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e386b444 | 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 | |
373ade0e | 11 | Copyright (c) 2006 - 2008, Intel Corporation \r |
e386b444 | 12 | All rights reserved. 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 | |
e386b444 | 20 | **/\r |
21 | \r | |
c892d846 | 22 | \r |
c7d265a9 | 23 | #include <Uefi.h>\r |
c892d846 | 24 | \r |
c7d265a9 | 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 | |
e386b444 | 31 | \r |
98a14db6 | 32 | //\r |
33 | // Template for an end-of-device path node.\r | |
34 | //\r | |
34abfd7c | 35 | GLOBAL_REMOVE_IF_UNREFERENCED CONST EFI_DEVICE_PATH_PROTOCOL mUefiDevicePathLibEndDevicePath = {\r |
98a14db6 | 36 | END_DEVICE_PATH_TYPE,\r |
37 | END_ENTIRE_DEVICE_PATH_SUBTYPE,\r | |
697f4d59 | 38 | {\r |
39 | END_DEVICE_PATH_LENGTH,\r | |
40 | 0\r | |
41 | }\r | |
98a14db6 | 42 | };\r |
43 | \r | |
3dc728fb | 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 | DevicePathType (\r | |
58 | IN CONST VOID *Node\r | |
59 | )\r | |
60 | {\r | |
61 | ASSERT (Node != NULL);\r | |
62 | return ((EFI_DEVICE_PATH_PROTOCOL *)(Node))->Type;\r | |
63 | }\r | |
64 | \r | |
65 | /**\r | |
66 | Returns the SubType field of a device path node.\r | |
67 | \r | |
68 | Returns the SubType field of the device path node specified by Node.\r | |
69 | \r | |
70 | If Node is NULL, then ASSERT().\r | |
71 | \r | |
72 | @param Node A pointer to a device path node data structure.\r | |
73 | \r | |
74 | @return The SubType field of the device path node specified by Node.\r | |
75 | \r | |
76 | **/\r | |
77 | UINT8\r | |
78 | DevicePathSubType (\r | |
79 | IN CONST VOID *Node\r | |
80 | )\r | |
81 | {\r | |
82 | ASSERT (Node != NULL);\r | |
83 | return ((EFI_DEVICE_PATH_PROTOCOL *)(Node))->SubType;\r | |
84 | }\r | |
85 | \r | |
86 | /**\r | |
87 | Returns the 16-bit Length field of a device path node.\r | |
88 | \r | |
89 | Returns the 16-bit Length field of the device path node specified by Node. \r | |
90 | Node is not required to be aligned on a 16-bit boundary, so it is recommended\r | |
91 | that a function such as ReadUnaligned16() be used to extract the contents of \r | |
92 | the Length field.\r | |
93 | \r | |
94 | If Node is NULL, then ASSERT().\r | |
95 | \r | |
96 | @param Node A pointer to a device path node data structure.\r | |
97 | \r | |
98 | @return The 16-bit Length field of the device path node specified by Node.\r | |
99 | \r | |
100 | **/\r | |
101 | UINTN\r | |
102 | DevicePathNodeLength (\r | |
103 | IN CONST VOID *Node\r | |
104 | )\r | |
105 | {\r | |
106 | ASSERT (Node != NULL);\r | |
107 | return ReadUnaligned16 ((UINT16 *)&((EFI_DEVICE_PATH_PROTOCOL *)(Node))->Length[0]);\r | |
108 | }\r | |
109 | \r | |
110 | /**\r | |
111 | Returns a pointer to the next node in a device path.\r | |
112 | \r | |
113 | Returns a pointer to the device path node that follows the device path node specified by Node.\r | |
114 | \r | |
115 | If Node is NULL, then ASSERT().\r | |
116 | \r | |
117 | @param Node A pointer to a device path node data structure.\r | |
118 | \r | |
119 | @return a pointer to the device path node that follows the device path node specified by Node.\r | |
120 | \r | |
121 | **/\r | |
122 | EFI_DEVICE_PATH_PROTOCOL *\r | |
123 | NextDevicePathNode (\r | |
124 | IN CONST VOID *Node\r | |
125 | )\r | |
126 | {\r | |
127 | ASSERT (Node != NULL);\r | |
128 | return (EFI_DEVICE_PATH_PROTOCOL *)((UINT8 *)(Node) + DevicePathNodeLength(Node));\r | |
129 | }\r | |
130 | \r | |
131 | /**\r | |
132 | Determines if a device path node is an end node of a device path.\r | |
133 | This includes nodes that are the end of a device path instance and nodes that are the end of an entire device path.\r | |
134 | \r | |
135 | Determines if the device path node specified by Node is an end node of a device path. \r | |
136 | This includes nodes that are the end of a device path instance and nodes that are the \r | |
137 | end of an entire device path. If Node represents an end node of a device path, \r | |
138 | then TRUE is returned. Otherwise, FALSE is returned.\r | |
139 | \r | |
140 | If Node is NULL, then ASSERT().\r | |
141 | \r | |
142 | @param Node A pointer to a device path node data structure.\r | |
143 | \r | |
144 | @retval TRUE The device path node specified by Node is an end node of a device path.\r | |
145 | @retval FALSE The device path node specified by Node is not an end node of a device path.\r | |
146 | \r | |
147 | **/\r | |
148 | BOOLEAN\r | |
149 | IsDevicePathEndType (\r | |
150 | IN CONST VOID *Node\r | |
151 | )\r | |
152 | {\r | |
153 | ASSERT (Node != NULL);\r | |
a9b896f4 | 154 | return (BOOLEAN) (DevicePathType (Node) == END_DEVICE_PATH_TYPE);\r |
3dc728fb | 155 | }\r |
156 | \r | |
157 | /**\r | |
158 | Determines if a device path node is an end node of an entire device path.\r | |
159 | \r | |
160 | Determines if a device path node specified by Node is an end node of an entire device path.\r | |
161 | If Node represents the end of an entire device path, then TRUE is returned. Otherwise, FALSE is returned.\r | |
162 | \r | |
163 | If Node is NULL, then ASSERT().\r | |
164 | \r | |
165 | @param Node A pointer to a device path node data structure.\r | |
166 | \r | |
167 | @retval TRUE The device path node specified by Node is the end of an entire device path.\r | |
168 | @retval FALSE The device path node specified by Node is not the end of an entire device path.\r | |
169 | \r | |
170 | **/\r | |
171 | BOOLEAN\r | |
172 | IsDevicePathEnd (\r | |
173 | IN CONST VOID *Node\r | |
174 | )\r | |
175 | {\r | |
176 | ASSERT (Node != NULL);\r | |
5fc55555 | 177 | return (BOOLEAN) (IsDevicePathEndType (Node) && DevicePathSubType(Node) == END_ENTIRE_DEVICE_PATH_SUBTYPE);\r |
3dc728fb | 178 | }\r |
179 | \r | |
180 | /**\r | |
181 | Determines if a device path node is an end node of a device path instance.\r | |
182 | \r | |
183 | Determines if a device path node specified by Node is an end node of a device path instance.\r | |
184 | If Node represents the end of a device path instance, then TRUE is returned. Otherwise, FALSE is returned.\r | |
185 | \r | |
186 | If Node is NULL, then ASSERT().\r | |
187 | \r | |
188 | @param Node A pointer to a device path node data structure.\r | |
189 | \r | |
190 | @retval TRUE The device path node specified by Node is the end of a device path instance.\r | |
191 | @retval FALSE The device path node specified by Node is not the end of a device path instance.\r | |
192 | \r | |
193 | **/\r | |
194 | BOOLEAN\r | |
195 | IsDevicePathEndInstance (\r | |
196 | IN CONST VOID *Node\r | |
197 | )\r | |
198 | {\r | |
199 | ASSERT (Node != NULL);\r | |
5fc55555 | 200 | return (BOOLEAN) (IsDevicePathEndType (Node) && DevicePathSubType(Node) == END_INSTANCE_DEVICE_PATH_SUBTYPE);\r |
3dc728fb | 201 | }\r |
202 | \r | |
203 | /**\r | |
204 | Sets the length, in bytes, of a device path node.\r | |
205 | \r | |
206 | Sets the length of the device path node specified by Node to the value specified \r | |
207 | by NodeLength. NodeLength is returned. Node is not required to be aligned on \r | |
208 | a 16-bit boundary, so it is recommended that a function such as WriteUnaligned16()\r | |
209 | be used to set the contents of the Length field.\r | |
210 | \r | |
211 | If Node is NULL, then ASSERT().\r | |
212 | If NodeLength >= 0x10000, then ASSERT().\r | |
213 | \r | |
214 | @param Node A pointer to a device path node data structure.\r | |
215 | @param Length The length, in bytes, of the device path node.\r | |
216 | \r | |
217 | @return Length\r | |
218 | \r | |
219 | **/\r | |
220 | UINT16\r | |
221 | SetDevicePathNodeLength (\r | |
9bb407c6 | 222 | IN OUT VOID *Node,\r |
8f0dd97e | 223 | IN UINTN Length\r |
3dc728fb | 224 | )\r |
225 | {\r | |
226 | ASSERT (Node != NULL);\r | |
8f0dd97e | 227 | ASSERT (Length < 0x10000);\r |
228 | return WriteUnaligned16 ((UINT16 *)&((EFI_DEVICE_PATH_PROTOCOL *)(Node))->Length[0], (UINT16)(Length));\r | |
3dc728fb | 229 | }\r |
230 | \r | |
231 | /**\r | |
232 | Fills in all the fields of a device path node that is the end of an entire device path.\r | |
233 | \r | |
234 | Fills in all the fields of a device path node specified by Node so Node represents \r | |
235 | the end of an entire device path. The Type field of Node is set to \r | |
236 | END_DEVICE_PATH_TYPE, the SubType field of Node is set to \r | |
237 | END_ENTIRE_DEVICE_PATH_SUBTYPE, and the Length field of Node is set to \r | |
238 | END_DEVICE_PATH_LENGTH. Node is not required to be aligned on a 16-bit boundary, \r | |
239 | so it is recommended that a function such as WriteUnaligned16() be used to set \r | |
240 | the contents of the Length field. \r | |
241 | \r | |
242 | If Node is NULL, then ASSERT(). \r | |
243 | \r | |
244 | @param Node A pointer to a device path node data structure.\r | |
245 | \r | |
246 | **/\r | |
247 | VOID\r | |
248 | SetDevicePathEndNode (\r | |
9bb407c6 | 249 | OUT VOID *Node\r |
3dc728fb | 250 | )\r |
251 | {\r | |
252 | ASSERT (Node != NULL);\r | |
253 | CopyMem (Node, &mUefiDevicePathLibEndDevicePath, sizeof (mUefiDevicePathLibEndDevicePath));\r | |
254 | }\r | |
255 | \r | |
e386b444 | 256 | /**\r |
257 | Returns the size of a device path in bytes.\r | |
258 | \r | |
259 | This function returns the size, in bytes, of the device path data structure specified by\r | |
260 | DevicePath including the end of device path node. If DevicePath is NULL, then 0 is returned.\r | |
261 | \r | |
262 | @param DevicePath A pointer to a device path data structure.\r | |
3e5c3238 | 263 | \r |
264 | @retval 0 If DevicePath is NULL.\r | |
265 | @retval Others The size of a device path in bytes.\r | |
e386b444 | 266 | \r |
267 | **/\r | |
268 | UINTN\r | |
269 | EFIAPI\r | |
270 | GetDevicePathSize (\r | |
271 | IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath\r | |
272 | )\r | |
273 | {\r | |
274 | CONST EFI_DEVICE_PATH_PROTOCOL *Start;\r | |
275 | \r | |
276 | if (DevicePath == NULL) {\r | |
277 | return 0;\r | |
278 | }\r | |
279 | \r | |
280 | //\r | |
281 | // Search for the end of the device path structure\r | |
282 | //\r | |
283 | Start = DevicePath;\r | |
e5dab016 | 284 | while (!IsDevicePathEnd (DevicePath)) {\r |
285 | DevicePath = NextDevicePathNode (DevicePath);\r | |
e386b444 | 286 | }\r |
287 | \r | |
288 | //\r | |
289 | // Compute the size and add back in the size of the end device path structure\r | |
290 | //\r | |
e5dab016 | 291 | return ((UINTN) DevicePath - (UINTN) Start) + DevicePathNodeLength (DevicePath);\r |
e386b444 | 292 | }\r |
293 | \r | |
294 | /**\r | |
6a3f4ef9 | 295 | Creates a new copy of an existing device path.\r |
e386b444 | 296 | \r |
297 | This function allocates space for a new copy of the device path specified by DevicePath. If\r | |
298 | DevicePath is NULL, then NULL is returned. If the memory is successfully allocated, then the\r | |
299 | contents of DevicePath are copied to the newly allocated buffer, and a pointer to that buffer\r | |
300 | is returned. Otherwise, NULL is returned. \r | |
3e5c3238 | 301 | The memory for the new device path is allocated from EFI boot services memory. \r |
302 | It is the responsibility of the caller to free the memory allocated. \r | |
e386b444 | 303 | \r |
304 | @param DevicePath A pointer to a device path data structure.\r | |
305 | \r | |
3e5c3238 | 306 | @retval NULL If DevicePath is NULL.\r |
307 | @retval Others A pointer to the duplicated device path.\r | |
308 | \r | |
e386b444 | 309 | **/\r |
310 | EFI_DEVICE_PATH_PROTOCOL *\r | |
311 | EFIAPI\r | |
312 | DuplicateDevicePath (\r | |
313 | IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath\r | |
314 | )\r | |
315 | {\r | |
e386b444 | 316 | UINTN Size;\r |
317 | \r | |
318 | //\r | |
319 | // Compute the size\r | |
320 | //\r | |
321 | Size = GetDevicePathSize (DevicePath);\r | |
322 | if (Size == 0) {\r | |
323 | return NULL;\r | |
324 | }\r | |
325 | \r | |
326 | //\r | |
327 | // Allocate space for duplicate device path\r | |
328 | //\r | |
e386b444 | 329 | \r |
f008fc32 | 330 | return AllocateCopyPool (Size, DevicePath);\r |
e386b444 | 331 | }\r |
332 | \r | |
333 | /**\r | |
334 | Creates a new device path by appending a second device path to a first device path.\r | |
335 | \r | |
336 | This function creates a new device path by appending a copy of SecondDevicePath to a copy of\r | |
337 | FirstDevicePath in a newly allocated buffer. Only the end-of-device-path device node from\r | |
338 | SecondDevicePath is retained. The newly created device path is returned. \r | |
339 | If FirstDevicePath is NULL, then it is ignored, and a duplicate of SecondDevicePath is returned. \r | |
340 | If SecondDevicePath is NULL, then it is ignored, and a duplicate of FirstDevicePath is returned. \r | |
98a14db6 | 341 | If both FirstDevicePath and SecondDevicePath are NULL, then a copy of an end-of-device-path is\r |
342 | returned. \r | |
e386b444 | 343 | If there is not enough memory for the newly allocated buffer, then NULL is returned.\r |
344 | The memory for the new device path is allocated from EFI boot services memory. It is the\r | |
345 | responsibility of the caller to free the memory allocated.\r | |
346 | \r | |
347 | @param FirstDevicePath A pointer to a device path data structure.\r | |
348 | @param SecondDevicePath A pointer to a device path data structure.\r | |
3e5c3238 | 349 | \r |
350 | @retval NULL If there is not enough memory for the newly allocated buffer.\r | |
351 | @retval Others A pointer to the new device path if success.\r | |
352 | Or a copy an end-of-device-path if both FirstDevicePath and SecondDevicePath are NULL.\r | |
e386b444 | 353 | \r |
354 | **/\r | |
355 | EFI_DEVICE_PATH_PROTOCOL *\r | |
356 | EFIAPI\r | |
357 | AppendDevicePath (\r | |
358 | IN CONST EFI_DEVICE_PATH_PROTOCOL *FirstDevicePath, OPTIONAL\r | |
359 | IN CONST EFI_DEVICE_PATH_PROTOCOL *SecondDevicePath OPTIONAL\r | |
360 | )\r | |
361 | {\r | |
362 | UINTN Size;\r | |
363 | UINTN Size1;\r | |
364 | UINTN Size2;\r | |
365 | EFI_DEVICE_PATH_PROTOCOL *NewDevicePath;\r | |
366 | EFI_DEVICE_PATH_PROTOCOL *DevicePath2;\r | |
367 | \r | |
368 | //\r | |
369 | // If there's only 1 path, just duplicate it.\r | |
370 | //\r | |
371 | if (FirstDevicePath == NULL) {\r | |
34abfd7c | 372 | return DuplicateDevicePath ((SecondDevicePath != NULL) ? SecondDevicePath : &mUefiDevicePathLibEndDevicePath);\r |
e386b444 | 373 | }\r |
374 | \r | |
375 | if (SecondDevicePath == NULL) {\r | |
376 | return DuplicateDevicePath (FirstDevicePath);\r | |
377 | }\r | |
378 | \r | |
379 | //\r | |
380 | // Allocate space for the combined device path. It only has one end node of\r | |
381 | // length EFI_DEVICE_PATH_PROTOCOL.\r | |
382 | //\r | |
383 | Size1 = GetDevicePathSize (FirstDevicePath);\r | |
384 | Size2 = GetDevicePathSize (SecondDevicePath);\r | |
e5dab016 | 385 | Size = Size1 + Size2 - END_DEVICE_PATH_LENGTH;\r |
e386b444 | 386 | \r |
387 | NewDevicePath = AllocatePool (Size);\r | |
388 | \r | |
389 | if (NewDevicePath != NULL) {\r | |
390 | NewDevicePath = CopyMem (NewDevicePath, FirstDevicePath, Size1);\r | |
391 | //\r | |
392 | // Over write FirstDevicePath EndNode and do the copy\r | |
393 | //\r | |
394 | DevicePath2 = (EFI_DEVICE_PATH_PROTOCOL *) ((CHAR8 *) NewDevicePath +\r | |
e5dab016 | 395 | (Size1 - END_DEVICE_PATH_LENGTH));\r |
e386b444 | 396 | CopyMem (DevicePath2, SecondDevicePath, Size2);\r |
397 | }\r | |
398 | \r | |
399 | return NewDevicePath;\r | |
400 | }\r | |
401 | \r | |
402 | /**\r | |
403 | Creates a new path by appending the device node to the device path.\r | |
404 | \r | |
405 | This function creates a new device path by appending a copy of the device node specified by\r | |
406 | DevicePathNode to a copy of the device path specified by DevicePath in an allocated buffer.\r | |
407 | The end-of-device-path device node is moved after the end of the appended device node.\r | |
98a14db6 | 408 | If DevicePathNode is NULL then a copy of DevicePath is returned.\r |
6336a895 | 409 | If DevicePath is NULL then a copy of DevicePathNode, followed by an end-of-device path device\r |
410 | node is returned.\r | |
98a14db6 | 411 | If both DevicePathNode and DevicePath are NULL then a copy of an end-of-device-path device node\r |
412 | is returned.\r | |
e386b444 | 413 | If there is not enough memory to allocate space for the new device path, then NULL is returned. \r |
414 | The memory is allocated from EFI boot services memory. It is the responsibility of the caller to\r | |
415 | free the memory allocated.\r | |
416 | \r | |
417 | @param DevicePath A pointer to a device path data structure.\r | |
418 | @param DevicePathNode A pointer to a single device path node.\r | |
419 | \r | |
3e5c3238 | 420 | @retval NULL If there is not enough memory for the new device path.\r |
421 | @retval Others A pointer to the new device path if success.\r | |
422 | A copy of DevicePathNode followed by an end-of-device-path node \r | |
423 | if both FirstDevicePath and SecondDevicePath are NULL.\r | |
424 | A copy of an end-of-device-path node if both FirstDevicePath and SecondDevicePath are NULL.\r | |
e386b444 | 425 | \r |
426 | **/\r | |
427 | EFI_DEVICE_PATH_PROTOCOL *\r | |
428 | EFIAPI\r | |
429 | AppendDevicePathNode (\r | |
430 | IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath, OPTIONAL\r | |
431 | IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePathNode OPTIONAL\r | |
432 | )\r | |
433 | {\r | |
434 | EFI_DEVICE_PATH_PROTOCOL *TempDevicePath;\r | |
435 | EFI_DEVICE_PATH_PROTOCOL *NextNode;\r | |
436 | EFI_DEVICE_PATH_PROTOCOL *NewDevicePath;\r | |
437 | UINTN NodeLength;\r | |
438 | \r | |
98a14db6 | 439 | if (DevicePathNode == NULL) {\r |
34abfd7c | 440 | return DuplicateDevicePath ((DevicePath != NULL) ? DevicePath : &mUefiDevicePathLibEndDevicePath);\r |
e386b444 | 441 | }\r |
442 | //\r | |
443 | // Build a Node that has a terminator on it\r | |
444 | //\r | |
445 | NodeLength = DevicePathNodeLength (DevicePathNode);\r | |
446 | \r | |
e5dab016 | 447 | TempDevicePath = AllocatePool (NodeLength + END_DEVICE_PATH_LENGTH);\r |
e386b444 | 448 | if (TempDevicePath == NULL) {\r |
449 | return NULL;\r | |
450 | }\r | |
451 | TempDevicePath = CopyMem (TempDevicePath, DevicePathNode, NodeLength);\r | |
452 | //\r | |
453 | // Add and end device path node to convert Node to device path\r | |
454 | //\r | |
455 | NextNode = NextDevicePathNode (TempDevicePath);\r | |
456 | SetDevicePathEndNode (NextNode);\r | |
457 | //\r | |
458 | // Append device paths\r | |
459 | //\r | |
460 | NewDevicePath = AppendDevicePath (DevicePath, TempDevicePath);\r | |
461 | \r | |
462 | FreePool (TempDevicePath);\r | |
463 | \r | |
464 | return NewDevicePath;\r | |
465 | }\r | |
466 | \r | |
467 | /**\r | |
468 | Creates a new device path by appending the specified device path instance to the specified device\r | |
469 | path.\r | |
470 | \r | |
471 | This function creates a new device path by appending a copy of the device path instance specified\r | |
472 | by DevicePathInstance to a copy of the device path secified by DevicePath in a allocated buffer.\r | |
473 | The end-of-device-path device node is moved after the end of the appended device path instance\r | |
474 | and a new end-of-device-path-instance node is inserted between. \r | |
475 | If DevicePath is NULL, then a copy if DevicePathInstance is returned.\r | |
476 | If DevicePathInstance is NULL, then NULL is returned.\r | |
477 | If there is not enough memory to allocate space for the new device path, then NULL is returned. \r | |
478 | The memory is allocated from EFI boot services memory. It is the responsibility of the caller to\r | |
479 | free the memory allocated.\r | |
480 | \r | |
481 | @param DevicePath A pointer to a device path data structure.\r | |
482 | @param DevicePathInstance A pointer to a device path instance.\r | |
483 | \r | |
484 | @return A pointer to the new device path.\r | |
485 | \r | |
486 | **/\r | |
487 | EFI_DEVICE_PATH_PROTOCOL *\r | |
488 | EFIAPI\r | |
489 | AppendDevicePathInstance (\r | |
490 | IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath, OPTIONAL\r | |
491 | IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePathInstance OPTIONAL\r | |
492 | )\r | |
493 | {\r | |
494 | EFI_DEVICE_PATH_PROTOCOL *NewDevicePath;\r | |
495 | EFI_DEVICE_PATH_PROTOCOL *TempDevicePath;\r | |
496 | UINTN SrcSize;\r | |
497 | UINTN InstanceSize;\r | |
498 | \r | |
499 | if (DevicePath == NULL) {\r | |
500 | return DuplicateDevicePath (DevicePathInstance);\r | |
501 | }\r | |
502 | \r | |
503 | if (DevicePathInstance == NULL) {\r | |
504 | return NULL;\r | |
505 | }\r | |
506 | \r | |
507 | SrcSize = GetDevicePathSize (DevicePath);\r | |
508 | InstanceSize = GetDevicePathSize (DevicePathInstance);\r | |
509 | \r | |
510 | NewDevicePath = AllocatePool (SrcSize + InstanceSize);\r | |
511 | if (NewDevicePath != NULL) {\r | |
512 | \r | |
513 | TempDevicePath = CopyMem (NewDevicePath, DevicePath, SrcSize);;\r | |
514 | \r | |
515 | while (!IsDevicePathEnd (TempDevicePath)) {\r | |
516 | TempDevicePath = NextDevicePathNode (TempDevicePath);\r | |
517 | }\r | |
518 | \r | |
519 | TempDevicePath->SubType = END_INSTANCE_DEVICE_PATH_SUBTYPE;\r | |
520 | TempDevicePath = NextDevicePathNode (TempDevicePath);\r | |
521 | CopyMem (TempDevicePath, DevicePathInstance, InstanceSize);\r | |
522 | }\r | |
523 | \r | |
524 | return NewDevicePath;\r | |
525 | }\r | |
526 | \r | |
527 | /**\r | |
528 | Creates a copy of the current device path instance and returns a pointer to the next device path\r | |
529 | instance.\r | |
530 | \r | |
531 | This function creates a copy of the current device path instance. It also updates DevicePath to\r | |
532 | point to the next device path instance in the device path (or NULL if no more) and updates Size\r | |
533 | to hold the size of the device path instance copy.\r | |
534 | If DevicePath is NULL, then NULL is returned.\r | |
535 | If there is not enough memory to allocate space for the new device path, then NULL is returned. \r | |
536 | The memory is allocated from EFI boot services memory. It is the responsibility of the caller to\r | |
537 | free the memory allocated.\r | |
538 | If Size is NULL, then ASSERT().\r | |
539 | \r | |
540 | @param DevicePath On input, this holds the pointer to the current device path\r | |
541 | instance. On output, this holds the pointer to the next device\r | |
542 | path instance or NULL if there are no more device path\r | |
543 | instances in the device path pointer to a device path data\r | |
544 | structure.\r | |
545 | @param Size On output, this holds the size of the device path instance, in\r | |
546 | bytes or zero, if DevicePath is NULL.\r | |
547 | \r | |
548 | @return A pointer to the current device path instance.\r | |
549 | \r | |
550 | **/\r | |
551 | EFI_DEVICE_PATH_PROTOCOL *\r | |
552 | EFIAPI\r | |
553 | GetNextDevicePathInstance (\r | |
554 | IN OUT EFI_DEVICE_PATH_PROTOCOL **DevicePath,\r | |
555 | OUT UINTN *Size\r | |
556 | )\r | |
557 | {\r | |
558 | EFI_DEVICE_PATH_PROTOCOL *DevPath;\r | |
559 | EFI_DEVICE_PATH_PROTOCOL *ReturnValue;\r | |
560 | UINT8 Temp;\r | |
561 | \r | |
562 | ASSERT (Size != NULL);\r | |
563 | \r | |
564 | if (DevicePath == NULL || *DevicePath == NULL) {\r | |
565 | *Size = 0;\r | |
566 | return NULL;\r | |
567 | }\r | |
568 | \r | |
569 | //\r | |
570 | // Find the end of the device path instance\r | |
571 | //\r | |
572 | DevPath = *DevicePath;\r | |
573 | while (!IsDevicePathEndType (DevPath)) {\r | |
574 | DevPath = NextDevicePathNode (DevPath);\r | |
575 | }\r | |
576 | \r | |
577 | //\r | |
578 | // Compute the size of the device path instance\r | |
579 | //\r | |
580 | *Size = ((UINTN) DevPath - (UINTN) (*DevicePath)) + sizeof (EFI_DEVICE_PATH_PROTOCOL);\r | |
581 | \r | |
582 | //\r | |
583 | // Make a copy and return the device path instance\r | |
584 | //\r | |
585 | Temp = DevPath->SubType;\r | |
586 | DevPath->SubType = END_ENTIRE_DEVICE_PATH_SUBTYPE;\r | |
587 | ReturnValue = DuplicateDevicePath (*DevicePath);\r | |
588 | DevPath->SubType = Temp;\r | |
589 | \r | |
590 | //\r | |
591 | // If DevPath is the end of an entire device path, then another instance\r | |
592 | // does not follow, so *DevicePath is set to NULL.\r | |
593 | //\r | |
594 | if (DevicePathSubType (DevPath) == END_ENTIRE_DEVICE_PATH_SUBTYPE) {\r | |
595 | *DevicePath = NULL;\r | |
596 | } else {\r | |
597 | *DevicePath = NextDevicePathNode (DevPath);\r | |
598 | }\r | |
599 | \r | |
600 | return ReturnValue;\r | |
601 | }\r | |
602 | \r | |
603 | /**\r | |
3e5c3238 | 604 | Creates a device node.\r |
e386b444 | 605 | \r |
606 | This function creates a new device node in a newly allocated buffer of size NodeLength and\r | |
607 | initializes the device path node header with NodeType and NodeSubType. The new device path node\r | |
608 | is returned.\r | |
609 | If NodeLength is smaller than a device path header, then NULL is returned. \r | |
610 | If there is not enough memory to allocate space for the new device path, then NULL is returned. \r | |
611 | The memory is allocated from EFI boot services memory. It is the responsibility of the caller to\r | |
612 | free the memory allocated.\r | |
613 | \r | |
614 | @param NodeType The device node type for the new device node.\r | |
615 | @param NodeSubType The device node sub-type for the new device node.\r | |
616 | @param NodeLength The length of the new device node.\r | |
617 | \r | |
3e5c3238 | 618 | @return The new device path.\r |
e386b444 | 619 | \r |
620 | **/\r | |
621 | EFI_DEVICE_PATH_PROTOCOL *\r | |
622 | EFIAPI\r | |
623 | CreateDeviceNode (\r | |
624 | IN UINT8 NodeType,\r | |
625 | IN UINT8 NodeSubType,\r | |
626 | IN UINT16 NodeLength\r | |
627 | )\r | |
628 | {\r | |
629 | EFI_DEVICE_PATH_PROTOCOL *DevicePath;\r | |
630 | \r | |
631 | if (NodeLength < sizeof (EFI_DEVICE_PATH_PROTOCOL)) {\r | |
632 | //\r | |
633 | // NodeLength is less than the size of the header.\r | |
634 | //\r | |
635 | return NULL;\r | |
636 | }\r | |
637 | \r | |
6577541d | 638 | DevicePath = AllocateZeroPool (NodeLength);\r |
e386b444 | 639 | if (DevicePath != NULL) {\r |
640 | DevicePath->Type = NodeType;\r | |
641 | DevicePath->SubType = NodeSubType;\r | |
642 | SetDevicePathNodeLength (DevicePath, NodeLength);\r | |
643 | }\r | |
644 | \r | |
645 | return DevicePath;\r | |
646 | }\r | |
647 | \r | |
648 | /**\r | |
649 | Determines if a device path is single or multi-instance.\r | |
650 | \r | |
651 | This function returns TRUE if the device path specified by DevicePath is multi-instance.\r | |
652 | Otherwise, FALSE is returned. If DevicePath is NULL, then FALSE is returned.\r | |
653 | \r | |
654 | @param DevicePath A pointer to a device path data structure.\r | |
655 | \r | |
656 | @retval TRUE DevicePath is multi-instance.\r | |
657 | @retval FALSE DevicePath is not multi-instance or DevicePath is NULL.\r | |
658 | \r | |
659 | **/\r | |
660 | BOOLEAN\r | |
661 | EFIAPI\r | |
662 | IsDevicePathMultiInstance (\r | |
663 | IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath\r | |
664 | )\r | |
665 | {\r | |
666 | CONST EFI_DEVICE_PATH_PROTOCOL *Node;\r | |
667 | \r | |
668 | if (DevicePath == NULL) {\r | |
669 | return FALSE;\r | |
670 | }\r | |
671 | \r | |
672 | Node = DevicePath;\r | |
e5dab016 | 673 | while (!IsDevicePathEnd (Node)) {\r |
674 | if (IsDevicePathEndInstance (Node)) {\r | |
e386b444 | 675 | return TRUE;\r |
676 | }\r | |
677 | \r | |
e5dab016 | 678 | Node = NextDevicePathNode (Node);\r |
e386b444 | 679 | }\r |
680 | \r | |
681 | return FALSE;\r | |
682 | }\r | |
683 | \r | |
684 | \r | |
685 | /**\r | |
686 | Retrieves the device path protocol from a handle.\r | |
687 | \r | |
688 | This function returns the device path protocol from the handle specified by Handle. If Handle is\r | |
689 | NULL or Handle does not contain a device path protocol, then NULL is returned.\r | |
690 | \r | |
691 | @param Handle The handle from which to retrieve the device path protocol.\r | |
692 | \r | |
693 | @return The device path protocol from the handle specified by Handle.\r | |
694 | \r | |
695 | **/\r | |
696 | EFI_DEVICE_PATH_PROTOCOL *\r | |
697 | EFIAPI\r | |
698 | DevicePathFromHandle (\r | |
699 | IN EFI_HANDLE Handle\r | |
700 | )\r | |
701 | {\r | |
702 | EFI_DEVICE_PATH_PROTOCOL *DevicePath;\r | |
703 | EFI_STATUS Status;\r | |
704 | \r | |
705 | Status = gBS->HandleProtocol (\r | |
706 | Handle,\r | |
707 | &gEfiDevicePathProtocolGuid,\r | |
708 | (VOID *) &DevicePath\r | |
709 | );\r | |
710 | if (EFI_ERROR (Status)) {\r | |
711 | DevicePath = NULL;\r | |
712 | }\r | |
713 | return DevicePath;\r | |
714 | }\r | |
715 | \r | |
716 | /**\r | |
717 | Allocates a device path for a file and appends it to an existing device path.\r | |
718 | \r | |
719 | If Device is a valid device handle that contains a device path protocol, then a device path for\r | |
720 | the file specified by FileName is allocated and appended to the device path associated with the\r | |
721 | handle Device. The allocated device path is returned. If Device is NULL or Device is a handle\r | |
722 | that does not support the device path protocol, then a device path containing a single device\r | |
723 | path node for the file specified by FileName is allocated and returned.\r | |
3e5c3238 | 724 | The memory for the new device path is allocated from EFI boot services memory. It is the responsibility\r |
725 | of the caller to free the memory allocated.\r | |
726 | \r | |
e386b444 | 727 | If FileName is NULL, then ASSERT().\r |
3e5c3238 | 728 | If FileName is not aligned on a 16-bit boundary, then ASSERT().\r |
e386b444 | 729 | \r |
730 | @param Device A pointer to a device handle. This parameter is optional and\r | |
731 | may be NULL.\r | |
732 | @param FileName A pointer to a Null-terminated Unicode string.\r | |
733 | \r | |
3e5c3238 | 734 | @return The allocated device path.\r |
e386b444 | 735 | \r |
736 | **/\r | |
737 | EFI_DEVICE_PATH_PROTOCOL *\r | |
738 | EFIAPI\r | |
739 | FileDevicePath (\r | |
740 | IN EFI_HANDLE Device, OPTIONAL\r | |
741 | IN CONST CHAR16 *FileName\r | |
742 | )\r | |
743 | {\r | |
e5dab016 | 744 | UINT16 Size;\r |
e386b444 | 745 | FILEPATH_DEVICE_PATH *FilePath;\r |
746 | EFI_DEVICE_PATH_PROTOCOL *DevicePath;\r | |
747 | EFI_DEVICE_PATH_PROTOCOL *FileDevicePath;\r | |
748 | \r | |
749 | DevicePath = NULL;\r | |
750 | \r | |
e5dab016 | 751 | Size = (UINT16) StrSize (FileName);\r |
752 | \r | |
753 | FileDevicePath = AllocatePool (Size + SIZE_OF_FILEPATH_DEVICE_PATH + END_DEVICE_PATH_LENGTH);\r | |
e386b444 | 754 | if (FileDevicePath != NULL) {\r |
755 | FilePath = (FILEPATH_DEVICE_PATH *) FileDevicePath;\r | |
756 | FilePath->Header.Type = MEDIA_DEVICE_PATH;\r | |
757 | FilePath->Header.SubType = MEDIA_FILEPATH_DP;\r | |
758 | CopyMem (&FilePath->PathName, FileName, Size);\r | |
759 | SetDevicePathNodeLength (&FilePath->Header, Size + SIZE_OF_FILEPATH_DEVICE_PATH);\r | |
760 | SetDevicePathEndNode (NextDevicePathNode (&FilePath->Header));\r | |
761 | \r | |
762 | if (Device != NULL) {\r | |
763 | DevicePath = DevicePathFromHandle (Device);\r | |
764 | }\r | |
765 | \r | |
766 | DevicePath = AppendDevicePath (DevicePath, FileDevicePath);\r | |
767 | FreePool (FileDevicePath);\r | |
768 | }\r | |
769 | \r | |
770 | return DevicePath;\r | |
771 | }\r | |
772 | \r |