1 files changed, 92 insertions, 0 deletions
diff --git a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPeiDxe.c b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPeiDxe.c
new file mode 100644
index 000000000..f693cff29
--- /dev/null
+++ b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPeiDxe.c
@@ -0,0 +1,92 @@
+/** @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>
+
+  This program and the accompanying materials are licensed and made available
+  under the terms and conditions of the BSD License which accompanies this
+  distribution.  The full text of the license may be found at
+  http://opensource.org/licenses/bsd-license.php
+
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
+  WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+**/
+
+#include <Library/DebugLib.h>
+#include <Library/QemuFwCfgLib.h>
+
+STATIC BOOLEAN mQemuFwCfgSupported = FALSE;
+
+
+/**
+  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
+  )
+{
+  UINT32 Signature;
+  UINT32 Revision;
+
+  //
+  // Enable the access routines while probing to see if it is supported.
+  //
+  mQemuFwCfgSupported = TRUE;
+
+  QemuFwCfgSelectItem (QemuFwCfgItemSignature);
+  Signature = QemuFwCfgRead32 ();
+  DEBUG ((EFI_D_INFO, "FW CFG Signature: 0x%x\n", Signature));
+  QemuFwCfgSelectItem (QemuFwCfgItemInterfaceVersion);
+  Revision = QemuFwCfgRead32 ();
+  DEBUG ((EFI_D_INFO, "FW CFG Revision: 0x%x\n", Revision));
+  if ((Signature != SIGNATURE_32 ('Q', 'E', 'M', 'U')) ||
+      (Revision < 1)
+     ) {
+    DEBUG ((EFI_D_INFO, "QemuFwCfg interface not supported.\n"));
+    mQemuFwCfgSupported = FALSE;
+    return RETURN_SUCCESS;
+  }
+
+  DEBUG ((EFI_D_INFO, "QemuFwCfg interface is supported.\n"));
+  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
+EFIAPI
+InternalQemuFwCfgIsAvailable (
+  VOID
+  )
+{
+  return mQemuFwCfgSupported;
+}