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 /**
  15   Locates and extracts the QEMU SMBIOS data if present in fw_cfg
  16
  17   @return                 Address of extracted QEMU SMBIOS data
  18
  19 **/
  20 UINT8 *
  21 GetQemuSmbiosTables (
  22   VOID
  23   )
  24 {
  25   EFI_STATUS            Status;
  26   FIRMWARE_CONFIG_ITEM  Tables;
  27   UINTN                 TablesSize;
  28   UINT8                 *QemuTables;
  29
  30   if (!PcdGetBool (PcdQemuSmbiosValidated)) {
  31     return NULL;
  32   }
  33
  34   Status = QemuFwCfgFindFile (
  35              "etc/smbios/smbios-tables",
  36              &Tables,
  37              &TablesSize
  38              );
  39   ASSERT_EFI_ERROR (Status);
  40   ASSERT (TablesSize > 0);
  41
  42   QemuTables = AllocatePool (TablesSize);
  43   if (QemuTables == NULL) {
  44     return NULL;
  45   }
  46
  47   QemuFwCfgSelectItem (Tables);
  48   QemuFwCfgReadBytes (TablesSize, QemuTables);
  49
  50   return QemuTables;
  51 }