MdePkg/Library/DxePcdLib/DxePcdLib.c

   1 /** @file
   2 Implementation of PcdLib class library for DXE phase.
   3
   4 Copyright (c) 2006, Intel Corporation<BR>
   5 All rights reserved. This program and the accompanying materials
   6 are licensed and made available under the terms and conditions of the BSD License
   7 which accompanies this distribution.  The full text of the license may be found at
   8 http://opensource.org/licenses/bsd-license.php
   9
  10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13
  14 **/
  15
  16
  17 #include <PiDxe.h>
  18
  19 #include <Protocol/Pcd.h>
  20
  21 #include <Library/PcdLib.h>
  22 #include <Library/DebugLib.h>
  23 #include <Library/UefiBootServicesTableLib.h>
  24 #include <Library/BaseMemoryLib.h>
  25
  26 PCD_PROTOCOL  *mPcd = NULL;
  27
  28
  29 /**
  30   The constructor function caches the PCD_PROTOCOL pointer.
  31
  32   @param[in] ImageHandle The firmware allocated handle for the EFI image.
  33   @param[in] SystemTable A pointer to the EFI System Table.
  34
  35   @retval EFI_SUCCESS The constructor always return EFI_SUCCESS.
  36
  37 **/
  38 EFI_STATUS
  39 EFIAPI
  40 PcdLibConstructor (
  41   IN EFI_HANDLE        ImageHandle,
  42   IN EFI_SYSTEM_TABLE  *SystemTable
  43   )
  44 {
  45   EFI_STATUS  Status;
  46
  47   //
  48   // PCD protocol has not been installed, but a module needs to access a
  49   // dynamic PCD entry.
  50   //
  51   Status = gBS->LocateProtocol (&gPcdProtocolGuid, NULL, (VOID **)&mPcd);
  52   ASSERT_EFI_ERROR (Status);
  53   ASSERT (mPcd!= NULL);
  54
  55   return Status;
  56 }
  57
  58
  59 /**
  60   Sets the current SKU in the PCD database to the value specified by SkuId.  SkuId is returned.
  61   If SkuId is not less than PCD_MAX_SKU_ID, then ASSERT().
  62
  63   @param[in]  SkuId     System SKU ID. The SKU value that will be used when the PCD service will retrieve and
  64                         set values.
  65
  66   @return Return the SKU ID that just be set.
  67
  68 **/
  69 UINTN
  70 EFIAPI
  71 LibPcdSetSku (
  72   IN UINTN  SkuId
  73   )
  74 {
  75   ASSERT (SkuId < PCD_MAX_SKU_ID);
  76
  77   mPcd->SetSku (SkuId);
  78
  79   return SkuId;
  80 }
  81
  82
  83
  84 /**
  85   Returns the 8-bit value for the token specified by TokenNumber.
  86
  87   @param[in]  TokenNumber   The PCD token number to retrieve a current value for.
  88
  89   @return Returns the 8-bit value for the token specified by TokenNumber.
  90
  91 **/
  92 UINT8
  93 EFIAPI
  94 LibPcdGet8 (
  95   IN UINTN             TokenNumber
  96   )
  97 {
  98   return mPcd->Get8 (TokenNumber);
  99 }
 100
 101
 102
 103 /**
 104   Returns the 16-bit value for the token specified by TokenNumber.
 105
 106   @param[in]  TokenNumber   The PCD token number to retrieve a current value for.
 107
 108   @return Returns the 16-bit value for the token specified by TokenNumber.
 109
 110 **/
 111 UINT16
 112 EFIAPI
 113 LibPcdGet16 (
 114   IN UINTN             TokenNumber
 115   )
 116 {
 117   return mPcd->Get16 (TokenNumber);
 118 }
 119
 120
 121
 122 /**
 123   Returns the 32-bit value for the token specified by TokenNumber.
 124
 125   @param[in]  TokenNumber The PCD token number to retrieve a current value for.
 126
 127   @return Returns the 32-bit value for the token specified by TokenNumber.
 128
 129 **/
 130 UINT32
 131 EFIAPI
 132 LibPcdGet32 (
 133   IN UINTN             TokenNumber
 134   )
 135 {
 136   return mPcd->Get32 (TokenNumber);
 137 }
 138
 139
 140
 141 /**
 142   Returns the 64-bit value for the token specified by TokenNumber.
 143
 144   @param[in]  TokenNumber The PCD token number to retrieve a current value for.
 145
 146   @return Returns the 64-bit value for the token specified by TokenNumber.
 147
 148 **/
 149 UINT64
 150 EFIAPI
 151 LibPcdGet64 (
 152   IN UINTN             TokenNumber
 153   )
 154 {
 155   return mPcd->Get64 (TokenNumber);
 156 }
 157
 158
 159
 160 /**
 161   Returns the pointer to the buffer of the token specified by TokenNumber.
 162
 163   @param[in]  TokenNumber The PCD token number to retrieve a current value for.
 164
 165   @return Returns the pointer to the token specified by TokenNumber.
 166
 167 **/
 168 VOID *
 169 EFIAPI
 170 LibPcdGetPtr (
 171   IN UINTN             TokenNumber
 172   )
 173 {
 174   return mPcd->GetPtr (TokenNumber);
 175 }
 176
 177
 178
 179 /**
 180   Returns the Boolean value of the token specified by TokenNumber.
 181
 182   @param[in]  TokenNumber The PCD token number to retrieve a current value for.
 183
 184   @return Returns the Boolean value of the token specified by TokenNumber.
 185
 186 **/
 187 BOOLEAN
 188 EFIAPI
 189 LibPcdGetBool (
 190   IN UINTN             TokenNumber
 191   )
 192 {
 193   return mPcd->GetBool (TokenNumber);
 194 }
 195
 196
 197
 198 /**
 199   Returns the size of the token specified by TokenNumber.
 200
 201   @param[in]  TokenNumber The PCD token number to retrieve a current value for.
 202
 203   @return Returns the size of the token specified by TokenNumber.
 204
 205 **/
 206 UINTN
 207 EFIAPI
 208 LibPcdGetSize (
 209   IN UINTN             TokenNumber
 210   )
 211 {
 212   return mPcd->GetSize (TokenNumber);
 213 }
 214
 215
 216
 217 /**
 218   Returns the 8-bit value for the token specified by TokenNumber and Guid.
 219   If Guid is NULL, then ASSERT().
 220
 221   @param[in]  Guid Pointer to a 128-bit unique value that designates
 222               which namespace to retrieve a value from.
 223   @param[in]  TokenNumber The PCD token number to retrieve a current value for.
 224
 225   @return Return the UINT8.
 226
 227 **/
 228 UINT8
 229 EFIAPI
 230 LibPcdGetEx8 (
 231   IN CONST GUID        *Guid,
 232   IN UINTN             TokenNumber
 233   )
 234 {
 235   ASSERT (Guid != NULL);
 236
 237   return mPcd->Get8Ex (Guid, TokenNumber);
 238 }
 239
 240
 241 /**
 242   Returns the 16-bit value for the token specified by TokenNumber and Guid.
 243   If Guid is NULL, then ASSERT().
 244
 245   @param[in]  Guid Pointer to a 128-bit unique value that designates
 246               which namespace to retrieve a value from.
 247   @param[in]  TokenNumber The PCD token number to retrieve a current value for.
 248
 249   @return Return the UINT16.
 250
 251 **/
 252 UINT16
 253 EFIAPI
 254 LibPcdGetEx16 (
 255   IN CONST GUID        *Guid,
 256   IN UINTN             TokenNumber
 257   )
 258 {
 259   ASSERT (Guid != NULL);
 260
 261   return mPcd->Get16Ex (Guid, TokenNumber);
 262 }
 263
 264
 265 /**
 266   Returns the 32-bit value for the token specified by TokenNumber and Guid.
 267   If Guid is NULL, then ASSERT().
 268
 269   @param[in]  Guid Pointer to a 128-bit unique value that designates
 270               which namespace to retrieve a value from.
 271   @param[in]  TokenNumber The PCD token number to retrieve a current value for.
 272
 273   @return Return the UINT32.
 274
 275 **/
 276 UINT32
 277 EFIAPI
 278 LibPcdGetEx32 (
 279   IN CONST GUID        *Guid,
 280   IN UINTN             TokenNumber
 281   )
 282 {
 283   ASSERT (Guid != NULL);
 284
 285   return mPcd->Get32Ex (Guid, TokenNumber);
 286 }
 287
 288
 289
 290 /**
 291   Returns the 64-bit value for the token specified by TokenNumber and Guid.
 292   If Guid is NULL, then ASSERT().
 293
 294   @param[in]  Guid Pointer to a 128-bit unique value that designates
 295               which namespace to retrieve a value from.
 296   @param[in]  TokenNumber The PCD token number to retrieve a current value for.
 297
 298   @return Return the UINT64.
 299
 300 **/
 301 UINT64
 302 EFIAPI
 303 LibPcdGetEx64 (
 304   IN CONST GUID        *Guid,
 305   IN UINTN             TokenNumber
 306   )
 307 {
 308   ASSERT (Guid != NULL);
 309
 310   return mPcd->Get64Ex (Guid, TokenNumber);
 311 }
 312
 313
 314
 315 /**
 316   Returns the pointer to the token specified by TokenNumber and Guid.
 317   If Guid is NULL, then ASSERT().
 318
 319   @param[in]  Guid Pointer to a 128-bit unique value that designates
 320               which namespace to retrieve a value from.
 321   @param[in]  TokenNumber The PCD token number to retrieve a current value for.
 322
 323   @return Return the VOID* pointer.
 324
 325 **/
 326 VOID *
 327 EFIAPI
 328 LibPcdGetExPtr (
 329   IN CONST GUID        *Guid,
 330   IN UINTN             TokenNumber
 331   )
 332 {
 333   ASSERT (Guid != NULL);
 334
 335   return mPcd->GetPtrEx (Guid, TokenNumber);
 336 }
 337
 338
 339
 340 /**
 341   Returns the Boolean value of the token specified by TokenNumber and Guid.
 342   If Guid is NULL, then ASSERT().
 343
 344   @param[in]  Guid Pointer to a 128-bit unique value that designates
 345               which namespace to retrieve a value from.
 346   @param[in]  TokenNumber The PCD token number to retrieve a current value for.
 347
 348   @return Return the BOOLEAN.
 349
 350 **/
 351 BOOLEAN
 352 EFIAPI
 353 LibPcdGetExBool (
 354   IN CONST GUID        *Guid,
 355   IN UINTN             TokenNumber
 356   )
 357 {
 358   ASSERT (Guid != NULL);
 359
 360   return mPcd->GetBoolEx (Guid, TokenNumber);
 361 }
 362
 363
 364
 365 /**
 366   Returns the size of the token specified by TokenNumber and Guid.
 367   If Guid is NULL, then ASSERT().
 368
 369   @param[in]  Guid Pointer to a 128-bit unique value that designates
 370               which namespace to retrieve a value from.
 371   @param[in]  TokenNumber The PCD token number to retrieve a current value for.
 372
 373   @return Return the size.
 374
 375 **/
 376 UINTN
 377 EFIAPI
 378 LibPcdGetExSize (
 379   IN CONST GUID        *Guid,
 380   IN UINTN             TokenNumber
 381   )
 382 {
 383   ASSERT (Guid != NULL);
 384
 385   return mPcd->GetSizeEx (Guid, TokenNumber);
 386 }
 387
 388
 389
 390 /**
 391   Sets the 8-bit value for the token specified by TokenNumber
 392   to the value specified by Value.  Value is returned.
 393   If fail to set pcd value, then ASSERT_EFI_ERROR().
 394
 395   @param[in]  TokenNumber The PCD token number to set a current value for.
 396   @param[in]  Value The 8-bit value to set.
 397
 398   @return Return the value been set.
 399
 400 **/
 401 UINT8
 402 EFIAPI
 403 LibPcdSet8 (
 404   IN UINTN             TokenNumber,
 405   IN UINT8             Value
 406   )
 407 {
 408   EFI_STATUS Status;
 409
 410   Status = mPcd->Set8 (TokenNumber, Value);
 411
 412   ASSERT_EFI_ERROR (Status);
 413
 414   return Value;
 415 }
 416
 417
 418
 419 /**
 420   Sets the 16-bit value for the token specified by TokenNumber
 421   to the value specified by Value.  Value is returned.
 422   If fail to set pcd value, then ASSERT_EFI_ERROR().
 423
 424   @param[in]  TokenNumber The PCD token number to set a current value for.
 425   @param[in]  Value The 16-bit value to set.
 426
 427   @return Return the value been set.
 428
 429 **/
 430 UINT16
 431 EFIAPI
 432 LibPcdSet16 (
 433   IN UINTN             TokenNumber,
 434   IN UINT16            Value
 435   )
 436 {
 437   EFI_STATUS Status;
 438
 439   Status = mPcd->Set16 (TokenNumber, Value);
 440
 441   ASSERT_EFI_ERROR (Status);
 442
 443   return Value;
 444 }
 445
 446
 447
 448 /**
 449   Sets the 32-bit value for the token specified by TokenNumber
 450   to the value specified by Value.  Value is returned.
 451   If fail to set pcd value, then ASSERT_EFI_ERROR().
 452
 453   @param[in]  TokenNumber The PCD token number to set a current value for.
 454   @param[in]  Value The 32-bit value to set.
 455
 456   @return Return the value been set.
 457
 458 **/
 459 UINT32
 460 EFIAPI
 461 LibPcdSet32 (
 462   IN UINTN             TokenNumber,
 463   IN UINT32             Value
 464   )
 465 {
 466   EFI_STATUS Status;
 467   Status = mPcd->Set32 (TokenNumber, Value);
 468
 469   ASSERT_EFI_ERROR (Status);
 470
 471   return Value;
 472 }
 473
 474
 475
 476 /**
 477   Sets the 64-bit value for the token specified by TokenNumber
 478   to the value specified by Value.  Value is returned.
 479   If fail to set pcd value, then ASSERT_EFI_ERROR().
 480
 481   @param[in]  TokenNumber The PCD token number to set a current value for.
 482   @param[in]  Value The 64-bit value to set.
 483
 484   @return Return the value been set.
 485
 486 **/
 487 UINT64
 488 EFIAPI
 489 LibPcdSet64 (
 490   IN UINTN             TokenNumber,
 491   IN UINT64             Value
 492   )
 493 {
 494   EFI_STATUS Status;
 495
 496   Status = mPcd->Set64 (TokenNumber, Value);
 497
 498   ASSERT_EFI_ERROR (Status);
 499
 500   return Value;
 501 }
 502
 503
 504
 505 /**
 506   Sets a buffer for the token specified by TokenNumber to
 507   the value specified by Buffer and SizeOfBuffer.  Buffer to
 508   be set is returned. The content of the buffer could be
 509   overwritten if a Callback on SET is registered with this
 510   TokenNumber.
 511
 512   If SizeOfBuffer is greater than the maximum
 513   size support by TokenNumber, then set SizeOfBuffer to the
 514   maximum size supported by TokenNumber and return NULL to
 515   indicate that the set operation was not actually performed.
 516
 517   If SizeOfBuffer > 0 and Buffer is NULL, then ASSERT().
 518
 519   @param[in]      TokenNumber   The PCD token number to set a current value for.
 520   @param[in, out] SizeOfBuffer  The size, in bytes, of Buffer.
 521                                 In out, returns actual size of buff is set.
 522   @param[in]      Buffer        A pointer to the buffer to set.
 523
 524   @return Return the pointer for the buffer been set.
 525
 526 **/
 527 VOID *
 528 EFIAPI
 529 LibPcdSetPtr (
 530   IN        UINTN             TokenNumber,
 531   IN OUT    UINTN             *SizeOfBuffer,
 532   IN        VOID              *Buffer
 533   )
 534 {
 535   EFI_STATUS Status;
 536
 537   ASSERT (SizeOfBuffer != NULL);
 538
 539   if (*SizeOfBuffer > 0) {
 540     ASSERT (Buffer != NULL);
 541   }
 542
 543   Status = mPcd->SetPtr (TokenNumber, SizeOfBuffer, Buffer);
 544
 545   if (EFI_ERROR (Status)) {
 546     return NULL;
 547   }
 548
 549   return Buffer;
 550 }
 551
 552
 553
 554 /**
 555   Sets the Boolean value for the token specified by TokenNumber
 556   to the value specified by Value.  Value is returned.
 557   If fail to set pcd value, then ASSERT_EFI_ERROR().
 558
 559   @param[in]  TokenNumber The PCD token number to set a current value for.
 560   @param[in]  Value       The boolean value to set.
 561
 562   @return Return the value been set.
 563
 564 **/
 565 BOOLEAN
 566 EFIAPI
 567 LibPcdSetBool (
 568   IN UINTN             TokenNumber,
 569   IN BOOLEAN           Value
 570   )
 571 {
 572   EFI_STATUS Status;
 573
 574   Status = mPcd->SetBool (TokenNumber, Value);
 575
 576   ASSERT_EFI_ERROR (Status);
 577
 578   return Value;
 579 }
 580
 581
 582
 583 /**
 584   Sets the 8-bit value for the token specified by TokenNumber and
 585   Guid to the value specified by Value. Value is returned.
 586   If Guid is NULL, then ASSERT().
 587   If fail to set pcd value, then ASSERT_EFI_ERROR().
 588
 589   @param[in]  Guid Pointer to a 128-bit unique value that
 590               designates which namespace to set a value from.
 591   @param[in]  TokenNumber The PCD token number to set a current value for.
 592   @param[in]  Value The 8-bit value to set.
 593
 594   @return Return the value been set.
 595
 596 **/
 597 UINT8
 598 EFIAPI
 599 LibPcdSetEx8 (
 600   IN CONST GUID        *Guid,
 601   IN UINTN             TokenNumber,
 602   IN UINT8             Value
 603   )
 604 {
 605   EFI_STATUS Status;
 606
 607   ASSERT (Guid != NULL);
 608
 609   Status = mPcd->Set8Ex (Guid, TokenNumber, Value);
 610
 611   ASSERT_EFI_ERROR (Status);
 612
 613   return Value;
 614 }
 615
 616
 617
 618 /**
 619   Sets the 16-bit value for the token specified by TokenNumber and
 620   Guid to the value specified by Value. Value is returned.
 621   If Guid is NULL, then ASSERT().
 622   If fail to set pcd value, then ASSERT_EFI_ERROR().
 623
 624   @param[in]  Guid Pointer to a 128-bit unique value that
 625               designates which namespace to set a value from.
 626   @param[in]  TokenNumber The PCD token number to set a current value for.
 627   @param[in]  Value The 16-bit value to set.
 628
 629   @return Return the value been set.
 630
 631 **/
 632 UINT16
 633 EFIAPI
 634 LibPcdSetEx16 (
 635   IN CONST GUID        *Guid,
 636   IN UINTN             TokenNumber,
 637   IN UINT16            Value
 638   )
 639 {
 640   EFI_STATUS Status;
 641
 642   ASSERT (Guid != NULL);
 643
 644   Status = mPcd->Set16Ex (Guid, TokenNumber, Value);
 645
 646   ASSERT_EFI_ERROR (Status);
 647
 648   return Value;
 649 }
 650
 651
 652
 653 /**
 654   Sets the 32-bit value for the token specified by TokenNumber and
 655   Guid to the value specified by Value. Value is returned.
 656   If Guid is NULL, then ASSERT().
 657   If fail to set pcd value, then ASSERT_EFI_ERROR().
 658
 659   @param[in]  Guid Pointer to a 128-bit unique value that
 660               designates which namespace to set a value from.
 661   @param[in]  TokenNumber The PCD token number to set a current value for.
 662   @param[in]  Value The 32-bit value to set.
 663
 664   @return Return the value been set.
 665
 666 **/
 667 UINT32
 668 EFIAPI
 669 LibPcdSetEx32 (
 670   IN CONST GUID        *Guid,
 671   IN UINTN             TokenNumber,
 672   IN UINT32             Value
 673   )
 674 {
 675   EFI_STATUS Status;
 676
 677   ASSERT (Guid != NULL);
 678
 679   Status = mPcd->Set32Ex (Guid, TokenNumber, Value);
 680
 681   ASSERT_EFI_ERROR (Status);
 682
 683   return Value;
 684 }
 685
 686
 687
 688 /**
 689   Sets the 64-bit value for the token specified by TokenNumber and
 690   Guid to the value specified by Value. Value is returned.
 691   If Guid is NULL, then ASSERT().
 692
 693   @param[in]  Guid Pointer to a 128-bit unique value that
 694               designates which namespace to set a value from.
 695   @param[in]  TokenNumber The PCD token number to set a current value for.
 696   @param[in]  Value The 64-bit value to set.
 697
 698   @return Return the value been set.
 699
 700 **/
 701 UINT64
 702 EFIAPI
 703 LibPcdSetEx64 (
 704   IN CONST GUID        *Guid,
 705   IN UINTN             TokenNumber,
 706   IN UINT64             Value
 707   )
 708 {
 709   EFI_STATUS Status;
 710
 711   ASSERT (Guid != NULL);
 712
 713   Status = mPcd->Set64Ex (Guid, TokenNumber, Value);
 714
 715   ASSERT_EFI_ERROR (Status);
 716
 717   return Value;
 718 }
 719
 720
 721
 722 /**
 723   Sets a buffer for the token specified by TokenNumber to the value specified by
 724   Buffer and SizeOfBuffer.  Buffer is returned.  If SizeOfBuffer is greater than
 725   the maximum size support by TokenNumber, then set SizeOfBuffer to the maximum size
 726   supported by TokenNumber and return NULL to indicate that the set operation
 727   was not actually performed.
 728
 729   If SizeOfBuffer > 0 and Buffer is NULL, then ASSERT().
 730
 731   @param[in]        Guid Pointer to a 128-bit unique value that
 732                     designates which namespace to set a value from.
 733   @param[in]        TokenNumber The PCD token number to set a current value for.
 734   @param[in, out]   SizeOfBuffer The size, in bytes, of Buffer.
 735                     In out, returns actual size of buffer is set.
 736   @param[in]        Buffer A pointer to the buffer to set.
 737
 738   @return Return the pinter to the buffer been set.
 739
 740 **/
 741 VOID *
 742 EFIAPI
 743 LibPcdSetExPtr (
 744   IN      CONST GUID        *Guid,
 745   IN      UINTN             TokenNumber,
 746   IN OUT  UINTN             *SizeOfBuffer,
 747   IN      VOID              *Buffer
 748   )
 749 {
 750   EFI_STATUS  Status;
 751
 752   ASSERT (Guid != NULL);
 753
 754   ASSERT (SizeOfBuffer != NULL);
 755
 756   if (*SizeOfBuffer > 0) {
 757     ASSERT (Buffer != NULL);
 758   }
 759
 760   Status = mPcd->SetPtrEx (Guid, TokenNumber, SizeOfBuffer, Buffer);
 761
 762   if (EFI_ERROR (Status)) {
 763     return NULL;
 764   }
 765
 766   return Buffer;
 767 }
 768
 769
 770
 771 /**
 772   Sets the Boolean value for the token specified by TokenNumber and
 773   Guid to the value specified by Value. Value is returned.
 774   If Guid is NULL, then ASSERT().
 775   If fail to set pcd value, then ASSERT_EFI_ERROR().
 776
 777   @param[in]  Guid Pointer to a 128-bit unique value that
 778               designates which namespace to set a value from.
 779   @param[in]  TokenNumber The PCD token number to set a current value for.
 780   @param[in]  Value The Boolean value to set.
 781
 782   @return Return the value been set.
 783
 784 **/
 785 BOOLEAN
 786 EFIAPI
 787 LibPcdSetExBool (
 788   IN CONST GUID        *Guid,
 789   IN UINTN             TokenNumber,
 790   IN BOOLEAN           Value
 791   )
 792 {
 793   EFI_STATUS Status;
 794
 795   ASSERT (Guid != NULL);
 796
 797   Status = mPcd->SetBoolEx (Guid, TokenNumber, Value);
 798
 799   ASSERT_EFI_ERROR (Status);
 800
 801   return Value;
 802 }
 803
 804
 805
 806 /**
 807   When the token specified by TokenNumber and Guid is set,
 808   then notification function specified by NotificationFunction is called.
 809   If Guid is NULL, then the default token space is used.
 810   If NotificationFunction is NULL, then ASSERT().
 811   If fail to set callback function, then ASSERT_EFI_ERROR().
 812
 813   @param[in]  Guid Pointer to a 128-bit unique value that designates which
 814               namespace to set a value from.  If NULL, then the default
 815               token space is used.
 816   @param[in]  TokenNumber The PCD token number to monitor.
 817   @param[in]  NotificationFunction The function to call when the token
 818               specified by Guid and TokenNumber is set.
 819 **/
 820 VOID
 821 EFIAPI
 822 LibPcdCallbackOnSet (
 823   IN CONST GUID               *Guid,       OPTIONAL
 824   IN UINTN                    TokenNumber,
 825   IN PCD_CALLBACK             NotificationFunction
 826   )
 827 {
 828   EFI_STATUS Status;
 829
 830   ASSERT (NotificationFunction != NULL);
 831
 832   Status = mPcd->CallbackOnSet (Guid, TokenNumber, NotificationFunction);
 833
 834   ASSERT_EFI_ERROR (Status);
 835
 836   return;
 837 }
 838
 839
 840
 841 /**
 842   Disable a notification function that was established with LibPcdCallbackonSet().
 843   If NotificationFunction is NULL, then ASSERT().
 844   If fail to cancel callback function, then ASSERT_EFI_ERROR().
 845
 846   @param[in]  Guid Specify the GUID token space.
 847   @param[in]  TokenNumber Specify the token number.
 848   @param[in]  NotificationFunction The callback function to be unregistered.
 849
 850 **/
 851 VOID
 852 EFIAPI
 853 LibPcdCancelCallback (
 854   IN CONST GUID               *Guid,       OPTIONAL
 855   IN UINTN                    TokenNumber,
 856   IN PCD_CALLBACK             NotificationFunction
 857   )
 858 {
 859   EFI_STATUS Status;
 860
 861   ASSERT (NotificationFunction != NULL);
 862
 863   Status = mPcd->CancelCallback (Guid, TokenNumber, NotificationFunction);
 864
 865   ASSERT_EFI_ERROR (Status);
 866
 867   return;
 868 }
 869
 870
 871
 872 /**
 873   Retrieves the next PCD token number from the token space specified by Guid.
 874   If Guid is NULL, then the default token space is used.  If TokenNumber is 0,
 875   then the first token number is returned.  Otherwise, the token number that
 876   follows TokenNumber in the token space is returned.  If TokenNumber is the last
 877   token number in the token space, then 0 is returned.  If TokenNumber is not 0 and
 878   is not in the token space specified by Guid, then ASSERT().
 879   If Fail to get next token, then ASSERT_EFI_ERROR().
 880
 881   @param[in]  Guid        Pointer to a 128-bit unique value that designates which namespace
 882                           to set a value from.  If NULL, then the default token space is used.
 883   @param[in]  TokenNumber The previous PCD token number.  If 0, then retrieves the first PCD
 884                           token number.
 885
 886   @return The next valid token number.
 887
 888 **/
 889 UINTN
 890 EFIAPI
 891 LibPcdGetNextToken (
 892   IN CONST GUID             *Guid, OPTIONAL
 893   IN       UINTN            TokenNumber
 894   )
 895 {
 896   EFI_STATUS Status;
 897
 898   Status = mPcd->GetNextToken (Guid, &TokenNumber);
 899
 900   ASSERT_EFI_ERROR (Status);
 901
 902   return TokenNumber;
 903 }
 904
 905
 906
 907 /**
 908   Used to retrieve the list of available PCD token space GUIDs.
 909
 910   Retrieves the next PCD token space from a token space specified by Guid.
 911   Guid of NULL is reserved to mark the default local token namespace on the current
 912   platform. If Guid is NULL, then the GUID of the first non-local token space of the
 913   current platform is returned. If Guid is the last non-local token space,
 914   then NULL is returned.
 915
 916   If Guid is not NULL and is not a valid token space in the current platform, then ASSERT().
 917   If fail to get next token space, then ASSERT_EFI_ERROR().
 918
 919   @param[in]  Guid  Pointer to a 128-bit unique value that designates from which namespace
 920                     to start the search.
 921
 922   @return The next valid token namespace.
 923
 924 **/
 925 GUID *
 926 EFIAPI
 927 LibPcdGetNextTokenSpace (
 928   IN CONST GUID  *TokenSpaceGuid
 929   )
 930 {
 931   EFI_STATUS Status;
 932
 933   Status = mPcd->GetNextTokenSpace (&TokenSpaceGuid);
 934
 935   ASSERT_EFI_ERROR (Status);
 936
 937   return (GUID *) TokenSpaceGuid;
 938 }
 939
 940
 941 /**
 942   Sets the PCD entry specified by PatchVariable to the value specified by Buffer
 943   and SizeOfBuffer.  Buffer is returned.  If SizeOfBuffer is greater than
 944   MaximumDatumSize, then set SizeOfBuffer to MaximumDatumSize and return
 945   NULL to indicate that the set operation was not actually performed.
 946   If SizeOfBuffer is set to MAX_ADDRESS, then SizeOfBuffer must be set to
 947   MaximumDatumSize and NULL must be returned.
 948
 949   If PatchVariable is NULL, then ASSERT().
 950   If SizeOfBuffer is NULL, then ASSERT().
 951   If SizeOfBuffer > 0 and Buffer is NULL, then ASSERT().
 952
 953   @param[in] PatchVariable      A pointer to the global variable in a module that is
 954                                 the target of the set operation.
 955   @param[in] MaximumDatumSize   The maximum size allowed for the PCD entry specified by PatchVariable.
 956   @param[in, out] SizeOfBuffer  A pointer to the size, in bytes, of Buffer.
 957                                 In out, returns actual size of buffer is set.
 958   @param[in] Buffer             A pointer to the buffer to used to set the target variable.
 959
 960   @return Return the pinter to the buffer been set.
 961   @retval NULL   If SizeOfBuffer is set to MAX_ADDRESS or larger than MaximumDatumSize,
 962                  then SizeOfBuffer must be set to MaximumDatumSize and NULL must be returned.
 963 **/
 964 VOID *
 965 EFIAPI
 966 LibPatchPcdSetPtr (
 967   IN        VOID        *PatchVariable,
 968   IN        UINTN       MaximumDatumSize,
 969   IN OUT    UINTN       *SizeOfBuffer,
 970   IN CONST  VOID        *Buffer
 971   )
 972 {
 973   ASSERT (PatchVariable != NULL);
 974   ASSERT (SizeOfBuffer  != NULL);
 975
 976   if (*SizeOfBuffer > 0) {
 977     ASSERT (Buffer != NULL);
 978   }
 979
 980   if ((*SizeOfBuffer > MaximumDatumSize) ||
 981       (*SizeOfBuffer == MAX_ADDRESS)) {
 982     *SizeOfBuffer = MaximumDatumSize;
 983     return NULL;
 984   }
 985
 986   CopyMem (PatchVariable, Buffer, *SizeOfBuffer);
 987
 988   return (VOID *) Buffer;
 989 }
 990
 991
 992