1 /****************************************************************************** 2 * 3 * Module Name: dtutils.c - Utility routines for the data table compiler 4 * 5 *****************************************************************************/ 6 7 /* 8 * Copyright (C) 2000 - 2021, Intel Corp. 9 * All rights reserved. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions, and the following disclaimer, 16 * without modification. 17 * 2. Redistributions in binary form must reproduce at minimum a disclaimer 18 * substantially similar to the "NO WARRANTY" disclaimer below 19 * ("Disclaimer") and any redistribution must be conditioned upon 20 * including a substantially similar Disclaimer requirement for further 21 * binary redistribution. 22 * 3. Neither the names of the above-listed copyright holders nor the names 23 * of any contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * Alternatively, this software may be distributed under the terms of the 27 * GNU General Public License ("GPL") version 2 as published by the Free 28 * Software Foundation. 29 * 30 * NO WARRANTY 31 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 32 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 33 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 34 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 35 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 36 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 37 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 38 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 40 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 41 * POSSIBILITY OF SUCH DAMAGES. 42 */ 43 44 #include "aslcompiler.h" 45 #include "actables.h" 46 47 #define _COMPONENT DT_COMPILER 48 ACPI_MODULE_NAME ("dtutils") 49 50 /* Local prototypes */ 51 52 static void 53 DtSum ( 54 DT_SUBTABLE *Subtable, 55 void *Context, 56 void *ReturnValue); 57 58 59 /****************************************************************************** 60 * 61 * FUNCTION: DtError 62 * 63 * PARAMETERS: Level - Seriousness (Warning/error, etc.) 64 * MessageId - Index into global message buffer 65 * Op - Parse node where error happened 66 * ExtraMessage - additional error message 67 * 68 * RETURN: None 69 * 70 * DESCRIPTION: Common error interface for data table compiler 71 * 72 *****************************************************************************/ 73 74 void 75 DtError ( 76 UINT8 Level, 77 UINT16 MessageId, 78 DT_FIELD *FieldObject, 79 char *ExtraMessage) 80 { 81 UINT32 Line = 0; 82 83 84 /* Field object could be NULL */ 85 86 if (FieldObject) 87 { 88 Line = FieldObject->Line; 89 } 90 91 /* Check if user wants to ignore this exception */ 92 93 if (AslIsExceptionIgnored (AslGbl_Files[ASL_FILE_INPUT].Filename, 94 Line, Level, MessageId)) 95 { 96 return; 97 } 98 99 if (FieldObject) 100 { 101 AslCommonError (Level, MessageId, 102 FieldObject->Line, 103 FieldObject->Line, 104 FieldObject->ByteOffset, 105 FieldObject->Column, 106 AslGbl_Files[ASL_FILE_INPUT].Filename, ExtraMessage); 107 } 108 else 109 { 110 AslCommonError (Level, MessageId, 0, 111 0, 0, 0, 0, ExtraMessage); 112 } 113 } 114 115 116 /****************************************************************************** 117 * 118 * FUNCTION: DtNameError 119 * 120 * PARAMETERS: Level - Seriousness (Warning/error, etc.) 121 * MessageId - Index into global message buffer 122 * Op - Parse node where error happened 123 * ExtraMessage - additional error message 124 * 125 * RETURN: None 126 * 127 * DESCRIPTION: Error interface for named objects 128 * 129 *****************************************************************************/ 130 131 void 132 DtNameError ( 133 UINT8 Level, 134 UINT16 MessageId, 135 DT_FIELD *FieldObject, 136 char *ExtraMessage) 137 { 138 139 switch (Level) 140 { 141 case ASL_WARNING2: 142 case ASL_WARNING3: 143 144 if (AslGbl_WarningLevel < Level) 145 { 146 return; 147 } 148 break; 149 150 default: 151 152 break; 153 } 154 155 if (FieldObject) 156 { 157 AslCommonError (Level, MessageId, 158 FieldObject->Line, 159 FieldObject->Line, 160 FieldObject->ByteOffset, 161 FieldObject->NameColumn, 162 AslGbl_Files[ASL_FILE_INPUT].Filename, ExtraMessage); 163 } 164 else 165 { 166 AslCommonError (Level, MessageId, 0, 167 0, 0, 0, 0, ExtraMessage); 168 } 169 } 170 171 172 /******************************************************************************* 173 * 174 * FUNCTION: DtFatal 175 * 176 * PARAMETERS: None 177 * 178 * RETURN: None 179 * 180 * DESCRIPTION: Dump the error log and abort the compiler. Used for serious 181 * compile or I/O errors 182 * 183 ******************************************************************************/ 184 185 void 186 DtFatal ( 187 UINT16 MessageId, 188 DT_FIELD *FieldObject, 189 char *ExtraMessage) 190 { 191 192 DtError (ASL_ERROR, MessageId, FieldObject, ExtraMessage); 193 194 /* 195 * TBD: remove this entire function, DtFatal 196 * 197 * We cannot abort the compiler on error, because we may be compiling a 198 * list of files. We must move on to the next file. 199 */ 200 #ifdef __OBSOLETE 201 CmCleanupAndExit (); 202 exit (1); 203 #endif 204 } 205 206 207 /******************************************************************************* 208 * 209 * FUNCTION: DtDoConstant 210 * 211 * PARAMETERS: String - Only hex constants are supported, 212 * regardless of whether the 0x prefix 213 * is used 214 * 215 * RETURN: Converted Integer 216 * 217 * DESCRIPTION: Convert a string to an integer, with overflow/error checking. 218 * 219 ******************************************************************************/ 220 221 UINT64 222 DtDoConstant ( 223 char *String) 224 { 225 UINT64 ConvertedInteger; 226 227 228 /* 229 * TBD: The ImplicitStrtoul64 function does not report overflow 230 * conditions. The input string is simply truncated. If it is 231 * desired to report overflow to the table compiler, this should 232 * somehow be added here. Note: integers that are prefixed with 0x 233 * or not are both hex integers. 234 */ 235 ConvertedInteger = AcpiUtImplicitStrtoul64 (String); 236 return (ConvertedInteger); 237 } 238 239 /****************************************************************************** 240 * 241 * FUNCTION: DtGetFieldValue 242 * 243 * PARAMETERS: Field - Current field list pointer 244 * 245 * RETURN: Field value 246 * 247 * DESCRIPTION: Get field value 248 * 249 *****************************************************************************/ 250 251 char * 252 DtGetFieldValue ( 253 DT_FIELD *Field) 254 { 255 if (!Field) 256 { 257 return (NULL); 258 } 259 260 return (Field->Value); 261 } 262 263 264 /****************************************************************************** 265 * 266 * FUNCTION: DtGetFieldType 267 * 268 * PARAMETERS: Info - Data table info 269 * 270 * RETURN: Field type 271 * 272 * DESCRIPTION: Get field type 273 * 274 *****************************************************************************/ 275 276 UINT8 277 DtGetFieldType ( 278 ACPI_DMTABLE_INFO *Info) 279 { 280 UINT8 Type; 281 282 283 /* DT_FLAG means that this is the start of a block of flag bits */ 284 /* TBD - we can make these a separate opcode later */ 285 286 if (Info->Flags & DT_FLAG) 287 { 288 return (DT_FIELD_TYPE_FLAGS_INTEGER); 289 } 290 291 /* Type is based upon the opcode for this field in the info table */ 292 293 switch (Info->Opcode) 294 { 295 case ACPI_DMT_FLAG0: 296 case ACPI_DMT_FLAG1: 297 case ACPI_DMT_FLAG2: 298 case ACPI_DMT_FLAG3: 299 case ACPI_DMT_FLAG4: 300 case ACPI_DMT_FLAG5: 301 case ACPI_DMT_FLAG6: 302 case ACPI_DMT_FLAG7: 303 case ACPI_DMT_FLAGS0: 304 case ACPI_DMT_FLAGS1: 305 case ACPI_DMT_FLAGS2: 306 case ACPI_DMT_FLAGS4: 307 case ACPI_DMT_FLAGS4_0: 308 case ACPI_DMT_FLAGS4_4: 309 case ACPI_DMT_FLAGS4_8: 310 case ACPI_DMT_FLAGS4_12: 311 case ACPI_DMT_FLAGS16_16: 312 313 Type = DT_FIELD_TYPE_FLAG; 314 break; 315 316 case ACPI_DMT_NAME4: 317 case ACPI_DMT_SIG: 318 case ACPI_DMT_NAME6: 319 case ACPI_DMT_NAME8: 320 case ACPI_DMT_STRING: 321 case ACPI_DMT_IVRS_UNTERMINATED_STRING: 322 323 Type = DT_FIELD_TYPE_STRING; 324 break; 325 326 case ACPI_DMT_BUFFER: 327 case ACPI_DMT_RAW_BUFFER: 328 case ACPI_DMT_BUF7: 329 case ACPI_DMT_BUF10: 330 case ACPI_DMT_BUF12: 331 case ACPI_DMT_BUF16: 332 case ACPI_DMT_BUF18: 333 case ACPI_DMT_BUF128: 334 case ACPI_DMT_PCI_PATH: 335 case ACPI_DMT_PMTT_VENDOR: 336 337 Type = DT_FIELD_TYPE_BUFFER; 338 break; 339 340 case ACPI_DMT_GAS: 341 case ACPI_DMT_HESTNTFY: 342 case ACPI_DMT_IORTMEM: 343 344 Type = DT_FIELD_TYPE_INLINE_SUBTABLE; 345 break; 346 347 case ACPI_DMT_UNICODE: 348 case ACPI_DMT_WPBT_UNICODE: 349 350 Type = DT_FIELD_TYPE_UNICODE; 351 break; 352 353 case ACPI_DMT_UUID: 354 355 Type = DT_FIELD_TYPE_UUID; 356 break; 357 358 case ACPI_DMT_DEVICE_PATH: 359 360 Type = DT_FIELD_TYPE_DEVICE_PATH; 361 break; 362 363 case ACPI_DMT_LABEL: 364 365 Type = DT_FIELD_TYPE_LABEL; 366 break; 367 368 default: 369 370 Type = DT_FIELD_TYPE_INTEGER; 371 break; 372 } 373 374 return (Type); 375 } 376 377 378 /****************************************************************************** 379 * 380 * FUNCTION: DtGetBufferLength 381 * 382 * PARAMETERS: Buffer - List of integers, 383 * for example "10 3A 4F 2E" 384 * 385 * RETURN: Count of integer 386 * 387 * DESCRIPTION: Get length of bytes needed to store the integers 388 * 389 *****************************************************************************/ 390 391 UINT32 392 DtGetBufferLength ( 393 char *Buffer) 394 { 395 UINT32 ByteLength = 0; 396 397 398 while (*Buffer) 399 { 400 if (*Buffer == ' ') 401 { 402 ByteLength++; 403 404 while (*Buffer == ' ') 405 { 406 Buffer++; 407 } 408 } 409 410 Buffer++; 411 } 412 413 return (++ByteLength); 414 } 415 416 417 /****************************************************************************** 418 * 419 * FUNCTION: DtGetFieldLength 420 * 421 * PARAMETERS: Field - Current field 422 * Info - Data table info 423 * 424 * RETURN: Field length 425 * 426 * DESCRIPTION: Get length of bytes needed to compile the field 427 * 428 * Note: This function must remain in sync with AcpiDmDumpTable. 429 * 430 *****************************************************************************/ 431 432 UINT32 433 DtGetFieldLength ( 434 DT_FIELD *Field, 435 ACPI_DMTABLE_INFO *Info) 436 { 437 UINT32 ByteLength = 0; 438 char *Value; 439 440 441 /* Length is based upon the opcode for this field in the info table */ 442 443 switch (Info->Opcode) 444 { 445 case ACPI_DMT_FLAG0: 446 case ACPI_DMT_FLAG1: 447 case ACPI_DMT_FLAG2: 448 case ACPI_DMT_FLAG3: 449 case ACPI_DMT_FLAG4: 450 case ACPI_DMT_FLAG5: 451 case ACPI_DMT_FLAG6: 452 case ACPI_DMT_FLAG7: 453 case ACPI_DMT_FLAGS0: 454 case ACPI_DMT_FLAGS1: 455 case ACPI_DMT_FLAGS2: 456 case ACPI_DMT_FLAGS4: 457 case ACPI_DMT_FLAGS4_0: 458 case ACPI_DMT_FLAGS4_4: 459 case ACPI_DMT_FLAGS4_8: 460 case ACPI_DMT_FLAGS4_12: 461 case ACPI_DMT_FLAGS16_16: 462 case ACPI_DMT_LABEL: 463 case ACPI_DMT_EXTRA_TEXT: 464 465 ByteLength = 0; 466 break; 467 468 case ACPI_DMT_UINT8: 469 case ACPI_DMT_CHKSUM: 470 case ACPI_DMT_SPACEID: 471 case ACPI_DMT_ACCWIDTH: 472 case ACPI_DMT_CEDT: 473 case ACPI_DMT_IVRS: 474 case ACPI_DMT_IVRS_DE: 475 case ACPI_DMT_GTDT: 476 case ACPI_DMT_MADT: 477 case ACPI_DMT_NHLT1: 478 case ACPI_DMT_NHLT1a: 479 case ACPI_DMT_NHLT1b: 480 case ACPI_DMT_NHLT1c: 481 case ACPI_DMT_NHLT1d: 482 case ACPI_DMT_NHLT1f: 483 case ACPI_DMT_PCCT: 484 case ACPI_DMT_PMTT: 485 case ACPI_DMT_PPTT: 486 case ACPI_DMT_RGRT: 487 case ACPI_DMT_SDEV: 488 case ACPI_DMT_SRAT: 489 case ACPI_DMT_AEST: 490 case ACPI_DMT_AEST_RES: 491 case ACPI_DMT_AEST_XFACE: 492 case ACPI_DMT_AEST_XRUPT: 493 case ACPI_DMT_ASF: 494 case ACPI_DMT_HESTNTYP: 495 case ACPI_DMT_FADTPM: 496 case ACPI_DMT_EINJACT: 497 case ACPI_DMT_EINJINST: 498 case ACPI_DMT_ERSTACT: 499 case ACPI_DMT_ERSTINST: 500 case ACPI_DMT_DMAR_SCOPE: 501 case ACPI_DMT_VIOT: 502 503 ByteLength = 1; 504 break; 505 506 case ACPI_DMT_UINT16: 507 case ACPI_DMT_DMAR: 508 case ACPI_DMT_HEST: 509 case ACPI_DMT_HMAT: 510 case ACPI_DMT_NFIT: 511 case ACPI_DMT_NHLT1e: 512 case ACPI_DMT_PCI_PATH: 513 case ACPI_DMT_PHAT: 514 515 ByteLength = 2; 516 break; 517 518 case ACPI_DMT_UINT24: 519 520 ByteLength = 3; 521 break; 522 523 case ACPI_DMT_UINT32: 524 case ACPI_DMT_AEST_CACHE: 525 case ACPI_DMT_AEST_GIC: 526 case ACPI_DMT_NAME4: 527 case ACPI_DMT_SIG: 528 case ACPI_DMT_LPIT: 529 case ACPI_DMT_TPM2: 530 531 ByteLength = 4; 532 break; 533 534 case ACPI_DMT_UINT40: 535 536 ByteLength = 5; 537 break; 538 539 case ACPI_DMT_UINT48: 540 case ACPI_DMT_NAME6: 541 542 ByteLength = 6; 543 break; 544 545 case ACPI_DMT_UINT56: 546 case ACPI_DMT_BUF7: 547 548 ByteLength = 7; 549 break; 550 551 case ACPI_DMT_UINT64: 552 case ACPI_DMT_NAME8: 553 554 ByteLength = 8; 555 break; 556 557 case ACPI_DMT_STRING: 558 559 Value = DtGetFieldValue (Field); 560 if (Value) 561 { 562 ByteLength = strlen (Value) + 1; 563 } 564 else 565 { /* At this point, this is a fatal error */ 566 567 snprintf (AslGbl_MsgBuffer, sizeof(AslGbl_MsgBuffer), "Expected \"%s\"", Info->Name); 568 DtFatal (ASL_MSG_COMPILER_INTERNAL, NULL, AslGbl_MsgBuffer); 569 return (0); 570 } 571 break; 572 573 case ACPI_DMT_IVRS_UNTERMINATED_STRING: 574 575 Value = DtGetFieldValue (Field); 576 if (Value) 577 { 578 ByteLength = strlen (Value); 579 } 580 else 581 { /* At this point, this is a fatal error */ 582 583 snprintf (AslGbl_MsgBuffer, sizeof(AslGbl_MsgBuffer), "Expected \"%s\"", Info->Name); 584 DtFatal (ASL_MSG_COMPILER_INTERNAL, NULL, AslGbl_MsgBuffer); 585 return (0); 586 } 587 break; 588 589 case ACPI_DMT_GAS: 590 591 ByteLength = sizeof (ACPI_GENERIC_ADDRESS); 592 break; 593 594 case ACPI_DMT_HESTNTFY: 595 596 ByteLength = sizeof (ACPI_HEST_NOTIFY); 597 break; 598 599 case ACPI_DMT_IORTMEM: 600 601 ByteLength = sizeof (ACPI_IORT_MEMORY_ACCESS); 602 break; 603 604 case ACPI_DMT_BUFFER: 605 case ACPI_DMT_RAW_BUFFER: 606 case ACPI_DMT_PMTT_VENDOR: 607 608 Value = DtGetFieldValue (Field); 609 if (Value) 610 { 611 ByteLength = DtGetBufferLength (Value); 612 } 613 else 614 { /* At this point, this is a fatal error */ 615 616 snprintf (AslGbl_MsgBuffer, sizeof(AslGbl_MsgBuffer), "Expected \"%s\"", Info->Name); 617 DtFatal (ASL_MSG_COMPILER_INTERNAL, NULL, AslGbl_MsgBuffer); 618 return (0); 619 } 620 break; 621 622 case ACPI_DMT_BUF10: 623 624 ByteLength = 10; 625 break; 626 627 case ACPI_DMT_BUF12: 628 629 ByteLength = 12; 630 break; 631 632 case ACPI_DMT_BUF16: 633 case ACPI_DMT_UUID: 634 635 ByteLength = 16; 636 break; 637 638 case ACPI_DMT_BUF18: 639 640 ByteLength = 18; 641 break; 642 643 case ACPI_DMT_BUF128: 644 645 ByteLength = 128; 646 break; 647 648 case ACPI_DMT_UNICODE: 649 case ACPI_DMT_WPBT_UNICODE: 650 651 Value = DtGetFieldValue (Field); 652 653 /* TBD: error if Value is NULL? (as below?) */ 654 655 ByteLength = (strlen (Value) + 1) * sizeof (UINT16); 656 break; 657 658 default: 659 660 DtFatal (ASL_MSG_COMPILER_INTERNAL, Field, "Invalid table opcode"); 661 return (0); 662 } 663 664 return (ByteLength); 665 } 666 667 668 /****************************************************************************** 669 * 670 * FUNCTION: DtSum 671 * 672 * PARAMETERS: DT_WALK_CALLBACK: 673 * Subtable - Subtable 674 * Context - Unused 675 * ReturnValue - Store the checksum of subtable 676 * 677 * RETURN: Status 678 * 679 * DESCRIPTION: Get the checksum of subtable 680 * 681 *****************************************************************************/ 682 683 static void 684 DtSum ( 685 DT_SUBTABLE *Subtable, 686 void *Context, 687 void *ReturnValue) 688 { 689 UINT8 Checksum; 690 UINT8 *Sum = ReturnValue; 691 692 693 Checksum = AcpiTbChecksum (Subtable->Buffer, Subtable->Length); 694 *Sum = (UINT8) (*Sum + Checksum); 695 } 696 697 698 /****************************************************************************** 699 * 700 * FUNCTION: DtSetTableChecksum 701 * 702 * PARAMETERS: ChecksumPointer - Where to return the checksum 703 * 704 * RETURN: None 705 * 706 * DESCRIPTION: Set checksum of the whole data table into the checksum field 707 * 708 *****************************************************************************/ 709 710 void 711 DtSetTableChecksum ( 712 UINT8 *ChecksumPointer) 713 { 714 UINT8 Checksum = 0; 715 UINT8 OldSum; 716 717 718 DtWalkTableTree (AslGbl_RootTable, DtSum, NULL, &Checksum); 719 720 OldSum = *ChecksumPointer; 721 Checksum = (UINT8) (Checksum - OldSum); 722 723 /* Compute the final checksum */ 724 725 Checksum = (UINT8) (0 - Checksum); 726 *ChecksumPointer = Checksum; 727 } 728 729 730 /****************************************************************************** 731 * 732 * FUNCTION: DtSetTableLength 733 * 734 * PARAMETERS: None 735 * 736 * RETURN: None 737 * 738 * DESCRIPTION: Walk the subtables and set all the length fields 739 * 740 *****************************************************************************/ 741 742 void 743 DtSetTableLength ( 744 void) 745 { 746 DT_SUBTABLE *ParentTable; 747 DT_SUBTABLE *ChildTable; 748 749 750 ParentTable = AslGbl_RootTable; 751 ChildTable = NULL; 752 753 if (!ParentTable) 754 { 755 return; 756 } 757 758 DtSetSubtableLength (ParentTable); 759 760 while (1) 761 { 762 ChildTable = DtGetNextSubtable (ParentTable, ChildTable); 763 if (ChildTable) 764 { 765 if (ChildTable->LengthField) 766 { 767 DtSetSubtableLength (ChildTable); 768 } 769 770 if (ChildTable->Child) 771 { 772 ParentTable = ChildTable; 773 ChildTable = NULL; 774 } 775 else 776 { 777 ParentTable->TotalLength += ChildTable->TotalLength; 778 if (ParentTable->LengthField) 779 { 780 DtSetSubtableLength (ParentTable); 781 } 782 } 783 } 784 else 785 { 786 ChildTable = ParentTable; 787 788 if (ChildTable == AslGbl_RootTable) 789 { 790 break; 791 } 792 793 ParentTable = DtGetParentSubtable (ParentTable); 794 795 ParentTable->TotalLength += ChildTable->TotalLength; 796 if (ParentTable->LengthField) 797 { 798 DtSetSubtableLength (ParentTable); 799 } 800 } 801 } 802 } 803 804 805 /****************************************************************************** 806 * 807 * FUNCTION: DtWalkTableTree 808 * 809 * PARAMETERS: StartTable - Subtable in the tree where walking begins 810 * UserFunction - Called during the walk 811 * Context - Passed to user function 812 * ReturnValue - The return value of UserFunction 813 * 814 * RETURN: None 815 * 816 * DESCRIPTION: Performs a depth-first walk of the subtable tree 817 * 818 *****************************************************************************/ 819 820 void 821 DtWalkTableTree ( 822 DT_SUBTABLE *StartTable, 823 DT_WALK_CALLBACK UserFunction, 824 void *Context, 825 void *ReturnValue) 826 { 827 DT_SUBTABLE *ParentTable; 828 DT_SUBTABLE *ChildTable; 829 830 831 ParentTable = StartTable; 832 ChildTable = NULL; 833 834 if (!ParentTable) 835 { 836 return; 837 } 838 839 UserFunction (ParentTable, Context, ReturnValue); 840 841 while (1) 842 { 843 ChildTable = DtGetNextSubtable (ParentTable, ChildTable); 844 if (ChildTable) 845 { 846 UserFunction (ChildTable, Context, ReturnValue); 847 848 if (ChildTable->Child) 849 { 850 ParentTable = ChildTable; 851 ChildTable = NULL; 852 } 853 } 854 else 855 { 856 ChildTable = ParentTable; 857 if (ChildTable == AslGbl_RootTable) 858 { 859 break; 860 } 861 862 ParentTable = DtGetParentSubtable (ParentTable); 863 864 if (ChildTable->Peer == StartTable) 865 { 866 break; 867 } 868 } 869 } 870 } 871