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1 | /** @file\r | |
2 | Device Path services. The thing to remember is device paths are built out of\r | |
3 | nodes. The device path is terminated by an end node that is length\r | |
4 | sizeof(EFI_DEVICE_PATH_PROTOCOL). That would be why there is sizeof(EFI_DEVICE_PATH_PROTOCOL)\r | |
5 | all over this file.\r | |
6 | \r | |
7 | The only place where multi-instance device paths are supported is in\r | |
8 | environment varibles. Multi-instance device paths should never be placed\r | |
9 | on a Handle.\r | |
10 | \r | |
11 | Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>\r | |
12 | This program and the accompanying materials \r | |
13 | are licensed and made available under the terms and conditions of the BSD License \r | |
14 | which accompanies this distribution. The full text of the license may be found at \r | |
15 | http://opensource.org/licenses/bsd-license.php. \r | |
16 | \r | |
17 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, \r | |
18 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. \r | |
19 | \r | |
20 | **/\r | |
21 | \r | |
22 | \r | |
23 | #include <Uefi.h>\r | |
24 | \r | |
25 | #include <Library/DevicePathLib.h>\r | |
26 | #include <Library/BaseMemoryLib.h>\r | |
27 | #include <Library/DebugLib.h>\r | |
28 | #include <Library/MemoryAllocationLib.h>\r | |
29 | #include <Library/UefiBootServicesTableLib.h>\r | |
30 | #include <Library/BaseLib.h>\r | |
31 | \r | |
32 | //\r | |
33 | // Template for an end-of-device path node.\r | |
34 | //\r | |
35 | GLOBAL_REMOVE_IF_UNREFERENCED CONST EFI_DEVICE_PATH_PROTOCOL mUefiDevicePathLibEndDevicePath = {\r | |
36 | END_DEVICE_PATH_TYPE,\r | |
37 | END_ENTIRE_DEVICE_PATH_SUBTYPE,\r | |
38 | {\r | |
39 | END_DEVICE_PATH_LENGTH,\r | |
40 | 0\r | |
41 | }\r | |
42 | };\r | |
43 | \r | |
44 | /**\r | |
45 | Returns the Type field of a device path node.\r | |
46 | \r | |
47 | Returns the Type field of the device path node specified by Node.\r | |
48 | \r | |
49 | If Node is NULL, then ASSERT().\r | |
50 | \r | |
51 | @param Node A pointer to a device path node data structure.\r | |
52 | \r | |
53 | @return The Type field of the device path node specified by Node.\r | |
54 | \r | |
55 | **/\r | |
56 | UINT8\r | |
57 | EFIAPI\r | |
58 | DevicePathType (\r | |
59 | IN CONST VOID *Node\r | |
60 | )\r | |
61 | {\r | |
62 | ASSERT (Node != NULL);\r | |
63 | return ((EFI_DEVICE_PATH_PROTOCOL *)(Node))->Type;\r | |
64 | }\r | |
65 | \r | |
66 | /**\r | |
67 | Returns the SubType field of a device path node.\r | |
68 | \r | |
69 | Returns the SubType field of the device path node specified by Node.\r | |
70 | \r | |
71 | If Node is NULL, then ASSERT().\r | |
72 | \r | |
73 | @param Node A pointer to a device path node data structure.\r | |
74 | \r | |
75 | @return The SubType field of the device path node specified by Node.\r | |
76 | \r | |
77 | **/\r | |
78 | UINT8\r | |
79 | EFIAPI\r | |
80 | DevicePathSubType (\r | |
81 | IN CONST VOID *Node\r | |
82 | )\r | |
83 | {\r | |
84 | ASSERT (Node != NULL);\r | |
85 | return ((EFI_DEVICE_PATH_PROTOCOL *)(Node))->SubType;\r | |
86 | }\r | |
87 | \r | |
88 | /**\r | |
89 | Returns the 16-bit Length field of a device path node.\r | |
90 | \r | |
91 | Returns the 16-bit Length field of the device path node specified by Node. \r | |
92 | Node is not required to be aligned on a 16-bit boundary, so it is recommended\r | |
93 | that a function such as ReadUnaligned16() be used to extract the contents of \r | |
94 | the Length field.\r | |
95 | \r | |
96 | If Node is NULL, then ASSERT().\r | |
97 | \r | |
98 | @param Node A pointer to a device path node data structure.\r | |
99 | \r | |
100 | @return The 16-bit Length field of the device path node specified by Node.\r | |
101 | \r | |
102 | **/\r | |
103 | UINTN\r | |
104 | EFIAPI\r | |
105 | DevicePathNodeLength (\r | |
106 | IN CONST VOID *Node\r | |
107 | )\r | |
108 | {\r | |
109 | ASSERT (Node != NULL);\r | |
110 | return ReadUnaligned16 ((UINT16 *)&((EFI_DEVICE_PATH_PROTOCOL *)(Node))->Length[0]);\r | |
111 | }\r | |
112 | \r | |
113 | /**\r | |
114 | Returns a pointer to the next node in a device path.\r | |
115 | \r | |
116 | Returns a pointer to the device path node that follows the device path node \r | |
117 | specified by Node.\r | |
118 | \r | |
119 | If Node is NULL, then ASSERT().\r | |
120 | \r | |
121 | @param Node A pointer to a device path node data structure.\r | |
122 | \r | |
123 | @return a pointer to the device path node that follows the device path node \r | |
124 | specified by Node.\r | |
125 | \r | |
126 | **/\r | |
127 | EFI_DEVICE_PATH_PROTOCOL *\r | |
128 | EFIAPI\r | |
129 | NextDevicePathNode (\r | |
130 | IN CONST VOID *Node\r | |
131 | )\r | |
132 | {\r | |
133 | ASSERT (Node != NULL);\r | |
134 | return (EFI_DEVICE_PATH_PROTOCOL *)((UINT8 *)(Node) + DevicePathNodeLength(Node));\r | |
135 | }\r | |
136 | \r | |
137 | /**\r | |
138 | Determines if a device path node is an end node of a device path.\r | |
139 | This includes nodes that are the end of a device path instance and nodes that \r | |
140 | are the end of an entire device path.\r | |
141 | \r | |
142 | Determines if the device path node specified by Node is an end node of a device path. \r | |
143 | This includes nodes that are the end of a device path instance and nodes that are the \r | |
144 | end of an entire device path. If Node represents an end node of a device path, \r | |
145 | then TRUE is returned. Otherwise, FALSE is returned.\r | |
146 | \r | |
147 | If Node is NULL, then ASSERT().\r | |
148 | \r | |
149 | @param Node A pointer to a device path node data structure.\r | |
150 | \r | |
151 | @retval TRUE The device path node specified by Node is an end node of a \r | |
152 | device path.\r | |
153 | @retval FALSE The device path node specified by Node is not an end node of \r | |
154 | a device path.\r | |
155 | \r | |
156 | **/\r | |
157 | BOOLEAN\r | |
158 | EFIAPI\r | |
159 | IsDevicePathEndType (\r | |
160 | IN CONST VOID *Node\r | |
161 | )\r | |
162 | {\r | |
163 | ASSERT (Node != NULL);\r | |
164 | return (BOOLEAN) (DevicePathType (Node) == END_DEVICE_PATH_TYPE);\r | |
165 | }\r | |
166 | \r | |
167 | /**\r | |
168 | Determines if a device path node is an end node of an entire device path.\r | |
169 | \r | |
170 | Determines if a device path node specified by Node is an end node of an entire \r | |
171 | device path. If Node represents the end of an entire device path, then TRUE is \r | |
172 | returned. Otherwise, FALSE is returned.\r | |
173 | \r | |
174 | If Node is NULL, then ASSERT().\r | |
175 | \r | |
176 | @param Node A pointer to a device path node data structure.\r | |
177 | \r | |
178 | @retval TRUE The device path node specified by Node is the end of an entire \r | |
179 | device path.\r | |
180 | @retval FALSE The device path node specified by Node is not the end of an \r | |
181 | entire device path.\r | |
182 | \r | |
183 | **/\r | |
184 | BOOLEAN\r | |
185 | EFIAPI\r | |
186 | IsDevicePathEnd (\r | |
187 | IN CONST VOID *Node\r | |
188 | )\r | |
189 | {\r | |
190 | ASSERT (Node != NULL);\r | |
191 | return (BOOLEAN) (IsDevicePathEndType (Node) && DevicePathSubType(Node) == END_ENTIRE_DEVICE_PATH_SUBTYPE);\r | |
192 | }\r | |
193 | \r | |
194 | /**\r | |
195 | Determines if a device path node is an end node of a device path instance.\r | |
196 | \r | |
197 | Determines if a device path node specified by Node is an end node of a device \r | |
198 | path instance. If Node represents the end of a device path instance, then TRUE \r | |
199 | is returned. Otherwise, FALSE is returned.\r | |
200 | \r | |
201 | If Node is NULL, then ASSERT().\r | |
202 | \r | |
203 | @param Node A pointer to a device path node data structure.\r | |
204 | \r | |
205 | @retval TRUE The device path node specified by Node is the end of a device \r | |
206 | path instance.\r | |
207 | @retval FALSE The device path node specified by Node is not the end of a \r | |
208 | device path instance.\r | |
209 | \r | |
210 | **/\r | |
211 | BOOLEAN\r | |
212 | EFIAPI\r | |
213 | IsDevicePathEndInstance (\r | |
214 | IN CONST VOID *Node\r | |
215 | )\r | |
216 | {\r | |
217 | ASSERT (Node != NULL);\r | |
218 | return (BOOLEAN) (IsDevicePathEndType (Node) && DevicePathSubType(Node) == END_INSTANCE_DEVICE_PATH_SUBTYPE);\r | |
219 | }\r | |
220 | \r | |
221 | /**\r | |
222 | Sets the length, in bytes, of a device path node.\r | |
223 | \r | |
224 | Sets the length of the device path node specified by Node to the value specified \r | |
225 | by NodeLength. NodeLength is returned. Node is not required to be aligned on \r | |
226 | a 16-bit boundary, so it is recommended that a function such as WriteUnaligned16()\r | |
227 | be used to set the contents of the Length field.\r | |
228 | \r | |
229 | If Node is NULL, then ASSERT().\r | |
230 | If NodeLength >= 0x10000, then ASSERT().\r | |
231 | \r | |
232 | @param Node A pointer to a device path node data structure.\r | |
233 | @param Length The length, in bytes, of the device path node.\r | |
234 | \r | |
235 | @return Length\r | |
236 | \r | |
237 | **/\r | |
238 | UINT16\r | |
239 | EFIAPI\r | |
240 | SetDevicePathNodeLength (\r | |
241 | IN OUT VOID *Node,\r | |
242 | IN UINTN Length\r | |
243 | )\r | |
244 | {\r | |
245 | ASSERT (Node != NULL);\r | |
246 | ASSERT (Length < 0x10000);\r | |
247 | return WriteUnaligned16 ((UINT16 *)&((EFI_DEVICE_PATH_PROTOCOL *)(Node))->Length[0], (UINT16)(Length));\r | |
248 | }\r | |
249 | \r | |
250 | /**\r | |
251 | Fills in all the fields of a device path node that is the end of an entire device path.\r | |
252 | \r | |
253 | Fills in all the fields of a device path node specified by Node so Node represents \r | |
254 | the end of an entire device path. The Type field of Node is set to \r | |
255 | END_DEVICE_PATH_TYPE, the SubType field of Node is set to \r | |
256 | END_ENTIRE_DEVICE_PATH_SUBTYPE, and the Length field of Node is set to \r | |
257 | END_DEVICE_PATH_LENGTH. Node is not required to be aligned on a 16-bit boundary, \r | |
258 | so it is recommended that a function such as WriteUnaligned16() be used to set \r | |
259 | the contents of the Length field. \r | |
260 | \r | |
261 | If Node is NULL, then ASSERT(). \r | |
262 | \r | |
263 | @param Node A pointer to a device path node data structure.\r | |
264 | \r | |
265 | **/\r | |
266 | VOID\r | |
267 | EFIAPI\r | |
268 | SetDevicePathEndNode (\r | |
269 | OUT VOID *Node\r | |
270 | )\r | |
271 | {\r | |
272 | ASSERT (Node != NULL);\r | |
273 | CopyMem (Node, &mUefiDevicePathLibEndDevicePath, sizeof (mUefiDevicePathLibEndDevicePath));\r | |
274 | }\r | |
275 | \r | |
276 | /**\r | |
277 | Returns the size of a device path in bytes.\r | |
278 | \r | |
279 | This function returns the size, in bytes, of the device path data structure \r | |
280 | specified by DevicePath including the end of device path node. If DevicePath \r | |
281 | is NULL, then 0 is returned.\r | |
282 | \r | |
283 | @param DevicePath A pointer to a device path data structure.\r | |
284 | \r | |
285 | @retval 0 If DevicePath is NULL.\r | |
286 | @retval Others The size of a device path in bytes.\r | |
287 | \r | |
288 | **/\r | |
289 | UINTN\r | |
290 | EFIAPI\r | |
291 | GetDevicePathSize (\r | |
292 | IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath\r | |
293 | )\r | |
294 | {\r | |
295 | CONST EFI_DEVICE_PATH_PROTOCOL *Start;\r | |
296 | \r | |
297 | if (DevicePath == NULL) {\r | |
298 | return 0;\r | |
299 | }\r | |
300 | \r | |
301 | //\r | |
302 | // Search for the end of the device path structure\r | |
303 | //\r | |
304 | Start = DevicePath;\r | |
305 | while (!IsDevicePathEnd (DevicePath)) {\r | |
306 | DevicePath = NextDevicePathNode (DevicePath);\r | |
307 | }\r | |
308 | \r | |
309 | //\r | |
310 | // Compute the size and add back in the size of the end device path structure\r | |
311 | //\r | |
312 | return ((UINTN) DevicePath - (UINTN) Start) + DevicePathNodeLength (DevicePath);\r | |
313 | }\r | |
314 | \r | |
315 | /**\r | |
316 | Creates a new copy of an existing device path.\r | |
317 | \r | |
318 | This function allocates space for a new copy of the device path specified by DevicePath. \r | |
319 | If DevicePath is NULL, then NULL is returned. If the memory is successfully \r | |
320 | allocated, then the contents of DevicePath are copied to the newly allocated \r | |
321 | buffer, and a pointer to that buffer is returned. Otherwise, NULL is returned. \r | |
322 | The memory for the new device path is allocated from EFI boot services memory. \r | |
323 | It is the responsibility of the caller to free the memory allocated. \r | |
324 | \r | |
325 | @param DevicePath A pointer to a device path data structure.\r | |
326 | \r | |
327 | @retval NULL If DevicePath is NULL.\r | |
328 | @retval Others A pointer to the duplicated device path.\r | |
329 | \r | |
330 | **/\r | |
331 | EFI_DEVICE_PATH_PROTOCOL *\r | |
332 | EFIAPI\r | |
333 | DuplicateDevicePath (\r | |
334 | IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath\r | |
335 | )\r | |
336 | {\r | |
337 | UINTN Size;\r | |
338 | \r | |
339 | //\r | |
340 | // Compute the size\r | |
341 | //\r | |
342 | Size = GetDevicePathSize (DevicePath);\r | |
343 | if (Size == 0) {\r | |
344 | return NULL;\r | |
345 | }\r | |
346 | \r | |
347 | //\r | |
348 | // Allocate space for duplicate device path\r | |
349 | //\r | |
350 | \r | |
351 | return AllocateCopyPool (Size, DevicePath);\r | |
352 | }\r | |
353 | \r | |
354 | /**\r | |
355 | Creates a new device path by appending a second device path to a first device path.\r | |
356 | \r | |
357 | This function creates a new device path by appending a copy of SecondDevicePath \r | |
358 | to a copy of FirstDevicePath in a newly allocated buffer. Only the end-of-device-path \r | |
359 | device node from SecondDevicePath is retained. The newly created device path is \r | |
360 | returned. If FirstDevicePath is NULL, then it is ignored, and a duplicate of \r | |
361 | SecondDevicePath is returned. If SecondDevicePath is NULL, then it is ignored, \r | |
362 | and a duplicate of FirstDevicePath is returned. If both FirstDevicePath and \r | |
363 | SecondDevicePath are NULL, then a copy of an end-of-device-path is returned. \r | |
364 | \r | |
365 | If there is not enough memory for the newly allocated buffer, then NULL is returned.\r | |
366 | The memory for the new device path is allocated from EFI boot services memory. \r | |
367 | It is the responsibility of the caller to free the memory allocated.\r | |
368 | \r | |
369 | @param FirstDevicePath A pointer to a device path data structure.\r | |
370 | @param SecondDevicePath A pointer to a device path data structure.\r | |
371 | \r | |
372 | @retval NULL If there is not enough memory for the newly allocated buffer.\r | |
373 | @retval Others A pointer to the new device path if success.\r | |
374 | Or a copy an end-of-device-path if both FirstDevicePath and SecondDevicePath are NULL.\r | |
375 | \r | |
376 | **/\r | |
377 | EFI_DEVICE_PATH_PROTOCOL *\r | |
378 | EFIAPI\r | |
379 | AppendDevicePath (\r | |
380 | IN CONST EFI_DEVICE_PATH_PROTOCOL *FirstDevicePath, OPTIONAL\r | |
381 | IN CONST EFI_DEVICE_PATH_PROTOCOL *SecondDevicePath OPTIONAL\r | |
382 | )\r | |
383 | {\r | |
384 | UINTN Size;\r | |
385 | UINTN Size1;\r | |
386 | UINTN Size2;\r | |
387 | EFI_DEVICE_PATH_PROTOCOL *NewDevicePath;\r | |
388 | EFI_DEVICE_PATH_PROTOCOL *DevicePath2;\r | |
389 | \r | |
390 | //\r | |
391 | // If there's only 1 path, just duplicate it.\r | |
392 | //\r | |
393 | if (FirstDevicePath == NULL) {\r | |
394 | return DuplicateDevicePath ((SecondDevicePath != NULL) ? SecondDevicePath : &mUefiDevicePathLibEndDevicePath);\r | |
395 | }\r | |
396 | \r | |
397 | if (SecondDevicePath == NULL) {\r | |
398 | return DuplicateDevicePath (FirstDevicePath);\r | |
399 | }\r | |
400 | \r | |
401 | //\r | |
402 | // Allocate space for the combined device path. It only has one end node of\r | |
403 | // length EFI_DEVICE_PATH_PROTOCOL.\r | |
404 | //\r | |
405 | Size1 = GetDevicePathSize (FirstDevicePath);\r | |
406 | Size2 = GetDevicePathSize (SecondDevicePath);\r | |
407 | Size = Size1 + Size2 - END_DEVICE_PATH_LENGTH;\r | |
408 | \r | |
409 | NewDevicePath = AllocatePool (Size);\r | |
410 | \r | |
411 | if (NewDevicePath != NULL) {\r | |
412 | NewDevicePath = CopyMem (NewDevicePath, FirstDevicePath, Size1);\r | |
413 | //\r | |
414 | // Over write FirstDevicePath EndNode and do the copy\r | |
415 | //\r | |
416 | DevicePath2 = (EFI_DEVICE_PATH_PROTOCOL *) ((CHAR8 *) NewDevicePath +\r | |
417 | (Size1 - END_DEVICE_PATH_LENGTH));\r | |
418 | CopyMem (DevicePath2, SecondDevicePath, Size2);\r | |
419 | }\r | |
420 | \r | |
421 | return NewDevicePath;\r | |
422 | }\r | |
423 | \r | |
424 | /**\r | |
425 | Creates a new path by appending the device node to the device path.\r | |
426 | \r | |
427 | This function creates a new device path by appending a copy of the device node \r | |
428 | specified by DevicePathNode to a copy of the device path specified by DevicePath \r | |
429 | in an allocated buffer. The end-of-device-path device node is moved after the \r | |
430 | end of the appended device node.\r | |
431 | If DevicePathNode is NULL then a copy of DevicePath is returned.\r | |
432 | If DevicePath is NULL then a copy of DevicePathNode, followed by an end-of-device \r | |
433 | path device node is returned.\r | |
434 | If both DevicePathNode and DevicePath are NULL then a copy of an end-of-device-path \r | |
435 | device node is returned.\r | |
436 | If there is not enough memory to allocate space for the new device path, then \r | |
437 | NULL is returned. \r | |
438 | The memory is allocated from EFI boot services memory. It is the responsibility \r | |
439 | of the caller to free the memory allocated.\r | |
440 | \r | |
441 | @param DevicePath A pointer to a device path data structure.\r | |
442 | @param DevicePathNode A pointer to a single device path node.\r | |
443 | \r | |
444 | @retval NULL If there is not enough memory for the new device path.\r | |
445 | @retval Others A pointer to the new device path if success.\r | |
446 | A copy of DevicePathNode followed by an end-of-device-path node \r | |
447 | if both FirstDevicePath and SecondDevicePath are NULL.\r | |
448 | A copy of an end-of-device-path node if both FirstDevicePath \r | |
449 | and SecondDevicePath are NULL.\r | |
450 | \r | |
451 | **/\r | |
452 | EFI_DEVICE_PATH_PROTOCOL *\r | |
453 | EFIAPI\r | |
454 | AppendDevicePathNode (\r | |
455 | IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath, OPTIONAL\r | |
456 | IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePathNode OPTIONAL\r | |
457 | )\r | |
458 | {\r | |
459 | EFI_DEVICE_PATH_PROTOCOL *TempDevicePath;\r | |
460 | EFI_DEVICE_PATH_PROTOCOL *NextNode;\r | |
461 | EFI_DEVICE_PATH_PROTOCOL *NewDevicePath;\r | |
462 | UINTN NodeLength;\r | |
463 | \r | |
464 | if (DevicePathNode == NULL) {\r | |
465 | return DuplicateDevicePath ((DevicePath != NULL) ? DevicePath : &mUefiDevicePathLibEndDevicePath);\r | |
466 | }\r | |
467 | //\r | |
468 | // Build a Node that has a terminator on it\r | |
469 | //\r | |
470 | NodeLength = DevicePathNodeLength (DevicePathNode);\r | |
471 | \r | |
472 | TempDevicePath = AllocatePool (NodeLength + END_DEVICE_PATH_LENGTH);\r | |
473 | if (TempDevicePath == NULL) {\r | |
474 | return NULL;\r | |
475 | }\r | |
476 | TempDevicePath = CopyMem (TempDevicePath, DevicePathNode, NodeLength);\r | |
477 | //\r | |
478 | // Add and end device path node to convert Node to device path\r | |
479 | //\r | |
480 | NextNode = NextDevicePathNode (TempDevicePath);\r | |
481 | SetDevicePathEndNode (NextNode);\r | |
482 | //\r | |
483 | // Append device paths\r | |
484 | //\r | |
485 | NewDevicePath = AppendDevicePath (DevicePath, TempDevicePath);\r | |
486 | \r | |
487 | FreePool (TempDevicePath);\r | |
488 | \r | |
489 | return NewDevicePath;\r | |
490 | }\r | |
491 | \r | |
492 | /**\r | |
493 | Creates a new device path by appending the specified device path instance to the specified device\r | |
494 | path.\r | |
495 | \r | |
496 | This function creates a new device path by appending a copy of the device path \r | |
497 | instance specified by DevicePathInstance to a copy of the device path specified \r | |
498 | by DevicePath in a allocated buffer.\r | |
499 | The end-of-device-path device node is moved after the end of the appended device \r | |
500 | path instance and a new end-of-device-path-instance node is inserted between. \r | |
501 | If DevicePath is NULL, then a copy if DevicePathInstance is returned.\r | |
502 | If DevicePathInstance is NULL, then NULL is returned.\r | |
503 | If there is not enough memory to allocate space for the new device path, then \r | |
504 | NULL is returned. \r | |
505 | The memory is allocated from EFI boot services memory. It is the responsibility \r | |
506 | of the caller to free the memory allocated.\r | |
507 | \r | |
508 | @param DevicePath A pointer to a device path data structure.\r | |
509 | @param DevicePathInstance A pointer to a device path instance.\r | |
510 | \r | |
511 | @return A pointer to the new device path.\r | |
512 | \r | |
513 | **/\r | |
514 | EFI_DEVICE_PATH_PROTOCOL *\r | |
515 | EFIAPI\r | |
516 | AppendDevicePathInstance (\r | |
517 | IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath, OPTIONAL\r | |
518 | IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePathInstance OPTIONAL\r | |
519 | )\r | |
520 | {\r | |
521 | EFI_DEVICE_PATH_PROTOCOL *NewDevicePath;\r | |
522 | EFI_DEVICE_PATH_PROTOCOL *TempDevicePath;\r | |
523 | UINTN SrcSize;\r | |
524 | UINTN InstanceSize;\r | |
525 | \r | |
526 | if (DevicePath == NULL) {\r | |
527 | return DuplicateDevicePath (DevicePathInstance);\r | |
528 | }\r | |
529 | \r | |
530 | if (DevicePathInstance == NULL) {\r | |
531 | return NULL;\r | |
532 | }\r | |
533 | \r | |
534 | SrcSize = GetDevicePathSize (DevicePath);\r | |
535 | InstanceSize = GetDevicePathSize (DevicePathInstance);\r | |
536 | \r | |
537 | NewDevicePath = AllocatePool (SrcSize + InstanceSize);\r | |
538 | if (NewDevicePath != NULL) {\r | |
539 | \r | |
540 | TempDevicePath = CopyMem (NewDevicePath, DevicePath, SrcSize);;\r | |
541 | \r | |
542 | while (!IsDevicePathEnd (TempDevicePath)) {\r | |
543 | TempDevicePath = NextDevicePathNode (TempDevicePath);\r | |
544 | }\r | |
545 | \r | |
546 | TempDevicePath->SubType = END_INSTANCE_DEVICE_PATH_SUBTYPE;\r | |
547 | TempDevicePath = NextDevicePathNode (TempDevicePath);\r | |
548 | CopyMem (TempDevicePath, DevicePathInstance, InstanceSize);\r | |
549 | }\r | |
550 | \r | |
551 | return NewDevicePath;\r | |
552 | }\r | |
553 | \r | |
554 | /**\r | |
555 | Creates a copy of the current device path instance and returns a pointer to the next device path\r | |
556 | instance.\r | |
557 | \r | |
558 | This function creates a copy of the current device path instance. It also updates \r | |
559 | DevicePath to point to the next device path instance in the device path (or NULL \r | |
560 | if no more) and updates Size to hold the size of the device path instance copy.\r | |
561 | If DevicePath is NULL, then NULL is returned.\r | |
562 | If there is not enough memory to allocate space for the new device path, then \r | |
563 | NULL is returned. \r | |
564 | The memory is allocated from EFI boot services memory. It is the responsibility \r | |
565 | of the caller to free the memory allocated.\r | |
566 | If Size is NULL, then ASSERT().\r | |
567 | \r | |
568 | @param DevicePath On input, this holds the pointer to the current \r | |
569 | device path instance. On output, this holds \r | |
570 | the pointer to the next device path instance \r | |
571 | or NULL if there are no more device path\r | |
572 | instances in the device path pointer to a \r | |
573 | device path data structure.\r | |
574 | @param Size On output, this holds the size of the device \r | |
575 | path instance, in bytes or zero, if DevicePath \r | |
576 | is NULL.\r | |
577 | \r | |
578 | @return A pointer to the current device path instance.\r | |
579 | \r | |
580 | **/\r | |
581 | EFI_DEVICE_PATH_PROTOCOL *\r | |
582 | EFIAPI\r | |
583 | GetNextDevicePathInstance (\r | |
584 | IN OUT EFI_DEVICE_PATH_PROTOCOL **DevicePath,\r | |
585 | OUT UINTN *Size\r | |
586 | )\r | |
587 | {\r | |
588 | EFI_DEVICE_PATH_PROTOCOL *DevPath;\r | |
589 | EFI_DEVICE_PATH_PROTOCOL *ReturnValue;\r | |
590 | UINT8 Temp;\r | |
591 | \r | |
592 | ASSERT (Size != NULL);\r | |
593 | \r | |
594 | if (DevicePath == NULL || *DevicePath == NULL) {\r | |
595 | *Size = 0;\r | |
596 | return NULL;\r | |
597 | }\r | |
598 | \r | |
599 | //\r | |
600 | // Find the end of the device path instance\r | |
601 | //\r | |
602 | DevPath = *DevicePath;\r | |
603 | while (!IsDevicePathEndType (DevPath)) {\r | |
604 | DevPath = NextDevicePathNode (DevPath);\r | |
605 | }\r | |
606 | \r | |
607 | //\r | |
608 | // Compute the size of the device path instance\r | |
609 | //\r | |
610 | *Size = ((UINTN) DevPath - (UINTN) (*DevicePath)) + sizeof (EFI_DEVICE_PATH_PROTOCOL);\r | |
611 | \r | |
612 | //\r | |
613 | // Make a copy and return the device path instance\r | |
614 | //\r | |
615 | Temp = DevPath->SubType;\r | |
616 | DevPath->SubType = END_ENTIRE_DEVICE_PATH_SUBTYPE;\r | |
617 | ReturnValue = DuplicateDevicePath (*DevicePath);\r | |
618 | DevPath->SubType = Temp;\r | |
619 | \r | |
620 | //\r | |
621 | // If DevPath is the end of an entire device path, then another instance\r | |
622 | // does not follow, so *DevicePath is set to NULL.\r | |
623 | //\r | |
624 | if (DevicePathSubType (DevPath) == END_ENTIRE_DEVICE_PATH_SUBTYPE) {\r | |
625 | *DevicePath = NULL;\r | |
626 | } else {\r | |
627 | *DevicePath = NextDevicePathNode (DevPath);\r | |
628 | }\r | |
629 | \r | |
630 | return ReturnValue;\r | |
631 | }\r | |
632 | \r | |
633 | /**\r | |
634 | Creates a device node.\r | |
635 | \r | |
636 | This function creates a new device node in a newly allocated buffer of size \r | |
637 | NodeLength and initializes the device path node header with NodeType and NodeSubType. \r | |
638 | The new device path node is returned.\r | |
639 | If NodeLength is smaller than a device path header, then NULL is returned. \r | |
640 | If there is not enough memory to allocate space for the new device path, then \r | |
641 | NULL is returned. \r | |
642 | The memory is allocated from EFI boot services memory. It is the responsibility \r | |
643 | of the caller to free the memory allocated.\r | |
644 | \r | |
645 | @param NodeType The device node type for the new device node.\r | |
646 | @param NodeSubType The device node sub-type for the new device node.\r | |
647 | @param NodeLength The length of the new device node.\r | |
648 | \r | |
649 | @return The new device path.\r | |
650 | \r | |
651 | **/\r | |
652 | EFI_DEVICE_PATH_PROTOCOL *\r | |
653 | EFIAPI\r | |
654 | CreateDeviceNode (\r | |
655 | IN UINT8 NodeType,\r | |
656 | IN UINT8 NodeSubType,\r | |
657 | IN UINT16 NodeLength\r | |
658 | )\r | |
659 | {\r | |
660 | EFI_DEVICE_PATH_PROTOCOL *DevicePath;\r | |
661 | \r | |
662 | if (NodeLength < sizeof (EFI_DEVICE_PATH_PROTOCOL)) {\r | |
663 | //\r | |
664 | // NodeLength is less than the size of the header.\r | |
665 | //\r | |
666 | return NULL;\r | |
667 | }\r | |
668 | \r | |
669 | DevicePath = AllocateZeroPool (NodeLength);\r | |
670 | if (DevicePath != NULL) {\r | |
671 | DevicePath->Type = NodeType;\r | |
672 | DevicePath->SubType = NodeSubType;\r | |
673 | SetDevicePathNodeLength (DevicePath, NodeLength);\r | |
674 | }\r | |
675 | \r | |
676 | return DevicePath;\r | |
677 | }\r | |
678 | \r | |
679 | /**\r | |
680 | Determines if a device path is single or multi-instance.\r | |
681 | \r | |
682 | This function returns TRUE if the device path specified by DevicePath is\r | |
683 | multi-instance.\r | |
684 | Otherwise, FALSE is returned. If DevicePath is NULL, then FALSE is returned.\r | |
685 | \r | |
686 | @param DevicePath A pointer to a device path data structure.\r | |
687 | \r | |
688 | @retval TRUE DevicePath is multi-instance.\r | |
689 | @retval FALSE DevicePath is not multi-instance or DevicePath \r | |
690 | is NULL.\r | |
691 | \r | |
692 | **/\r | |
693 | BOOLEAN\r | |
694 | EFIAPI\r | |
695 | IsDevicePathMultiInstance (\r | |
696 | IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath\r | |
697 | )\r | |
698 | {\r | |
699 | CONST EFI_DEVICE_PATH_PROTOCOL *Node;\r | |
700 | \r | |
701 | if (DevicePath == NULL) {\r | |
702 | return FALSE;\r | |
703 | }\r | |
704 | \r | |
705 | Node = DevicePath;\r | |
706 | while (!IsDevicePathEnd (Node)) {\r | |
707 | if (IsDevicePathEndInstance (Node)) {\r | |
708 | return TRUE;\r | |
709 | }\r | |
710 | \r | |
711 | Node = NextDevicePathNode (Node);\r | |
712 | }\r | |
713 | \r | |
714 | return FALSE;\r | |
715 | }\r | |
716 | \r | |
717 | \r | |
718 | /**\r | |
719 | Retrieves the device path protocol from a handle.\r | |
720 | \r | |
721 | This function returns the device path protocol from the handle specified by Handle. \r | |
722 | If Handle is NULL or Handle does not contain a device path protocol, then NULL \r | |
723 | is returned.\r | |
724 | \r | |
725 | @param Handle The handle from which to retrieve the device \r | |
726 | path protocol.\r | |
727 | \r | |
728 | @return The device path protocol from the handle specified by Handle.\r | |
729 | \r | |
730 | **/\r | |
731 | EFI_DEVICE_PATH_PROTOCOL *\r | |
732 | EFIAPI\r | |
733 | DevicePathFromHandle (\r | |
734 | IN EFI_HANDLE Handle\r | |
735 | )\r | |
736 | {\r | |
737 | EFI_DEVICE_PATH_PROTOCOL *DevicePath;\r | |
738 | EFI_STATUS Status;\r | |
739 | \r | |
740 | Status = gBS->HandleProtocol (\r | |
741 | Handle,\r | |
742 | &gEfiDevicePathProtocolGuid,\r | |
743 | (VOID *) &DevicePath\r | |
744 | );\r | |
745 | if (EFI_ERROR (Status)) {\r | |
746 | DevicePath = NULL;\r | |
747 | }\r | |
748 | return DevicePath;\r | |
749 | }\r | |
750 | \r | |
751 | /**\r | |
752 | Allocates a device path for a file and appends it to an existing device path.\r | |
753 | \r | |
754 | If Device is a valid device handle that contains a device path protocol, then a device path for\r | |
755 | the file specified by FileName is allocated and appended to the device path associated with the\r | |
756 | handle Device. The allocated device path is returned. If Device is NULL or Device is a handle\r | |
757 | that does not support the device path protocol, then a device path containing a single device\r | |
758 | path node for the file specified by FileName is allocated and returned.\r | |
759 | The memory for the new device path is allocated from EFI boot services memory. It is the responsibility\r | |
760 | of the caller to free the memory allocated.\r | |
761 | \r | |
762 | If FileName is NULL, then ASSERT().\r | |
763 | If FileName is not aligned on a 16-bit boundary, then ASSERT().\r | |
764 | \r | |
765 | @param Device A pointer to a device handle. This parameter \r | |
766 | is optional and may be NULL.\r | |
767 | @param FileName A pointer to a Null-terminated Unicode string.\r | |
768 | \r | |
769 | @return The allocated device path.\r | |
770 | \r | |
771 | **/\r | |
772 | EFI_DEVICE_PATH_PROTOCOL *\r | |
773 | EFIAPI\r | |
774 | FileDevicePath (\r | |
775 | IN EFI_HANDLE Device, OPTIONAL\r | |
776 | IN CONST CHAR16 *FileName\r | |
777 | )\r | |
778 | {\r | |
779 | UINT16 Size;\r | |
780 | FILEPATH_DEVICE_PATH *FilePath;\r | |
781 | EFI_DEVICE_PATH_PROTOCOL *DevicePath;\r | |
782 | EFI_DEVICE_PATH_PROTOCOL *FileDevicePath;\r | |
783 | \r | |
784 | DevicePath = NULL;\r | |
785 | \r | |
786 | Size = (UINT16) StrSize (FileName);\r | |
787 | \r | |
788 | FileDevicePath = AllocatePool (Size + SIZE_OF_FILEPATH_DEVICE_PATH + END_DEVICE_PATH_LENGTH);\r | |
789 | if (FileDevicePath != NULL) {\r | |
790 | FilePath = (FILEPATH_DEVICE_PATH *) FileDevicePath;\r | |
791 | FilePath->Header.Type = MEDIA_DEVICE_PATH;\r | |
792 | FilePath->Header.SubType = MEDIA_FILEPATH_DP;\r | |
793 | CopyMem (&FilePath->PathName, FileName, Size);\r | |
794 | SetDevicePathNodeLength (&FilePath->Header, Size + SIZE_OF_FILEPATH_DEVICE_PATH);\r | |
795 | SetDevicePathEndNode (NextDevicePathNode (&FilePath->Header));\r | |
796 | \r | |
797 | if (Device != NULL) {\r | |
798 | DevicePath = DevicePathFromHandle (Device);\r | |
799 | }\r | |
800 | \r | |
801 | DevicePath = AppendDevicePath (DevicePath, FileDevicePath);\r | |
802 | FreePool (FileDevicePath);\r | |
803 | }\r | |
804 | \r | |
805 | return DevicePath;\r | |
806 | }\r | |
807 | \r |