dtutils.c revision 1.21 1 /******************************************************************************
2 *
3 * Module Name: dtutils.c - Utility routines for the data table compiler
4 *
5 *****************************************************************************/
6
7 /*
8 * Copyright (C) 2000 - 2022, 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_FLAGS8_2:
307 case ACPI_DMT_FLAGS4:
308 case ACPI_DMT_FLAGS4_0:
309 case ACPI_DMT_FLAGS4_4:
310 case ACPI_DMT_FLAGS4_8:
311 case ACPI_DMT_FLAGS4_12:
312 case ACPI_DMT_FLAGS16_16:
313
314 Type = DT_FIELD_TYPE_FLAG;
315 break;
316
317 case ACPI_DMT_NAME4:
318 case ACPI_DMT_SIG:
319 case ACPI_DMT_NAME6:
320 case ACPI_DMT_NAME8:
321 case ACPI_DMT_STRING:
322 case ACPI_DMT_IVRS_UNTERMINATED_STRING:
323
324 Type = DT_FIELD_TYPE_STRING;
325 break;
326
327 case ACPI_DMT_BUFFER:
328 case ACPI_DMT_RAW_BUFFER:
329 case ACPI_DMT_BUF7:
330 case ACPI_DMT_BUF10:
331 case ACPI_DMT_BUF12:
332 case ACPI_DMT_BUF16:
333 case ACPI_DMT_BUF18:
334 case ACPI_DMT_BUF128:
335 case ACPI_DMT_PCI_PATH:
336 case ACPI_DMT_PMTT_VENDOR:
337
338 Type = DT_FIELD_TYPE_BUFFER;
339 break;
340
341 case ACPI_DMT_GAS:
342 case ACPI_DMT_HESTNTFY:
343 case ACPI_DMT_IORTMEM:
344
345 Type = DT_FIELD_TYPE_INLINE_SUBTABLE;
346 break;
347
348 case ACPI_DMT_UNICODE:
349 case ACPI_DMT_WPBT_UNICODE:
350
351 Type = DT_FIELD_TYPE_UNICODE;
352 break;
353
354 case ACPI_DMT_UUID:
355
356 Type = DT_FIELD_TYPE_UUID;
357 break;
358
359 case ACPI_DMT_DEVICE_PATH:
360
361 Type = DT_FIELD_TYPE_DEVICE_PATH;
362 break;
363
364 case ACPI_DMT_LABEL:
365
366 Type = DT_FIELD_TYPE_LABEL;
367 break;
368
369 default:
370
371 Type = DT_FIELD_TYPE_INTEGER;
372 break;
373 }
374
375 return (Type);
376 }
377
378
379 /******************************************************************************
380 *
381 * FUNCTION: DtGetBufferLength
382 *
383 * PARAMETERS: Buffer - List of integers,
384 * for example "10 3A 4F 2E"
385 *
386 * RETURN: Count of integer
387 *
388 * DESCRIPTION: Get length of bytes needed to store the integers
389 *
390 *****************************************************************************/
391
392 UINT32
393 DtGetBufferLength (
394 char *Buffer)
395 {
396 UINT32 ByteLength = 0;
397
398
399 while (*Buffer)
400 {
401 if (*Buffer == ' ')
402 {
403 ByteLength++;
404
405 while (*Buffer == ' ')
406 {
407 Buffer++;
408 }
409 }
410
411 Buffer++;
412 }
413
414 return (++ByteLength);
415 }
416
417
418 /******************************************************************************
419 *
420 * FUNCTION: DtGetFieldLength
421 *
422 * PARAMETERS: Field - Current field
423 * Info - Data table info
424 *
425 * RETURN: Field length
426 *
427 * DESCRIPTION: Get length of bytes needed to compile the field
428 *
429 * Note: This function must remain in sync with AcpiDmDumpTable.
430 *
431 *****************************************************************************/
432
433 UINT32
434 DtGetFieldLength (
435 DT_FIELD *Field,
436 ACPI_DMTABLE_INFO *Info)
437 {
438 UINT32 ByteLength = 0;
439 char *Value;
440
441
442 /* Length is based upon the opcode for this field in the info table */
443
444 switch (Info->Opcode)
445 {
446 case ACPI_DMT_FLAG0:
447 case ACPI_DMT_FLAG1:
448 case ACPI_DMT_FLAG2:
449 case ACPI_DMT_FLAG3:
450 case ACPI_DMT_FLAG4:
451 case ACPI_DMT_FLAG5:
452 case ACPI_DMT_FLAG6:
453 case ACPI_DMT_FLAG7:
454 case ACPI_DMT_FLAGS0:
455 case ACPI_DMT_FLAGS1:
456 case ACPI_DMT_FLAGS2:
457 case ACPI_DMT_FLAGS8_2:
458 case ACPI_DMT_FLAGS4:
459 case ACPI_DMT_FLAGS4_0:
460 case ACPI_DMT_FLAGS4_4:
461 case ACPI_DMT_FLAGS4_8:
462 case ACPI_DMT_FLAGS4_12:
463 case ACPI_DMT_FLAGS16_16:
464 case ACPI_DMT_LABEL:
465 case ACPI_DMT_EXTRA_TEXT:
466
467 ByteLength = 0;
468 break;
469
470 case ACPI_DMT_UINT8:
471 case ACPI_DMT_CHKSUM:
472 case ACPI_DMT_SPACEID:
473 case ACPI_DMT_ACCWIDTH:
474 case ACPI_DMT_CEDT:
475 case ACPI_DMT_IVRS:
476 case ACPI_DMT_IVRS_DE:
477 case ACPI_DMT_GTDT:
478 case ACPI_DMT_MADT:
479 case ACPI_DMT_NHLT1:
480 case ACPI_DMT_NHLT1a:
481 case ACPI_DMT_NHLT1b:
482 case ACPI_DMT_NHLT1c:
483 case ACPI_DMT_NHLT1d:
484 case ACPI_DMT_NHLT1f:
485 case ACPI_DMT_PCCT:
486 case ACPI_DMT_PMTT:
487 case ACPI_DMT_PPTT:
488 case ACPI_DMT_RGRT:
489 case ACPI_DMT_SDEV:
490 case ACPI_DMT_SRAT:
491 case ACPI_DMT_AEST:
492 case ACPI_DMT_AEST_RES:
493 case ACPI_DMT_AEST_XFACE:
494 case ACPI_DMT_AEST_XRUPT:
495 case ACPI_DMT_ASF:
496 case ACPI_DMT_CDAT:
497 case ACPI_DMT_HESTNTYP:
498 case ACPI_DMT_FADTPM:
499 case ACPI_DMT_EINJACT:
500 case ACPI_DMT_EINJINST:
501 case ACPI_DMT_ERSTACT:
502 case ACPI_DMT_ERSTINST:
503 case ACPI_DMT_DMAR_SCOPE:
504 case ACPI_DMT_VIOT:
505
506 ByteLength = 1;
507 break;
508
509 case ACPI_DMT_UINT16:
510 case ACPI_DMT_DMAR:
511 case ACPI_DMT_HEST:
512 case ACPI_DMT_HMAT:
513 case ACPI_DMT_NFIT:
514 case ACPI_DMT_NHLT1e:
515 case ACPI_DMT_PCI_PATH:
516 case ACPI_DMT_PHAT:
517
518 ByteLength = 2;
519 break;
520
521 case ACPI_DMT_UINT24:
522
523 ByteLength = 3;
524 break;
525
526 case ACPI_DMT_UINT32:
527 case ACPI_DMT_AEST_CACHE:
528 case ACPI_DMT_AEST_GIC:
529 case ACPI_DMT_NAME4:
530 case ACPI_DMT_SIG:
531 case ACPI_DMT_LPIT:
532 case ACPI_DMT_TPM2:
533
534 ByteLength = 4;
535 break;
536
537 case ACPI_DMT_UINT40:
538
539 ByteLength = 5;
540 break;
541
542 case ACPI_DMT_UINT48:
543 case ACPI_DMT_NAME6:
544
545 ByteLength = 6;
546 break;
547
548 case ACPI_DMT_UINT56:
549 case ACPI_DMT_BUF7:
550
551 ByteLength = 7;
552 break;
553
554 case ACPI_DMT_UINT64:
555 case ACPI_DMT_NAME8:
556
557 ByteLength = 8;
558 break;
559
560 case ACPI_DMT_STRING:
561
562 Value = DtGetFieldValue (Field);
563 if (Value)
564 {
565 ByteLength = strlen (Value) + 1;
566 }
567 else
568 { /* At this point, this is a fatal error */
569
570 snprintf (AslGbl_MsgBuffer, sizeof(AslGbl_MsgBuffer), "Expected \"%s\"", Info->Name);
571 DtFatal (ASL_MSG_COMPILER_INTERNAL, NULL, AslGbl_MsgBuffer);
572 return (0);
573 }
574 break;
575
576 case ACPI_DMT_IVRS_UNTERMINATED_STRING:
577
578 Value = DtGetFieldValue (Field);
579 if (Value)
580 {
581 ByteLength = strlen (Value);
582 }
583 else
584 { /* At this point, this is a fatal error */
585
586 snprintf (AslGbl_MsgBuffer, sizeof(AslGbl_MsgBuffer), "Expected \"%s\"", Info->Name);
587 DtFatal (ASL_MSG_COMPILER_INTERNAL, NULL, AslGbl_MsgBuffer);
588 return (0);
589 }
590 break;
591
592 case ACPI_DMT_GAS:
593
594 ByteLength = sizeof (ACPI_GENERIC_ADDRESS);
595 break;
596
597 case ACPI_DMT_HESTNTFY:
598
599 ByteLength = sizeof (ACPI_HEST_NOTIFY);
600 break;
601
602 case ACPI_DMT_IORTMEM:
603
604 ByteLength = sizeof (ACPI_IORT_MEMORY_ACCESS);
605 break;
606
607 case ACPI_DMT_BUFFER:
608 case ACPI_DMT_RAW_BUFFER:
609 case ACPI_DMT_PMTT_VENDOR:
610
611 Value = DtGetFieldValue (Field);
612 if (Value)
613 {
614 ByteLength = DtGetBufferLength (Value);
615 }
616 else
617 { /* At this point, this is a fatal error */
618
619 snprintf (AslGbl_MsgBuffer, sizeof(AslGbl_MsgBuffer), "Expected \"%s\"", Info->Name);
620 DtFatal (ASL_MSG_COMPILER_INTERNAL, NULL, AslGbl_MsgBuffer);
621 return (0);
622 }
623 break;
624
625 case ACPI_DMT_BUF10:
626
627 ByteLength = 10;
628 break;
629
630 case ACPI_DMT_BUF12:
631
632 ByteLength = 12;
633 break;
634
635 case ACPI_DMT_BUF16:
636 case ACPI_DMT_UUID:
637
638 ByteLength = 16;
639 break;
640
641 case ACPI_DMT_BUF18:
642
643 ByteLength = 18;
644 break;
645
646 case ACPI_DMT_BUF128:
647
648 ByteLength = 128;
649 break;
650
651 case ACPI_DMT_UNICODE:
652 case ACPI_DMT_WPBT_UNICODE:
653
654 Value = DtGetFieldValue (Field);
655
656 /* TBD: error if Value is NULL? (as below?) */
657
658 ByteLength = (strlen (Value) + 1) * sizeof (UINT16);
659 break;
660
661 default:
662
663 DtFatal (ASL_MSG_COMPILER_INTERNAL, Field, "Invalid table opcode");
664 return (0);
665 }
666
667 return (ByteLength);
668 }
669
670
671 /******************************************************************************
672 *
673 * FUNCTION: DtSum
674 *
675 * PARAMETERS: DT_WALK_CALLBACK:
676 * Subtable - Subtable
677 * Context - Unused
678 * ReturnValue - Store the checksum of subtable
679 *
680 * RETURN: Status
681 *
682 * DESCRIPTION: Get the checksum of subtable
683 *
684 *****************************************************************************/
685
686 static void
687 DtSum (
688 DT_SUBTABLE *Subtable,
689 void *Context,
690 void *ReturnValue)
691 {
692 UINT8 Checksum;
693 UINT8 *Sum = ReturnValue;
694
695
696 Checksum = AcpiUtChecksum (Subtable->Buffer, Subtable->Length);
697 *Sum = (UINT8) (*Sum + Checksum);
698 }
699
700
701 /******************************************************************************
702 *
703 * FUNCTION: DtSetTableChecksum
704 *
705 * PARAMETERS: ChecksumPointer - Where to return the checksum
706 *
707 * RETURN: None
708 *
709 * DESCRIPTION: Set checksum of the whole data table into the checksum field
710 *
711 *****************************************************************************/
712
713 void
714 DtSetTableChecksum (
715 UINT8 *ChecksumPointer)
716 {
717 UINT8 Checksum = 0;
718 UINT8 OldSum;
719
720
721 DtWalkTableTree (AslGbl_RootTable, DtSum, NULL, &Checksum);
722
723 OldSum = *ChecksumPointer;
724 Checksum = (UINT8) (Checksum - OldSum);
725
726 /* Compute the final checksum */
727
728 Checksum = (UINT8) (0 - Checksum);
729 *ChecksumPointer = Checksum;
730 }
731
732
733 /******************************************************************************
734 *
735 * FUNCTION: DtSetTableLength
736 *
737 * PARAMETERS: None
738 *
739 * RETURN: None
740 *
741 * DESCRIPTION: Walk the subtables and set all the length fields
742 *
743 *****************************************************************************/
744
745 void
746 DtSetTableLength (
747 void)
748 {
749 DT_SUBTABLE *ParentTable;
750 DT_SUBTABLE *ChildTable;
751
752
753 ParentTable = AslGbl_RootTable;
754 ChildTable = NULL;
755
756 if (!ParentTable)
757 {
758 return;
759 }
760
761 DtSetSubtableLength (ParentTable);
762
763 while (1)
764 {
765 ChildTable = DtGetNextSubtable (ParentTable, ChildTable);
766 if (ChildTable)
767 {
768 if (ChildTable->LengthField)
769 {
770 DtSetSubtableLength (ChildTable);
771 }
772
773 if (ChildTable->Child)
774 {
775 ParentTable = ChildTable;
776 ChildTable = NULL;
777 }
778 else
779 {
780 ParentTable->TotalLength += ChildTable->TotalLength;
781 if (ParentTable->LengthField)
782 {
783 DtSetSubtableLength (ParentTable);
784 }
785 }
786 }
787 else
788 {
789 ChildTable = ParentTable;
790
791 if (ChildTable == AslGbl_RootTable)
792 {
793 break;
794 }
795
796 ParentTable = DtGetParentSubtable (ParentTable);
797
798 ParentTable->TotalLength += ChildTable->TotalLength;
799 if (ParentTable->LengthField)
800 {
801 DtSetSubtableLength (ParentTable);
802 }
803 }
804 }
805 }
806
807
808 /******************************************************************************
809 *
810 * FUNCTION: DtWalkTableTree
811 *
812 * PARAMETERS: StartTable - Subtable in the tree where walking begins
813 * UserFunction - Called during the walk
814 * Context - Passed to user function
815 * ReturnValue - The return value of UserFunction
816 *
817 * RETURN: None
818 *
819 * DESCRIPTION: Performs a depth-first walk of the subtable tree
820 *
821 *****************************************************************************/
822
823 void
824 DtWalkTableTree (
825 DT_SUBTABLE *StartTable,
826 DT_WALK_CALLBACK UserFunction,
827 void *Context,
828 void *ReturnValue)
829 {
830 DT_SUBTABLE *ParentTable;
831 DT_SUBTABLE *ChildTable;
832
833
834 ParentTable = StartTable;
835 ChildTable = NULL;
836
837 if (!ParentTable)
838 {
839 return;
840 }
841
842 UserFunction (ParentTable, Context, ReturnValue);
843
844 while (1)
845 {
846 ChildTable = DtGetNextSubtable (ParentTable, ChildTable);
847 if (ChildTable)
848 {
849 UserFunction (ChildTable, Context, ReturnValue);
850
851 if (ChildTable->Child)
852 {
853 ParentTable = ChildTable;
854 ChildTable = NULL;
855 }
856 }
857 else
858 {
859 ChildTable = ParentTable;
860 if (ChildTable == AslGbl_RootTable)
861 {
862 break;
863 }
864
865 ParentTable = DtGetParentSubtable (ParentTable);
866
867 if (ChildTable->Peer == StartTable)
868 {
869 break;
870 }
871 }
872 }
873 }
874