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 /**
  34   Selects a firmware configuration item for reading.
  35
  36   Following this call, any data read from this item will start from
  37   the beginning of the configuration item's data.
  38
  39   @param[in] QemuFwCfgItem - Firmware Configuration item to read
  40
  41 **/
  42 VOID
  43 EFIAPI
  44 QemuFwCfgSelectItem (
  45   IN FIRMWARE_CONFIG_ITEM   QemuFwCfgItem
  46   );
  47
  48
  49 /**
  50   Reads firmware configuration bytes into a buffer
  51
  52   If called multiple times, then the data read will
  53   continue at the offset of the firmware configuration
  54   item where the previous read ended.
  55
  56   @param[in] Size - Size in bytes to read
  57   @param[in] Buffer - Buffer to store data into
  58
  59 **/
  60 VOID
  61 EFIAPI
  62 QemuFwCfgReadBytes (
  63   IN UINTN                  Size,
  64   IN VOID                   *Buffer  OPTIONAL
  65   );
  66
  67
  68 /**
  69   Writes firmware configuration bytes from a buffer
  70
  71   If called multiple times, then the data written will
  72   continue at the offset of the firmware configuration
  73   item where the previous write ended.
  74
  75   @param[in] Size - Size in bytes to write
  76   @param[in] Buffer - Buffer to read data from
  77
  78 **/
  79 VOID
  80 EFIAPI
  81 QemuFwCfgWriteBytes (
  82   IN UINTN                  Size,
  83   IN VOID                   *Buffer
  84   );
  85
  86
  87 /**
  88   Skip bytes in the firmware configuration item.
  89
  90   Increase the offset of the firmware configuration item without transferring
  91   bytes between the item and a caller-provided buffer. Subsequent read, write
  92   or skip operations will commence at the increased offset.
  93
  94   @param[in] Size  Number of bytes to skip.
  95 **/
  96 VOID
  97 EFIAPI
  98 QemuFwCfgSkipBytes (
  99   IN UINTN                  Size
 100   );
 101
 102
 103 /**
 104   Reads a UINT8 firmware configuration value
 105
 106   @return    Value of Firmware Configuration item read
 107
 108 **/
 109 UINT8
 110 EFIAPI
 111 QemuFwCfgRead8 (
 112   VOID
 113   );
 114
 115
 116 /**
 117   Reads a UINT16 firmware configuration value
 118
 119   @return    Value of Firmware Configuration item read
 120
 121 **/
 122 UINT16
 123 EFIAPI
 124 QemuFwCfgRead16 (
 125   VOID
 126   );
 127
 128
 129 /**
 130   Reads a UINT32 firmware configuration value
 131
 132   @return    Value of Firmware Configuration item read
 133
 134 **/
 135 UINT32
 136 EFIAPI
 137 QemuFwCfgRead32 (
 138   VOID
 139   );
 140
 141
 142 /**
 143   Reads a UINT64 firmware configuration value
 144
 145   @return    Value of Firmware Configuration item read
 146
 147 **/
 148 UINT64
 149 EFIAPI
 150 QemuFwCfgRead64 (
 151   VOID
 152   );
 153
 154
 155 /**
 156   Find the configuration item corresponding to the firmware configuration file.
 157
 158   @param[in]  Name - Name of file to look up.
 159   @param[out] Item - Configuration item corresponding to the file, to be passed
 160                      to QemuFwCfgSelectItem ().
 161   @param[out] Size - Number of bytes in the file.
 162
 163   @return    RETURN_SUCCESS       If file is found.
 164              RETURN_NOT_FOUND     If file is not found.
 165              RETURN_UNSUPPORTED   If firmware configuration is unavailable.
 166
 167 **/
 168 RETURN_STATUS
 169 EFIAPI
 170 QemuFwCfgFindFile (
 171   IN   CONST CHAR8           *Name,
 172   OUT  FIRMWARE_CONFIG_ITEM  *Item,
 173   OUT  UINTN                 *Size
 174   );
 175
 176 #endif
 177