Vishal Bhoj | 82c8071 | 2015-12-15 21:13:33 +0530 | [diff] [blame^] | 1 | /** @file
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| 2 | Device Path services. The thing to remember is device paths are built out of
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| 3 | nodes. The device path is terminated by an end node that is length
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| 4 | sizeof(EFI_DEVICE_PATH_PROTOCOL). That would be why there is sizeof(EFI_DEVICE_PATH_PROTOCOL)
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| 5 | all over this file.
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| 6 |
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| 7 | The only place where multi-instance device paths are supported is in
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| 8 | environment varibles. Multi-instance device paths should never be placed
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| 9 | on a Handle.
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| 10 |
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| 11 | Copyright (c) 2006 - 2014, Intel Corporation. All rights reserved.<BR>
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| 12 | This program and the accompanying materials
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| 13 | are licensed and made available under the terms and conditions of the BSD License
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| 14 | which accompanies this distribution. The full text of the license may be found at
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| 15 | http://opensource.org/licenses/bsd-license.php.
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| 16 |
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| 17 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
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| 18 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
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| 19 |
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| 20 | **/
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| 21 |
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| 22 | #include "UefiDevicePathLib.h"
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| 23 |
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| 24 | //
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| 25 | // Template for an end-of-device path node.
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| 26 | //
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| 27 | GLOBAL_REMOVE_IF_UNREFERENCED CONST EFI_DEVICE_PATH_PROTOCOL mUefiDevicePathLibEndDevicePath = {
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| 28 | END_DEVICE_PATH_TYPE,
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| 29 | END_ENTIRE_DEVICE_PATH_SUBTYPE,
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| 30 | {
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| 31 | END_DEVICE_PATH_LENGTH,
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| 32 | 0
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| 33 | }
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| 34 | };
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| 35 |
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| 36 | /**
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| 37 | Determine whether a given device path is valid.
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| 38 | If DevicePath is NULL, then ASSERT().
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| 39 |
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| 40 | @param DevicePath A pointer to a device path data structure.
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| 41 | @param MaxSize The maximum size of the device path data structure.
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| 42 |
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| 43 | @retval TRUE DevicePath is valid.
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| 44 | @retval FALSE The length of any node node in the DevicePath is less
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| 45 | than sizeof (EFI_DEVICE_PATH_PROTOCOL).
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| 46 | @retval FALSE If MaxSize is not zero, the size of the DevicePath
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| 47 | exceeds MaxSize.
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| 48 | @retval FALSE If PcdMaximumDevicePathNodeCount is not zero, the node
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| 49 | count of the DevicePath exceeds PcdMaximumDevicePathNodeCount.
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| 50 | **/
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| 51 | BOOLEAN
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| 52 | EFIAPI
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| 53 | IsDevicePathValid (
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| 54 | IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath,
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| 55 | IN UINTN MaxSize
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| 56 | )
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| 57 | {
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| 58 | UINTN Count;
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| 59 | UINTN Size;
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| 60 | UINTN NodeLength;
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| 61 |
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| 62 | ASSERT (DevicePath != NULL);
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| 63 |
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| 64 | for (Count = 0, Size = 0; !IsDevicePathEnd (DevicePath); DevicePath = NextDevicePathNode (DevicePath)) {
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| 65 | NodeLength = DevicePathNodeLength (DevicePath);
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| 66 | if (NodeLength < sizeof (EFI_DEVICE_PATH_PROTOCOL)) {
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| 67 | return FALSE;
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| 68 | }
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| 69 |
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| 70 | if (MaxSize > 0) {
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| 71 | Size += NodeLength;
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| 72 | if (Size + END_DEVICE_PATH_LENGTH > MaxSize) {
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| 73 | return FALSE;
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| 74 | }
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| 75 | }
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| 76 |
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| 77 | if (PcdGet32 (PcdMaximumDevicePathNodeCount) > 0) {
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| 78 | Count++;
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| 79 | if (Count >= PcdGet32 (PcdMaximumDevicePathNodeCount)) {
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| 80 | return FALSE;
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| 81 | }
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| 82 | }
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| 83 | }
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| 84 |
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| 85 | //
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| 86 | // Only return TRUE when the End Device Path node is valid.
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| 87 | //
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| 88 | return (BOOLEAN) (DevicePathNodeLength (DevicePath) == END_DEVICE_PATH_LENGTH);
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| 89 | }
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| 90 |
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| 91 | /**
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| 92 | Returns the Type field of a device path node.
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| 93 |
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| 94 | Returns the Type field of the device path node specified by Node.
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| 95 |
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| 96 | If Node is NULL, then ASSERT().
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| 97 |
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| 98 | @param Node A pointer to a device path node data structure.
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| 99 |
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| 100 | @return The Type field of the device path node specified by Node.
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| 101 |
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| 102 | **/
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| 103 | UINT8
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| 104 | EFIAPI
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| 105 | DevicePathType (
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| 106 | IN CONST VOID *Node
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| 107 | )
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| 108 | {
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| 109 | ASSERT (Node != NULL);
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| 110 | return ((EFI_DEVICE_PATH_PROTOCOL *)(Node))->Type;
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| 111 | }
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| 112 |
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| 113 | /**
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| 114 | Returns the SubType field of a device path node.
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| 115 |
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| 116 | Returns the SubType field of the device path node specified by Node.
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| 117 |
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| 118 | If Node is NULL, then ASSERT().
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| 119 |
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| 120 | @param Node A pointer to a device path node data structure.
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| 121 |
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| 122 | @return The SubType field of the device path node specified by Node.
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| 123 |
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| 124 | **/
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| 125 | UINT8
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| 126 | EFIAPI
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| 127 | DevicePathSubType (
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| 128 | IN CONST VOID *Node
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| 129 | )
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| 130 | {
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| 131 | ASSERT (Node != NULL);
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| 132 | return ((EFI_DEVICE_PATH_PROTOCOL *)(Node))->SubType;
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| 133 | }
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| 134 |
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| 135 | /**
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| 136 | Returns the 16-bit Length field of a device path node.
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| 137 |
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| 138 | Returns the 16-bit Length field of the device path node specified by Node.
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| 139 | Node is not required to be aligned on a 16-bit boundary, so it is recommended
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| 140 | that a function such as ReadUnaligned16() be used to extract the contents of
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| 141 | the Length field.
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| 142 |
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| 143 | If Node is NULL, then ASSERT().
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| 144 |
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| 145 | @param Node A pointer to a device path node data structure.
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| 146 |
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| 147 | @return The 16-bit Length field of the device path node specified by Node.
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| 148 |
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| 149 | **/
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| 150 | UINTN
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| 151 | EFIAPI
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| 152 | DevicePathNodeLength (
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| 153 | IN CONST VOID *Node
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| 154 | )
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| 155 | {
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| 156 | ASSERT (Node != NULL);
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| 157 | return ReadUnaligned16 ((UINT16 *)&((EFI_DEVICE_PATH_PROTOCOL *)(Node))->Length[0]);
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| 158 | }
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| 159 |
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| 160 | /**
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| 161 | Returns a pointer to the next node in a device path.
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| 162 |
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| 163 | Returns a pointer to the device path node that follows the device path node
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| 164 | specified by Node.
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| 165 |
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| 166 | If Node is NULL, then ASSERT().
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| 167 |
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| 168 | @param Node A pointer to a device path node data structure.
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| 169 |
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| 170 | @return a pointer to the device path node that follows the device path node
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| 171 | specified by Node.
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| 172 |
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| 173 | **/
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| 174 | EFI_DEVICE_PATH_PROTOCOL *
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| 175 | EFIAPI
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| 176 | NextDevicePathNode (
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| 177 | IN CONST VOID *Node
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| 178 | )
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| 179 | {
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| 180 | ASSERT (Node != NULL);
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| 181 | return (EFI_DEVICE_PATH_PROTOCOL *)((UINT8 *)(Node) + DevicePathNodeLength(Node));
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| 182 | }
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| 183 |
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| 184 | /**
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| 185 | Determines if a device path node is an end node of a device path.
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| 186 | This includes nodes that are the end of a device path instance and nodes that
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| 187 | are the end of an entire device path.
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| 188 |
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| 189 | Determines if the device path node specified by Node is an end node of a device path.
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| 190 | This includes nodes that are the end of a device path instance and nodes that are the
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| 191 | end of an entire device path. If Node represents an end node of a device path,
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| 192 | then TRUE is returned. Otherwise, FALSE is returned.
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| 193 |
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| 194 | If Node is NULL, then ASSERT().
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| 195 |
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| 196 | @param Node A pointer to a device path node data structure.
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| 197 |
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| 198 | @retval TRUE The device path node specified by Node is an end node of a
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| 199 | device path.
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| 200 | @retval FALSE The device path node specified by Node is not an end node of
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| 201 | a device path.
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| 202 |
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| 203 | **/
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| 204 | BOOLEAN
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| 205 | EFIAPI
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| 206 | IsDevicePathEndType (
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| 207 | IN CONST VOID *Node
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| 208 | )
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| 209 | {
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| 210 | ASSERT (Node != NULL);
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| 211 | return (BOOLEAN) (DevicePathType (Node) == END_DEVICE_PATH_TYPE);
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| 212 | }
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| 213 |
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| 214 | /**
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| 215 | Determines if a device path node is an end node of an entire device path.
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| 216 |
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| 217 | Determines if a device path node specified by Node is an end node of an entire
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| 218 | device path. If Node represents the end of an entire device path, then TRUE is
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| 219 | returned. Otherwise, FALSE is returned.
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| 220 |
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| 221 | If Node is NULL, then ASSERT().
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| 222 |
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| 223 | @param Node A pointer to a device path node data structure.
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| 224 |
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| 225 | @retval TRUE The device path node specified by Node is the end of an entire
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| 226 | device path.
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| 227 | @retval FALSE The device path node specified by Node is not the end of an
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| 228 | entire device path.
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| 229 |
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| 230 | **/
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| 231 | BOOLEAN
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| 232 | EFIAPI
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| 233 | IsDevicePathEnd (
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| 234 | IN CONST VOID *Node
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| 235 | )
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| 236 | {
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| 237 | ASSERT (Node != NULL);
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| 238 | return (BOOLEAN) (IsDevicePathEndType (Node) && DevicePathSubType(Node) == END_ENTIRE_DEVICE_PATH_SUBTYPE);
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| 239 | }
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| 240 |
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| 241 | /**
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| 242 | Determines if a device path node is an end node of a device path instance.
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| 243 |
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| 244 | Determines if a device path node specified by Node is an end node of a device
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| 245 | path instance. If Node represents the end of a device path instance, then TRUE
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| 246 | is returned. Otherwise, FALSE is returned.
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| 247 |
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| 248 | If Node is NULL, then ASSERT().
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| 249 |
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| 250 | @param Node A pointer to a device path node data structure.
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| 251 |
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| 252 | @retval TRUE The device path node specified by Node is the end of a device
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| 253 | path instance.
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| 254 | @retval FALSE The device path node specified by Node is not the end of a
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| 255 | device path instance.
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| 256 |
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| 257 | **/
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| 258 | BOOLEAN
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| 259 | EFIAPI
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| 260 | IsDevicePathEndInstance (
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| 261 | IN CONST VOID *Node
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| 262 | )
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| 263 | {
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| 264 | ASSERT (Node != NULL);
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| 265 | return (BOOLEAN) (IsDevicePathEndType (Node) && DevicePathSubType(Node) == END_INSTANCE_DEVICE_PATH_SUBTYPE);
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| 266 | }
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| 267 |
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| 268 | /**
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| 269 | Sets the length, in bytes, of a device path node.
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| 270 |
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| 271 | Sets the length of the device path node specified by Node to the value specified
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| 272 | by NodeLength. NodeLength is returned. Node is not required to be aligned on
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| 273 | a 16-bit boundary, so it is recommended that a function such as WriteUnaligned16()
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| 274 | be used to set the contents of the Length field.
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| 275 |
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| 276 | If Node is NULL, then ASSERT().
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| 277 | If NodeLength >= SIZE_64KB, then ASSERT().
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| 278 | If NodeLength < sizeof (EFI_DEVICE_PATH_PROTOCOL), then ASSERT().
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| 279 |
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| 280 | @param Node A pointer to a device path node data structure.
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| 281 | @param Length The length, in bytes, of the device path node.
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| 282 |
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| 283 | @return Length
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| 284 |
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| 285 | **/
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| 286 | UINT16
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| 287 | EFIAPI
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| 288 | SetDevicePathNodeLength (
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| 289 | IN OUT VOID *Node,
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| 290 | IN UINTN Length
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| 291 | )
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| 292 | {
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| 293 | ASSERT (Node != NULL);
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| 294 | ASSERT ((Length >= sizeof (EFI_DEVICE_PATH_PROTOCOL)) && (Length < SIZE_64KB));
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| 295 | return WriteUnaligned16 ((UINT16 *)&((EFI_DEVICE_PATH_PROTOCOL *)(Node))->Length[0], (UINT16)(Length));
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| 296 | }
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| 297 |
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| 298 | /**
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| 299 | Fills in all the fields of a device path node that is the end of an entire device path.
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| 300 |
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| 301 | Fills in all the fields of a device path node specified by Node so Node represents
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| 302 | the end of an entire device path. The Type field of Node is set to
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| 303 | END_DEVICE_PATH_TYPE, the SubType field of Node is set to
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| 304 | END_ENTIRE_DEVICE_PATH_SUBTYPE, and the Length field of Node is set to
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| 305 | END_DEVICE_PATH_LENGTH. Node is not required to be aligned on a 16-bit boundary,
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| 306 | so it is recommended that a function such as WriteUnaligned16() be used to set
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| 307 | the contents of the Length field.
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| 308 |
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| 309 | If Node is NULL, then ASSERT().
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| 310 |
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| 311 | @param Node A pointer to a device path node data structure.
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| 312 |
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| 313 | **/
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| 314 | VOID
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| 315 | EFIAPI
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| 316 | SetDevicePathEndNode (
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| 317 | OUT VOID *Node
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| 318 | )
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| 319 | {
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| 320 | ASSERT (Node != NULL);
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| 321 | CopyMem (Node, &mUefiDevicePathLibEndDevicePath, sizeof (mUefiDevicePathLibEndDevicePath));
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| 322 | }
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| 323 |
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| 324 | /**
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| 325 | Returns the size of a device path in bytes.
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| 326 |
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| 327 | This function returns the size, in bytes, of the device path data structure
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| 328 | specified by DevicePath including the end of device path node.
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| 329 | If DevicePath is NULL or invalid, then 0 is returned.
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| 330 |
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| 331 | @param DevicePath A pointer to a device path data structure.
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| 332 |
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| 333 | @retval 0 If DevicePath is NULL or invalid.
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| 334 | @retval Others The size of a device path in bytes.
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| 335 |
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| 336 | **/
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| 337 | UINTN
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| 338 | EFIAPI
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| 339 | UefiDevicePathLibGetDevicePathSize (
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| 340 | IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath
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| 341 | )
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| 342 | {
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| 343 | CONST EFI_DEVICE_PATH_PROTOCOL *Start;
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| 344 |
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| 345 | if (DevicePath == NULL) {
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| 346 | return 0;
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| 347 | }
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| 348 |
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| 349 | if (!IsDevicePathValid (DevicePath, 0)) {
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| 350 | return 0;
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| 351 | }
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| 352 |
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| 353 | //
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| 354 | // Search for the end of the device path structure
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| 355 | //
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| 356 | Start = DevicePath;
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| 357 | while (!IsDevicePathEnd (DevicePath)) {
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| 358 | DevicePath = NextDevicePathNode (DevicePath);
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| 359 | }
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| 360 |
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| 361 | //
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| 362 | // Compute the size and add back in the size of the end device path structure
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| 363 | //
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| 364 | return ((UINTN) DevicePath - (UINTN) Start) + DevicePathNodeLength (DevicePath);
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| 365 | }
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| 366 |
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| 367 | /**
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| 368 | Creates a new copy of an existing device path.
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| 369 |
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| 370 | This function allocates space for a new copy of the device path specified by DevicePath.
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| 371 | If DevicePath is NULL, then NULL is returned. If the memory is successfully
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| 372 | allocated, then the contents of DevicePath are copied to the newly allocated
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| 373 | buffer, and a pointer to that buffer is returned. Otherwise, NULL is returned.
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| 374 | The memory for the new device path is allocated from EFI boot services memory.
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| 375 | It is the responsibility of the caller to free the memory allocated.
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| 376 |
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| 377 | @param DevicePath A pointer to a device path data structure.
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| 378 |
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| 379 | @retval NULL DevicePath is NULL or invalid.
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| 380 | @retval Others A pointer to the duplicated device path.
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| 381 |
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| 382 | **/
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| 383 | EFI_DEVICE_PATH_PROTOCOL *
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| 384 | EFIAPI
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| 385 | UefiDevicePathLibDuplicateDevicePath (
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| 386 | IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath
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| 387 | )
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| 388 | {
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| 389 | UINTN Size;
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| 390 |
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| 391 | //
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| 392 | // Compute the size
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| 393 | //
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| 394 | Size = GetDevicePathSize (DevicePath);
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| 395 | if (Size == 0) {
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| 396 | return NULL;
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| 397 | }
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| 398 |
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| 399 | //
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| 400 | // Allocate space for duplicate device path
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| 401 | //
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| 402 |
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| 403 | return AllocateCopyPool (Size, DevicePath);
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| 404 | }
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| 405 |
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| 406 | /**
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| 407 | Creates a new device path by appending a second device path to a first device path.
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| 408 |
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| 409 | This function creates a new device path by appending a copy of SecondDevicePath
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| 410 | to a copy of FirstDevicePath in a newly allocated buffer. Only the end-of-device-path
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| 411 | device node from SecondDevicePath is retained. The newly created device path is
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| 412 | returned. If FirstDevicePath is NULL, then it is ignored, and a duplicate of
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| 413 | SecondDevicePath is returned. If SecondDevicePath is NULL, then it is ignored,
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| 414 | and a duplicate of FirstDevicePath is returned. If both FirstDevicePath and
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| 415 | SecondDevicePath are NULL, then a copy of an end-of-device-path is returned.
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| 416 |
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| 417 | If there is not enough memory for the newly allocated buffer, then NULL is returned.
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| 418 | The memory for the new device path is allocated from EFI boot services memory.
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| 419 | It is the responsibility of the caller to free the memory allocated.
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| 420 |
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| 421 | @param FirstDevicePath A pointer to a device path data structure.
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| 422 | @param SecondDevicePath A pointer to a device path data structure.
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| 423 |
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| 424 | @retval NULL If there is not enough memory for the newly allocated buffer.
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| 425 | @retval NULL If FirstDevicePath or SecondDevicePath is invalid.
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| 426 | @retval Others A pointer to the new device path if success.
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| 427 | Or a copy an end-of-device-path if both FirstDevicePath and SecondDevicePath are NULL.
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| 428 |
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| 429 | **/
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| 430 | EFI_DEVICE_PATH_PROTOCOL *
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| 431 | EFIAPI
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| 432 | UefiDevicePathLibAppendDevicePath (
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| 433 | IN CONST EFI_DEVICE_PATH_PROTOCOL *FirstDevicePath, OPTIONAL
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| 434 | IN CONST EFI_DEVICE_PATH_PROTOCOL *SecondDevicePath OPTIONAL
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| 435 | )
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| 436 | {
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| 437 | UINTN Size;
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| 438 | UINTN Size1;
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| 439 | UINTN Size2;
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| 440 | EFI_DEVICE_PATH_PROTOCOL *NewDevicePath;
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| 441 | EFI_DEVICE_PATH_PROTOCOL *DevicePath2;
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| 442 |
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| 443 | //
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| 444 | // If there's only 1 path, just duplicate it.
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| 445 | //
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| 446 | if (FirstDevicePath == NULL) {
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| 447 | return DuplicateDevicePath ((SecondDevicePath != NULL) ? SecondDevicePath : &mUefiDevicePathLibEndDevicePath);
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| 448 | }
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| 449 |
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| 450 | if (SecondDevicePath == NULL) {
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| 451 | return DuplicateDevicePath (FirstDevicePath);
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| 452 | }
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| 453 |
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| 454 | if (!IsDevicePathValid (FirstDevicePath, 0) || !IsDevicePathValid (SecondDevicePath, 0)) {
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| 455 | return NULL;
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| 456 | }
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| 457 |
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| 458 | //
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| 459 | // Allocate space for the combined device path. It only has one end node of
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| 460 | // length EFI_DEVICE_PATH_PROTOCOL.
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| 461 | //
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| 462 | Size1 = GetDevicePathSize (FirstDevicePath);
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| 463 | Size2 = GetDevicePathSize (SecondDevicePath);
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| 464 | Size = Size1 + Size2 - END_DEVICE_PATH_LENGTH;
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| 465 |
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| 466 | NewDevicePath = AllocatePool (Size);
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| 467 |
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| 468 | if (NewDevicePath != NULL) {
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| 469 | NewDevicePath = CopyMem (NewDevicePath, FirstDevicePath, Size1);
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| 470 | //
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| 471 | // Over write FirstDevicePath EndNode and do the copy
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| 472 | //
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| 473 | DevicePath2 = (EFI_DEVICE_PATH_PROTOCOL *) ((CHAR8 *) NewDevicePath +
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| 474 | (Size1 - END_DEVICE_PATH_LENGTH));
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| 475 | CopyMem (DevicePath2, SecondDevicePath, Size2);
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| 476 | }
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| 477 |
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| 478 | return NewDevicePath;
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| 479 | }
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| 480 |
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| 481 | /**
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| 482 | Creates a new path by appending the device node to the device path.
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| 483 |
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| 484 | This function creates a new device path by appending a copy of the device node
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| 485 | specified by DevicePathNode to a copy of the device path specified by DevicePath
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| 486 | in an allocated buffer. The end-of-device-path device node is moved after the
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| 487 | end of the appended device node.
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| 488 | If DevicePathNode is NULL then a copy of DevicePath is returned.
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| 489 | If DevicePath is NULL then a copy of DevicePathNode, followed by an end-of-device
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| 490 | path device node is returned.
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| 491 | If both DevicePathNode and DevicePath are NULL then a copy of an end-of-device-path
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| 492 | device node is returned.
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| 493 | If there is not enough memory to allocate space for the new device path, then
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| 494 | NULL is returned.
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| 495 | The memory is allocated from EFI boot services memory. It is the responsibility
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| 496 | of the caller to free the memory allocated.
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| 497 |
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| 498 | @param DevicePath A pointer to a device path data structure.
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| 499 | @param DevicePathNode A pointer to a single device path node.
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| 500 |
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| 501 | @retval NULL If there is not enough memory for the new device path.
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| 502 | @retval Others A pointer to the new device path if success.
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| 503 | A copy of DevicePathNode followed by an end-of-device-path node
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| 504 | if both FirstDevicePath and SecondDevicePath are NULL.
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| 505 | A copy of an end-of-device-path node if both FirstDevicePath
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| 506 | and SecondDevicePath are NULL.
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| 507 |
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| 508 | **/
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| 509 | EFI_DEVICE_PATH_PROTOCOL *
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| 510 | EFIAPI
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| 511 | UefiDevicePathLibAppendDevicePathNode (
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| 512 | IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath, OPTIONAL
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| 513 | IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePathNode OPTIONAL
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| 514 | )
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| 515 | {
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| 516 | EFI_DEVICE_PATH_PROTOCOL *TempDevicePath;
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| 517 | EFI_DEVICE_PATH_PROTOCOL *NextNode;
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| 518 | EFI_DEVICE_PATH_PROTOCOL *NewDevicePath;
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| 519 | UINTN NodeLength;
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| 520 |
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| 521 | if (DevicePathNode == NULL) {
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| 522 | return DuplicateDevicePath ((DevicePath != NULL) ? DevicePath : &mUefiDevicePathLibEndDevicePath);
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| 523 | }
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| 524 | //
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| 525 | // Build a Node that has a terminator on it
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| 526 | //
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| 527 | NodeLength = DevicePathNodeLength (DevicePathNode);
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| 528 |
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| 529 | TempDevicePath = AllocatePool (NodeLength + END_DEVICE_PATH_LENGTH);
|
| 530 | if (TempDevicePath == NULL) {
|
| 531 | return NULL;
|
| 532 | }
|
| 533 | TempDevicePath = CopyMem (TempDevicePath, DevicePathNode, NodeLength);
|
| 534 | //
|
| 535 | // Add and end device path node to convert Node to device path
|
| 536 | //
|
| 537 | NextNode = NextDevicePathNode (TempDevicePath);
|
| 538 | SetDevicePathEndNode (NextNode);
|
| 539 | //
|
| 540 | // Append device paths
|
| 541 | //
|
| 542 | NewDevicePath = AppendDevicePath (DevicePath, TempDevicePath);
|
| 543 |
|
| 544 | FreePool (TempDevicePath);
|
| 545 |
|
| 546 | return NewDevicePath;
|
| 547 | }
|
| 548 |
|
| 549 | /**
|
| 550 | Creates a new device path by appending the specified device path instance to the specified device
|
| 551 | path.
|
| 552 |
|
| 553 | This function creates a new device path by appending a copy of the device path
|
| 554 | instance specified by DevicePathInstance to a copy of the device path specified
|
| 555 | by DevicePath in a allocated buffer.
|
| 556 | The end-of-device-path device node is moved after the end of the appended device
|
| 557 | path instance and a new end-of-device-path-instance node is inserted between.
|
| 558 | If DevicePath is NULL, then a copy if DevicePathInstance is returned.
|
| 559 | If DevicePathInstance is NULL, then NULL is returned.
|
| 560 | If DevicePath or DevicePathInstance is invalid, then NULL is returned.
|
| 561 | If there is not enough memory to allocate space for the new device path, then
|
| 562 | NULL is returned.
|
| 563 | The memory is allocated from EFI boot services memory. It is the responsibility
|
| 564 | of the caller to free the memory allocated.
|
| 565 |
|
| 566 | @param DevicePath A pointer to a device path data structure.
|
| 567 | @param DevicePathInstance A pointer to a device path instance.
|
| 568 |
|
| 569 | @return A pointer to the new device path.
|
| 570 |
|
| 571 | **/
|
| 572 | EFI_DEVICE_PATH_PROTOCOL *
|
| 573 | EFIAPI
|
| 574 | UefiDevicePathLibAppendDevicePathInstance (
|
| 575 | IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath, OPTIONAL
|
| 576 | IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePathInstance OPTIONAL
|
| 577 | )
|
| 578 | {
|
| 579 | EFI_DEVICE_PATH_PROTOCOL *NewDevicePath;
|
| 580 | EFI_DEVICE_PATH_PROTOCOL *TempDevicePath;
|
| 581 | UINTN SrcSize;
|
| 582 | UINTN InstanceSize;
|
| 583 |
|
| 584 | if (DevicePath == NULL) {
|
| 585 | return DuplicateDevicePath (DevicePathInstance);
|
| 586 | }
|
| 587 |
|
| 588 | if (DevicePathInstance == NULL) {
|
| 589 | return NULL;
|
| 590 | }
|
| 591 |
|
| 592 | if (!IsDevicePathValid (DevicePath, 0) || !IsDevicePathValid (DevicePathInstance, 0)) {
|
| 593 | return NULL;
|
| 594 | }
|
| 595 |
|
| 596 | SrcSize = GetDevicePathSize (DevicePath);
|
| 597 | InstanceSize = GetDevicePathSize (DevicePathInstance);
|
| 598 |
|
| 599 | NewDevicePath = AllocatePool (SrcSize + InstanceSize);
|
| 600 | if (NewDevicePath != NULL) {
|
| 601 |
|
| 602 | TempDevicePath = CopyMem (NewDevicePath, DevicePath, SrcSize);;
|
| 603 |
|
| 604 | while (!IsDevicePathEnd (TempDevicePath)) {
|
| 605 | TempDevicePath = NextDevicePathNode (TempDevicePath);
|
| 606 | }
|
| 607 |
|
| 608 | TempDevicePath->SubType = END_INSTANCE_DEVICE_PATH_SUBTYPE;
|
| 609 | TempDevicePath = NextDevicePathNode (TempDevicePath);
|
| 610 | CopyMem (TempDevicePath, DevicePathInstance, InstanceSize);
|
| 611 | }
|
| 612 |
|
| 613 | return NewDevicePath;
|
| 614 | }
|
| 615 |
|
| 616 | /**
|
| 617 | Creates a copy of the current device path instance and returns a pointer to the next device path
|
| 618 | instance.
|
| 619 |
|
| 620 | This function creates a copy of the current device path instance. It also updates
|
| 621 | DevicePath to point to the next device path instance in the device path (or NULL
|
| 622 | if no more) and updates Size to hold the size of the device path instance copy.
|
| 623 | If DevicePath is NULL, then NULL is returned.
|
| 624 | If DevicePath points to a invalid device path, then NULL is returned.
|
| 625 | If there is not enough memory to allocate space for the new device path, then
|
| 626 | NULL is returned.
|
| 627 | The memory is allocated from EFI boot services memory. It is the responsibility
|
| 628 | of the caller to free the memory allocated.
|
| 629 | If Size is NULL, then ASSERT().
|
| 630 |
|
| 631 | @param DevicePath On input, this holds the pointer to the current
|
| 632 | device path instance. On output, this holds
|
| 633 | the pointer to the next device path instance
|
| 634 | or NULL if there are no more device path
|
| 635 | instances in the device path pointer to a
|
| 636 | device path data structure.
|
| 637 | @param Size On output, this holds the size of the device
|
| 638 | path instance, in bytes or zero, if DevicePath
|
| 639 | is NULL.
|
| 640 |
|
| 641 | @return A pointer to the current device path instance.
|
| 642 |
|
| 643 | **/
|
| 644 | EFI_DEVICE_PATH_PROTOCOL *
|
| 645 | EFIAPI
|
| 646 | UefiDevicePathLibGetNextDevicePathInstance (
|
| 647 | IN OUT EFI_DEVICE_PATH_PROTOCOL **DevicePath,
|
| 648 | OUT UINTN *Size
|
| 649 | )
|
| 650 | {
|
| 651 | EFI_DEVICE_PATH_PROTOCOL *DevPath;
|
| 652 | EFI_DEVICE_PATH_PROTOCOL *ReturnValue;
|
| 653 | UINT8 Temp;
|
| 654 |
|
| 655 | ASSERT (Size != NULL);
|
| 656 |
|
| 657 | if (DevicePath == NULL || *DevicePath == NULL) {
|
| 658 | *Size = 0;
|
| 659 | return NULL;
|
| 660 | }
|
| 661 |
|
| 662 | if (!IsDevicePathValid (*DevicePath, 0)) {
|
| 663 | return NULL;
|
| 664 | }
|
| 665 |
|
| 666 | //
|
| 667 | // Find the end of the device path instance
|
| 668 | //
|
| 669 | DevPath = *DevicePath;
|
| 670 | while (!IsDevicePathEndType (DevPath)) {
|
| 671 | DevPath = NextDevicePathNode (DevPath);
|
| 672 | }
|
| 673 |
|
| 674 | //
|
| 675 | // Compute the size of the device path instance
|
| 676 | //
|
| 677 | *Size = ((UINTN) DevPath - (UINTN) (*DevicePath)) + sizeof (EFI_DEVICE_PATH_PROTOCOL);
|
| 678 |
|
| 679 | //
|
| 680 | // Make a copy and return the device path instance
|
| 681 | //
|
| 682 | Temp = DevPath->SubType;
|
| 683 | DevPath->SubType = END_ENTIRE_DEVICE_PATH_SUBTYPE;
|
| 684 | ReturnValue = DuplicateDevicePath (*DevicePath);
|
| 685 | DevPath->SubType = Temp;
|
| 686 |
|
| 687 | //
|
| 688 | // If DevPath is the end of an entire device path, then another instance
|
| 689 | // does not follow, so *DevicePath is set to NULL.
|
| 690 | //
|
| 691 | if (DevicePathSubType (DevPath) == END_ENTIRE_DEVICE_PATH_SUBTYPE) {
|
| 692 | *DevicePath = NULL;
|
| 693 | } else {
|
| 694 | *DevicePath = NextDevicePathNode (DevPath);
|
| 695 | }
|
| 696 |
|
| 697 | return ReturnValue;
|
| 698 | }
|
| 699 |
|
| 700 | /**
|
| 701 | Creates a device node.
|
| 702 |
|
| 703 | This function creates a new device node in a newly allocated buffer of size
|
| 704 | NodeLength and initializes the device path node header with NodeType and NodeSubType.
|
| 705 | The new device path node is returned.
|
| 706 | If NodeLength is smaller than a device path header, then NULL is returned.
|
| 707 | If there is not enough memory to allocate space for the new device path, then
|
| 708 | NULL is returned.
|
| 709 | The memory is allocated from EFI boot services memory. It is the responsibility
|
| 710 | of the caller to free the memory allocated.
|
| 711 |
|
| 712 | @param NodeType The device node type for the new device node.
|
| 713 | @param NodeSubType The device node sub-type for the new device node.
|
| 714 | @param NodeLength The length of the new device node.
|
| 715 |
|
| 716 | @return The new device path.
|
| 717 |
|
| 718 | **/
|
| 719 | EFI_DEVICE_PATH_PROTOCOL *
|
| 720 | EFIAPI
|
| 721 | UefiDevicePathLibCreateDeviceNode (
|
| 722 | IN UINT8 NodeType,
|
| 723 | IN UINT8 NodeSubType,
|
| 724 | IN UINT16 NodeLength
|
| 725 | )
|
| 726 | {
|
| 727 | EFI_DEVICE_PATH_PROTOCOL *DevicePath;
|
| 728 |
|
| 729 | if (NodeLength < sizeof (EFI_DEVICE_PATH_PROTOCOL)) {
|
| 730 | //
|
| 731 | // NodeLength is less than the size of the header.
|
| 732 | //
|
| 733 | return NULL;
|
| 734 | }
|
| 735 |
|
| 736 | DevicePath = AllocateZeroPool (NodeLength);
|
| 737 | if (DevicePath != NULL) {
|
| 738 | DevicePath->Type = NodeType;
|
| 739 | DevicePath->SubType = NodeSubType;
|
| 740 | SetDevicePathNodeLength (DevicePath, NodeLength);
|
| 741 | }
|
| 742 |
|
| 743 | return DevicePath;
|
| 744 | }
|
| 745 |
|
| 746 | /**
|
| 747 | Determines if a device path is single or multi-instance.
|
| 748 |
|
| 749 | This function returns TRUE if the device path specified by DevicePath is
|
| 750 | multi-instance.
|
| 751 | Otherwise, FALSE is returned.
|
| 752 | If DevicePath is NULL or invalid, then FALSE is returned.
|
| 753 |
|
| 754 | @param DevicePath A pointer to a device path data structure.
|
| 755 |
|
| 756 | @retval TRUE DevicePath is multi-instance.
|
| 757 | @retval FALSE DevicePath is not multi-instance, or DevicePath
|
| 758 | is NULL or invalid.
|
| 759 |
|
| 760 | **/
|
| 761 | BOOLEAN
|
| 762 | EFIAPI
|
| 763 | UefiDevicePathLibIsDevicePathMultiInstance (
|
| 764 | IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath
|
| 765 | )
|
| 766 | {
|
| 767 | CONST EFI_DEVICE_PATH_PROTOCOL *Node;
|
| 768 |
|
| 769 | if (DevicePath == NULL) {
|
| 770 | return FALSE;
|
| 771 | }
|
| 772 |
|
| 773 | if (!IsDevicePathValid (DevicePath, 0)) {
|
| 774 | return FALSE;
|
| 775 | }
|
| 776 |
|
| 777 | Node = DevicePath;
|
| 778 | while (!IsDevicePathEnd (Node)) {
|
| 779 | if (IsDevicePathEndInstance (Node)) {
|
| 780 | return TRUE;
|
| 781 | }
|
| 782 |
|
| 783 | Node = NextDevicePathNode (Node);
|
| 784 | }
|
| 785 |
|
| 786 | return FALSE;
|
| 787 | }
|
| 788 |
|
| 789 |
|
| 790 | /**
|
| 791 | Retrieves the device path protocol from a handle.
|
| 792 |
|
| 793 | This function returns the device path protocol from the handle specified by Handle.
|
| 794 | If Handle is NULL or Handle does not contain a device path protocol, then NULL
|
| 795 | is returned.
|
| 796 |
|
| 797 | @param Handle The handle from which to retrieve the device
|
| 798 | path protocol.
|
| 799 |
|
| 800 | @return The device path protocol from the handle specified by Handle.
|
| 801 |
|
| 802 | **/
|
| 803 | EFI_DEVICE_PATH_PROTOCOL *
|
| 804 | EFIAPI
|
| 805 | DevicePathFromHandle (
|
| 806 | IN EFI_HANDLE Handle
|
| 807 | )
|
| 808 | {
|
| 809 | EFI_DEVICE_PATH_PROTOCOL *DevicePath;
|
| 810 | EFI_STATUS Status;
|
| 811 |
|
| 812 | Status = gBS->HandleProtocol (
|
| 813 | Handle,
|
| 814 | &gEfiDevicePathProtocolGuid,
|
| 815 | (VOID *) &DevicePath
|
| 816 | );
|
| 817 | if (EFI_ERROR (Status)) {
|
| 818 | DevicePath = NULL;
|
| 819 | }
|
| 820 | return DevicePath;
|
| 821 | }
|
| 822 |
|
| 823 | /**
|
| 824 | Allocates a device path for a file and appends it to an existing device path.
|
| 825 |
|
| 826 | If Device is a valid device handle that contains a device path protocol, then a device path for
|
| 827 | the file specified by FileName is allocated and appended to the device path associated with the
|
| 828 | handle Device. The allocated device path is returned. If Device is NULL or Device is a handle
|
| 829 | that does not support the device path protocol, then a device path containing a single device
|
| 830 | path node for the file specified by FileName is allocated and returned.
|
| 831 | The memory for the new device path is allocated from EFI boot services memory. It is the responsibility
|
| 832 | of the caller to free the memory allocated.
|
| 833 |
|
| 834 | If FileName is NULL, then ASSERT().
|
| 835 | If FileName is not aligned on a 16-bit boundary, then ASSERT().
|
| 836 |
|
| 837 | @param Device A pointer to a device handle. This parameter
|
| 838 | is optional and may be NULL.
|
| 839 | @param FileName A pointer to a Null-terminated Unicode string.
|
| 840 |
|
| 841 | @return The allocated device path.
|
| 842 |
|
| 843 | **/
|
| 844 | EFI_DEVICE_PATH_PROTOCOL *
|
| 845 | EFIAPI
|
| 846 | FileDevicePath (
|
| 847 | IN EFI_HANDLE Device, OPTIONAL
|
| 848 | IN CONST CHAR16 *FileName
|
| 849 | )
|
| 850 | {
|
| 851 | UINTN Size;
|
| 852 | FILEPATH_DEVICE_PATH *FilePath;
|
| 853 | EFI_DEVICE_PATH_PROTOCOL *DevicePath;
|
| 854 | EFI_DEVICE_PATH_PROTOCOL *FileDevicePath;
|
| 855 |
|
| 856 | DevicePath = NULL;
|
| 857 |
|
| 858 | Size = StrSize (FileName);
|
| 859 | FileDevicePath = AllocatePool (Size + SIZE_OF_FILEPATH_DEVICE_PATH + END_DEVICE_PATH_LENGTH);
|
| 860 | if (FileDevicePath != NULL) {
|
| 861 | FilePath = (FILEPATH_DEVICE_PATH *) FileDevicePath;
|
| 862 | FilePath->Header.Type = MEDIA_DEVICE_PATH;
|
| 863 | FilePath->Header.SubType = MEDIA_FILEPATH_DP;
|
| 864 | CopyMem (&FilePath->PathName, FileName, Size);
|
| 865 | SetDevicePathNodeLength (&FilePath->Header, Size + SIZE_OF_FILEPATH_DEVICE_PATH);
|
| 866 | SetDevicePathEndNode (NextDevicePathNode (&FilePath->Header));
|
| 867 |
|
| 868 | if (Device != NULL) {
|
| 869 | DevicePath = DevicePathFromHandle (Device);
|
| 870 | }
|
| 871 |
|
| 872 | DevicePath = AppendDevicePath (DevicePath, FileDevicePath);
|
| 873 | FreePool (FileDevicePath);
|
| 874 | }
|
| 875 |
|
| 876 | return DevicePath;
|
| 877 | }
|
| 878 |
|