1 /** @file
2 Device Path services. The thing to remember is device paths are built out of
3 nodes. The device path is terminated by an end node that is length
4 sizeof(EFI_DEVICE_PATH_PROTOCOL). That would be why there is sizeof(EFI_DEVICE_PATH_PROTOCOL)
5 all over this file.
6
7 The only place where multi-instance device paths are supported is in
8 environment varibles. Multi-instance device paths should never be placed
9 on a Handle.
10
11 Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
12 SPDX-License-Identifier: BSD-2-Clause-Patent
13
14 **/
15
16
17 #include "UefiDevicePathLib.h"
18
19 /**
20 Returns the size of a device path in bytes.
21
22 This function returns the size, in bytes, of the device path data structure
23 specified by DevicePath including the end of device path node.
24 If DevicePath is NULL or invalid, then 0 is returned.
25
26 @param DevicePath A pointer to a device path data structure.
27
28 @retval 0 If DevicePath is NULL or invalid.
29 @retval Others The size of a device path in bytes.
30
31 **/
32 UINTN
33 EFIAPI
GetDevicePathSize(IN CONST EFI_DEVICE_PATH_PROTOCOL * DevicePath)34 GetDevicePathSize (
35 IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath
36 )
37 {
38 return UefiDevicePathLibGetDevicePathSize (DevicePath);
39 }
40
41 /**
42 Creates a new copy of an existing device path.
43
44 This function allocates space for a new copy of the device path specified by DevicePath.
45 If DevicePath is NULL, then NULL is returned. If the memory is successfully
46 allocated, then the contents of DevicePath are copied to the newly allocated
47 buffer, and a pointer to that buffer is returned. Otherwise, NULL is returned.
48 The memory for the new device path is allocated from EFI boot services memory.
49 It is the responsibility of the caller to free the memory allocated.
50
51 @param DevicePath A pointer to a device path data structure.
52
53 @retval NULL DevicePath is NULL or invalid.
54 @retval Others A pointer to the duplicated device path.
55
56 **/
57 EFI_DEVICE_PATH_PROTOCOL *
58 EFIAPI
DuplicateDevicePath(IN CONST EFI_DEVICE_PATH_PROTOCOL * DevicePath)59 DuplicateDevicePath (
60 IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath
61 )
62 {
63 return UefiDevicePathLibDuplicateDevicePath (DevicePath);
64 }
65
66 /**
67 Creates a new device path by appending a second device path to a first device path.
68
69 This function creates a new device path by appending a copy of SecondDevicePath
70 to a copy of FirstDevicePath in a newly allocated buffer. Only the end-of-device-path
71 device node from SecondDevicePath is retained. The newly created device path is
72 returned. If FirstDevicePath is NULL, then it is ignored, and a duplicate of
73 SecondDevicePath is returned. If SecondDevicePath is NULL, then it is ignored,
74 and a duplicate of FirstDevicePath is returned. If both FirstDevicePath and
75 SecondDevicePath are NULL, then a copy of an end-of-device-path is returned.
76
77 If there is not enough memory for the newly allocated buffer, then NULL is returned.
78 The memory for the new device path is allocated from EFI boot services memory.
79 It is the responsibility of the caller to free the memory allocated.
80
81 @param FirstDevicePath A pointer to a device path data structure.
82 @param SecondDevicePath A pointer to a device path data structure.
83
84 @retval NULL If there is not enough memory for the newly allocated buffer.
85 @retval NULL If FirstDevicePath or SecondDevicePath is invalid.
86 @retval Others A pointer to the new device path if success.
87 Or a copy an end-of-device-path if both FirstDevicePath and SecondDevicePath are NULL.
88
89 **/
90 EFI_DEVICE_PATH_PROTOCOL *
91 EFIAPI
AppendDevicePath(IN CONST EFI_DEVICE_PATH_PROTOCOL * FirstDevicePath,OPTIONAL IN CONST EFI_DEVICE_PATH_PROTOCOL * SecondDevicePath OPTIONAL)92 AppendDevicePath (
93 IN CONST EFI_DEVICE_PATH_PROTOCOL *FirstDevicePath, OPTIONAL
94 IN CONST EFI_DEVICE_PATH_PROTOCOL *SecondDevicePath OPTIONAL
95 )
96 {
97 return UefiDevicePathLibAppendDevicePath (FirstDevicePath, SecondDevicePath);
98 }
99
100 /**
101 Creates a new path by appending the device node to the device path.
102
103 This function creates a new device path by appending a copy of the device node
104 specified by DevicePathNode to a copy of the device path specified by DevicePath
105 in an allocated buffer. The end-of-device-path device node is moved after the
106 end of the appended device node.
107 If DevicePathNode is NULL then a copy of DevicePath is returned.
108 If DevicePath is NULL then a copy of DevicePathNode, followed by an end-of-device
109 path device node is returned.
110 If both DevicePathNode and DevicePath are NULL then a copy of an end-of-device-path
111 device node is returned.
112 If there is not enough memory to allocate space for the new device path, then
113 NULL is returned.
114 The memory is allocated from EFI boot services memory. It is the responsibility
115 of the caller to free the memory allocated.
116
117 @param DevicePath A pointer to a device path data structure.
118 @param DevicePathNode A pointer to a single device path node.
119
120 @retval NULL If there is not enough memory for the new device path.
121 @retval Others A pointer to the new device path if success.
122 A copy of DevicePathNode followed by an end-of-device-path node
123 if both FirstDevicePath and SecondDevicePath are NULL.
124 A copy of an end-of-device-path node if both FirstDevicePath
125 and SecondDevicePath are NULL.
126
127 **/
128 EFI_DEVICE_PATH_PROTOCOL *
129 EFIAPI
AppendDevicePathNode(IN CONST EFI_DEVICE_PATH_PROTOCOL * DevicePath,OPTIONAL IN CONST EFI_DEVICE_PATH_PROTOCOL * DevicePathNode OPTIONAL)130 AppendDevicePathNode (
131 IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath, OPTIONAL
132 IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePathNode OPTIONAL
133 )
134 {
135 return UefiDevicePathLibAppendDevicePathNode (DevicePath, DevicePathNode);
136 }
137
138 /**
139 Creates a new device path by appending the specified device path instance to the specified device
140 path.
141
142 This function creates a new device path by appending a copy of the device path
143 instance specified by DevicePathInstance to a copy of the device path specified
144 by DevicePath in a allocated buffer.
145 The end-of-device-path device node is moved after the end of the appended device
146 path instance and a new end-of-device-path-instance node is inserted between.
147 If DevicePath is NULL, then a copy if DevicePathInstance is returned.
148 If DevicePathInstance is NULL, then NULL is returned.
149 If DevicePath or DevicePathInstance is invalid, then NULL is returned.
150 If there is not enough memory to allocate space for the new device path, then
151 NULL is returned.
152 The memory is allocated from EFI boot services memory. It is the responsibility
153 of the caller to free the memory allocated.
154
155 @param DevicePath A pointer to a device path data structure.
156 @param DevicePathInstance A pointer to a device path instance.
157
158 @return A pointer to the new device path.
159
160 **/
161 EFI_DEVICE_PATH_PROTOCOL *
162 EFIAPI
AppendDevicePathInstance(IN CONST EFI_DEVICE_PATH_PROTOCOL * DevicePath,OPTIONAL IN CONST EFI_DEVICE_PATH_PROTOCOL * DevicePathInstance OPTIONAL)163 AppendDevicePathInstance (
164 IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath, OPTIONAL
165 IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePathInstance OPTIONAL
166 )
167 {
168 return UefiDevicePathLibAppendDevicePathInstance (DevicePath, DevicePathInstance);
169 }
170
171 /**
172 Creates a copy of the current device path instance and returns a pointer to the next device path
173 instance.
174
175 This function creates a copy of the current device path instance. It also updates
176 DevicePath to point to the next device path instance in the device path (or NULL
177 if no more) and updates Size to hold the size of the device path instance copy.
178 If DevicePath is NULL, then NULL is returned.
179 If DevicePath points to a invalid device path, then NULL is returned.
180 If there is not enough memory to allocate space for the new device path, then
181 NULL is returned.
182 The memory is allocated from EFI boot services memory. It is the responsibility
183 of the caller to free the memory allocated.
184 If Size is NULL, then ASSERT().
185
186 @param DevicePath On input, this holds the pointer to the current
187 device path instance. On output, this holds
188 the pointer to the next device path instance
189 or NULL if there are no more device path
190 instances in the device path pointer to a
191 device path data structure.
192 @param Size On output, this holds the size of the device
193 path instance, in bytes or zero, if DevicePath
194 is NULL.
195
196 @return A pointer to the current device path instance.
197
198 **/
199 EFI_DEVICE_PATH_PROTOCOL *
200 EFIAPI
GetNextDevicePathInstance(IN OUT EFI_DEVICE_PATH_PROTOCOL ** DevicePath,OUT UINTN * Size)201 GetNextDevicePathInstance (
202 IN OUT EFI_DEVICE_PATH_PROTOCOL **DevicePath,
203 OUT UINTN *Size
204 )
205 {
206 return UefiDevicePathLibGetNextDevicePathInstance (DevicePath, Size);
207 }
208
209 /**
210 Creates a device node.
211
212 This function creates a new device node in a newly allocated buffer of size
213 NodeLength and initializes the device path node header with NodeType and NodeSubType.
214 The new device path node is returned.
215 If NodeLength is smaller than a device path header, then NULL is returned.
216 If there is not enough memory to allocate space for the new device path, then
217 NULL is returned.
218 The memory is allocated from EFI boot services memory. It is the responsibility
219 of the caller to free the memory allocated.
220
221 @param NodeType The device node type for the new device node.
222 @param NodeSubType The device node sub-type for the new device node.
223 @param NodeLength The length of the new device node.
224
225 @return The new device path.
226
227 **/
228 EFI_DEVICE_PATH_PROTOCOL *
229 EFIAPI
CreateDeviceNode(IN UINT8 NodeType,IN UINT8 NodeSubType,IN UINT16 NodeLength)230 CreateDeviceNode (
231 IN UINT8 NodeType,
232 IN UINT8 NodeSubType,
233 IN UINT16 NodeLength
234 )
235 {
236 return UefiDevicePathLibCreateDeviceNode (NodeType, NodeSubType, NodeLength);
237 }
238
239 /**
240 Determines if a device path is single or multi-instance.
241
242 This function returns TRUE if the device path specified by DevicePath is
243 multi-instance.
244 Otherwise, FALSE is returned.
245 If DevicePath is NULL or invalid, then FALSE is returned.
246
247 @param DevicePath A pointer to a device path data structure.
248
249 @retval TRUE DevicePath is multi-instance.
250 @retval FALSE DevicePath is not multi-instance, or DevicePath
251 is NULL or invalid.
252
253 **/
254 BOOLEAN
255 EFIAPI
IsDevicePathMultiInstance(IN CONST EFI_DEVICE_PATH_PROTOCOL * DevicePath)256 IsDevicePathMultiInstance (
257 IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath
258 )
259 {
260 return UefiDevicePathLibIsDevicePathMultiInstance (DevicePath);
261 }
262
263 /**
264 Converts a device node to its string representation.
265
266 @param DeviceNode A Pointer to the device node to be converted.
267 @param DisplayOnly If DisplayOnly is TRUE, then the shorter text representation
268 of the display node is used, where applicable. If DisplayOnly
269 is FALSE, then the longer text representation of the display node
270 is used.
271 @param AllowShortcuts If AllowShortcuts is TRUE, then the shortcut forms of text
272 representation for a device node can be used, where applicable.
273
274 @return A pointer to the allocated text representation of the device node or NULL if DeviceNode
275 is NULL or there was insufficient memory.
276
277 **/
278 CHAR16 *
279 EFIAPI
ConvertDeviceNodeToText(IN CONST EFI_DEVICE_PATH_PROTOCOL * DeviceNode,IN BOOLEAN DisplayOnly,IN BOOLEAN AllowShortcuts)280 ConvertDeviceNodeToText (
281 IN CONST EFI_DEVICE_PATH_PROTOCOL *DeviceNode,
282 IN BOOLEAN DisplayOnly,
283 IN BOOLEAN AllowShortcuts
284 )
285 {
286 return UefiDevicePathLibConvertDeviceNodeToText (DeviceNode, DisplayOnly, AllowShortcuts);
287 }
288
289 /**
290 Converts a device path to its text representation.
291
292 @param DevicePath A Pointer to the device to be converted.
293 @param DisplayOnly If DisplayOnly is TRUE, then the shorter text representation
294 of the display node is used, where applicable. If DisplayOnly
295 is FALSE, then the longer text representation of the display node
296 is used.
297 @param AllowShortcuts If AllowShortcuts is TRUE, then the shortcut forms of text
298 representation for a device node can be used, where applicable.
299
300 @return A pointer to the allocated text representation of the device path or
301 NULL if DeviceNode is NULL or there was insufficient memory.
302
303 **/
304 CHAR16 *
305 EFIAPI
ConvertDevicePathToText(IN CONST EFI_DEVICE_PATH_PROTOCOL * DevicePath,IN BOOLEAN DisplayOnly,IN BOOLEAN AllowShortcuts)306 ConvertDevicePathToText (
307 IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath,
308 IN BOOLEAN DisplayOnly,
309 IN BOOLEAN AllowShortcuts
310 )
311 {
312 return UefiDevicePathLibConvertDevicePathToText (DevicePath, DisplayOnly, AllowShortcuts);
313 }
314
315 /**
316 Convert text to the binary representation of a device node.
317
318 @param TextDeviceNode TextDeviceNode points to the text representation of a device
319 node. Conversion starts with the first character and continues
320 until the first non-device node character.
321
322 @return A pointer to the EFI device node or NULL if TextDeviceNode is NULL or there was
323 insufficient memory or text unsupported.
324
325 **/
326 EFI_DEVICE_PATH_PROTOCOL *
327 EFIAPI
ConvertTextToDeviceNode(IN CONST CHAR16 * TextDeviceNode)328 ConvertTextToDeviceNode (
329 IN CONST CHAR16 *TextDeviceNode
330 )
331 {
332 return UefiDevicePathLibConvertTextToDeviceNode (TextDeviceNode);
333 }
334
335 /**
336 Convert text to the binary representation of a device path.
337
338
339 @param TextDevicePath TextDevicePath points to the text representation of a device
340 path. Conversion starts with the first character and continues
341 until the first non-device node character.
342
343 @return A pointer to the allocated device path or NULL if TextDeviceNode is NULL or
344 there was insufficient memory.
345
346 **/
347 EFI_DEVICE_PATH_PROTOCOL *
348 EFIAPI
ConvertTextToDevicePath(IN CONST CHAR16 * TextDevicePath)349 ConvertTextToDevicePath (
350 IN CONST CHAR16 *TextDevicePath
351 )
352 {
353 return UefiDevicePathLibConvertTextToDevicePath (TextDevicePath);
354 }
355