OvmfPkg/SmbiosPlatformDxe/Xen.c

   1 /** @file
   2   Detect Xen hvmloader SMBIOS data for usage by OVMF.
   3
   4   Copyright (c) 2011, Bei Guan <gbtju85@gmail.com>
   5   Copyright (c) 2011, Intel Corporation. All rights reserved.<BR>
   6
   7   This program and the accompanying materials
   8   are licensed and made available under the terms and conditions of the BSD License
   9   which accompanies this distribution.  The full text of the license may be found at
  10   http://opensource.org/licenses/bsd-license.php
  11
  12   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  13   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  14
  15 **/
  16
  17 #include "SmbiosPlatformDxe.h"
  18 #include <Library/HobLib.h>
  19 #include <Guid/XenInfo.h>
  20
  21 #define XEN_SMBIOS_PHYSICAL_ADDRESS       0x000EB000
  22 #define XEN_SMBIOS_PHYSICAL_END           0x000F0000
  23
  24 /**
  25   Locates the Xen SMBIOS data if it exists
  26
  27   @return SMBIOS_TABLE_ENTRY_POINT   Address of Xen SMBIOS data
  28
  29 **/
  30 SMBIOS_TABLE_ENTRY_POINT *
  31 GetXenSmbiosTables (
  32   VOID
  33   )
  34 {
  35   UINT8                     *XenSmbiosPtr;
  36   SMBIOS_TABLE_ENTRY_POINT  *XenSmbiosEntryPointStructure;
  37   EFI_HOB_GUID_TYPE         *GuidHob;
  38
  39   //
  40   // See if a XenInfo HOB is available
  41   //
  42   GuidHob = GetFirstGuidHob (&gEfiXenInfoGuid);
  43   if (GuidHob == NULL) {
  44     return NULL;
  45   }
  46
  47   for (XenSmbiosPtr = (UINT8*)(UINTN) XEN_SMBIOS_PHYSICAL_ADDRESS;
  48        XenSmbiosPtr < (UINT8*)(UINTN) XEN_SMBIOS_PHYSICAL_END;
  49        XenSmbiosPtr += 0x10) {
  50
  51     XenSmbiosEntryPointStructure = (SMBIOS_TABLE_ENTRY_POINT *) XenSmbiosPtr;
  52
  53     if (!AsciiStrnCmp ((CHAR8 *) XenSmbiosEntryPointStructure->AnchorString, "_SM_", 4) &&
  54         !AsciiStrnCmp ((CHAR8 *) XenSmbiosEntryPointStructure->IntermediateAnchorString, "_DMI_", 5) &&
  55         IsEntryPointStructureValid (XenSmbiosEntryPointStructure)) {
  56
  57       return XenSmbiosEntryPointStructure;
  58
  59     }
  60   }
  61
  62   return NULL;
  63 }