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   SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7   @par Revision Reference:
   8   This Protocol is introduced in UEFI Specification 2.6
   9
  10 **/
  11
  12 #ifndef __RAM_DISK_PROTOCOL_H__
  13 #define __RAM_DISK_PROTOCOL_H__
  14
  15 //
  16 // EFI RAM Disk Protocol GUID value
  17 //
  18 #define EFI_RAM_DISK_PROTOCOL_GUID \
  19   { 0xab38a0df, 0x6873, 0x44a9, { 0x87, 0xe6, 0xd4, 0xeb, 0x56, 0x14, 0x84, 0x49 }};
  20
  21 //
  22 // Forward reference for pure ANSI compatability
  23 //
  24 typedef struct _EFI_RAM_DISK_PROTOCOL  EFI_RAM_DISK_PROTOCOL;
  25
  26 /**
  27   Register a RAM disk with specified address, size and type.
  28
  29   @param[in]  RamDiskBase    The base address of registered RAM disk.
  30   @param[in]  RamDiskSize    The size of registered RAM disk.
  31   @param[in]  RamDiskType    The type of registered RAM disk. The GUID can be
  32                              any of the values defined in section 9.3.6.9, or a
  33                              vendor defined GUID.
  34   @param[in]  ParentDevicePath
  35                              Pointer to the parent device path. If there is no
  36                              parent device path then ParentDevicePath is NULL.
  37   @param[out] DevicePath     On return, points to a pointer to the device path
  38                              of the RAM disk device.
  39                              If ParentDevicePath is not NULL, the returned
  40                              DevicePath is created by appending a RAM disk node
  41                              to the parent device path. If ParentDevicePath is
  42                              NULL, the returned DevicePath is a RAM disk device
  43                              path without appending. This function is
  44                              responsible for allocating the buffer DevicePath
  45                              with the boot service AllocatePool().
  46
  47   @retval EFI_SUCCESS             The RAM disk is registered successfully.
  48   @retval EFI_INVALID_PARAMETER   DevicePath or RamDiskType is NULL.
  49                                   RamDiskSize is 0.
  50   @retval EFI_ALREADY_STARTED     A Device Path Protocol instance to be created
  51                                   is already present in the handle database.
  52   @retval EFI_OUT_OF_RESOURCES    The RAM disk register operation fails due to
  53                                   resource limitation.
  54
  55 **/
  56 typedef
  57 EFI_STATUS
  58 (EFIAPI *EFI_RAM_DISK_REGISTER_RAMDISK) (
  59   IN UINT64                       RamDiskBase,
  60   IN UINT64                       RamDiskSize,
  61   IN EFI_GUID                     *RamDiskType,
  62   IN EFI_DEVICE_PATH              *ParentDevicePath     OPTIONAL,
  63   OUT EFI_DEVICE_PATH_PROTOCOL    **DevicePath
  64   );
  65
  66 /**
  67   Unregister a RAM disk specified by DevicePath.
  68
  69   @param[in] DevicePath      A pointer to the device path that describes a RAM
  70                              Disk device.
  71
  72   @retval EFI_SUCCESS             The RAM disk is unregistered successfully.
  73   @retval EFI_INVALID_PARAMETER   DevicePath is NULL.
  74   @retval EFI_UNSUPPORTED         The device specified by DevicePath is not a
  75                                   valid ramdisk device path and not supported
  76                                   by the driver.
  77   @retval EFI_NOT_FOUND           The RAM disk pointed by DevicePath doesn't
  78                                   exist.
  79
  80 **/
  81 typedef
  82 EFI_STATUS
  83 (EFIAPI *EFI_RAM_DISK_UNREGISTER_RAMDISK) (
  84   IN  EFI_DEVICE_PATH_PROTOCOL    *DevicePath
  85   );
  86
  87 ///
  88 /// RAM Disk Protocol structure.
  89 ///
  90 struct _EFI_RAM_DISK_PROTOCOL {
  91   EFI_RAM_DISK_REGISTER_RAMDISK        Register;
  92   EFI_RAM_DISK_UNREGISTER_RAMDISK      Unregister;
  93 };
  94
  95 ///
  96 /// RAM Disk Protocol GUID variable.
  97 ///
  98 extern EFI_GUID gEfiRamDiskProtocolGuid;
  99
 100 #endif