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 (QemuFwCfgFindFile (
  49                       "etc/smbios/smbios-anchor", &Anchor, &AnchorSize)) ||
  50       RETURN_ERROR (QemuFwCfgFindFile (
  51                       "etc/smbios/smbios-tables", &Tables, &TablesSize)) ||
  52       TablesSize == 0) {
  53     return RETURN_SUCCESS;
  54   }
  55
  56   QemuFwCfgSelectItem (Anchor);
  57
  58   switch (AnchorSize) {
  59   case sizeof QemuAnchor.V2:
  60     QemuFwCfgReadBytes (AnchorSize, &QemuAnchor);
  61
  62     if (QemuAnchor.V2.MajorVersion != 2 ||
  63         QemuAnchor.V2.TableLength != TablesSize ||
  64         CompareMem (QemuAnchor.V2.AnchorString, "_SM_", 4) != 0 ||
  65         CompareMem (QemuAnchor.V2.IntermediateAnchorString, "_DMI_", 5) != 0) {
  66       return RETURN_SUCCESS;
  67     }
  68     SmbiosVersion = (UINT16)(QemuAnchor.V2.MajorVersion << 8 |
  69                              QemuAnchor.V2.MinorVersion);
  70     break;
  71
  72   case sizeof QemuAnchor.V3:
  73     QemuFwCfgReadBytes (AnchorSize, &QemuAnchor);
  74
  75     if (QemuAnchor.V3.MajorVersion != 3 ||
  76         QemuAnchor.V3.TableMaximumSize != TablesSize ||
  77         CompareMem (QemuAnchor.V3.AnchorString, "_SM3_", 5) != 0) {
  78       return RETURN_SUCCESS;
  79     }
  80     SmbiosVersion = (UINT16)(QemuAnchor.V3.MajorVersion << 8 |
  81                              QemuAnchor.V3.MinorVersion);
  82
  83     DEBUG ((DEBUG_INFO, "%a: SMBIOS 3.x DocRev from QEMU: 0x%02x\n",
  84       __FUNCTION__, QemuAnchor.V3.DocRev));
  85     PcdStatus = PcdSet8S (PcdSmbiosDocRev, QemuAnchor.V3.DocRev);
  86     ASSERT_RETURN_ERROR (PcdStatus);
  87     break;
  88
  89   default:
  90     return RETURN_SUCCESS;
  91   }
  92
  93   DEBUG ((DEBUG_INFO, "%a: SMBIOS version from QEMU: 0x%04x\n", __FUNCTION__,
  94     SmbiosVersion));
  95   PcdStatus = PcdSet16S (PcdSmbiosVersion, SmbiosVersion);
  96   ASSERT_RETURN_ERROR (PcdStatus);
  97
  98   //
  99   // SMBIOS platform drivers can now fetch and install
 100   // "etc/smbios/smbios-tables" from QEMU.
 101   //
 102   PcdStatus = PcdSetBoolS (PcdQemuSmbiosValidated, TRUE);
 103   ASSERT_RETURN_ERROR (PcdStatus);
 104   return RETURN_SUCCESS;
 105 }