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   SPDX-License-Identifier: BSD-2-Clause-Patent
   8
   9 **/
  10
  11 #ifndef __FW_CFG_LIB__
  12 #define __FW_CFG_LIB__
  13
  14 #include <IndustryStandard/QemuFwCfg.h>
  15
  16 /**
  17   Returns a boolean indicating if the firmware configuration interface
  18   is available or not.
  19
  20   This function may change fw_cfg state.
  21
  22   @retval    TRUE   The interface is available
  23   @retval    FALSE  The interface is not available
  24
  25 **/
  26 BOOLEAN
  27 EFIAPI
  28 QemuFwCfgIsAvailable (
  29   VOID
  30   );
  31
  32 /**
  33   Selects a firmware configuration item for reading.
  34
  35   Following this call, any data read from this item will start from
  36   the beginning of the configuration item's data.
  37
  38   @param[in] QemuFwCfgItem - Firmware Configuration item to read
  39
  40 **/
  41 VOID
  42 EFIAPI
  43 QemuFwCfgSelectItem (
  44   IN FIRMWARE_CONFIG_ITEM  QemuFwCfgItem
  45   );
  46
  47 /**
  48   Reads firmware configuration bytes into a buffer
  49
  50   If called multiple times, then the data read will
  51   continue at the offset of the firmware configuration
  52   item where the previous read ended.
  53
  54   @param[in] Size - Size in bytes to read
  55   @param[in] Buffer - Buffer to store data into
  56
  57 **/
  58 VOID
  59 EFIAPI
  60 QemuFwCfgReadBytes (
  61   IN UINTN  Size,
  62   IN VOID   *Buffer  OPTIONAL
  63   );
  64
  65 /**
  66   Writes firmware configuration bytes from a buffer
  67
  68   If called multiple times, then the data written will
  69   continue at the offset of the firmware configuration
  70   item where the previous write ended.
  71
  72   @param[in] Size - Size in bytes to write
  73   @param[in] Buffer - Buffer to read data from
  74
  75 **/
  76 VOID
  77 EFIAPI
  78 QemuFwCfgWriteBytes (
  79   IN UINTN  Size,
  80   IN VOID   *Buffer
  81   );
  82
  83 /**
  84   Skip bytes in the firmware configuration item.
  85
  86   Increase the offset of the firmware configuration item without transferring
  87   bytes between the item and a caller-provided buffer. Subsequent read, write
  88   or skip operations will commence at the increased offset.
  89
  90   @param[in] Size  Number of bytes to skip.
  91 **/
  92 VOID
  93 EFIAPI
  94 QemuFwCfgSkipBytes (
  95   IN UINTN  Size
  96   );
  97
  98 /**
  99   Reads a UINT8 firmware configuration value
 100
 101   @return    Value of Firmware Configuration item read
 102
 103 **/
 104 UINT8
 105 EFIAPI
 106 QemuFwCfgRead8 (
 107   VOID
 108   );
 109
 110 /**
 111   Reads a UINT16 firmware configuration value
 112
 113   @return    Value of Firmware Configuration item read
 114
 115 **/
 116 UINT16
 117 EFIAPI
 118 QemuFwCfgRead16 (
 119   VOID
 120   );
 121
 122 /**
 123   Reads a UINT32 firmware configuration value
 124
 125   @return    Value of Firmware Configuration item read
 126
 127 **/
 128 UINT32
 129 EFIAPI
 130 QemuFwCfgRead32 (
 131   VOID
 132   );
 133
 134 /**
 135   Reads a UINT64 firmware configuration value
 136
 137   @return    Value of Firmware Configuration item read
 138
 139 **/
 140 UINT64
 141 EFIAPI
 142 QemuFwCfgRead64 (
 143   VOID
 144   );
 145
 146 /**
 147   Find the configuration item corresponding to the firmware configuration file.
 148
 149   @param[in]  Name - Name of file to look up.
 150   @param[out] Item - Configuration item corresponding to the file, to be passed
 151                      to QemuFwCfgSelectItem ().
 152   @param[out] Size - Number of bytes in the file.
 153
 154   @return    RETURN_SUCCESS       If file is found.
 155              RETURN_NOT_FOUND     If file is not found.
 156              RETURN_UNSUPPORTED   If firmware configuration is unavailable.
 157
 158 **/
 159 RETURN_STATUS
 160 EFIAPI
 161 QemuFwCfgFindFile (
 162   IN   CONST CHAR8           *Name,
 163   OUT  FIRMWARE_CONFIG_ITEM  *Item,
 164   OUT  UINTN                 *Size
 165   );
 166
 167 #endif