MdePkg/Include/Protocol/RamDisk.h

   1 /** @file
   2   This file defines the EFI RAM Disk Protocol.
   3
   4   Copyright (c) 2016, Intel Corporation. All rights reserved.<BR>
   5   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   @par Revision Reference:
  14   This Protocol is introduced in UEFI Specification 2.6
  15
  16 **/
  17
  18 #ifndef __RAM_DISK_PROTOCOL_H__
  19 #define __RAM_DISK_PROTOCOL_H__
  20
  21 //
  22 // EFI RAM Disk Protocol GUID value
  23 //
  24 #define EFI_RAM_DISK_PROTOCOL_GUID \
  25   { 0xab38a0df, 0x6873, 0x44a9, { 0x87, 0xe6, 0xd4, 0xeb, 0x56, 0x14, 0x84, 0x49 }};
  26
  27 //
  28 // Forward reference for pure ANSI compatability
  29 //
  30 typedef struct _EFI_RAM_DISK_PROTOCOL  EFI_RAM_DISK_PROTOCOL;
  31
  32 /**
  33   Register a RAM disk with specified address, size and type.
  34
  35   @param[in]  RamDiskBase    The base address of registered RAM disk.
  36   @param[in]  RamDiskSize    The size of registered RAM disk.
  37   @param[in]  RamDiskType    The type of registered RAM disk. The GUID can be
  38                              any of the values defined in section 9.3.6.9, or a
  39                              vendor defined GUID.
  40   @param[in]  ParentDevicePath
  41                              Pointer to the parent device path. If there is no
  42                              parent device path then ParentDevicePath is NULL.
  43   @param[out] DevicePath     On return, points to a pointer to the device path
  44                              of the RAM disk device.
  45                              If ParentDevicePath is not NULL, the returned
  46                              DevicePath is created by appending a RAM disk node
  47                              to the parent device path. If ParentDevicePath is
  48                              NULL, the returned DevicePath is a RAM disk device
  49                              path without appending. This function is
  50                              responsible for allocating the buffer DevicePath
  51                              with the boot service AllocatePool().
  52
  53   @retval EFI_SUCCESS             The RAM disk is registered successfully.
  54   @retval EFI_INVALID_PARAMETER   DevicePath or RamDiskType is NULL.
  55                                   RamDiskSize is 0.
  56   @retval EFI_ALREADY_STARTED     A Device Path Protocol instance to be created
  57                                   is already present in the handle database.
  58   @retval EFI_OUT_OF_RESOURCES    The RAM disk register operation fails due to
  59                                   resource limitation.
  60
  61 **/
  62 typedef
  63 EFI_STATUS
  64 (EFIAPI *EFI_RAM_DISK_REGISTER_RAMDISK) (
  65   IN UINT64                       RamDiskBase,
  66   IN UINT64                       RamDiskSize,
  67   IN EFI_GUID                     *RamDiskType,
  68   IN EFI_DEVICE_PATH              *ParentDevicePath     OPTIONAL,
  69   OUT EFI_DEVICE_PATH_PROTOCOL    **DevicePath
  70   );
  71
  72 /**
  73   Unregister a RAM disk specified by DevicePath.
  74
  75   @param[in] DevicePath      A pointer to the device path that describes a RAM
  76                              Disk device.
  77
  78   @retval EFI_SUCCESS             The RAM disk is unregistered successfully.
  79   @retval EFI_INVALID_PARAMETER   DevicePath is NULL.
  80   @retval EFI_UNSUPPORTED         The device specified by DevicePath is not a
  81                                   valid ramdisk device path and not supported
  82                                   by the driver.
  83   @retval EFI_NOT_FOUND           The RAM disk pointed by DevicePath doesn't
  84                                   exist.
  85
  86 **/
  87 typedef
  88 EFI_STATUS
  89 (EFIAPI *EFI_RAM_DISK_UNREGISTER_RAMDISK) (
  90   IN  EFI_DEVICE_PATH_PROTOCOL    *DevicePath
  91   );
  92
  93 ///
  94 /// RAM Disk Protocol structure.
  95 ///
  96 struct _EFI_RAM_DISK_PROTOCOL {
  97   EFI_RAM_DISK_REGISTER_RAMDISK        Register;
  98   EFI_RAM_DISK_UNREGISTER_RAMDISK      Unregister;
  99 };
 100
 101 ///
 102 /// RAM Disk Protocol GUID variable.
 103 ///
 104 extern EFI_GUID gEfiRamDiskProtocolGuid;
 105
 106 #endif