBootLogo (
 199   IN EFI_BOOT_LOGO_PROTOCOL            *This,
 200   IN EFI_GRAPHICS_OUTPUT_BLT_PIXEL     *BltBuffer       OPTIONAL,
 201   IN UINTN                             DestinationX,
 202   IN UINTN                             DestinationY,
 203   IN UINTN                             Width,
 204   IN UINTN                             Height
 205   )
 206 {
 207   //
 208   // Call same service in Boot Logo 2 Protocol
 209   //
 210   return SetBootLogo2 (
 211            &mBootLogo2ProtocolTemplate,
 212            BltBuffer,
 213            DestinationX,
 214            DestinationY,
 215            Width,
 216            Height
 217            );
 218 }
 219
 220 /**
 221   Update information of logo image drawn on screen.
 222
 223   @param[in] This          The pointer to the Boot Logo protocol 2 instance.
 224   @param[in] BltBuffer     The BLT buffer for logo drawn on screen. If BltBuffer
 225                            is set to NULL, it indicates that logo image is no
 226                            longer on the screen.
 227   @param[in] DestinationX  X coordinate of destination for the BltBuffer.
 228   @param[in] DestinationY  Y coordinate of destination for the BltBuffer.
 229   @param[in] Width         Width of rectangle in BltBuffer in pixels.
 230   @param[in] Height        Hight of rectangle in BltBuffer in pixels.
 231
 232   @retval EFI_SUCCESS            The boot logo information was updated.
 233   @retval EFI_INVALID_PARAMETER  One of the parameters has an invalid value.
 234   @retval EFI_OUT_OF_RESOURCES   The logo information was not updated due to
 235                                  insufficient memory resources.
 236 **/
 237 EFI_STATUS
 238 EFIAPI
 239 SetBootLogo2 (
 240   IN EDKII_BOOT_LOGO2_PROTOCOL      *This,
 241   IN EFI_GRAPHICS_OUTPUT_BLT_PIXEL  *BltBuffer       OPTIONAL,
 242   IN UINTN                          DestinationX,
 243   IN UINTN                          DestinationY,
 244   IN UINTN                          Width,
 245   IN UINTN                          Height
 246   )
 247 {
 248   EFI_STATUS  Status;
 249   UINTN       BufferSize;
 250   UINT32      Result32;
 251
 252   if (BltBuffer == NULL) {
 253     mIsLogoValid = FALSE;
 254     mAcpiBgrtStatusChanged = TRUE;
 255     return EFI_SUCCESS;
 256   }
 257
 258   //
 259   // Width and height are not allowed to be zero.
 260   //
 261   if (Width == 0 || Height == 0) {
 262     return EFI_INVALID_PARAMETER;
 263   }
 264
 265   //
 266   // Verify destination, width, and height do not overflow 32-bit values.
 267   // The Boot Graphics Resource Table only has 32-bit fields for these values.
 268   //
 269   Status = SafeUintnToUint32 (DestinationX, &Result32);
 270   if (EFI_ERROR (Status)) {
 271     return EFI_INVALID_PARAMETER;
 272   }
 273   Status = SafeUintnToUint32 (DestinationY, &Result32);
 274   if (EFI_ERROR (Status)) {
 275     return EFI_INVALID_PARAMETER;
 276   }
 277   Status = SafeUintnToUint32 (Width, &Result32);
 278   if (EFI_ERROR (Status)) {
 279     return EFI_INVALID_PARAMETER;
 280   }
 281   Status = SafeUintnToUint32 (Height, &Result32);
 282   if (EFI_ERROR (Status)) {
 283     return EFI_INVALID_PARAMETER;
 284   }
 285
 286   //
 287   // Ensure the Height * Width * sizeof (EFI_GRAPHICS_OUTPUT_BLT_PIXEL) does
 288   // not overflow UINTN
 289   //
 290   Status = SafeUintnMult (
 291              Width,
 292              Height,
 293              &BufferSize
 294              );
 295   if (EFI_ERROR (Status)) {
 296     return EFI_UNSUPPORTED;
 297   }
 298   Status = SafeUintnMult (
 299              BufferSize,
 300              sizeof (EFI_GRAPHICS_OUTPUT_BLT_PIXEL),
 301              &BufferSize
 302              );
 303   if (EFI_ERROR (Status)) {
 304     return EFI_UNSUPPORTED;
 305   }
 306
 307   //
 308   // Update state
 309   //
 310   mAcpiBgrtBufferChanged = TRUE;
 311
 312   //
 313   // Free old logo buffer
 314   //
 315   if (mLogoBltBuffer != NULL) {
 316     FreePool (mLogoBltBuffer);
 317     mLogoBltBuffer = NULL;
 318   }
 319
 320   //
 321   // Allocate new logo buffer
 322   //
 323   mLogoBltBuffer = AllocateCopyPool (BufferSize, BltBuffer);
 324   if (mLogoBltBuffer == NULL) {
 325     return EFI_OUT_OF_RESOURCES;
 326   }
 327
 328   mLogoDestX   = DestinationX;
 329   mLogoDestY   = DestinationY;
 330   mLogoWidth   = Width;
 331   mLogoHeight  = Height;
 332   mIsLogoValid = TRUE;
 333
 334   return EFI_SUCCESS;
 335 }
 336
 337 /**
 338   Get the location of the boot logo on the screen.
 339
 340   @param[in]  This          The pointer to the Boot Logo Protocol 2 instance
 341   @param[out] BltBuffer     Returns pointer to the GOP BLT buffer that was
 342                             previously registered with SetBootLogo2(). The
 343                             buffer returned must not be modified or freed.
 344   @param[out] DestinationX  Returns the X start position of the GOP BLT buffer
 345                             that was previously registered with SetBootLogo2().
 346   @param[out] DestinationY  Returns the Y start position of the GOP BLT buffer
 347                             that was previously registered with SetBootLogo2().
 348   @param[out] Width         Returns the width of the GOP BLT buffer
 349                             that was previously registered with SetBootLogo2().
 350   @param[out] Height        Returns the height of the GOP BLT buffer
 351                             that was previously registered with SetBootLogo2().
 352
 353   @retval EFI_SUCCESS            The location of the boot logo was returned.
 354   @retval EFI_NOT_READY          The boot logo has not been set.
 355   @retval EFI_INVALID_PARAMETER  BltBuffer is NULL.
 356   @retval EFI_INVALID_PARAMETER  DestinationX is NULL.
 357   @retval EFI_INVALID_PARAMETER  DestinationY is NULL.
 358   @retval EFI_INVALID_PARAMETER  Width is NULL.
 359   @retval EFI_INVALID_PARAMETER  Height is NULL.
 360 **/
 361 EFI_STATUS
 362 EFIAPI
 363 GetBootLogo2 (
 364   IN  EDKII_BOOT_LOGO2_PROTOCOL      *This,
 365   OUT EFI_GRAPHICS_OUTPUT_BLT_PIXEL  **BltBuffer,
 366   OUT UINTN                          *DestinationX,
 367   OUT UINTN                          *DestinationY,
 368   OUT UINTN                          *Width,
 369   OUT UINTN                          *Height
 370   )
 371 {
 372   //
 373   // If the boot logo has not been set with SetBootLogo() or SetBootLogo() was
 374   // called with a NULL BltBuffer then the boot logo is not valid and
 375   // EFI_NOT_READY is returned.
 376   //
 377   if (mLogoBltBuffer == NULL) {
 378     DEBUG ((DEBUG_ERROR, "Request to get boot logo location before boot logo has been set.\n"));
 379     return EFI_NOT_READY;
 380   }
 381
 382   //
 383   // Make sure none of the boot logo location parameters are NULL.
 384   //
 385   if (BltBuffer == NULL || DestinationX == NULL || DestinationY == NULL ||
 386       Width == NULL || Height == NULL) {
 387     return EFI_INVALID_PARAMETER;
 388   }
 389
 390   //
 391   // Boot logo is valid.  Return values from module globals.
 392   //
 393   *BltBuffer    = mLogoBltBuffer;
 394   *DestinationX = mLogoDestX;
 395   *DestinationY = mLogoDestY;
 396   *Width        = mLogoWidth;
 397   *Height       = mLogoHeight;
 398
 399   return EFI_SUCCESS;
 400 }
 401
 402 /**
 403   Notify function for event group EFI_EVENT_GROUP_READY_TO_BOOT. This is used to
 404   install the Boot Graphics Resource Table.
 405
 406   @param[in]  Event   The Event that is being processed.
 407   @param[in]  Context The Event Context.
 408
 409 **/
 410 VOID
 411 EFIAPI
 412 BgrtReadyToBootEventNotify (
 413   IN EFI_EVENT  Event,
 414   IN VOID       *Context
 415   )
 416 {
 417   EFI_STATUS               Status;
 418   EFI_ACPI_TABLE_PROTOCOL  *AcpiTableProtocol;
 419   VOID                     *ImageBuffer;
 420   UINT32                   BmpSize;
 421
 422   //
 423   // Get ACPI Table protocol.
 424   //
 425   Status = gBS->LocateProtocol (
 426                   &gEfiAcpiTableProtocolGuid,
 427                   NULL,
 428                   (VOID **) &AcpiTableProtocol
 429                   );
 430   if (EFI_ERROR (Status)) {
 431     return;
 432   }
 433
 434   //
 435   // Check whether Boot Graphics Resource Table is already installed.
 436   //
 437   if (mAcpiBgrtInstalled) {
 438     if (!mAcpiBgrtStatusChanged && !mAcpiBgrtBufferChanged) {
 439       //
 440       // Nothing has changed
 441       //
 442       return;
 443     } else {
 444       //
 445       // If BGRT data change happens, then uninstall orignal AcpiTable first
 446       //
 447       Status = AcpiTableProtocol->UninstallAcpiTable (
 448                                     AcpiTableProtocol,
 449                                     mBootGraphicsResourceTableKey
 450                                     );
 451       if (EFI_ERROR (Status)) {
 452         return;
 453       }
 454     }
 455   } else {
 456     //
 457     // Check whether Logo exists
 458     //
 459     if (mLogoBltBuffer == NULL) {
 460       return;
 461     }
 462   }
 463
 464   if (mAcpiBgrtBufferChanged) {
 465     //
 466     // Free the old BMP image buffer
 467     //
 468     ImageBuffer = (UINT8 *)(UINTN)mBootGraphicsResourceTableTemplate.ImageAddress;
 469     if (ImageBuffer != NULL) {
 470       FreePool (ImageBuffer);
 471     }
 472
 473     //
 474     // Convert GOP Blt buffer to BMP image.  Pass in ImageBuffer set to NULL
 475     // so the BMP image is allocated by TranslateGopBltToBmp().
 476     //
 477     ImageBuffer = NULL;
 478     Status = TranslateGopBltToBmp (
 479                mLogoBltBuffer,
 480                (UINT32)mLogoHeight,
 481                (UINT32)mLogoWidth,
 482                &ImageBuffer,
 483                &BmpSize
 484                );
 485     if (EFI_ERROR (Status)) {
 486       return;
 487     }
 488
 489     //
 490     // Free the logo buffer
 491     //
 492     FreePool (mLogoBltBuffer);
 493     mLogoBltBuffer = NULL;
 494
 495     //
 496     // Update BMP image fields of the Boot Graphics Resource Table
 497     //
 498     mBootGraphicsResourceTableTemplate.ImageAddress = (UINT64)(UINTN)ImageBuffer;
 499     mBootGraphicsResourceTableTemplate.ImageOffsetX = (UINT32)mLogoDestX;
 500     mBootGraphicsResourceTableTemplate.ImageOffsetY = (UINT32)mLogoDestY;
 501   }
 502
 503   //
 504   // Update Status field of Boot Graphics Resource Table
 505   //
 506   if (mIsLogoValid) {
 507     mBootGraphicsResourceTableTemplate.Status = EFI_ACPI_5_0_BGRT_STATUS_VALID;
 508   } else {
 509     mBootGraphicsResourceTableTemplate.Status = EFI_ACPI_5_0_BGRT_STATUS_INVALID;
 510   }
 511
 512   //
 513   // Update Checksum of Boot Graphics Resource Table
 514   //
 515   mBootGraphicsResourceTableTemplate.Header.Checksum = 0;
 516   mBootGraphicsResourceTableTemplate.Header.Checksum =
 517     CalculateCheckSum8 (
 518       (UINT8 *)&mBootGraphicsResourceTableTemplate,
 519       sizeof (EFI_ACPI_5_0_BOOT_GRAPHICS_RESOURCE_TABLE)
 520       );
 521
 522   //
 523   // Publish Boot Graphics Resource Table.
 524   //
 525   Status = AcpiTableProtocol->InstallAcpiTable (
 526                                 AcpiTableProtocol,
 527                                 &mBootGraphicsResourceTableTemplate,
 528                                 sizeof (EFI_ACPI_5_0_BOOT_GRAPHICS_RESOURCE_TABLE),
 529                                 &mBootGraphicsResourceTableKey
 530                                 );
 531   if (EFI_ERROR (Status)) {
 532     return;
 533   }
 534
 535   mAcpiBgrtInstalled     = TRUE;
 536   mAcpiBgrtStatusChanged = FALSE;
 537   mAcpiBgrtBufferChanged = FALSE;
 538 }
 539
 540 /**
 541   The module Entry Point of the Boot Graphics Resource Table DXE driver.
 542
 543   @param[in]  ImageHandle    The firmware allocated handle for the EFI image.
 544   @param[in]  SystemTable    A pointer to the EFI System Table.
 545
 546   @retval EFI_SUCCESS    The entry point is executed successfully.
 547   @retval Other          Some error occurs when executing this entry point.
 548
 549 **/
 550 EFI_STATUS
 551 EFIAPI
 552 BootGraphicsDxeEntryPoint (
 553   IN EFI_HANDLE        ImageHandle,
 554   IN EFI_SYSTEM_TABLE  *SystemTable
 555   )
 556 {
 557   EFI_STATUS                   Status;
 558   EFI_ACPI_DESCRIPTION_HEADER  *Header;
 559
 560   //
 561   // Update Header fields of Boot Graphics Resource Table from PCDs
 562   //
 563   Header = &mBootGraphicsResourceTableTemplate.Header;
 564   ZeroMem (Header->OemId, sizeof (Header->OemId));
 565   CopyMem (
 566     Header->OemId,
 567     PcdGetPtr (PcdAcpiDefaultOemId),
 568     MIN (PcdGetSize (PcdAcpiDefaultOemId), sizeof (Header->OemId))
 569     );
 570   WriteUnaligned64 (&Header->OemTableId, PcdGet64 (PcdAcpiDefaultOemTableId));
 571   Header->OemRevision     = PcdGet32 (PcdAcpiDefaultOemRevision);
 572   Header->CreatorId       = PcdGet32 (PcdAcpiDefaultCreatorId);
 573   Header->CreatorRevision = PcdGet32 (PcdAcpiDefaultCreatorRevision);
 574
 575   //
 576   // Install Boot Logo and Boot Logo 2 Protocols.
 577   //
 578   Status = gBS->InstallMultipleProtocolInterfaces (
 579                   &mBootLogoHandle,
 580                   &gEfiBootLogoProtocolGuid,
 581                   &mBootLogoProtocolTemplate,
 582                   &gEdkiiBootLogo2ProtocolGuid,
 583                   &mBootLogo2ProtocolTemplate,
 584                   NULL
 585                   );
 586   ASSERT_EFI_ERROR (Status);
 587
 588   //
 589   // Register notify function to install BGRT on ReadyToBoot Event.
 590   //
 591   Status = gBS->CreateEventEx (
 592                   EVT_NOTIFY_SIGNAL,
 593                   TPL_CALLBACK,
 594                   BgrtReadyToBootEventNotify,
 595                   NULL,
 596                   &gEfiEventReadyToBootGuid,
 597                   &mBootGraphicsReadyToBootEvent
 598                   );
 599   ASSERT_EFI_ERROR (Status);
 600
 601   return Status;
 602 }