1 /** @file 2 The UEFI Library provides functions and macros that simplify the development of 3 UEFI Drivers and UEFI Applications. These functions and macros help manage EFI 4 events, build simple locks utilizing EFI Task Priority Levels (TPLs), install 5 EFI Driver Model related protocols, manage Unicode string tables for UEFI Drivers, 6 and print messages on the console output and standard error devices. 7 8 Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR> 9 This program and the accompanying materials 10 are licensed and made available under the terms and conditions of the BSD License 11 which accompanies this distribution. The full text of the license may be found at 12 http://opensource.org/licenses/bsd-license.php 13 14 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, 15 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. 16 17 **/ 18 19 20 #include "UefiLibInternal.h" 21 22 /** 23 Compare whether two names of languages are identical. 24 25 @param Language1 Name of language 1. 26 @param Language2 Name of language 2. 27 28 @retval TRUE Language 1 and language 2 are the same. 29 @retval FALSE Language 1 and language 2 are not the same. 30 31 **/ 32 BOOLEAN 33 CompareIso639LanguageCode ( 34 IN CONST CHAR8 *Language1, 35 IN CONST CHAR8 *Language2 36 ) 37 { 38 UINT32 Name1; 39 UINT32 Name2; 40 41 Name1 = ReadUnaligned24 ((CONST UINT32 *) Language1); 42 Name2 = ReadUnaligned24 ((CONST UINT32 *) Language2); 43 44 return (BOOLEAN) (Name1 == Name2); 45 } 46 47 /** 48 Retrieves a pointer to the system configuration table from the EFI System Table 49 based on a specified GUID. 50 51 This function searches the list of configuration tables stored in the EFI System Table 52 for a table with a GUID that matches TableGuid. If a match is found, then a pointer to 53 the configuration table is returned in Table., and EFI_SUCCESS is returned. If a matching GUID 54 is not found, then EFI_NOT_FOUND is returned. 55 If TableGuid is NULL, then ASSERT(). 56 If Table is NULL, then ASSERT(). 57 58 @param TableGuid Pointer to table's GUID type.. 59 @param Table Pointer to the table associated with TableGuid in the EFI System Table. 60 61 @retval EFI_SUCCESS A configuration table matching TableGuid was found. 62 @retval EFI_NOT_FOUND A configuration table matching TableGuid could not be found. 63 64 **/ 65 EFI_STATUS 66 EFIAPI 67 EfiGetSystemConfigurationTable ( 68 IN EFI_GUID *TableGuid, 69 OUT VOID **Table 70 ) 71 { 72 EFI_SYSTEM_TABLE *SystemTable; 73 UINTN Index; 74 75 ASSERT (TableGuid != NULL); 76 ASSERT (Table != NULL); 77 78 SystemTable = gST; 79 *Table = NULL; 80 for (Index = 0; Index < SystemTable->NumberOfTableEntries; Index++) { 81 if (CompareGuid (TableGuid, &(SystemTable->ConfigurationTable[Index].VendorGuid))) { 82 *Table = SystemTable->ConfigurationTable[Index].VendorTable; 83 return EFI_SUCCESS; 84 } 85 } 86 87 return EFI_NOT_FOUND; 88 } 89 90 /** 91 Creates and returns a notification event and registers that event with all the protocol 92 instances specified by ProtocolGuid. 93 94 This function causes the notification function to be executed for every protocol of type 95 ProtocolGuid instance that exists in the system when this function is invoked. If there are 96 no instances of ProtocolGuid in the handle database at the time this function is invoked, 97 then the notification function is still executed one time. In addition, every time a protocol 98 of type ProtocolGuid instance is installed or reinstalled, the notification function is also 99 executed. This function returns the notification event that was created. 100 If ProtocolGuid is NULL, then ASSERT(). 101 If NotifyTpl is not a legal TPL value, then ASSERT(). 102 If NotifyFunction is NULL, then ASSERT(). 103 If Registration is NULL, then ASSERT(). 104 105 106 @param ProtocolGuid Supplies GUID of the protocol upon whose installation the event is fired. 107 @param NotifyTpl Supplies the task priority level of the event notifications. 108 @param NotifyFunction Supplies the function to notify when the event is signaled. 109 @param NotifyContext The context parameter to pass to NotifyFunction. 110 @param Registration A pointer to a memory location to receive the registration value. 111 This value is passed to LocateHandle() to obtain new handles that 112 have been added that support the ProtocolGuid-specified protocol. 113 114 @return The notification event that was created. 115 116 **/ 117 EFI_EVENT 118 EFIAPI 119 EfiCreateProtocolNotifyEvent( 120 IN EFI_GUID *ProtocolGuid, 121 IN EFI_TPL NotifyTpl, 122 IN EFI_EVENT_NOTIFY NotifyFunction, 123 IN VOID *NotifyContext, OPTIONAL 124 OUT VOID **Registration 125 ) 126 { 127 EFI_STATUS Status; 128 EFI_EVENT Event; 129 130 ASSERT (ProtocolGuid != NULL); 131 ASSERT (NotifyFunction != NULL); 132 ASSERT (Registration != NULL); 133 134 // 135 // Create the event 136 // 137 138 Status = gBS->CreateEvent ( 139 EVT_NOTIFY_SIGNAL, 140 NotifyTpl, 141 NotifyFunction, 142 NotifyContext, 143 &Event 144 ); 145 ASSERT_EFI_ERROR (Status); 146 147 // 148 // Register for protocol notifications on this event 149 // 150 151 Status = gBS->RegisterProtocolNotify ( 152 ProtocolGuid, 153 Event, 154 Registration 155 ); 156 157 ASSERT_EFI_ERROR (Status); 158 159 // 160 // Kick the event so we will perform an initial pass of 161 // current installed drivers 162 // 163 164 gBS->SignalEvent (Event); 165 return Event; 166 } 167 168 /** 169 Creates a named event that can be signaled with EfiNamedEventSignal(). 170 171 This function creates an event using NotifyTpl, NoifyFunction, and NotifyContext. 172 This event is signaled with EfiNamedEventSignal(). This provides the ability for one or more 173 listeners on the same event named by the GUID specified by Name. 174 If Name is NULL, then ASSERT(). 175 If NotifyTpl is not a legal TPL value, then ASSERT(). 176 If NotifyFunction is NULL, then ASSERT(). 177 178 @param Name Supplies GUID name of the event. 179 @param NotifyTpl Supplies the task priority level of the event notifications. 180 @param NotifyFunction Supplies the function to notify when the event is signaled. 181 @param NotifyContext The context parameter to pass to NotifyFunction. 182 @param Registration A pointer to a memory location to receive the registration value. 183 184 @retval EFI_SUCCESS A named event was created. 185 @retval EFI_OUT_OF_RESOURCES There are not enough resource to create the named event. 186 187 **/ 188 EFI_STATUS 189 EFIAPI 190 EfiNamedEventListen ( 191 IN CONST EFI_GUID *Name, 192 IN EFI_TPL NotifyTpl, 193 IN EFI_EVENT_NOTIFY NotifyFunction, 194 IN CONST VOID *NotifyContext, OPTIONAL 195 OUT VOID *Registration OPTIONAL 196 ) 197 { 198 EFI_STATUS Status; 199 EFI_EVENT Event; 200 VOID *RegistrationLocal; 201 202 ASSERT (Name != NULL); 203 ASSERT (NotifyFunction != NULL); 204 ASSERT (NotifyTpl <= TPL_HIGH_LEVEL); 205 206 // 207 // Create event 208 // 209 Status = gBS->CreateEvent ( 210 EVT_NOTIFY_SIGNAL, 211 NotifyTpl, 212 NotifyFunction, 213 (VOID *) NotifyContext, 214 &Event 215 ); 216 ASSERT_EFI_ERROR (Status); 217 218 // 219 // The Registration is not optional to RegisterProtocolNotify(). 220 // To make it optional to EfiNamedEventListen(), may need to substitute with a local. 221 // 222 if (Registration != NULL) { 223 RegistrationLocal = Registration; 224 } else { 225 RegistrationLocal = &RegistrationLocal; 226 } 227 228 // 229 // Register for an installation of protocol interface 230 // 231 232 Status = gBS->RegisterProtocolNotify ( 233 (EFI_GUID *) Name, 234 Event, 235 RegistrationLocal 236 ); 237 ASSERT_EFI_ERROR (Status); 238 239 return Status; 240 } 241 242 /** 243 Signals a named event created with EfiNamedEventListen(). 244 245 This function signals the named event specified by Name. The named event must have been 246 created with EfiNamedEventListen(). 247 If Name is NULL, then ASSERT(). 248 249 @param Name Supplies GUID name of the event. 250 251 @retval EFI_SUCCESS A named event was signaled. 252 @retval EFI_OUT_OF_RESOURCES There are not enough resource to signal the named event. 253 254 **/ 255 EFI_STATUS 256 EFIAPI 257 EfiNamedEventSignal ( 258 IN CONST EFI_GUID *Name 259 ) 260 { 261 EFI_STATUS Status; 262 EFI_HANDLE Handle; 263 264 ASSERT(Name != NULL); 265 266 Handle = NULL; 267 Status = gBS->InstallProtocolInterface ( 268 &Handle, 269 (EFI_GUID *) Name, 270 EFI_NATIVE_INTERFACE, 271 NULL 272 ); 273 ASSERT_EFI_ERROR (Status); 274 275 Status = gBS->UninstallProtocolInterface ( 276 Handle, 277 (EFI_GUID *) Name, 278 NULL 279 ); 280 ASSERT_EFI_ERROR (Status); 281 282 return Status; 283 } 284 285 /** 286 Returns the current TPL. 287 288 This function returns the current TPL. There is no EFI service to directly 289 retrieve the current TPL. Instead, the RaiseTPL() function is used to raise 290 the TPL to TPL_HIGH_LEVEL. This will return the current TPL. The TPL level 291 can then immediately be restored back to the current TPL level with a call 292 to RestoreTPL(). 293 294 @return The current TPL. 295 296 **/ 297 EFI_TPL 298 EFIAPI 299 EfiGetCurrentTpl ( 300 VOID 301 ) 302 { 303 EFI_TPL Tpl; 304 305 Tpl = gBS->RaiseTPL (TPL_HIGH_LEVEL); 306 gBS->RestoreTPL (Tpl); 307 308 return Tpl; 309 } 310 311 312 /** 313 Initializes a basic mutual exclusion lock. 314 315 This function initializes a basic mutual exclusion lock to the released state 316 and returns the lock. Each lock provides mutual exclusion access at its task 317 priority level. Since there is no preemption or multiprocessor support in EFI, 318 acquiring the lock only consists of raising to the locks TPL. 319 If Lock is NULL, then ASSERT(). 320 If Priority is not a valid TPL value, then ASSERT(). 321 322 @param Lock A pointer to the lock data structure to initialize. 323 @param Priority EFI TPL associated with the lock. 324 325 @return The lock. 326 327 **/ 328 EFI_LOCK * 329 EFIAPI 330 EfiInitializeLock ( 331 IN OUT EFI_LOCK *Lock, 332 IN EFI_TPL Priority 333 ) 334 { 335 ASSERT (Lock != NULL); 336 ASSERT (Priority <= TPL_HIGH_LEVEL); 337 338 Lock->Tpl = Priority; 339 Lock->OwnerTpl = TPL_APPLICATION; 340 Lock->Lock = EfiLockReleased ; 341 return Lock; 342 } 343 344 /** 345 Acquires ownership of a lock. 346 347 This function raises the system's current task priority level to the task 348 priority level of the mutual exclusion lock. Then, it places the lock in the 349 acquired state. 350 If Lock is NULL, then ASSERT(). 351 If Lock is not initialized, then ASSERT(). 352 If Lock is already in the acquired state, then ASSERT(). 353 354 @param Lock A pointer to the lock to acquire. 355 356 **/ 357 VOID 358 EFIAPI 359 EfiAcquireLock ( 360 IN EFI_LOCK *Lock 361 ) 362 { 363 ASSERT (Lock != NULL); 364 ASSERT (Lock->Lock == EfiLockReleased); 365 366 Lock->OwnerTpl = gBS->RaiseTPL (Lock->Tpl); 367 Lock->Lock = EfiLockAcquired; 368 } 369 370 /** 371 Acquires ownership of a lock. 372 373 This function raises the system's current task priority level to the task priority 374 level of the mutual exclusion lock. Then, it attempts to place the lock in the acquired state. 375 If the lock is already in the acquired state, then EFI_ACCESS_DENIED is returned. 376 Otherwise, EFI_SUCCESS is returned. 377 If Lock is NULL, then ASSERT(). 378 If Lock is not initialized, then ASSERT(). 379 380 @param Lock A pointer to the lock to acquire. 381 382 @retval EFI_SUCCESS The lock was acquired. 383 @retval EFI_ACCESS_DENIED The lock could not be acquired because it is already owned. 384 385 **/ 386 EFI_STATUS 387 EFIAPI 388 EfiAcquireLockOrFail ( 389 IN EFI_LOCK *Lock 390 ) 391 { 392 393 ASSERT (Lock != NULL); 394 ASSERT (Lock->Lock != EfiLockUninitialized); 395 396 if (Lock->Lock == EfiLockAcquired) { 397 // 398 // Lock is already owned, so bail out 399 // 400 return EFI_ACCESS_DENIED; 401 } 402 403 Lock->OwnerTpl = gBS->RaiseTPL (Lock->Tpl); 404 405 Lock->Lock = EfiLockAcquired; 406 407 return EFI_SUCCESS; 408 } 409 410 /** 411 Releases ownership of a lock. 412 413 This function transitions a mutual exclusion lock from the acquired state to 414 the released state, and restores the system's task priority level to its 415 previous level. 416 If Lock is NULL, then ASSERT(). 417 If Lock is not initialized, then ASSERT(). 418 If Lock is already in the released state, then ASSERT(). 419 420 @param Lock A pointer to the lock to release. 421 422 **/ 423 VOID 424 EFIAPI 425 EfiReleaseLock ( 426 IN EFI_LOCK *Lock 427 ) 428 { 429 EFI_TPL Tpl; 430 431 ASSERT (Lock != NULL); 432 ASSERT (Lock->Lock == EfiLockAcquired); 433 434 Tpl = Lock->OwnerTpl; 435 436 Lock->Lock = EfiLockReleased; 437 438 gBS->RestoreTPL (Tpl); 439 } 440 441 /** 442 Tests whether a controller handle is being managed by a specific driver. 443 444 This function tests whether the driver specified by DriverBindingHandle is 445 currently managing the controller specified by ControllerHandle. This test 446 is performed by evaluating if the the protocol specified by ProtocolGuid is 447 present on ControllerHandle and is was opened by DriverBindingHandle with an 448 attribute of EFI_OPEN_PROTOCOL_BY_DRIVER. 449 If ProtocolGuid is NULL, then ASSERT(). 450 451 @param ControllerHandle A handle for a controller to test. 452 @param DriverBindingHandle Specifies the driver binding handle for the 453 driver. 454 @param ProtocolGuid Specifies the protocol that the driver specified 455 by DriverBindingHandle opens in its Start() 456 function. 457 458 @retval EFI_SUCCESS ControllerHandle is managed by the driver 459 specified by DriverBindingHandle. 460 @retval EFI_UNSUPPORTED ControllerHandle is not managed by the driver 461 specified by DriverBindingHandle. 462 463 **/ 464 EFI_STATUS 465 EFIAPI 466 EfiTestManagedDevice ( 467 IN CONST EFI_HANDLE ControllerHandle, 468 IN CONST EFI_HANDLE DriverBindingHandle, 469 IN CONST EFI_GUID *ProtocolGuid 470 ) 471 { 472 EFI_STATUS Status; 473 VOID *ManagedInterface; 474 475 ASSERT (ProtocolGuid != NULL); 476 477 Status = gBS->OpenProtocol ( 478 ControllerHandle, 479 (EFI_GUID *) ProtocolGuid, 480 &ManagedInterface, 481 DriverBindingHandle, 482 ControllerHandle, 483 EFI_OPEN_PROTOCOL_BY_DRIVER 484 ); 485 if (!EFI_ERROR (Status)) { 486 gBS->CloseProtocol ( 487 ControllerHandle, 488 (EFI_GUID *) ProtocolGuid, 489 DriverBindingHandle, 490 ControllerHandle 491 ); 492 return EFI_UNSUPPORTED; 493 } 494 495 if (Status != EFI_ALREADY_STARTED) { 496 return EFI_UNSUPPORTED; 497 } 498 499 return EFI_SUCCESS; 500 } 501 502 /** 503 Tests whether a child handle is a child device of the controller. 504 505 This function tests whether ChildHandle is one of the children of 506 ControllerHandle. This test is performed by checking to see if the protocol 507 specified by ProtocolGuid is present on ControllerHandle and opened by 508 ChildHandle with an attribute of EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER. 509 If ProtocolGuid is NULL, then ASSERT(). 510 511 @param ControllerHandle A handle for a (parent) controller to test. 512 @param ChildHandle A child handle to test. 513 @param ProtocolGuid Supplies the protocol that the child controller 514 opens on its parent controller. 515 516 @retval EFI_SUCCESS ChildHandle is a child of the ControllerHandle. 517 @retval EFI_UNSUPPORTED ChildHandle is not a child of the 518 ControllerHandle. 519 520 **/ 521 EFI_STATUS 522 EFIAPI 523 EfiTestChildHandle ( 524 IN CONST EFI_HANDLE ControllerHandle, 525 IN CONST EFI_HANDLE ChildHandle, 526 IN CONST EFI_GUID *ProtocolGuid 527 ) 528 { 529 EFI_STATUS Status; 530 EFI_OPEN_PROTOCOL_INFORMATION_ENTRY *OpenInfoBuffer; 531 UINTN EntryCount; 532 UINTN Index; 533 534 ASSERT (ProtocolGuid != NULL); 535 536 // 537 // Retrieve the list of agents that are consuming the specific protocol 538 // on ControllerHandle. 539 // 540 Status = gBS->OpenProtocolInformation ( 541 ControllerHandle, 542 (EFI_GUID *) ProtocolGuid, 543 &OpenInfoBuffer, 544 &EntryCount 545 ); 546 if (EFI_ERROR (Status)) { 547 return EFI_UNSUPPORTED; 548 } 549 550 // 551 // Inspect if ChildHandle is one of the agents. 552 // 553 Status = EFI_UNSUPPORTED; 554 for (Index = 0; Index < EntryCount; Index++) { 555 if ((OpenInfoBuffer[Index].ControllerHandle == ChildHandle) && 556 (OpenInfoBuffer[Index].Attributes & EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER) != 0) { 557 Status = EFI_SUCCESS; 558 break; 559 } 560 } 561 562 FreePool (OpenInfoBuffer); 563 return Status; 564 } 565 566 /** 567 This function looks up a Unicode string in UnicodeStringTable. 568 569 If Language is a member of SupportedLanguages and a Unicode string is found in 570 UnicodeStringTable that matches the language code specified by Language, then it 571 is returned in UnicodeString. 572 573 @param Language A pointer to the ISO 639-2 language code for the 574 Unicode string to look up and return. 575 @param SupportedLanguages A pointer to the set of ISO 639-2 language codes 576 that the Unicode string table supports. Language 577 must be a member of this set. 578 @param UnicodeStringTable A pointer to the table of Unicode strings. 579 @param UnicodeString A pointer to the Unicode string from UnicodeStringTable 580 that matches the language specified by Language. 581 582 @retval EFI_SUCCESS The Unicode string that matches the language 583 specified by Language was found 584 in the table of Unicode strings UnicodeStringTable, 585 and it was returned in UnicodeString. 586 @retval EFI_INVALID_PARAMETER Language is NULL. 587 @retval EFI_INVALID_PARAMETER UnicodeString is NULL. 588 @retval EFI_UNSUPPORTED SupportedLanguages is NULL. 589 @retval EFI_UNSUPPORTED UnicodeStringTable is NULL. 590 @retval EFI_UNSUPPORTED The language specified by Language is not a 591 member of SupportedLanguages. 592 @retval EFI_UNSUPPORTED The language specified by Language is not 593 supported by UnicodeStringTable. 594 595 **/ 596 EFI_STATUS 597 EFIAPI 598 LookupUnicodeString ( 599 IN CONST CHAR8 *Language, 600 IN CONST CHAR8 *SupportedLanguages, 601 IN CONST EFI_UNICODE_STRING_TABLE *UnicodeStringTable, 602 OUT CHAR16 **UnicodeString 603 ) 604 { 605 // 606 // Make sure the parameters are valid 607 // 608 if (Language == NULL || UnicodeString == NULL) { 609 return EFI_INVALID_PARAMETER; 610 } 611 612 // 613 // If there are no supported languages, or the Unicode String Table is empty, then the 614 // Unicode String specified by Language is not supported by this Unicode String Table 615 // 616 if (SupportedLanguages == NULL || UnicodeStringTable == NULL) { 617 return EFI_UNSUPPORTED; 618 } 619 620 // 621 // Make sure Language is in the set of Supported Languages 622 // 623 while (*SupportedLanguages != 0) { 624 if (CompareIso639LanguageCode (Language, SupportedLanguages)) { 625 626 // 627 // Search the Unicode String Table for the matching Language specifier 628 // 629 while (UnicodeStringTable->Language != NULL) { 630 if (CompareIso639LanguageCode (Language, UnicodeStringTable->Language)) { 631 632 // 633 // A matching string was found, so return it 634 // 635 *UnicodeString = UnicodeStringTable->UnicodeString; 636 return EFI_SUCCESS; 637 } 638 639 UnicodeStringTable++; 640 } 641 642 return EFI_UNSUPPORTED; 643 } 644 645 SupportedLanguages += 3; 646 } 647 648 return EFI_UNSUPPORTED; 649 } 650 651 652 653 /** 654 This function looks up a Unicode string in UnicodeStringTable. 655 656 If Language is a member of SupportedLanguages and a Unicode string is found in 657 UnicodeStringTable that matches the language code specified by Language, then 658 it is returned in UnicodeString. 659 660 @param Language A pointer to an ASCII string containing the ISO 639-2 or the 661 RFC 4646 language code for the Unicode string to look up and 662 return. If Iso639Language is TRUE, then this ASCII string is 663 not assumed to be Null-terminated, and only the first three 664 characters are used. If Iso639Language is FALSE, then this ASCII 665 string must be Null-terminated. 666 @param SupportedLanguages A pointer to a Null-terminated ASCII string that contains a 667 set of ISO 639-2 or RFC 4646 language codes that the Unicode 668 string table supports. Language must be a member of this set. 669 If Iso639Language is TRUE, then this string contains one or more 670 ISO 639-2 language codes with no separator characters. If Iso639Language 671 is FALSE, then is string contains one or more RFC 4646 language 672 codes separated by ';'. 673 @param UnicodeStringTable A pointer to the table of Unicode strings. Type EFI_UNICODE_STRING_TABLE 674 is defined in "Related Definitions". 675 @param UnicodeString A pointer to the Null-terminated Unicode string from UnicodeStringTable 676 that matches the language specified by Language. 677 @param Iso639Language Specifies the supported language code format. If it is TRUE, then 678 Language and SupportedLanguages follow ISO 639-2 language code format. 679 Otherwise, they follow RFC 4646 language code format. 680 681 682 @retval EFI_SUCCESS The Unicode string that matches the language specified by Language 683 was found in the table of Unicode strings UnicodeStringTable, and 684 it was returned in UnicodeString. 685 @retval EFI_INVALID_PARAMETER Language is NULL. 686 @retval EFI_INVALID_PARAMETER UnicodeString is NULL. 687 @retval EFI_UNSUPPORTED SupportedLanguages is NULL. 688 @retval EFI_UNSUPPORTED UnicodeStringTable is NULL. 689 @retval EFI_UNSUPPORTED The language specified by Language is not a member of SupportedLanguages. 690 @retval EFI_UNSUPPORTED The language specified by Language is not supported by UnicodeStringTable. 691 692 **/ 693 EFI_STATUS 694 EFIAPI 695 LookupUnicodeString2 ( 696 IN CONST CHAR8 *Language, 697 IN CONST CHAR8 *SupportedLanguages, 698 IN CONST EFI_UNICODE_STRING_TABLE *UnicodeStringTable, 699 OUT CHAR16 **UnicodeString, 700 IN BOOLEAN Iso639Language 701 ) 702 { 703 BOOLEAN Found; 704 UINTN Index; 705 CHAR8 *LanguageString; 706 707 // 708 // Make sure the parameters are valid 709 // 710 if (Language == NULL || UnicodeString == NULL) { 711 return EFI_INVALID_PARAMETER; 712 } 713 714 // 715 // If there are no supported languages, or the Unicode String Table is empty, then the 716 // Unicode String specified by Language is not supported by this Unicode String Table 717 // 718 if (SupportedLanguages == NULL || UnicodeStringTable == NULL) { 719 return EFI_UNSUPPORTED; 720 } 721 722 // 723 // Make sure Language is in the set of Supported Languages 724 // 725 Found = FALSE; 726 while (*SupportedLanguages != 0) { 727 if (Iso639Language) { 728 if (CompareIso639LanguageCode (Language, SupportedLanguages)) { 729 Found = TRUE; 730 break; 731 } 732 SupportedLanguages += 3; 733 } else { 734 for (Index = 0; SupportedLanguages[Index] != 0 && SupportedLanguages[Index] != ';'; Index++); 735 if ((AsciiStrnCmp(SupportedLanguages, Language, Index) == 0) && (Language[Index] == 0)) { 736 Found = TRUE; 737 break; 738 } 739 SupportedLanguages += Index; 740 for (; *SupportedLanguages != 0 && *SupportedLanguages == ';'; SupportedLanguages++); 741 } 742 } 743 744 // 745 // If Language is not a member of SupportedLanguages, then return EFI_UNSUPPORTED 746 // 747 if (!Found) { 748 return EFI_UNSUPPORTED; 749 } 750 751 // 752 // Search the Unicode String Table for the matching Language specifier 753 // 754 while (UnicodeStringTable->Language != NULL) { 755 LanguageString = UnicodeStringTable->Language; 756 while (0 != *LanguageString) { 757 for (Index = 0 ;LanguageString[Index] != 0 && LanguageString[Index] != ';'; Index++); 758 if (AsciiStrnCmp(LanguageString, Language, Index) == 0) { 759 *UnicodeString = UnicodeStringTable->UnicodeString; 760 return EFI_SUCCESS; 761 } 762 LanguageString += Index; 763 for (Index = 0 ;LanguageString[Index] != 0 && LanguageString[Index] == ';'; Index++); 764 } 765 UnicodeStringTable++; 766 } 767 768 return EFI_UNSUPPORTED; 769 } 770 771 772 /** 773 This function adds a Unicode string to UnicodeStringTable. 774 775 If Language is a member of SupportedLanguages then UnicodeString is added to 776 UnicodeStringTable. New buffers are allocated for both Language and 777 UnicodeString. The contents of Language and UnicodeString are copied into 778 these new buffers. These buffers are automatically freed when 779 FreeUnicodeStringTable() is called. 780 781 @param Language A pointer to the ISO 639-2 language code for the Unicode 782 string to add. 783 @param SupportedLanguages A pointer to the set of ISO 639-2 language codes 784 that the Unicode string table supports. 785 Language must be a member of this set. 786 @param UnicodeStringTable A pointer to the table of Unicode strings. 787 @param UnicodeString A pointer to the Unicode string to add. 788 789 @retval EFI_SUCCESS The Unicode string that matches the language 790 specified by Language was found in the table of 791 Unicode strings UnicodeStringTable, and it was 792 returned in UnicodeString. 793 @retval EFI_INVALID_PARAMETER Language is NULL. 794 @retval EFI_INVALID_PARAMETER UnicodeString is NULL. 795 @retval EFI_INVALID_PARAMETER UnicodeString is an empty string. 796 @retval EFI_UNSUPPORTED SupportedLanguages is NULL. 797 @retval EFI_ALREADY_STARTED A Unicode string with language Language is 798 already present in UnicodeStringTable. 799 @retval EFI_OUT_OF_RESOURCES There is not enough memory to add another 800 Unicode string to UnicodeStringTable. 801 @retval EFI_UNSUPPORTED The language specified by Language is not a 802 member of SupportedLanguages. 803 804 **/ 805 EFI_STATUS 806 EFIAPI 807 AddUnicodeString ( 808 IN CONST CHAR8 *Language, 809 IN CONST CHAR8 *SupportedLanguages, 810 IN EFI_UNICODE_STRING_TABLE **UnicodeStringTable, 811 IN CONST CHAR16 *UnicodeString 812 ) 813 { 814 UINTN NumberOfEntries; 815 EFI_UNICODE_STRING_TABLE *OldUnicodeStringTable; 816 EFI_UNICODE_STRING_TABLE *NewUnicodeStringTable; 817 UINTN UnicodeStringLength; 818 819 // 820 // Make sure the parameter are valid 821 // 822 if (Language == NULL || UnicodeString == NULL || UnicodeStringTable == NULL) { 823 return EFI_INVALID_PARAMETER; 824 } 825 826 // 827 // If there are no supported languages, then a Unicode String can not be added 828 // 829 if (SupportedLanguages == NULL) { 830 return EFI_UNSUPPORTED; 831 } 832 833 // 834 // If the Unicode String is empty, then a Unicode String can not be added 835 // 836 if (UnicodeString[0] == 0) { 837 return EFI_INVALID_PARAMETER; 838 } 839 840 // 841 // Make sure Language is a member of SupportedLanguages 842 // 843 while (*SupportedLanguages != 0) { 844 if (CompareIso639LanguageCode (Language, SupportedLanguages)) { 845 846 // 847 // Determine the size of the Unicode String Table by looking for a NULL Language entry 848 // 849 NumberOfEntries = 0; 850 if (*UnicodeStringTable != NULL) { 851 OldUnicodeStringTable = *UnicodeStringTable; 852 while (OldUnicodeStringTable->Language != NULL) { 853 if (CompareIso639LanguageCode (Language, OldUnicodeStringTable->Language)) { 854 return EFI_ALREADY_STARTED; 855 } 856 857 OldUnicodeStringTable++; 858 NumberOfEntries++; 859 } 860 } 861 862 // 863 // Allocate space for a new Unicode String Table. It must hold the current number of 864 // entries, plus 1 entry for the new Unicode String, plus 1 entry for the end of table 865 // marker 866 // 867 NewUnicodeStringTable = AllocatePool ((NumberOfEntries + 2) * sizeof (EFI_UNICODE_STRING_TABLE)); 868 if (NewUnicodeStringTable == NULL) { 869 return EFI_OUT_OF_RESOURCES; 870 } 871 872 // 873 // If the current Unicode String Table contains any entries, then copy them to the 874 // newly allocated Unicode String Table. 875 // 876 if (*UnicodeStringTable != NULL) { 877 CopyMem ( 878 NewUnicodeStringTable, 879 *UnicodeStringTable, 880 NumberOfEntries * sizeof (EFI_UNICODE_STRING_TABLE) 881 ); 882 } 883 884 // 885 // Allocate space for a copy of the Language specifier 886 // 887 NewUnicodeStringTable[NumberOfEntries].Language = AllocateCopyPool (3, Language); 888 if (NewUnicodeStringTable[NumberOfEntries].Language == NULL) { 889 gBS->FreePool (NewUnicodeStringTable); 890 return EFI_OUT_OF_RESOURCES; 891 } 892 893 // 894 // Compute the length of the Unicode String 895 // 896 for (UnicodeStringLength = 0; UnicodeString[UnicodeStringLength] != 0; UnicodeStringLength++) 897 ; 898 899 // 900 // Allocate space for a copy of the Unicode String 901 // 902 NewUnicodeStringTable[NumberOfEntries].UnicodeString = AllocateCopyPool ( 903 (UnicodeStringLength + 1) * sizeof (CHAR16), 904 UnicodeString 905 ); 906 if (NewUnicodeStringTable[NumberOfEntries].UnicodeString == NULL) { 907 gBS->FreePool (NewUnicodeStringTable[NumberOfEntries].Language); 908 gBS->FreePool (NewUnicodeStringTable); 909 return EFI_OUT_OF_RESOURCES; 910 } 911 912 // 913 // Mark the end of the Unicode String Table 914 // 915 NewUnicodeStringTable[NumberOfEntries + 1].Language = NULL; 916 NewUnicodeStringTable[NumberOfEntries + 1].UnicodeString = NULL; 917 918 // 919 // Free the old Unicode String Table 920 // 921 if (*UnicodeStringTable != NULL) { 922 gBS->FreePool (*UnicodeStringTable); 923 } 924 925 // 926 // Point UnicodeStringTable at the newly allocated Unicode String Table 927 // 928 *UnicodeStringTable = NewUnicodeStringTable; 929 930 return EFI_SUCCESS; 931 } 932 933 SupportedLanguages += 3; 934 } 935 936 return EFI_UNSUPPORTED; 937 } 938 939 940 /** 941 This function adds the Null-terminated Unicode string specified by UnicodeString 942 to UnicodeStringTable. 943 944 If Language is a member of SupportedLanguages then UnicodeString is added to 945 UnicodeStringTable. New buffers are allocated for both Language and UnicodeString. 946 The contents of Language and UnicodeString are copied into these new buffers. 947 These buffers are automatically freed when EfiLibFreeUnicodeStringTable() is called. 948 949 @param Language A pointer to an ASCII string containing the ISO 639-2 or 950 the RFC 4646 language code for the Unicode string to add. 951 If Iso639Language is TRUE, then this ASCII string is not 952 assumed to be Null-terminated, and only the first three 953 chacters are used. If Iso639Language is FALSE, then this 954 ASCII string must be Null-terminated. 955 @param SupportedLanguages A pointer to a Null-terminated ASCII string that contains 956 a set of ISO 639-2 or RFC 4646 language codes that the Unicode 957 string table supports. Language must be a member of this set. 958 If Iso639Language is TRUE, then this string contains one or more 959 ISO 639-2 language codes with no separator characters. 960 If Iso639Language is FALSE, then is string contains one or more 961 RFC 4646 language codes separated by ';'. 962 @param UnicodeStringTable A pointer to the table of Unicode strings. Type EFI_UNICODE_STRING_TABLE 963 is defined in "Related Definitions". 964 @param UnicodeString A pointer to the Unicode string to add. 965 @param Iso639Language Specifies the supported language code format. If it is TRUE, 966 then Language and SupportedLanguages follow ISO 639-2 language code format. 967 Otherwise, they follow RFC 4646 language code format. 968 969 @retval EFI_SUCCESS The Unicode string that matches the language specified by 970 Language was found in the table of Unicode strings UnicodeStringTable, 971 and it was returned in UnicodeString. 972 @retval EFI_INVALID_PARAMETER Language is NULL. 973 @retval EFI_INVALID_PARAMETER UnicodeString is NULL. 974 @retval EFI_INVALID_PARAMETER UnicodeString is an empty string. 975 @retval EFI_UNSUPPORTED SupportedLanguages is NULL. 976 @retval EFI_ALREADY_STARTED A Unicode string with language Language is already present in 977 UnicodeStringTable. 978 @retval EFI_OUT_OF_RESOURCES There is not enough memory to add another Unicode string UnicodeStringTable. 979 @retval EFI_UNSUPPORTED The language specified by Language is not a member of SupportedLanguages. 980 981 **/ 982 EFI_STATUS 983 EFIAPI 984 AddUnicodeString2 ( 985 IN CONST CHAR8 *Language, 986 IN CONST CHAR8 *SupportedLanguages, 987 IN EFI_UNICODE_STRING_TABLE **UnicodeStringTable, 988 IN CONST CHAR16 *UnicodeString, 989 IN BOOLEAN Iso639Language 990 ) 991 { 992 UINTN NumberOfEntries; 993 EFI_UNICODE_STRING_TABLE *OldUnicodeStringTable; 994 EFI_UNICODE_STRING_TABLE *NewUnicodeStringTable; 995 UINTN UnicodeStringLength; 996 BOOLEAN Found; 997 UINTN Index; 998 CHAR8 *LanguageString; 999 1000 // 1001 // Make sure the parameter are valid 1002 // 1003 if (Language == NULL || UnicodeString == NULL || UnicodeStringTable == NULL) { 1004 return EFI_INVALID_PARAMETER; 1005 } 1006 1007 // 1008 // If there are no supported languages, then a Unicode String can not be added 1009 // 1010 if (SupportedLanguages == NULL) { 1011 return EFI_UNSUPPORTED; 1012 } 1013 1014 // 1015 // If the Unicode String is empty, then a Unicode String can not be added 1016 // 1017 if (UnicodeString[0] == 0) { 1018 return EFI_INVALID_PARAMETER; 1019 } 1020 1021 // 1022 // Make sure Language is a member of SupportedLanguages 1023 // 1024 Found = FALSE; 1025 while (*SupportedLanguages != 0) { 1026 if (Iso639Language) { 1027 if (CompareIso639LanguageCode (Language, SupportedLanguages)) { 1028 Found = TRUE; 1029 break; 1030 } 1031 SupportedLanguages += 3; 1032 } else { 1033 for (Index = 0; SupportedLanguages[Index] != 0 && SupportedLanguages[Index] != ';'; Index++); 1034 if (AsciiStrnCmp(SupportedLanguages, Language, Index) == 0) { 1035 Found = TRUE; 1036 break; 1037 } 1038 SupportedLanguages += Index; 1039 for (; *SupportedLanguages != 0 && *SupportedLanguages == ';'; SupportedLanguages++); 1040 } 1041 } 1042 1043 // 1044 // If Language is not a member of SupportedLanguages, then return EFI_UNSUPPORTED 1045 // 1046 if (!Found) { 1047 return EFI_UNSUPPORTED; 1048 } 1049 1050 // 1051 // Determine the size of the Unicode String Table by looking for a NULL Language entry 1052 // 1053 NumberOfEntries = 0; 1054 if (*UnicodeStringTable != NULL) { 1055 OldUnicodeStringTable = *UnicodeStringTable; 1056 while (OldUnicodeStringTable->Language != NULL) { 1057 LanguageString = OldUnicodeStringTable->Language; 1058 1059 while (*LanguageString != 0) { 1060 for (Index = 0; LanguageString[Index] != 0 && LanguageString[Index] != ';'; Index++); 1061 1062 if (AsciiStrnCmp (Language, LanguageString, Index) == 0) { 1063 return EFI_ALREADY_STARTED; 1064 } 1065 LanguageString += Index; 1066 for (; *LanguageString != 0 && *LanguageString == ';'; LanguageString++); 1067 } 1068 OldUnicodeStringTable++; 1069 NumberOfEntries++; 1070 } 1071 } 1072 1073 // 1074 // Allocate space for a new Unicode String Table. It must hold the current number of 1075 // entries, plus 1 entry for the new Unicode String, plus 1 entry for the end of table 1076 // marker 1077 // 1078 NewUnicodeStringTable = AllocatePool ((NumberOfEntries + 2) * sizeof (EFI_UNICODE_STRING_TABLE)); 1079 if (NewUnicodeStringTable == NULL) { 1080 return EFI_OUT_OF_RESOURCES; 1081 } 1082 1083 // 1084 // If the current Unicode String Table contains any entries, then copy them to the 1085 // newly allocated Unicode String Table. 1086 // 1087 if (*UnicodeStringTable != NULL) { 1088 CopyMem ( 1089 NewUnicodeStringTable, 1090 *UnicodeStringTable, 1091 NumberOfEntries * sizeof (EFI_UNICODE_STRING_TABLE) 1092 ); 1093 } 1094 1095 // 1096 // Allocate space for a copy of the Language specifier 1097 // 1098 NewUnicodeStringTable[NumberOfEntries].Language = AllocateCopyPool (AsciiStrSize(Language), Language); 1099 if (NewUnicodeStringTable[NumberOfEntries].Language == NULL) { 1100 gBS->FreePool (NewUnicodeStringTable); 1101 return EFI_OUT_OF_RESOURCES; 1102 } 1103 1104 // 1105 // Compute the length of the Unicode String 1106 // 1107 for (UnicodeStringLength = 0; UnicodeString[UnicodeStringLength] != 0; UnicodeStringLength++); 1108 1109 // 1110 // Allocate space for a copy of the Unicode String 1111 // 1112 NewUnicodeStringTable[NumberOfEntries].UnicodeString = AllocateCopyPool (StrSize (UnicodeString), UnicodeString); 1113 if (NewUnicodeStringTable[NumberOfEntries].UnicodeString == NULL) { 1114 gBS->FreePool (NewUnicodeStringTable[NumberOfEntries].Language); 1115 gBS->FreePool (NewUnicodeStringTable); 1116 return EFI_OUT_OF_RESOURCES; 1117 } 1118 1119 // 1120 // Mark the end of the Unicode String Table 1121 // 1122 NewUnicodeStringTable[NumberOfEntries + 1].Language = NULL; 1123 NewUnicodeStringTable[NumberOfEntries + 1].UnicodeString = NULL; 1124 1125 // 1126 // Free the old Unicode String Table 1127 // 1128 if (*UnicodeStringTable != NULL) { 1129 gBS->FreePool (*UnicodeStringTable); 1130 } 1131 1132 // 1133 // Point UnicodeStringTable at the newly allocated Unicode String Table 1134 // 1135 *UnicodeStringTable = NewUnicodeStringTable; 1136 1137 return EFI_SUCCESS; 1138 } 1139 1140 /** 1141 This function frees the table of Unicode strings in UnicodeStringTable. 1142 1143 If UnicodeStringTable is NULL, then EFI_SUCCESS is returned. 1144 Otherwise, each language code, and each Unicode string in the Unicode string 1145 table are freed, and EFI_SUCCESS is returned. 1146 1147 @param UnicodeStringTable A pointer to the table of Unicode strings. 1148 1149 @retval EFI_SUCCESS The Unicode string table was freed. 1150 1151 **/ 1152 EFI_STATUS 1153 EFIAPI 1154 FreeUnicodeStringTable ( 1155 IN EFI_UNICODE_STRING_TABLE *UnicodeStringTable 1156 ) 1157 { 1158 UINTN Index; 1159 1160 // 1161 // If the Unicode String Table is NULL, then it is already freed 1162 // 1163 if (UnicodeStringTable == NULL) { 1164 return EFI_SUCCESS; 1165 } 1166 1167 // 1168 // Loop through the Unicode String Table until we reach the end of table marker 1169 // 1170 for (Index = 0; UnicodeStringTable[Index].Language != NULL; Index++) { 1171 1172 // 1173 // Free the Language string from the Unicode String Table 1174 // 1175 gBS->FreePool (UnicodeStringTable[Index].Language); 1176 1177 // 1178 // Free the Unicode String from the Unicode String Table 1179 // 1180 if (UnicodeStringTable[Index].UnicodeString != NULL) { 1181 gBS->FreePool (UnicodeStringTable[Index].UnicodeString); 1182 } 1183 } 1184 1185 // 1186 // Free the Unicode String Table itself 1187 // 1188 gBS->FreePool (UnicodeStringTable); 1189 1190 return EFI_SUCCESS; 1191 } 1192 1193 /** 1194 Returns a pointer to an allocated buffer that contains the contents of a 1195 variable retrieved through the UEFI Runtime Service GetVariable(). The 1196 returned buffer is allocated using AllocatePool(). The caller is responsible 1197 for freeing this buffer with FreePool(). 1198 1199 If Name is NULL, then ASSERT(). 1200 If Guid is NULL, then ASSERT(). 1201 1202 @param[in] Name Pointer to a Null-terminated Unicode string. 1203 @param[in] Guid Pointer to an EFI_GUID structure 1204 1205 @retval NULL The variable could not be retrieved. 1206 @retval NULL There are not enough resources available for the variable contents. 1207 @retval Other A pointer to allocated buffer containing the variable contents. 1208 1209 **/ 1210 VOID * 1211 EFIAPI 1212 GetVariable ( 1213 IN CONST CHAR16 *Name, 1214 IN CONST EFI_GUID *Guid 1215 ) 1216 { 1217 EFI_STATUS Status; 1218 UINTN Size; 1219 VOID *Value; 1220 1221 ASSERT (Name != NULL); 1222 ASSERT (Guid != NULL); 1223 1224 // 1225 // Try to get the variable size. 1226 // 1227 Value = NULL; 1228 Size = 0; 1229 Status = gRT->GetVariable ((CHAR16 *) Name, (EFI_GUID *) Guid, NULL, &Size, Value); 1230 if (Status != EFI_BUFFER_TOO_SMALL) { 1231 return NULL; 1232 } 1233 1234 // 1235 // Allocate buffer to get the variable. 1236 // 1237 Value = AllocatePool (Size); 1238 if (Value == NULL) { 1239 return NULL; 1240 } 1241 1242 // 1243 // Get the variable data. 1244 // 1245 Status = gRT->GetVariable ((CHAR16 *) Name, (EFI_GUID *) Guid, NULL, &Size, Value); 1246 if (EFI_ERROR (Status)) { 1247 FreePool(Value); 1248 return NULL; 1249 } 1250 1251 return Value; 1252 } 1253 1254 1255 /** 1256 Returns a pointer to an allocated buffer that contains the contents of a 1257 variable retrieved through the UEFI Runtime Service GetVariable(). This 1258 function always uses the EFI_GLOBAL_VARIABLE GUID to retrieve variables. 1259 The returned buffer is allocated using AllocatePool(). The caller is 1260 responsible for freeing this buffer with FreePool(). 1261 1262 If Name is NULL, then ASSERT(). 1263 1264 @param[in] Name Pointer to a Null-terminated Unicode string. 1265 1266 @retval NULL The variable could not be retrieved. 1267 @retval NULL There are not enough resources available for the variable contents. 1268 @retval Other A pointer to allocated buffer containing the variable contents. 1269 1270 **/ 1271 VOID * 1272 EFIAPI 1273 GetEfiGlobalVariable ( 1274 IN CONST CHAR16 *Name 1275 ) 1276 { 1277 return GetVariable (Name, &gEfiGlobalVariableGuid); 1278 } 1279 1280 1281 /** 1282 Returns a pointer to an allocated buffer that contains the best matching language 1283 from a set of supported languages. 1284 1285 This function supports both ISO 639-2 and RFC 4646 language codes, but language 1286 code types may not be mixed in a single call to this function. The language 1287 code returned is allocated using AllocatePool(). The caller is responsible for 1288 freeing the allocated buffer using FreePool(). This function supports a variable 1289 argument list that allows the caller to pass in a prioritized list of language 1290 codes to test against all the language codes in SupportedLanguages. 1291 1292 If SupportedLanguages is NULL, then ASSERT(). 1293 1294 @param[in] SupportedLanguages A pointer to a Null-terminated ASCII string that 1295 contains a set of language codes in the format 1296 specified by Iso639Language. 1297 @param[in] Iso639Language If TRUE, then all language codes are assumed to be 1298 in ISO 639-2 format. If FALSE, then all language 1299 codes are assumed to be in RFC 4646 language format 1300 @param[in] ... A variable argument list that contains pointers to 1301 Null-terminated ASCII strings that contain one or more 1302 language codes in the format specified by Iso639Language. 1303 The first language code from each of these language 1304 code lists is used to determine if it is an exact or 1305 close match to any of the language codes in 1306 SupportedLanguages. Close matches only apply to RFC 4646 1307 language codes, and the matching algorithm from RFC 4647 1308 is used to determine if a close match is present. If 1309 an exact or close match is found, then the matching 1310 language code from SupportedLanguages is returned. If 1311 no matches are found, then the next variable argument 1312 parameter is evaluated. The variable argument list 1313 is terminated by a NULL. 1314 1315 @retval NULL The best matching language could not be found in SupportedLanguages. 1316 @retval NULL There are not enough resources available to return the best matching 1317 language. 1318 @retval Other A pointer to a Null-terminated ASCII string that is the best matching 1319 language in SupportedLanguages. 1320 1321 **/ 1322 CHAR8 * 1323 EFIAPI 1324 GetBestLanguage ( 1325 IN CONST CHAR8 *SupportedLanguages, 1326 IN BOOLEAN Iso639Language, 1327 ... 1328 ) 1329 { 1330 VA_LIST Args; 1331 CHAR8 *Language; 1332 UINTN CompareLength; 1333 UINTN LanguageLength; 1334 CONST CHAR8 *Supported; 1335 CHAR8 *BestLanguage; 1336 1337 ASSERT (SupportedLanguages != NULL); 1338 1339 VA_START (Args, Iso639Language); 1340 while ((Language = VA_ARG (Args, CHAR8 *)) != NULL) { 1341 // 1342 // Default to ISO 639-2 mode 1343 // 1344 CompareLength = 3; 1345 LanguageLength = MIN (3, AsciiStrLen (Language)); 1346 1347 // 1348 // If in RFC 4646 mode, then determine the length of the first RFC 4646 language code in Language 1349 // 1350 if (!Iso639Language) { 1351 for (LanguageLength = 0; Language[LanguageLength] != 0 && Language[LanguageLength] != ';'; LanguageLength++); 1352 } 1353 1354 // 1355 // Trim back the length of Language used until it is empty 1356 // 1357 while (LanguageLength > 0) { 1358 // 1359 // Loop through all language codes in SupportedLanguages 1360 // 1361 for (Supported = SupportedLanguages; *Supported != '\0'; Supported += CompareLength) { 1362 // 1363 // In RFC 4646 mode, then Loop through all language codes in SupportedLanguages 1364 // 1365 if (!Iso639Language) { 1366 // 1367 // Skip ';' characters in Supported 1368 // 1369 for (; *Supported != '\0' && *Supported == ';'; Supported++); 1370 // 1371 // Determine the length of the next language code in Supported 1372 // 1373 for (CompareLength = 0; Supported[CompareLength] != 0 && Supported[CompareLength] != ';'; CompareLength++); 1374 // 1375 // If Language is longer than the Supported, then skip to the next language 1376 // 1377 if (LanguageLength > CompareLength) { 1378 continue; 1379 } 1380 } 1381 // 1382 // See if the first LanguageLength characters in Supported match Language 1383 // 1384 if (AsciiStrnCmp (Supported, Language, LanguageLength) == 0) { 1385 VA_END (Args); 1386 // 1387 // Allocate, copy, and return the best matching language code from SupportedLanguages 1388 // 1389 BestLanguage = AllocateZeroPool (CompareLength + 1); 1390 if (BestLanguage == NULL) { 1391 return NULL; 1392 } 1393 return CopyMem (BestLanguage, Supported, CompareLength); 1394 } 1395 } 1396 1397 if (Iso639Language) { 1398 // 1399 // If ISO 639 mode, then each language can only be tested once 1400 // 1401 LanguageLength = 0; 1402 } else { 1403 // 1404 // If RFC 4646 mode, then trim Language from the right to the next '-' character 1405 // 1406 for (LanguageLength--; LanguageLength > 0 && Language[LanguageLength] != '-'; LanguageLength--); 1407 } 1408 } 1409 } 1410 VA_END (Args); 1411 1412 // 1413 // No matches were found 1414 // 1415 return NULL; 1416 } 1417 1418