MdeModulePkg/Universal/Variable/Pei/Variable.c

   1 /*++
   2
   3 Copyright (c) 2006 - 2007 Intel Corporation. <BR>
   4 All rights reserved. This program and the accompanying materials
   5 are licensed and made available under the terms and conditions of the BSD License
   6 which accompanies this distribution.  The full text of the license may be found at
   7 http://opensource.org/licenses/bsd-license.php
   8
   9 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11 Module Name:
  12
  13   Variable.c
  14
  15 Abstract:
  16
  17   Framework PEIM to provide the Variable functionality
  18
  19 --*/
  20
  21
  22 #include "Variable.h"
  23
  24 //
  25 // Module globals
  26 //
  27 static EFI_PEI_READ_ONLY_VARIABLE2_PPI mVariablePpi = {
  28   PeiGetVariable,
  29   PeiGetNextVariableName
  30 };
  31
  32 static EFI_PEI_PPI_DESCRIPTOR     mPpiListVariable = {
  33   (EFI_PEI_PPI_DESCRIPTOR_PPI | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST),
  34   &gEfiPeiReadOnlyVariable2PpiGuid,
  35   &mVariablePpi
  36 };
  37
  38 EFI_GUID mEfiVariableIndexTableGuid = EFI_VARIABLE_INDEX_TABLE_GUID;
  39
  40 EFI_STATUS
  41 EFIAPI
  42 PeimInitializeVariableServices (
  43   IN EFI_FFS_FILE_HEADER       *FfsHeader,
  44   IN EFI_PEI_SERVICES          **PeiServices
  45   )
  46 /*++
  47
  48 Routine Description:
  49
  50   Provide the functionality of the variable services.
  51
  52 Arguments:
  53
  54   FfsHeadher  - The FFS file header
  55   PeiServices - General purpose services available to every PEIM.
  56
  57 Returns:
  58
  59   Status -  EFI_SUCCESS if the interface could be successfully
  60             installed
  61
  62 --*/
  63 {
  64   //
  65   // Publish the variable capability to other modules
  66   //
  67   return (**PeiServices).InstallPpi (PeiServices, &mPpiListVariable);
  68
  69 }
  70
  71 STATIC
  72 VARIABLE_HEADER *
  73 GetNextVariablePtr (
  74   IN VARIABLE_HEADER  *Variable
  75   )
  76 /*++
  77
  78 Routine Description:
  79
  80   This code checks if variable header is valid or not.
  81
  82 Arguments:
  83   Variable       Pointer to the Variable Header.
  84
  85 Returns:
  86   TRUE            Variable header is valid.
  87   FALSE           Variable header is not valid.
  88
  89 --*/
  90 {
  91   return (VARIABLE_HEADER *) ((UINTN) GET_VARIABLE_DATA_PTR (Variable) + Variable->DataSize + GET_PAD_SIZE (Variable->DataSize));
  92 }
  93
  94 STATIC
  95 BOOLEAN
  96 EFIAPI
  97 IsValidVariableHeader (
  98   IN  VARIABLE_HEADER   *Variable
  99   )
 100 /*++
 101
 102 Routine Description:
 103
 104   This code checks if variable header is valid or not.
 105
 106 Arguments:
 107   Variable              Pointer to the Variable Header.
 108
 109 Returns:
 110   TRUE            Variable header is valid.
 111   FALSE           Variable header is not valid.
 112
 113 --*/
 114 {
 115   if (Variable == NULL ||
 116       Variable->StartId != VARIABLE_DATA ||
 117       (sizeof (VARIABLE_HEADER) + Variable->DataSize + Variable->NameSize) > MAX_VARIABLE_SIZE
 118       ) {
 119     return FALSE;
 120   }
 121
 122   return TRUE;
 123 }
 124
 125 STATIC
 126 VARIABLE_STORE_STATUS
 127 EFIAPI
 128 GetVariableStoreStatus (
 129   IN VARIABLE_STORE_HEADER *VarStoreHeader
 130   )
 131 /*++
 132
 133 Routine Description:
 134
 135   This code gets the pointer to the variable name.
 136
 137 Arguments:
 138
 139   VarStoreHeader  Pointer to the Variable Store Header.
 140
 141 Returns:
 142
 143   EfiRaw        Variable store is raw
 144   EfiValid      Variable store is valid
 145   EfiInvalid    Variable store is invalid
 146
 147 --*/
 148 {
 149   if (VarStoreHeader->Signature == VARIABLE_STORE_SIGNATURE &&
 150       VarStoreHeader->Format == VARIABLE_STORE_FORMATTED &&
 151       VarStoreHeader->State == VARIABLE_STORE_HEALTHY
 152       ) {
 153
 154     return EfiValid;
 155   }
 156
 157   if (VarStoreHeader->Signature == 0xffffffff &&
 158       VarStoreHeader->Size == 0xffffffff &&
 159       VarStoreHeader->Format == 0xff &&
 160       VarStoreHeader->State == 0xff
 161       ) {
 162
 163     return EfiRaw;
 164   } else {
 165     return EfiInvalid;
 166   }
 167 }
 168
 169 STATIC
 170 EFI_STATUS
 171 CompareWithValidVariable (
 172   IN  VARIABLE_HEADER               *Variable,
 173   IN  CONST CHAR16                  *VariableName,
 174   IN  CONST EFI_GUID                *VendorGuid,
 175   OUT VARIABLE_POINTER_TRACK        *PtrTrack
 176   )
 177 /*++
 178
 179 Routine Description:
 180
 181   This function compares a variable with variable entries in database
 182
 183 Arguments:
 184
 185   Variable       - Pointer to the variable in our database
 186   VariableName   - Name of the variable to compare to 'Variable'
 187   VendorGuid     - GUID of the variable to compare to 'Variable'
 188   PtrTrack       - Variable Track Pointer structure that contains
 189                    Variable Information.
 190
 191 Returns:
 192
 193   EFI_SUCCESS    - Found match variable
 194   EFI_NOT_FOUND  - Variable not found
 195
 196 --*/
 197 {
 198   if (VariableName[0] == 0) {
 199     PtrTrack->CurrPtr = Variable;
 200     return EFI_SUCCESS;
 201   } else {
 202     //
 203     // Don't use CompareGuid function here for performance reasons.
 204     // Instead we compare the GUID a UINT32 at a time and branch
 205     // on the first failed comparison.
 206     //
 207     if ((((INT32 *) VendorGuid)[0] == ((INT32 *) &Variable->VendorGuid)[0]) &&
 208         (((INT32 *) VendorGuid)[1] == ((INT32 *) &Variable->VendorGuid)[1]) &&
 209         (((INT32 *) VendorGuid)[2] == ((INT32 *) &Variable->VendorGuid)[2]) &&
 210         (((INT32 *) VendorGuid)[3] == ((INT32 *) &Variable->VendorGuid)[3])
 211         ) {
 212       if (!CompareMem (VariableName, GET_VARIABLE_NAME_PTR (Variable), Variable->NameSize)) {
 213         PtrTrack->CurrPtr = Variable;
 214         return EFI_SUCCESS;
 215       }
 216     }
 217   }
 218
 219   return EFI_NOT_FOUND;
 220 }
 221
 222 STATIC
 223 EFI_STATUS
 224 EFIAPI
 225 FindVariable (
 226   IN EFI_PEI_SERVICES         **PeiServices,
 227   IN CONST  CHAR16            *VariableName,
 228   IN CONST  EFI_GUID          *VendorGuid,
 229   OUT VARIABLE_POINTER_TRACK  *PtrTrack
 230   )
 231 /*++
 232
 233 Routine Description:
 234
 235   This code finds variable in storage blocks (Non-Volatile)
 236
 237 Arguments:
 238
 239   PeiServices    - General purpose services available to every PEIM.
 240   VariableName   - Name of the variable to be found
 241   VendorGuid     - Vendor GUID to be found.
 242   PtrTrack       - Variable Track Pointer structure that contains
 243                    Variable Information.
 244
 245 Returns:
 246
 247   EFI_SUCCESS      - Variable found successfully
 248   EFI_NOT_FOUND    - Variable not found
 249   EFI_INVALID_PARAMETER  - Invalid variable name
 250
 251 --*/
 252 {
 253   EFI_HOB_GUID_TYPE       *GuidHob;
 254   VARIABLE_STORE_HEADER   *VariableStoreHeader;
 255   VARIABLE_HEADER         *Variable;
 256   VARIABLE_HEADER         *MaxIndex;
 257   VARIABLE_INDEX_TABLE    *IndexTable;
 258   UINT32                  Count;
 259   UINT8                   *VariableBase;
 260
 261   if (VariableName != 0 && VendorGuid == NULL) {
 262     return EFI_INVALID_PARAMETER;
 263   }
 264   //
 265   // No Variable Address equals zero, so 0 as initial value is safe.
 266   //
 267   MaxIndex = 0;
 268
 269   GuidHob = GetFirstGuidHob (&mEfiVariableIndexTableGuid);
 270   if (GuidHob == NULL) {
 271     IndexTable = BuildGuidHob (&mEfiVariableIndexTableGuid, sizeof (VARIABLE_INDEX_TABLE));
 272     IndexTable->Length      = 0;
 273     IndexTable->StartPtr    = NULL;
 274     IndexTable->EndPtr      = NULL;
 275     IndexTable->GoneThrough = 0;
 276   } else {
 277     IndexTable = GET_GUID_HOB_DATA (GuidHob);
 278     for (Count = 0; Count < IndexTable->Length; Count++)
 279     {
 280       MaxIndex = GetVariableByIndex (IndexTable, Count);
 281
 282       if (CompareWithValidVariable (MaxIndex, VariableName, VendorGuid, PtrTrack) == EFI_SUCCESS) {
 283         PtrTrack->StartPtr  = IndexTable->StartPtr;
 284         PtrTrack->EndPtr    = IndexTable->EndPtr;
 285
 286         return EFI_SUCCESS;
 287       }
 288     }
 289
 290     if (IndexTable->GoneThrough) {
 291       return EFI_NOT_FOUND;
 292     }
 293   }
 294   //
 295   // If not found in HOB, then let's start from the MaxIndex we've found.
 296   //
 297   if (MaxIndex != NULL) {
 298     Variable = GetNextVariablePtr (MaxIndex);
 299   } else {
 300     if (IndexTable->StartPtr || IndexTable->EndPtr) {
 301       Variable = IndexTable->StartPtr;
 302     } else {
 303       VariableBase = (UINT8 *) (UINTN) PcdGet32 (PcdFlashNvStorageVariableBase);
 304       VariableStoreHeader = (VARIABLE_STORE_HEADER *) (VariableBase + \
 305                             ((EFI_FIRMWARE_VOLUME_HEADER *) (VariableBase)) -> HeaderLength);
 306
 307       if (GetVariableStoreStatus (VariableStoreHeader) != EfiValid) {
 308         return EFI_UNSUPPORTED;
 309       }
 310
 311       if (~VariableStoreHeader->Size == 0) {
 312         return EFI_NOT_FOUND;
 313       }
 314       //
 315       // Find the variable by walk through non-volatile variable store
 316       //
 317       IndexTable->StartPtr  = (VARIABLE_HEADER *) (VariableStoreHeader + 1);
 318       IndexTable->EndPtr    = (VARIABLE_HEADER *) ((UINTN) VariableStoreHeader + VariableStoreHeader->Size);
 319
 320       //
 321       // Start Pointers for the variable.
 322       // Actual Data Pointer where data can be written.
 323       //
 324       Variable = IndexTable->StartPtr;
 325     }
 326   }
 327   //
 328   // Find the variable by walk through non-volatile variable store
 329   //
 330   PtrTrack->StartPtr  = IndexTable->StartPtr;
 331   PtrTrack->EndPtr    = IndexTable->EndPtr;
 332
 333   while (IsValidVariableHeader (Variable) && (Variable <= IndexTable->EndPtr)) {
 334     if (Variable->State == VAR_ADDED) {
 335       //
 336       // Record Variable in VariableIndex HOB
 337       //
 338       if (IndexTable->Length < VARIABLE_INDEX_TABLE_VOLUME)
 339       {
 340         VariableIndexTableUpdate (IndexTable, Variable);
 341       }
 342
 343       if (CompareWithValidVariable (Variable, VariableName, VendorGuid, PtrTrack) == EFI_SUCCESS) {
 344         return EFI_SUCCESS;
 345       }
 346     }
 347
 348     Variable = GetNextVariablePtr (Variable);
 349   }
 350   //
 351   // If gone through the VariableStore, that means we never find in Firmware any more.
 352   //
 353   if (IndexTable->Length < VARIABLE_INDEX_TABLE_VOLUME) {
 354     IndexTable->GoneThrough = 1;
 355   }
 356
 357   PtrTrack->CurrPtr = NULL;
 358
 359   return EFI_NOT_FOUND;
 360 }
 361
 362 EFI_STATUS
 363 EFIAPI
 364 PeiGetVariable (
 365   IN CONST  EFI_PEI_READ_ONLY_VARIABLE2_PPI *This,
 366   IN CONST  CHAR16                          *VariableName,
 367   IN CONST  EFI_GUID                        *VariableGuid,
 368   OUT       UINT32                          *Attributes,
 369   IN OUT    UINTN                           *DataSize,
 370   OUT       VOID                            *Data
 371   )
 372 /*++
 373
 374 Routine Description:
 375
 376   Provide the read variable functionality of the variable services.
 377
 378 Arguments:
 379
 380   PeiServices - General purpose services available to every PEIM.
 381
 382   VariableName     - The variable name
 383
 384   VendorGuid       - The vendor's GUID
 385
 386   Attributes       - Pointer to the attribute
 387
 388   DataSize         - Size of data
 389
 390   Data             - Pointer to data
 391
 392 Returns:
 393
 394   EFI_SUCCESS           - The interface could be successfully installed
 395
 396   EFI_NOT_FOUND         - The variable could not be discovered
 397
 398   EFI_BUFFER_TOO_SMALL  - The caller buffer is not large enough
 399
 400 --*/
 401 {
 402   VARIABLE_POINTER_TRACK  Variable;
 403   UINTN                   VarDataSize;
 404   EFI_STATUS              Status;
 405   EFI_PEI_SERVICES        **PeiServices;
 406
 407   PeiServices = GetPeiServicesTablePointer ();
 408   if (VariableName == NULL || VariableGuid == NULL) {
 409     return EFI_INVALID_PARAMETER;
 410   }
 411   //
 412   // Find existing variable
 413   //
 414   Status = FindVariable (PeiServices, VariableName, VariableGuid, &Variable);
 415   if (Variable.CurrPtr == NULL || Status != EFI_SUCCESS) {
 416     return Status;
 417   }
 418   //
 419   // Get data size
 420   //
 421   VarDataSize = Variable.CurrPtr->DataSize;
 422   if (*DataSize >= VarDataSize) {
 423     (*PeiServices)->CopyMem (Data, GET_VARIABLE_DATA_PTR (Variable.CurrPtr), VarDataSize);
 424
 425     if (Attributes != NULL) {
 426       *Attributes = Variable.CurrPtr->Attributes;
 427     }
 428
 429     *DataSize = VarDataSize;
 430     return EFI_SUCCESS;
 431   } else {
 432     *DataSize = VarDataSize;
 433     return EFI_BUFFER_TOO_SMALL;
 434   }
 435 }
 436
 437 EFI_STATUS
 438 EFIAPI
 439 PeiGetNextVariableName (
 440   IN CONST  EFI_PEI_READ_ONLY_VARIABLE2_PPI *This,
 441   IN OUT UINTN                              *VariableNameSize,
 442   IN OUT CHAR16                             *VariableName,
 443   IN OUT EFI_GUID                           *VariableGuid
 444   )
 445 /*++
 446
 447 Routine Description:
 448
 449   Provide the get next variable functionality of the variable services.
 450
 451 Arguments:
 452
 453   PeiServices        - General purpose services available to every PEIM.
 454   VariabvleNameSize  - The variable name's size.
 455   VariableName       - A pointer to the variable's name.
 456   VariableGuid       - A pointer to the EFI_GUID structure.
 457
 458   VariableNameSize - Size of the variable name
 459
 460   VariableName     - The variable name
 461
 462   VendorGuid       - The vendor's GUID
 463
 464 Returns:
 465
 466   EFI_SUCCESS - The interface could be successfully installed
 467
 468   EFI_NOT_FOUND - The variable could not be discovered
 469
 470 --*/
 471 {
 472   VARIABLE_POINTER_TRACK  Variable;
 473   UINTN                   VarNameSize;
 474   EFI_STATUS              Status;
 475   EFI_PEI_SERVICES        **PeiServices;
 476
 477   PeiServices = GetPeiServicesTablePointer ();
 478   if (VariableName == NULL) {
 479     return EFI_INVALID_PARAMETER;
 480   }
 481
 482   Status = FindVariable (PeiServices, VariableName, VariableGuid, &Variable);
 483   if (Variable.CurrPtr == NULL || Status != EFI_SUCCESS) {
 484     return Status;
 485   }
 486
 487   if (VariableName[0] != 0) {
 488     //
 489     // If variable name is not NULL, get next variable
 490     //
 491     Variable.CurrPtr = GetNextVariablePtr (Variable.CurrPtr);
 492   }
 493
 494   while (!(Variable.CurrPtr >= Variable.EndPtr || Variable.CurrPtr == NULL)) {
 495     if (IsValidVariableHeader (Variable.CurrPtr)) {
 496       if (Variable.CurrPtr->State == VAR_ADDED) {
 497         VarNameSize = (UINTN) Variable.CurrPtr->NameSize;
 498         if (VarNameSize <= *VariableNameSize) {
 499           (*PeiServices)->CopyMem (VariableName, GET_VARIABLE_NAME_PTR (Variable.CurrPtr), VarNameSize);
 500
 501           (*PeiServices)->CopyMem (VariableGuid, &Variable.CurrPtr->VendorGuid, sizeof (EFI_GUID));
 502
 503           Status = EFI_SUCCESS;
 504         } else {
 505           Status = EFI_BUFFER_TOO_SMALL;
 506         }
 507
 508         *VariableNameSize = VarNameSize;
 509         return Status;
 510         //
 511         // Variable is found
 512         //
 513       } else {
 514         Variable.CurrPtr = GetNextVariablePtr (Variable.CurrPtr);
 515       }
 516     } else {
 517       break;
 518     }
 519   }
 520
 521   return EFI_NOT_FOUND;
 522 }