X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=blobdiff_plain;f=OvmfPkg%2FLibrary%2FQemuFwCfgLib%2FQemuFwCfgNull.c;fp=OvmfPkg%2FLibrary%2FQemuFwCfgLib%2FQemuFwCfgNull.c;h=edd97db49d4ace872eccc62b7c7d093bf620782d;hp=0000000000000000000000000000000000000000;hb=245bdd2cb94beef807ff12263b6060d6fdb40c9a;hpb=de15e7c2651ada46cc649c5b3c8c0c145354ac04

diff --git a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgNull.c b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgNull.c
new file mode 100644
index 0000000000..edd97db49d
--- /dev/null
+++ b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgNull.c
@@ -0,0 +1,209 @@
+/** @file
+
+  Null implementation of the fw_cfg library.
+
+  Copyright (C) 2020, Rebecca Cran <rebecca@bsdio.com>
+  Copyright (C) 2013, Red Hat, Inc.
+  Copyright (c) 2011 - 2013, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2017, Advanced Micro Devices. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#include <Library/DebugLib.h>
+#include <Library/QemuFwCfgLib.h>
+
+/**
+  Returns a boolean indicating if the firmware configuration interface
+  is available or not.
+
+  This function may change fw_cfg state.
+
+  @retval    TRUE   The interface is available
+  @retval    FALSE  The interface is not available
+
+**/
+BOOLEAN
+EFIAPI
+QemuFwCfgIsAvailable (
+  VOID
+  )
+{
+  return FALSE;
+}
+
+
+/**
+  Selects a firmware configuration item for reading.
+
+  Following this call, any data read from this item will start from
+  the beginning of the configuration item's data.
+
+  @param[in] QemuFwCfgItem - Firmware Configuration item to read
+
+**/
+VOID
+EFIAPI
+QemuFwCfgSelectItem (
+  IN FIRMWARE_CONFIG_ITEM   QemuFwCfgItem
+  )
+{
+  ASSERT (FALSE);
+}
+
+
+/**
+  Reads firmware configuration bytes into a buffer
+
+  If called multiple times, then the data read will
+  continue at the offset of the firmware configuration
+  item where the previous read ended.
+
+  @param[in] Size - Size in bytes to read
+  @param[in] Buffer - Buffer to store data into
+
+**/
+VOID
+EFIAPI
+QemuFwCfgReadBytes (
+  IN UINTN                  Size,
+  IN VOID                   *Buffer  OPTIONAL
+  )
+{
+  ASSERT (FALSE);
+}
+
+
+/**
+  Writes firmware configuration bytes from a buffer
+
+  If called multiple times, then the data written will
+  continue at the offset of the firmware configuration
+  item where the previous write ended.
+
+  @param[in] Size - Size in bytes to write
+  @param[in] Buffer - Buffer to read data from
+
+**/
+VOID
+EFIAPI
+QemuFwCfgWriteBytes (
+  IN UINTN                  Size,
+  IN VOID                   *Buffer
+  )
+{
+  ASSERT (FALSE);
+}
+
+
+/**
+  Skip bytes in the firmware configuration item.
+
+  Increase the offset of the firmware configuration item without transferring
+  bytes between the item and a caller-provided buffer. Subsequent read, write
+  or skip operations will commence at the increased offset.
+
+  @param[in] Size  Number of bytes to skip.
+**/
+VOID
+EFIAPI
+QemuFwCfgSkipBytes (
+  IN UINTN                  Size
+  )
+{
+  ASSERT (FALSE);
+}
+
+
+/**
+  Reads a UINT8 firmware configuration value
+
+  @return    Value of Firmware Configuration item read
+
+**/
+UINT8
+EFIAPI
+QemuFwCfgRead8 (
+  VOID
+  )
+{
+  ASSERT (FALSE);
+  return 0;
+}
+
+
+/**
+  Reads a UINT16 firmware configuration value
+
+  @return    Value of Firmware Configuration item read
+
+**/
+UINT16
+EFIAPI
+QemuFwCfgRead16 (
+  VOID
+  )
+{
+  ASSERT (FALSE);
+  return 0;
+}
+
+
+/**
+  Reads a UINT32 firmware configuration value
+
+  @return    Value of Firmware Configuration item read
+
+**/
+UINT32
+EFIAPI
+QemuFwCfgRead32 (
+  VOID
+  )
+{
+  ASSERT (FALSE);
+  return 0;
+}
+
+
+/**
+  Reads a UINT64 firmware configuration value
+
+  @return    Value of Firmware Configuration item read
+
+**/
+UINT64
+EFIAPI
+QemuFwCfgRead64 (
+  VOID
+  )
+{
+  ASSERT (FALSE);
+  return 0;
+}
+
+
+/**
+  Find the configuration item corresponding to the firmware configuration file.
+
+  @param[in]  Name - Name of file to look up.
+  @param[out] Item - Configuration item corresponding to the file, to be passed
+                     to QemuFwCfgSelectItem ().
+  @param[out] Size - Number of bytes in the file.
+
+  @return    RETURN_SUCCESS       If file is found.
+             RETURN_NOT_FOUND     If file is not found.
+             RETURN_UNSUPPORTED   If firmware configuration is unavailable.
+
+**/
+RETURN_STATUS
+EFIAPI
+QemuFwCfgFindFile (
+  IN   CONST CHAR8           *Name,
+  OUT  FIRMWARE_CONFIG_ITEM  *Item,
+  OUT  UINTN                 *Size
+  )
+{
+  return RETURN_UNSUPPORTED;
+}
+