OvmfPkg: SmbiosPlatformDxe: restrict current Xen code to IA32/X64

[mirror_edk2.git] / OvmfPkg / SmbiosPlatformDxe / X86Xen.c

diff --git a/OvmfPkg/SmbiosPlatformDxe/X86Xen.c b/OvmfPkg/SmbiosPlatformDxe/X86Xen.c
new file mode 100644 (file)
index 0000000..3f018d6
--- /dev/null
+++ b/OvmfPkg/SmbiosPlatformDxe/X86Xen.c
@@ -0,0 +1,98 @@
+/** @file
+  Detect Xen hvmloader SMBIOS data for usage by OVMF.
+
+  Copyright (c) 2011, Bei Guan <gbtju85@gmail.com>
+  Copyright (c) 2011, 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 "SmbiosPlatformDxe.h"
+#include <Library/HobLib.h>
+#include <Guid/XenInfo.h>
+
+#define XEN_SMBIOS_PHYSICAL_ADDRESS       0x000EB000
+#define XEN_SMBIOS_PHYSICAL_END           0x000F0000
+
+/**
+  Validates the SMBIOS entry point structure
+
+  @param  EntryPointStructure  SMBIOS entry point structure
+
+  @retval TRUE   The entry point structure is valid
+  @retval FALSE  The entry point structure is not valid
+
+**/
+STATIC
+BOOLEAN
+IsEntryPointStructureValid (
+  IN SMBIOS_TABLE_ENTRY_POINT  *EntryPointStructure
+  )
+{
+  UINTN                     Index;
+  UINT8                     Length;
+  UINT8                     Checksum;
+  UINT8                     *BytePtr;
+
+  BytePtr = (UINT8*) EntryPointStructure;
+  Length = EntryPointStructure->EntryPointLength;
+  Checksum = 0;
+
+  for (Index = 0; Index < Length; Index++) {
+    Checksum = Checksum + (UINT8) BytePtr[Index];
+  }
+
+  if (Checksum != 0) {
+    return FALSE;
+  } else {
+    return TRUE;
+  }
+}
+
+/**
+  Locates the Xen SMBIOS data if it exists
+
+  @return SMBIOS_TABLE_ENTRY_POINT   Address of Xen SMBIOS data
+
+**/
+SMBIOS_TABLE_ENTRY_POINT *
+GetXenSmbiosTables (
+  VOID
+  )
+{
+  UINT8                     *XenSmbiosPtr;
+  SMBIOS_TABLE_ENTRY_POINT  *XenSmbiosEntryPointStructure;
+  EFI_HOB_GUID_TYPE         *GuidHob;
+
+  //
+  // See if a XenInfo HOB is available
+  //
+  GuidHob = GetFirstGuidHob (&gEfiXenInfoGuid);
+  if (GuidHob == NULL) {
+    return NULL;
+  }
+
+  for (XenSmbiosPtr = (UINT8*)(UINTN) XEN_SMBIOS_PHYSICAL_ADDRESS;
+       XenSmbiosPtr < (UINT8*)(UINTN) XEN_SMBIOS_PHYSICAL_END;
+       XenSmbiosPtr += 0x10) {
+
+    XenSmbiosEntryPointStructure = (SMBIOS_TABLE_ENTRY_POINT *) XenSmbiosPtr;
+
+    if (!AsciiStrnCmp ((CHAR8 *) XenSmbiosEntryPointStructure->AnchorString, "_SM_", 4) &&
+        !AsciiStrnCmp ((CHAR8 *) XenSmbiosEntryPointStructure->IntermediateAnchorString, "_DMI_", 5) &&
+        IsEntryPointStructureValid (XenSmbiosEntryPointStructure)) {
+
+      return XenSmbiosEntryPointStructure;
+
+    }
+  }
+
+  return NULL;
+}