OvmfPkg/Include/Library/QemuFwCfgLib.h

   1 /** @file
   2   QEMU/KVM Firmware Configuration access
   3
   4   Copyright (c) 2011 - 2013, Intel Corporation. All rights reserved.<BR>
   5   Copyright (C) 2013, Red Hat, Inc.
   6
   7   This program and the accompanying materials
   8   are licensed and made available under the terms and conditions of the BSD License
   9   which accompanies this distribution.  The full text of the license may be found at
  10   http://opensource.org/licenses/bsd-license.php
  11
  12   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  13   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  14
  15 **/
  16
  17 #ifndef __FW_CFG_LIB__
  18 #define __FW_CFG_LIB__
  19
  20 #include <IndustryStandard/QemuFwCfg.h>
  21
  22 /**
  23   Returns a boolean indicating if the firmware configuration interface
  24   is available or not.
  25
  26   This function may change fw_cfg state.
  27
  28   @retval    TRUE   The interface is available
  29   @retval    FALSE  The interface is not available
  30
  31 **/
  32 BOOLEAN
  33 EFIAPI
  34 QemuFwCfgIsAvailable (
  35   VOID
  36   );
  37
  38
  39 /**
  40   Selects a firmware configuration item for reading.
  41
  42   Following this call, any data read from this item will start from
  43   the beginning of the configuration item's data.
  44
  45   @param[in] QemuFwCfgItem - Firmware Configuration item to read
  46
  47 **/
  48 VOID
  49 EFIAPI
  50 QemuFwCfgSelectItem (
  51   IN FIRMWARE_CONFIG_ITEM   QemuFwCfgItem
  52   );
  53
  54
  55 /**
  56   Reads firmware configuration bytes into a buffer
  57
  58   If called multiple times, then the data read will
  59   continue at the offset of the firmware configuration
  60   item where the previous read ended.
  61
  62   @param[in] Size - Size in bytes to read
  63   @param[in] Buffer - Buffer to store data into
  64
  65 **/
  66 VOID
  67 EFIAPI
  68 QemuFwCfgReadBytes (
  69   IN UINTN                  Size,
  70   IN VOID                   *Buffer  OPTIONAL
  71   );
  72
  73
  74 /**
  75   Writes firmware configuration bytes from a buffer
  76
  77   If called multiple times, then the data written will
  78   continue at the offset of the firmware configuration
  79   item where the previous write ended.
  80
  81   @param[in] Size - Size in bytes to write
  82   @param[in] Buffer - Buffer to read data from
  83
  84 **/
  85 VOID
  86 EFIAPI
  87 QemuFwCfgWriteBytes (
  88   IN UINTN                  Size,
  89   IN VOID                   *Buffer
  90   );
  91
  92
  93 /**
  94   Skip bytes in the firmware configuration item.
  95
  96   Increase the offset of the firmware configuration item without transferring
  97   bytes between the item and a caller-provided buffer. Subsequent read, write
  98   or skip operations will commence at the increased offset.
  99
 100   @param[in] Size  Number of bytes to skip.
 101 **/
 102 VOID
 103 EFIAPI
 104 QemuFwCfgSkipBytes (
 105   IN UINTN                  Size
 106   );
 107
 108
 109 /**
 110   Reads a UINT8 firmware configuration value
 111
 112   @return    Value of Firmware Configuration item read
 113
 114 **/
 115 UINT8
 116 EFIAPI
 117 QemuFwCfgRead8 (
 118   VOID
 119   );
 120
 121
 122 /**
 123   Reads a UINT16 firmware configuration value
 124
 125   @return    Value of Firmware Configuration item read
 126
 127 **/
 128 UINT16
 129 EFIAPI
 130 QemuFwCfgRead16 (
 131   VOID
 132   );
 133
 134
 135 /**
 136   Reads a UINT32 firmware configuration value
 137
 138   @return    Value of Firmware Configuration item read
 139
 140 **/
 141 UINT32
 142 EFIAPI
 143 QemuFwCfgRead32 (
 144   VOID
 145   );
 146
 147
 148 /**
 149   Reads a UINT64 firmware configuration value
 150
 151   @return    Value of Firmware Configuration item read
 152
 153 **/
 154 UINT64
 155 EFIAPI
 156 QemuFwCfgRead64 (
 157   VOID
 158   );
 159
 160
 161 /**
 162   Find the configuration item corresponding to the firmware configuration file.
 163
 164   @param[in]  Name - Name of file to look up.
 165   @param[out] Item - Configuration item corresponding to the file, to be passed
 166                      to QemuFwCfgSelectItem ().
 167   @param[out] Size - Number of bytes in the file.
 168
 169   @return    RETURN_SUCCESS       If file is found.
 170              RETURN_NOT_FOUND     If file is not found.
 171              RETURN_UNSUPPORTED   If firmware configuration is unavailable.
 172
 173 **/
 174 RETURN_STATUS
 175 EFIAPI
 176 QemuFwCfgFindFile (
 177   IN   CONST CHAR8           *Name,
 178   OUT  FIRMWARE_CONFIG_ITEM  *Item,
 179   OUT  UINTN                 *Size
 180   );
 181
 182 #endif
 183