Do not assert when the device path node length is invalid.
[mirror_edk2.git] / MdePkg / Library / UefiDevicePathLibDevicePathProtocol / UefiDevicePathLib.c
1 /** @file
2 Library instance that implement UEFI Device Path Library class based on protocol
3 gEfiDevicePathUtilitiesProtocolGuid.
4
5 Copyright (c) 2006 - 2014, Intel Corporation. All rights reserved.<BR>
6 This program and the accompanying materials
7 are licensed and made available under the terms and conditions of the BSD License
8 which accompanies this distribution. The full text of the license may be found at
9 http://opensource.org/licenses/bsd-license.php.
10
11 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
12 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
13
14 **/
15
16
17 #include <Uefi.h>
18
19 #include <Protocol/DevicePathUtilities.h>
20 #include <Protocol/DevicePathToText.h>
21 #include <Protocol/DevicePathFromText.h>
22
23 #include <Library/DevicePathLib.h>
24 #include <Library/DebugLib.h>
25 #include <Library/BaseLib.h>
26 #include <Library/MemoryAllocationLib.h>
27 #include <Library/BaseMemoryLib.h>
28 #include <Library/UefiBootServicesTableLib.h>
29 #include <Library/PcdLib.h>
30
31 GLOBAL_REMOVE_IF_UNREFERENCED EFI_DEVICE_PATH_UTILITIES_PROTOCOL *mDevicePathLibDevicePathUtilities = NULL;
32 GLOBAL_REMOVE_IF_UNREFERENCED EFI_DEVICE_PATH_TO_TEXT_PROTOCOL *mDevicePathLibDevicePathToText = NULL;
33 GLOBAL_REMOVE_IF_UNREFERENCED EFI_DEVICE_PATH_FROM_TEXT_PROTOCOL *mDevicePathLibDevicePathFromText = NULL;
34
35 //
36 // Template for an end-of-device path node.
37 //
38 GLOBAL_REMOVE_IF_UNREFERENCED CONST EFI_DEVICE_PATH_PROTOCOL mUefiDevicePathLibEndDevicePath = {
39 END_DEVICE_PATH_TYPE,
40 END_ENTIRE_DEVICE_PATH_SUBTYPE,
41 {
42 END_DEVICE_PATH_LENGTH,
43 0
44 }
45 };
46
47 /**
48 The constructor function caches the pointer to DevicePathUtilites protocol.
49
50 The constructor function locates DevicePathUtilities protocol from protocol database.
51 It will ASSERT() if that operation fails and it will always return EFI_SUCCESS.
52
53 @param ImageHandle The firmware allocated handle for the EFI image.
54 @param SystemTable A pointer to the EFI System Table.
55
56 @retval EFI_SUCCESS The constructor always returns EFI_SUCCESS.
57
58 **/
59 EFI_STATUS
60 EFIAPI
61 DevicePathLibConstructor (
62 IN EFI_HANDLE ImageHandle,
63 IN EFI_SYSTEM_TABLE *SystemTable
64 )
65 {
66 EFI_STATUS Status;
67
68 Status = gBS->LocateProtocol (
69 &gEfiDevicePathUtilitiesProtocolGuid,
70 NULL,
71 (VOID**) &mDevicePathLibDevicePathUtilities
72 );
73 ASSERT_EFI_ERROR (Status);
74 ASSERT (mDevicePathLibDevicePathUtilities != NULL);
75 return Status;
76 }
77
78 /**
79 Determine whether a given device path is valid.
80 If DevicePath is NULL, then ASSERT().
81
82 @param DevicePath A pointer to a device path data structure.
83 @param MaxSize The maximum size of the device path data structure.
84
85 @retval TRUE DevicePath is valid.
86 @retval FALSE The length of any node node in the DevicePath is less
87 than sizeof (EFI_DEVICE_PATH_PROTOCOL).
88 @retval FALSE If MaxSize is not zero, the size of the DevicePath
89 exceeds MaxSize.
90 @retval FALSE If PcdMaximumDevicePathNodeCount is not zero, the node
91 count of the DevicePath exceeds PcdMaximumDevicePathNodeCount.
92 **/
93 BOOLEAN
94 EFIAPI
95 IsDevicePathValid (
96 IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath,
97 IN UINTN MaxSize
98 )
99 {
100 UINTN Count;
101 UINTN Size;
102 UINTN NodeLength;
103
104 ASSERT (DevicePath != NULL);
105
106 for (Count = 0, Size = 0; !IsDevicePathEnd (DevicePath); DevicePath = NextDevicePathNode (DevicePath)) {
107 NodeLength = DevicePathNodeLength (DevicePath);
108 if (NodeLength < sizeof (EFI_DEVICE_PATH_PROTOCOL)) {
109 return FALSE;
110 }
111
112 if (MaxSize > 0) {
113 Size += NodeLength;
114 if (Size + END_DEVICE_PATH_LENGTH > MaxSize) {
115 return FALSE;
116 }
117 }
118
119 if (PcdGet32 (PcdMaximumDevicePathNodeCount) > 0) {
120 Count++;
121 if (Count >= PcdGet32 (PcdMaximumDevicePathNodeCount)) {
122 return FALSE;
123 }
124 }
125 }
126
127 //
128 // Only return TRUE when the End Device Path node is valid.
129 //
130 return (BOOLEAN) (DevicePathNodeLength (DevicePath) == END_DEVICE_PATH_LENGTH);
131 }
132
133 /**
134 Returns the Type field of a device path node.
135
136 Returns the Type field of the device path node specified by Node.
137
138 If Node is NULL, then ASSERT().
139
140 @param Node A pointer to a device path node data structure.
141
142 @return The Type field of the device path node specified by Node.
143
144 **/
145 UINT8
146 EFIAPI
147 DevicePathType (
148 IN CONST VOID *Node
149 )
150 {
151 ASSERT (Node != NULL);
152 return ((EFI_DEVICE_PATH_PROTOCOL *)(Node))->Type;
153 }
154
155 /**
156 Returns the SubType field of a device path node.
157
158 Returns the SubType field of the device path node specified by Node.
159
160 If Node is NULL, then ASSERT().
161
162 @param Node A pointer to a device path node data structure.
163
164 @return The SubType field of the device path node specified by Node.
165
166 **/
167 UINT8
168 EFIAPI
169 DevicePathSubType (
170 IN CONST VOID *Node
171 )
172 {
173 ASSERT (Node != NULL);
174 return ((EFI_DEVICE_PATH_PROTOCOL *)(Node))->SubType;
175 }
176
177 /**
178 Returns the 16-bit Length field of a device path node.
179
180 Returns the 16-bit Length field of the device path node specified by Node.
181 Node is not required to be aligned on a 16-bit boundary, so it is recommended
182 that a function such as ReadUnaligned16() be used to extract the contents of
183 the Length field.
184
185 If Node is NULL, then ASSERT().
186
187 @param Node A pointer to a device path node data structure.
188
189 @return The 16-bit Length field of the device path node specified by Node.
190
191 **/
192 UINTN
193 EFIAPI
194 DevicePathNodeLength (
195 IN CONST VOID *Node
196 )
197 {
198 ASSERT (Node != NULL);
199 return ReadUnaligned16 ((UINT16 *)&((EFI_DEVICE_PATH_PROTOCOL *)(Node))->Length[0]);
200 }
201
202 /**
203 Returns a pointer to the next node in a device path.
204
205 Returns a pointer to the device path node that follows the device path node
206 specified by Node.
207
208 If Node is NULL, then ASSERT().
209
210 @param Node A pointer to a device path node data structure.
211
212 @return a pointer to the device path node that follows the device path node
213 specified by Node.
214
215 **/
216 EFI_DEVICE_PATH_PROTOCOL *
217 EFIAPI
218 NextDevicePathNode (
219 IN CONST VOID *Node
220 )
221 {
222 ASSERT (Node != NULL);
223 return (EFI_DEVICE_PATH_PROTOCOL *)((UINT8 *)(Node) + DevicePathNodeLength(Node));
224 }
225
226 /**
227 Determines if a device path node is an end node of a device path.
228 This includes nodes that are the end of a device path instance and nodes that
229 are the end of an entire device path.
230
231 Determines if the device path node specified by Node is an end node of a device path.
232 This includes nodes that are the end of a device path instance and nodes that are the
233 end of an entire device path. If Node represents an end node of a device path,
234 then TRUE is returned. Otherwise, FALSE is returned.
235
236 If Node is NULL, then ASSERT().
237
238 @param Node A pointer to a device path node data structure.
239
240 @retval TRUE The device path node specified by Node is an end node of a device path.
241 @retval FALSE The device path node specified by Node is not an end node of
242 a device path.
243
244 **/
245 BOOLEAN
246 EFIAPI
247 IsDevicePathEndType (
248 IN CONST VOID *Node
249 )
250 {
251 ASSERT (Node != NULL);
252 return (BOOLEAN) (DevicePathType (Node) == END_DEVICE_PATH_TYPE);
253 }
254
255 /**
256 Determines if a device path node is an end node of an entire device path.
257
258 Determines if a device path node specified by Node is an end node of an entire
259 device path.
260 If Node represents the end of an entire device path, then TRUE is returned.
261 Otherwise, FALSE is returned.
262
263 If Node is NULL, then ASSERT().
264
265 @param Node A pointer to a device path node data structure.
266
267 @retval TRUE The device path node specified by Node is the end of an entire device path.
268 @retval FALSE The device path node specified by Node is not the end of an entire device path.
269
270 **/
271 BOOLEAN
272 EFIAPI
273 IsDevicePathEnd (
274 IN CONST VOID *Node
275 )
276 {
277 ASSERT (Node != NULL);
278 return (BOOLEAN) (IsDevicePathEndType (Node) && DevicePathSubType(Node) == END_ENTIRE_DEVICE_PATH_SUBTYPE);
279 }
280
281 /**
282 Determines if a device path node is an end node of a device path instance.
283
284 Determines if a device path node specified by Node is an end node of a device
285 path instance.
286 If Node represents the end of a device path instance, then TRUE is returned.
287 Otherwise, FALSE is returned.
288
289 If Node is NULL, then ASSERT().
290
291 @param Node A pointer to a device path node data structure.
292
293 @retval TRUE The device path node specified by Node is the end of a device
294 path instance.
295 @retval FALSE The device path node specified by Node is not the end of a
296 device path instance.
297
298 **/
299 BOOLEAN
300 EFIAPI
301 IsDevicePathEndInstance (
302 IN CONST VOID *Node
303 )
304 {
305 ASSERT (Node != NULL);
306 return (BOOLEAN) (IsDevicePathEndType (Node) && DevicePathSubType(Node) == END_INSTANCE_DEVICE_PATH_SUBTYPE);
307 }
308
309 /**
310 Sets the length, in bytes, of a device path node.
311
312 Sets the length of the device path node specified by Node to the value specified
313 by NodeLength. NodeLength is returned. Node is not required to be aligned on
314 a 16-bit boundary, so it is recommended that a function such as WriteUnaligned16()
315 be used to set the contents of the Length field.
316
317 If Node is NULL, then ASSERT().
318 If NodeLength >= SIZE_64KB, then ASSERT().
319 If NodeLength < sizeof (EFI_DEVICE_PATH_PROTOCOL), then ASSERT().
320
321 @param Node A pointer to a device path node data structure.
322 @param Length The length, in bytes, of the device path node.
323
324 @return Length
325
326 **/
327 UINT16
328 EFIAPI
329 SetDevicePathNodeLength (
330 IN OUT VOID *Node,
331 IN UINTN Length
332 )
333 {
334 ASSERT (Node != NULL);
335 ASSERT ((Length >= sizeof (EFI_DEVICE_PATH_PROTOCOL)) && (Length < SIZE_64KB));
336 return WriteUnaligned16 ((UINT16 *)&((EFI_DEVICE_PATH_PROTOCOL *)(Node))->Length[0], (UINT16)(Length));
337 }
338
339 /**
340 Fills in all the fields of a device path node that is the end of an entire device path.
341
342 Fills in all the fields of a device path node specified by Node so Node represents
343 the end of an entire device path. The Type field of Node is set to
344 END_DEVICE_PATH_TYPE, the SubType field of Node is set to
345 END_ENTIRE_DEVICE_PATH_SUBTYPE, and the Length field of Node is set to
346 END_DEVICE_PATH_LENGTH. Node is not required to be aligned on a 16-bit boundary,
347 so it is recommended that a function such as WriteUnaligned16() be used to set
348 the contents of the Length field.
349
350 If Node is NULL, then ASSERT().
351
352 @param Node A pointer to a device path node data structure.
353
354 **/
355 VOID
356 EFIAPI
357 SetDevicePathEndNode (
358 OUT VOID *Node
359 )
360 {
361 ASSERT (Node != NULL);
362 CopyMem (Node, &mUefiDevicePathLibEndDevicePath, sizeof (mUefiDevicePathLibEndDevicePath));
363 }
364
365 /**
366 Returns the size of a device path in bytes.
367
368 This function returns the size, in bytes, of the device path data structure
369 specified by DevicePath including the end of device path node.
370 If DevicePath is NULL or invalid, then 0 is returned.
371
372 @param DevicePath A pointer to a device path data structure.
373
374 @retval 0 If DevicePath is NULL or invalid.
375 @retval Others The size of a device path in bytes.
376
377 **/
378 UINTN
379 EFIAPI
380 GetDevicePathSize (
381 IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath
382 )
383 {
384 return mDevicePathLibDevicePathUtilities->GetDevicePathSize (DevicePath);
385 }
386
387 /**
388 Creates a new copy of an existing device path.
389
390 This function allocates space for a new copy of the device path specified by
391 DevicePath. If DevicePath is NULL, then NULL is returned.
392 If the memory is successfully allocated, then the
393 contents of DevicePath are copied to the newly allocated buffer, and a pointer to that buffer
394 is returned. Otherwise, NULL is returned.
395 The memory for the new device path is allocated from EFI boot services memory.
396 It is the responsibility of the caller to free the memory allocated.
397
398 @param DevicePath A pointer to a device path data structure.
399
400 @retval NULL If DevicePath is NULL or invalid.
401 @retval Others A pointer to the duplicated device path.
402
403 **/
404 EFI_DEVICE_PATH_PROTOCOL *
405 EFIAPI
406 DuplicateDevicePath (
407 IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath
408 )
409 {
410 return mDevicePathLibDevicePathUtilities->DuplicateDevicePath (DevicePath);
411 }
412
413 /**
414 Creates a new device path by appending a second device path to a first device path.
415
416 This function creates a new device path by appending a copy of SecondDevicePath to a copy of
417 FirstDevicePath in a newly allocated buffer. Only the end-of-device-path device node from
418 SecondDevicePath is retained. The newly created device path is returned.
419 If FirstDevicePath is NULL, then it is ignored, and a duplicate of SecondDevicePath is returned.
420 If SecondDevicePath is NULL, then it is ignored, and a duplicate of FirstDevicePath is returned.
421 If both FirstDevicePath and SecondDevicePath are NULL, then a copy of an end-of-device-path is
422 returned.
423 If there is not enough memory for the newly allocated buffer, then NULL is returned.
424 The memory for the new device path is allocated from EFI boot services memory. It is the
425 responsibility of the caller to free the memory allocated.
426
427 @param FirstDevicePath A pointer to a device path data structure.
428 @param SecondDevicePath A pointer to a device path data structure.
429
430 @retval NULL If there is not enough memory for the newly allocated buffer.
431 @retval NULL If FirstDevicePath or SecondDevicePath is invalid.
432 @retval Others A pointer to the new device path if success.
433 Or a copy an end-of-device-path if both FirstDevicePath and
434 SecondDevicePath are NULL.
435
436 **/
437 EFI_DEVICE_PATH_PROTOCOL *
438 EFIAPI
439 AppendDevicePath (
440 IN CONST EFI_DEVICE_PATH_PROTOCOL *FirstDevicePath, OPTIONAL
441 IN CONST EFI_DEVICE_PATH_PROTOCOL *SecondDevicePath OPTIONAL
442 )
443 {
444 return mDevicePathLibDevicePathUtilities->AppendDevicePath (FirstDevicePath, SecondDevicePath);
445 }
446
447 /**
448 Creates a new path by appending the device node to the device path.
449
450 This function creates a new device path by appending a copy of the device node
451 specified by DevicePathNode to a copy of the device path specified by DevicePath
452 in an allocated buffer.
453 The end-of-device-path device node is moved after the end of the appended device node.
454 If DevicePathNode is NULL then a copy of DevicePath is returned.
455 If DevicePath is NULL then a copy of DevicePathNode, followed by an end-of-device
456 path device node is returned.
457 If both DevicePathNode and DevicePath are NULL then a copy of an end-of-device-path
458 device node is returned.
459 If there is not enough memory to allocate space for the new device path, then
460 NULL is returned.
461 The memory is allocated from EFI boot services memory. It is the responsibility
462 of the caller to free the memory allocated.
463
464 @param DevicePath A pointer to a device path data structure.
465 @param DevicePathNode A pointer to a single device path node.
466
467 @retval NULL If there is not enough memory for the new device path.
468 @retval Others A pointer to the new device path if success.
469 A copy of DevicePathNode followed by an end-of-device-path node
470 if both FirstDevicePath and SecondDevicePath are NULL.
471 A copy of an end-of-device-path node if both FirstDevicePath
472 and SecondDevicePath are NULL.
473
474 **/
475 EFI_DEVICE_PATH_PROTOCOL *
476 EFIAPI
477 AppendDevicePathNode (
478 IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath, OPTIONAL
479 IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePathNode OPTIONAL
480 )
481 {
482 return mDevicePathLibDevicePathUtilities->AppendDeviceNode (DevicePath, DevicePathNode);
483 }
484
485 /**
486 Creates a new device path by appending the specified device path instance to
487 the specified device path.
488
489 This function creates a new device path by appending a copy of the device path
490 instance specified by DevicePathInstance to a copy of the device path specified
491 by DevicePath in a allocated buffer.
492 The end-of-device-path device node is moved after the end of the appended device
493 path instance and a new end-of-device-path-instance node is inserted between.
494 If DevicePath is NULL, then a copy if DevicePathInstance is returned.
495 If DevicePathInstance is NULL, then NULL is returned.
496 If DevicePath or DevicePathInstance is invalid, then NULL is returned.
497 If there is not enough memory to allocate space for the new device path, then
498 NULL is returned.
499 The memory is allocated from EFI boot services memory. It is the responsibility
500 of the caller to free the memory allocated.
501
502 @param DevicePath A pointer to a device path data structure.
503 @param DevicePathInstance A pointer to a device path instance.
504
505 @return A pointer to the new device path.
506
507 **/
508 EFI_DEVICE_PATH_PROTOCOL *
509 EFIAPI
510 AppendDevicePathInstance (
511 IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath, OPTIONAL
512 IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePathInstance OPTIONAL
513 )
514 {
515 return mDevicePathLibDevicePathUtilities->AppendDevicePathInstance (DevicePath, DevicePathInstance);
516 }
517
518 /**
519 Creates a copy of the current device path instance and returns a pointer to the
520 next device path instance.
521
522 This function creates a copy of the current device path instance. It also updates
523 DevicePath to point to the next device path instance in the device path (or NULL
524 if no more) and updates Size to hold the size of the device path instance copy.
525 If DevicePath is NULL, then NULL is returned.
526 If there is not enough memory to allocate space for the new device path, then
527 NULL is returned.
528 The memory is allocated from EFI boot services memory. It is the responsibility
529 of the caller to free the memory allocated.
530 If Size is NULL, then ASSERT().
531
532 @param DevicePath On input, this holds the pointer to the current
533 device path instance. On output, this holds
534 the pointer to the next device path instance
535 or NULL if there are no more device path
536 instances in the device path pointer to a
537 device path data structure.
538 @param Size On output, this holds the size of the device
539 path instance, in bytes or zero, if DevicePath
540 is NULL.
541
542 @return A pointer to the current device path instance.
543
544 **/
545 EFI_DEVICE_PATH_PROTOCOL *
546 EFIAPI
547 GetNextDevicePathInstance (
548 IN OUT EFI_DEVICE_PATH_PROTOCOL **DevicePath,
549 OUT UINTN *Size
550 )
551 {
552 ASSERT (Size != NULL);
553 return mDevicePathLibDevicePathUtilities->GetNextDevicePathInstance (DevicePath, Size);
554 }
555
556 /**
557 Creates a device node.
558
559 This function creates a new device node in a newly allocated buffer of size
560 NodeLength and initializes the device path node header with NodeType and NodeSubType.
561 The new device path node is returned.
562 If NodeLength is smaller than a device path header, then NULL is returned.
563 If there is not enough memory to allocate space for the new device path, then
564 NULL is returned.
565 The memory is allocated from EFI boot services memory. It is the responsibility
566 of the caller to free the memory allocated.
567
568 @param NodeType The device node type for the new device node.
569 @param NodeSubType The device node sub-type for the new device node.
570 @param NodeLength The length of the new device node.
571
572 @return The new device path.
573
574 **/
575 EFI_DEVICE_PATH_PROTOCOL *
576 EFIAPI
577 CreateDeviceNode (
578 IN UINT8 NodeType,
579 IN UINT8 NodeSubType,
580 IN UINT16 NodeLength
581 )
582 {
583 return mDevicePathLibDevicePathUtilities->CreateDeviceNode (NodeType, NodeSubType, NodeLength);
584 }
585
586 /**
587 Determines if a device path is single or multi-instance.
588
589 This function returns TRUE if the device path specified by DevicePath is
590 multi-instance.
591 Otherwise, FALSE is returned.
592 If DevicePath is NULL or invalid, then FALSE is returned.
593
594 @param DevicePath A pointer to a device path data structure.
595
596 @retval TRUE DevicePath is multi-instance.
597 @retval FALSE DevicePath is not multi-instance, or DevicePath
598 is NULL or invalid.
599
600 **/
601 BOOLEAN
602 EFIAPI
603 IsDevicePathMultiInstance (
604 IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath
605 )
606 {
607 return mDevicePathLibDevicePathUtilities->IsDevicePathMultiInstance (DevicePath);
608 }
609
610 /**
611 Retrieves the device path protocol from a handle.
612
613 This function returns the device path protocol from the handle specified by Handle.
614 If Handle is NULL or Handle does not contain a device path protocol, then NULL
615 is returned.
616
617 @param Handle The handle from which to retrieve the device
618 path protocol.
619
620 @return The device path protocol from the handle specified by Handle.
621
622 **/
623 EFI_DEVICE_PATH_PROTOCOL *
624 EFIAPI
625 DevicePathFromHandle (
626 IN EFI_HANDLE Handle
627 )
628 {
629 EFI_DEVICE_PATH_PROTOCOL *DevicePath;
630 EFI_STATUS Status;
631
632 Status = gBS->HandleProtocol (
633 Handle,
634 &gEfiDevicePathProtocolGuid,
635 (VOID *) &DevicePath
636 );
637 if (EFI_ERROR (Status)) {
638 DevicePath = NULL;
639 }
640 return DevicePath;
641 }
642
643 /**
644 Allocates a device path for a file and appends it to an existing device path.
645
646 If Device is a valid device handle that contains a device path protocol, then
647 a device path for the file specified by FileName is allocated and appended to
648 the device path associated with the handle Device. The allocated device path
649 is returned. If Device is NULL or Device is a handle that does not support the
650 device path protocol, then a device path containing a single device path node
651 for the file specified by FileName is allocated and returned.
652 The memory for the new device path is allocated from EFI boot services memory.
653 It is the responsibility of the caller to free the memory allocated.
654
655 If FileName is NULL, then ASSERT().
656 If FileName is not aligned on a 16-bit boundary, then ASSERT().
657
658 @param Device A pointer to a device handle. This parameter
659 is optional and may be NULL.
660 @param FileName A pointer to a Null-terminated Unicode string.
661
662 @return The allocated device path.
663
664 **/
665 EFI_DEVICE_PATH_PROTOCOL *
666 EFIAPI
667 FileDevicePath (
668 IN EFI_HANDLE Device, OPTIONAL
669 IN CONST CHAR16 *FileName
670 )
671 {
672 UINTN Size;
673 FILEPATH_DEVICE_PATH *FilePath;
674 EFI_DEVICE_PATH_PROTOCOL *DevicePath;
675 EFI_DEVICE_PATH_PROTOCOL *FileDevicePath;
676
677 DevicePath = NULL;
678
679 Size = StrSize (FileName);
680 FileDevicePath = AllocatePool (Size + SIZE_OF_FILEPATH_DEVICE_PATH + END_DEVICE_PATH_LENGTH);
681 if (FileDevicePath != NULL) {
682 FilePath = (FILEPATH_DEVICE_PATH *) FileDevicePath;
683 FilePath->Header.Type = MEDIA_DEVICE_PATH;
684 FilePath->Header.SubType = MEDIA_FILEPATH_DP;
685 CopyMem (&FilePath->PathName, FileName, Size);
686 SetDevicePathNodeLength (&FilePath->Header, Size + SIZE_OF_FILEPATH_DEVICE_PATH);
687 SetDevicePathEndNode (NextDevicePathNode (&FilePath->Header));
688
689 if (Device != NULL) {
690 DevicePath = DevicePathFromHandle (Device);
691 }
692
693 DevicePath = AppendDevicePath (DevicePath, FileDevicePath);
694 FreePool (FileDevicePath);
695 }
696
697 return DevicePath;
698 }
699
700 /**
701 Locate and return the protocol instance identified by the ProtocolGuid.
702
703 @param ProtocolGuid The GUID of the protocol.
704
705 @return A pointer to the protocol instance or NULL when absent.
706 **/
707 VOID *
708 UefiDevicePathLibLocateProtocol (
709 EFI_GUID *ProtocolGuid
710 )
711 {
712 EFI_STATUS Status;
713 VOID *Protocol;
714 Status = gBS->LocateProtocol (
715 ProtocolGuid,
716 NULL,
717 (VOID**) &Protocol
718 );
719 if (EFI_ERROR (Status)) {
720 return NULL;
721 } else {
722 return Protocol;
723 }
724 }
725
726 /**
727 Converts a device node to its string representation.
728
729 @param DeviceNode A Pointer to the device node to be converted.
730 @param DisplayOnly If DisplayOnly is TRUE, then the shorter text representation
731 of the display node is used, where applicable. If DisplayOnly
732 is FALSE, then the longer text representation of the display node
733 is used.
734 @param AllowShortcuts If AllowShortcuts is TRUE, then the shortcut forms of text
735 representation for a device node can be used, where applicable.
736
737 @return A pointer to the allocated text representation of the device node or NULL if DeviceNode
738 is NULL or there was insufficient memory.
739
740 **/
741 CHAR16 *
742 EFIAPI
743 ConvertDeviceNodeToText (
744 IN CONST EFI_DEVICE_PATH_PROTOCOL *DeviceNode,
745 IN BOOLEAN DisplayOnly,
746 IN BOOLEAN AllowShortcuts
747 )
748 {
749 if (mDevicePathLibDevicePathToText == NULL) {
750 mDevicePathLibDevicePathToText = UefiDevicePathLibLocateProtocol (&gEfiDevicePathToTextProtocolGuid);
751 }
752 if (mDevicePathLibDevicePathToText != NULL) {
753 return mDevicePathLibDevicePathToText->ConvertDeviceNodeToText (DeviceNode, DisplayOnly, AllowShortcuts);
754 } else {
755 return NULL;
756 }
757 }
758
759 /**
760 Converts a device path to its text representation.
761
762 @param DevicePath A Pointer to the device to be converted.
763 @param DisplayOnly If DisplayOnly is TRUE, then the shorter text representation
764 of the display node is used, where applicable. If DisplayOnly
765 is FALSE, then the longer text representation of the display node
766 is used.
767 @param AllowShortcuts If AllowShortcuts is TRUE, then the shortcut forms of text
768 representation for a device node can be used, where applicable.
769
770 @return A pointer to the allocated text representation of the device path or
771 NULL if DeviceNode is NULL or there was insufficient memory.
772
773 **/
774 CHAR16 *
775 EFIAPI
776 ConvertDevicePathToText (
777 IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath,
778 IN BOOLEAN DisplayOnly,
779 IN BOOLEAN AllowShortcuts
780 )
781 {
782 if (mDevicePathLibDevicePathToText == NULL) {
783 mDevicePathLibDevicePathToText = UefiDevicePathLibLocateProtocol (&gEfiDevicePathToTextProtocolGuid);
784 }
785 if (mDevicePathLibDevicePathToText != NULL) {
786 return mDevicePathLibDevicePathToText->ConvertDevicePathToText (DevicePath, DisplayOnly, AllowShortcuts);
787 } else {
788 return NULL;
789 }
790 }
791
792 /**
793 Convert text to the binary representation of a device node.
794
795 @param TextDeviceNode TextDeviceNode points to the text representation of a device
796 node. Conversion starts with the first character and continues
797 until the first non-device node character.
798
799 @return A pointer to the EFI device node or NULL if TextDeviceNode is NULL or there was
800 insufficient memory or text unsupported.
801
802 **/
803 EFI_DEVICE_PATH_PROTOCOL *
804 EFIAPI
805 ConvertTextToDeviceNode (
806 IN CONST CHAR16 *TextDeviceNode
807 )
808 {
809 if (mDevicePathLibDevicePathFromText == NULL) {
810 mDevicePathLibDevicePathFromText = UefiDevicePathLibLocateProtocol (&gEfiDevicePathFromTextProtocolGuid);
811 }
812 if (mDevicePathLibDevicePathFromText != NULL) {
813 return mDevicePathLibDevicePathFromText->ConvertTextToDeviceNode (TextDeviceNode);
814 } else {
815 return NULL;
816 }
817 }
818
819 /**
820 Convert text to the binary representation of a device path.
821
822
823 @param TextDevicePath TextDevicePath points to the text representation of a device
824 path. Conversion starts with the first character and continues
825 until the first non-device node character.
826
827 @return A pointer to the allocated device path or NULL if TextDeviceNode is NULL or
828 there was insufficient memory.
829
830 **/
831 EFI_DEVICE_PATH_PROTOCOL *
832 EFIAPI
833 ConvertTextToDevicePath (
834 IN CONST CHAR16 *TextDevicePath
835 )
836 {
837 if (mDevicePathLibDevicePathFromText == NULL) {
838 mDevicePathLibDevicePathFromText = UefiDevicePathLibLocateProtocol (&gEfiDevicePathFromTextProtocolGuid);
839 }
840 if (mDevicePathLibDevicePathFromText != NULL) {
841 return mDevicePathLibDevicePathFromText->ConvertTextToDevicePath (TextDevicePath);
842 } else {
843 return NULL;
844 }
845 }
846