1 files changed, 66 insertions, 0 deletions
diff --git a/OvmfPkg/SmbiosPlatformDxe/Qemu.c b/OvmfPkg/SmbiosPlatformDxe/Qemu.c
new file mode 100644
index 0000000000..f7ace4f1de
--- /dev/null
+++ b/OvmfPkg/SmbiosPlatformDxe/Qemu.c
@@ -0,0 +1,66 @@
+/** @file
+  Find and extract QEMU SMBIOS data from fw_cfg.
+
+  Copyright (C) 2014, Gabriel L. Somlo <somlo@cmu.edu>
+
+  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 "SmbiosPlatformDxe.h"
+#include <Library/QemuFwCfgLib.h>
+#include <Library/MemoryAllocationLib.h>
+
+/**
+  Locates and extracts the QEMU SMBIOS data if present in fw_cfg
+
+  @return                 Address of extracted QEMU SMBIOS data
+
+**/
+UINT8 *
+GetQemuSmbiosTables (
+  VOID
+  )
+{
+  SMBIOS_TABLE_ENTRY_POINT QemuAnchor;
+  FIRMWARE_CONFIG_ITEM     Anchor, Tables;
+  UINTN                    AnchorSize, TablesSize;
+  UINT8                    *QemuTables;
+
+  if (EFI_ERROR (QemuFwCfgFindFile (
+                   "etc/smbios/smbios-anchor", &Anchor, &AnchorSize)) ||
+      EFI_ERROR (QemuFwCfgFindFile (
+                   "etc/smbios/smbios-tables", &Tables, &TablesSize)) ||
+      AnchorSize != sizeof (QemuAnchor) ||
+      TablesSize == 0) {
+    return NULL;
+  }
+
+  //
+  // We copy the entry point structure to perform some additional checks,
+  // but discard it upon return.
+  //
+  QemuFwCfgSelectItem (Anchor);
+  QemuFwCfgReadBytes (AnchorSize, &QemuAnchor);
+
+  if (AsciiStrnCmp ((CHAR8 *)QemuAnchor.AnchorString, "_SM_", 4) ||
+      AsciiStrnCmp ((CHAR8 *)QemuAnchor.IntermediateAnchorString, "_DMI_", 5) ||
+      TablesSize != QemuAnchor.TableLength) {
+    return NULL;
+  }
+
+  QemuTables = AllocatePool (TablesSize);
+  if (QemuTables == NULL) {
+    return NULL;
+  }
+
+  QemuFwCfgSelectItem (Tables);
+  QemuFwCfgReadBytes (TablesSize, QemuTables);
+
+  return QemuTables;
+}