[PATCH 06/13] OvmfPkg: add QemuFwCfgPeiLibNull

["Rebecca Cran" <rebecca@bsdio.com>]

Add a null PEI implementation of QemuFwCfgLib for bhyve.

Signed-off-by: Rebecca Cran <rebecca@bsdio.com>
---
 .../QemuFwCfgLibNull/QemuFwCfgPeiLibNull.inf  |  36 ++++++
 .../QemuFwCfgLibNull/QemuFwCfgPeiNull.c       | 107 ++++++++++++++++++
 2 files changed, 143 insertions(+)
 create mode 100644 OvmfPkg/Library/QemuFwCfgLibNull/QemuFwCfgPeiLibNull.inf
 create mode 100644 OvmfPkg/Library/QemuFwCfgLibNull/QemuFwCfgPeiNull.c

diff --git a/OvmfPkg/Library/QemuFwCfgLibNull/QemuFwCfgPeiLibNull.inf b/OvmfPkg/Library/QemuFwCfgLibNull/QemuFwCfgPeiLibNull.inf
new file mode 100644
index 0000000000..e5a7683b9b
--- /dev/null
+++ b/OvmfPkg/Library/QemuFwCfgLibNull/QemuFwCfgPeiLibNull.inf
@@ -0,0 +1,36 @@
+## @file
+#
+#  Stateful, implicitly initialized fw_cfg library.
+#
+#  Copyright (C) 2013, Red Hat, Inc.
+#  Copyright (c) 2008 - 2012, Intel Corporation. All rights reserved.<BR>
+#  Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = QemuFwCfgPeiLibNull
+  FILE_GUID                      = 404DEFA4-548D-4535-9D6B-915B14D98BC2
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = QemuFwCfgLib|PEIM
+
+  CONSTRUCTOR                    = QemuFwCfgInitialize
+
+#
+# The following information is for reference only and not required by the build tools.
+#
+#  VALID_ARCHITECTURES           = IA32 X64
+#
+
+[Sources]
+  QemuFwCfgLibInternal.h
+  QemuFwCfgLibNull.c
+  QemuFwCfgPeiNull.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+  OvmfPkg/OvmfPkg.dec
diff --git a/OvmfPkg/Library/QemuFwCfgLibNull/QemuFwCfgPeiNull.c b/OvmfPkg/Library/QemuFwCfgLibNull/QemuFwCfgPeiNull.c
new file mode 100644
index 0000000000..54d5eb4e19
--- /dev/null
+++ b/OvmfPkg/Library/QemuFwCfgLibNull/QemuFwCfgPeiNull.c
@@ -0,0 +1,107 @@
+/** @file
+
+  Stateful and implicitly initialized fw_cfg library implementation.
+
+  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/BaseLib.h>
+#include <Library/IoLib.h>
+#include <Library/DebugLib.h>
+#include <Library/QemuFwCfgLib.h>
+#include <Library/MemEncryptSevLib.h>
+
+#include "QemuFwCfgLibInternal.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 InternalQemuFwCfgIsAvailable ();
+}
+
+
+RETURN_STATUS
+EFIAPI
+QemuFwCfgInitialize (
+  VOID
+  )
+{
+  return RETURN_SUCCESS;
+}
+
+
+/**
+  Returns a boolean indicating if the firmware configuration interface is
+  available for library-internal purposes.
+
+  This function never changes fw_cfg state.
+
+  @retval    TRUE   The interface is available internally.
+  @retval    FALSE  The interface is not available internally.
+**/
+BOOLEAN
+InternalQemuFwCfgIsAvailable (
+  VOID
+  )
+{
+  return FALSE;
+}
+
+/**
+  Returns a boolean indicating whether QEMU provides the DMA-like access method
+  for fw_cfg.
+
+  @retval    TRUE   The DMA-like access method is available.
+  @retval    FALSE  The DMA-like access method is unavailable.
+**/
+BOOLEAN
+InternalQemuFwCfgDmaIsAvailable (
+  VOID
+  )
+{
+  return FALSE;
+}
+
+/**
+  Transfer an array of bytes, or skip a number of bytes, using the DMA
+  interface.
+
+  @param[in]     Size     Size in bytes to transfer or skip.
+
+  @param[in,out] Buffer   Buffer to read data into or write data from. Ignored,
+                          and may be NULL, if Size is zero, or Control is
+                          FW_CFG_DMA_CTL_SKIP.
+
+  @param[in]     Control  One of the following:
+                          FW_CFG_DMA_CTL_WRITE - write to fw_cfg from Buffer.
+                          FW_CFG_DMA_CTL_READ  - read from fw_cfg into Buffer.
+                          FW_CFG_DMA_CTL_SKIP  - skip bytes in fw_cfg.
+**/
+VOID
+InternalQemuFwCfgDmaBytes (
+  IN     UINT32   Size,
+  IN OUT VOID     *Buffer OPTIONAL,
+  IN     UINT32   Control
+  )
+{
+
+}
+
-- 
2.26.1