OvmfPkg/Library/SmbiosVersionLib/DetectSmbiosVersionLib.c

   1 /** @file
   2
   3   A hook-in library for MdeModulePkg/Universal/SmbiosDxe, in order to set
   4   gEfiMdeModulePkgTokenSpaceGuid.PcdSmbiosVersion (and possibly other PCDs)
   5   just before SmbiosDxe consumes them.
   6
   7   Copyright (C) 2013, 2015, Red Hat, Inc.
   8   Copyright (c) 2008 - 2012, Intel Corporation. All rights reserved.<BR>
   9
  10   SPDX-License-Identifier: BSD-2-Clause-Patent
  11
  12 **/
  13
  14 #include <IndustryStandard/SmBios.h>
  15
  16 #include <Base.h>
  17 #include <Library/BaseMemoryLib.h>
  18 #include <Library/DebugLib.h>
  19 #include <Library/PcdLib.h>
  20 #include <Library/QemuFwCfgLib.h>
  21
  22 typedef union {
  23   SMBIOS_TABLE_ENTRY_POINT        V2;
  24   SMBIOS_TABLE_3_0_ENTRY_POINT    V3;
  25 } QEMU_SMBIOS_ANCHOR;
  26
  27 RETURN_STATUS
  28 EFIAPI
  29 DetectSmbiosVersion (
  30   VOID
  31   )
  32 {
  33   FIRMWARE_CONFIG_ITEM  Anchor, Tables;
  34   UINTN                 AnchorSize, TablesSize;
  35   QEMU_SMBIOS_ANCHOR    QemuAnchor;
  36   UINT16                SmbiosVersion;
  37   RETURN_STATUS         PcdStatus;
  38
  39   if (PcdGetBool (PcdQemuSmbiosValidated)) {
  40     //
  41     // Some other module, linked against this library, has already performed
  42     // the task at hand. This should never happen, but it's easy to handle;
  43     // just exit early.
  44     //
  45     return RETURN_SUCCESS;
  46   }
  47
  48   if (RETURN_ERROR (
  49         QemuFwCfgFindFile (
  50           "etc/smbios/smbios-anchor",
  51           &Anchor,
  52           &AnchorSize
  53           )
  54         ) ||
  55       RETURN_ERROR (
  56         QemuFwCfgFindFile (
  57           "etc/smbios/smbios-tables",
  58           &Tables,
  59           &TablesSize
  60           )
  61         ) ||
  62       (TablesSize == 0))
  63   {
  64     return RETURN_SUCCESS;
  65   }
  66
  67   QemuFwCfgSelectItem (Anchor);
  68
  69   switch (AnchorSize) {
  70     case sizeof QemuAnchor.V2:
  71       QemuFwCfgReadBytes (AnchorSize, &QemuAnchor);
  72
  73       if ((QemuAnchor.V2.MajorVersion != 2) ||
  74           (QemuAnchor.V2.TableLength != TablesSize) ||
  75           (CompareMem (QemuAnchor.V2.AnchorString, "_SM_", 4) != 0) ||
  76           (CompareMem (QemuAnchor.V2.IntermediateAnchorString, "_DMI_", 5) != 0))
  77       {
  78         return RETURN_SUCCESS;
  79       }
  80
  81       SmbiosVersion = (UINT16)(QemuAnchor.V2.MajorVersion << 8 |
  82                                QemuAnchor.V2.MinorVersion);
  83       break;
  84
  85     case sizeof QemuAnchor.V3:
  86       QemuFwCfgReadBytes (AnchorSize, &QemuAnchor);
  87
  88       if ((QemuAnchor.V3.MajorVersion != 3) ||
  89           (QemuAnchor.V3.TableMaximumSize != TablesSize) ||
  90           (CompareMem (QemuAnchor.V3.AnchorString, "_SM3_", 5) != 0))
  91       {
  92         return RETURN_SUCCESS;
  93       }
  94
  95       SmbiosVersion = (UINT16)(QemuAnchor.V3.MajorVersion << 8 |
  96                                QemuAnchor.V3.MinorVersion);
  97
  98       DEBUG ((
  99         DEBUG_INFO,
 100         "%a: SMBIOS 3.x DocRev from QEMU: 0x%02x\n",
 101         __FUNCTION__,
 102         QemuAnchor.V3.DocRev
 103         ));
 104       PcdStatus = PcdSet8S (PcdSmbiosDocRev, QemuAnchor.V3.DocRev);
 105       ASSERT_RETURN_ERROR (PcdStatus);
 106       break;
 107
 108     default:
 109       return RETURN_SUCCESS;
 110   }
 111
 112   DEBUG ((
 113     DEBUG_INFO,
 114     "%a: SMBIOS version from QEMU: 0x%04x\n",
 115     __FUNCTION__,
 116     SmbiosVersion
 117     ));
 118   PcdStatus = PcdSet16S (PcdSmbiosVersion, SmbiosVersion);
 119   ASSERT_RETURN_ERROR (PcdStatus);
 120
 121   //
 122   // SMBIOS platform drivers can now fetch and install
 123   // "etc/smbios/smbios-tables" from QEMU.
 124   //
 125   PcdStatus = PcdSetBoolS (PcdQemuSmbiosValidated, TRUE);
 126   ASSERT_RETURN_ERROR (PcdStatus);
 127   return RETURN_SUCCESS;
 128 }