OvmfPkg/SmbiosPlatformDxe/Qemu.c

   1 /** @file
   2   Find and extract QEMU SMBIOS data from fw_cfg.
   3
   4   Copyright (C) 2014, Gabriel L. Somlo <somlo@cmu.edu>
   5
   6   SPDX-License-Identifier: BSD-2-Clause-Patent
   7 **/
   8
   9 #include <Library/DebugLib.h>            // ASSERT_EFI_ERROR()
  10 #include <Library/MemoryAllocationLib.h> // AllocatePool()
  11 #include <Library/PcdLib.h>              // PcdGetBool()
  12 #include <Library/QemuFwCfgLib.h>        // QemuFwCfgFindFile()
  13
  14 #include "SmbiosPlatformDxe.h"
  15
  16 /**
  17   Locates and extracts the QEMU SMBIOS data if present in fw_cfg
  18
  19   @return                 Address of extracted QEMU SMBIOS data
  20
  21 **/
  22 UINT8 *
  23 GetQemuSmbiosTables (
  24   VOID
  25   )
  26 {
  27   EFI_STATUS               Status;
  28   FIRMWARE_CONFIG_ITEM     Tables;
  29   UINTN                    TablesSize;
  30   UINT8                    *QemuTables;
  31
  32   if (!PcdGetBool (PcdQemuSmbiosValidated)) {
  33     return NULL;
  34   }
  35
  36   Status = QemuFwCfgFindFile ("etc/smbios/smbios-tables", &Tables,
  37              &TablesSize);
  38   ASSERT_EFI_ERROR (Status);
  39   ASSERT (TablesSize > 0);
  40
  41   QemuTables = AllocatePool (TablesSize);
  42   if (QemuTables == NULL) {
  43     return NULL;
  44   }
  45
  46   QemuFwCfgSelectItem (Tables);
  47   QemuFwCfgReadBytes (TablesSize, QemuTables);
  48
  49   return QemuTables;
  50 }