OldMdePkg/Include/Library/DevicePathLib.h

   1 /** @file
   2   Entry point to a DXE Boot Services Driver
   3
   4   Copyright (c) 2006, Intel Corporation
   5   All rights reserved. This program and the accompanying materials
   6   are licensed and made available under the terms and conditions of the BSD License
   7   which accompanies this distribution.  The full text of the license may be found at
   8   http://opensource.org/licenses/bsd-license.php
   9
  10   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13   Module Name:  DevicePathLib.h
  14
  15 **/
  16
  17 #ifndef __DEVICE_PATH_LIB_H__
  18 #define __DEVICE_PATH_LIB_H__
  19
  20 /**
  21   Returns the size of a device path in bytes.
  22
  23   This function returns the size, in bytes, of the device path data structure specified by
  24   DevicePath including the end of device path node.  If DevicePath is NULL, then 0 is returned.
  25
  26   @param  DevicePath                 A pointer to a device path data structure.
  27
  28   @return The size of a device path in bytes.
  29
  30 **/
  31 UINTN
  32 EFIAPI
  33 GetDevicePathSize (
  34   IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePath
  35   );
  36
  37 /**
  38   Creates a new device path by appending a second device path to a first device path.
  39
  40   This function allocates space for a new copy of the device path specified by DevicePath.  If
  41   DevicePath is NULL, then NULL is returned.  If the memory is successfully allocated, then the
  42   contents of DevicePath are copied to the newly allocated buffer, and a pointer to that buffer
  43   is returned.  Otherwise, NULL is returned.
  44
  45   @param  DevicePath                 A pointer to a device path data structure.
  46
  47   @return A pointer to the duplicated device path.
  48
  49 **/
  50 EFI_DEVICE_PATH_PROTOCOL *
  51 EFIAPI
  52 DuplicateDevicePath (
  53   IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePath
  54   );
  55
  56 /**
  57   Creates a new device path by appending a second device path to a first device path.
  58
  59   This function creates a new device path by appending a copy of SecondDevicePath to a copy of
  60   FirstDevicePath in a newly allocated buffer.  Only the end-of-device-path device node from
  61   SecondDevicePath is retained. The newly created device path is returned.
  62   If FirstDevicePath is NULL, then it is ignored, and a duplicate of SecondDevicePath is returned.
  63   If SecondDevicePath is NULL, then it is ignored, and a duplicate of FirstDevicePath is returned.
  64   If both FirstDevicePath and SecondDevicePath are NULL, then NULL is returned.
  65   If there is not enough memory for the newly allocated buffer, then NULL is returned.
  66   The memory for the new device path is allocated from EFI boot services memory. It is the
  67   responsibility of the caller to free the memory allocated.
  68
  69   @param  FirstDevicePath            A pointer to a device path data structure.
  70   @param  SecondDevicePath           A pointer to a device path data structure.
  71
  72   @return A pointer to the new device path.
  73
  74 **/
  75 EFI_DEVICE_PATH_PROTOCOL *
  76 EFIAPI
  77 AppendDevicePath (
  78   IN CONST EFI_DEVICE_PATH_PROTOCOL  *FirstDevicePath,  OPTIONAL
  79   IN CONST EFI_DEVICE_PATH_PROTOCOL  *SecondDevicePath  OPTIONAL
  80   );
  81
  82 /**
  83   Creates a new path by appending the device node to the device path.
  84
  85   This function creates a new device path by appending a copy of the device node specified by
  86   DevicePathNode to a copy of the device path specified by DevicePath in an allocated buffer.
  87   The end-of-device-path device node is moved after the end of the appended device node.
  88   If DevicePath is NULL, then NULL is returned.
  89   If DevicePathNode is NULL, then NULL is returned.
  90   If there is not enough memory to allocate space for the new device path, then NULL is returned.
  91   The memory is allocated from EFI boot services memory. It is the responsibility of the caller to
  92   free the memory allocated.
  93
  94   @param  DevicePath                 A pointer to a device path data structure.
  95   @param  DevicePathNode             A pointer to a single device path node.
  96
  97   @return A pointer to the new device path.
  98
  99 **/
 100 EFI_DEVICE_PATH_PROTOCOL *
 101 EFIAPI
 102 AppendDevicePathNode (
 103   IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePath,     OPTIONAL
 104   IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePathNode  OPTIONAL
 105   );
 106
 107 /**
 108   Creates a new device path by appending the specified device path instance to the specified device
 109   path.
 110
 111   This function creates a new device path by appending a copy of the device path instance specified
 112   by DevicePathInstance to a copy of the device path secified by DevicePath in a allocated buffer.
 113   The end-of-device-path device node is moved after the end of the appended device path instance
 114   and a new end-of-device-path-instance node is inserted between.
 115   If DevicePath is NULL, then a copy if DevicePathInstance is returned.
 116   If DevicePathInstance is NULL, then NULL is returned.
 117   If there is not enough memory to allocate space for the new device path, then NULL is returned.
 118   The memory is allocated from EFI boot services memory. It is the responsibility of the caller to
 119   free the memory allocated.
 120
 121   @param  DevicePath                 A pointer to a device path data structure.
 122   @param  DevicePathInstance         A pointer to a device path instance.
 123
 124   @return A pointer to the new device path.
 125
 126 **/
 127 EFI_DEVICE_PATH_PROTOCOL *
 128 EFIAPI
 129 AppendDevicePathInstance (
 130   IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePath,        OPTIONAL
 131   IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePathInstance OPTIONAL
 132   );
 133
 134 /**
 135   Creates a copy of the current device path instance and returns a pointer to the next device path
 136   instance.
 137
 138   This function creates a copy of the current device path instance. It also updates DevicePath to
 139   point to the next device path instance in the device path (or NULL if no more) and updates Size
 140   to hold the size of the device path instance copy.
 141   If DevicePath is NULL, then NULL is returned.
 142   If there is not enough memory to allocate space for the new device path, then NULL is returned.
 143   The memory is allocated from EFI boot services memory. It is the responsibility of the caller to
 144   free the memory allocated.
 145   If Size is NULL, then ASSERT().
 146
 147   @param  DevicePath                 On input, this holds the pointer to the current device path
 148                                      instance. On output, this holds the pointer to the next device
 149                                      path instance or NULL if there are no more device path
 150                                      instances in the device path pointer to a device path data
 151                                      structure.
 152   @param  Size                       On output, this holds the size of the device path instance, in
 153                                      bytes or zero, if DevicePath is NULL.
 154
 155   @return A pointer to the current device path instance.
 156
 157 **/
 158 EFI_DEVICE_PATH_PROTOCOL *
 159 EFIAPI
 160 GetNextDevicePathInstance (
 161   IN OUT EFI_DEVICE_PATH_PROTOCOL    **DevicePath,
 162   OUT UINTN                          *Size
 163   );
 164
 165 /**
 166   Creates a copy of the current device path instance and returns a pointer to the next device path
 167   instance.
 168
 169   This function creates a new device node in a newly allocated buffer of size NodeLength and
 170   initializes the device path node header with NodeType and NodeSubType.  The new device path node
 171   is returned.
 172   If NodeLength is smaller than a device path header, then NULL is returned.
 173   If there is not enough memory to allocate space for the new device path, then NULL is returned.
 174   The memory is allocated from EFI boot services memory. It is the responsibility of the caller to
 175   free the memory allocated.
 176
 177   @param  NodeType                   The device node type for the new device node.
 178   @param  NodeSubType                The device node sub-type for the new device node.
 179   @param  NodeLength                 The length of the new device node.
 180
 181   @return The new device path.
 182
 183 **/
 184 EFI_DEVICE_PATH_PROTOCOL *
 185 EFIAPI
 186 CreateDeviceNode (
 187   IN UINT8                           NodeType,
 188   IN UINT8                           NodeSubType,
 189   IN UINT16                          NodeLength
 190   );
 191
 192 /**
 193   Determines if a device path is single or multi-instance.
 194
 195   This function returns TRUE if the device path specified by DevicePath is multi-instance.
 196   Otherwise, FALSE is returned.  If DevicePath is NULL, then FALSE is returned.
 197
 198   @param  DevicePath                 A pointer to a device path data structure.
 199
 200   @retval  TRUE                      DevicePath is multi-instance.
 201   @retval  FALSE                     DevicePath is not multi-instance or DevicePath is NULL.
 202
 203 **/
 204 BOOLEAN
 205 EFIAPI
 206 IsDevicePathMultiInstance (
 207   IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePath
 208   );
 209
 210 /**
 211   Retrieves the device path protocol from a handle.
 212
 213   This function returns the device path protocol from the handle specified by Handle.  If Handle is
 214   NULL or Handle does not contain a device path protocol, then NULL is returned.
 215
 216   @param  Handle                     The handle from which to retrieve the device path protocol.
 217
 218   @return The device path protocol from the handle specified by Handle.
 219
 220 **/
 221 EFI_DEVICE_PATH_PROTOCOL *
 222 EFIAPI
 223 DevicePathFromHandle (
 224   IN EFI_HANDLE                      Handle
 225   );
 226
 227 /**
 228   Allocates a device path for a file and appends it to an existing device path.
 229
 230   If Device is a valid device handle that contains a device path protocol, then a device path for
 231   the file specified by FileName  is allocated and appended to the device path associated with the
 232   handle Device.  The allocated device path is returned.  If Device is NULL or Device is a handle
 233   that does not support the device path protocol, then a device path containing a single device
 234   path node for the file specified by FileName is allocated and returned.
 235   If FileName is NULL, then ASSERT().
 236
 237   @param  Device                     A pointer to a device handle.  This parameter is optional and
 238                                      may be NULL.
 239   @param  FileName                   A pointer to a Null-terminated Unicode string.
 240
 241   @return The allocated device path.
 242
 243 **/
 244 EFI_DEVICE_PATH_PROTOCOL *
 245 EFIAPI
 246 FileDevicePath (
 247   IN EFI_HANDLE                      Device,     OPTIONAL
 248   IN CONST CHAR16                    *FileName
 249   );
 250
 251 #endif