ArmVirtPkg/QemuFwCfgToPcdDxe/QemuFwCfgToPcd.c

   1 /** @file
   2 *  An "early" DXE driver that parses well-known fw-cfg files into dynamic PCDs
   3 *  that control other (universal) DXE drivers.
   4 *
   5 *  Copyright (C) 2015, Red Hat, Inc.
   6 *  Copyright (c) 2014, Linaro Ltd. All rights reserved.<BR>
   7 *
   8 *  This program and the accompanying materials are licensed and made available
   9 *  under the terms and conditions of the BSD License which accompanies this
  10 *  distribution.  The full text of the license may be found at
  11 *  http://opensource.org/licenses/bsd-license.php
  12 *
  13 *  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  14 *  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR
  15 *  IMPLIED.
  16 *
  17 **/
  18
  19 #include <Uefi/UefiBaseType.h>
  20 #include <Uefi/UefiSpec.h>
  21
  22 #include <IndustryStandard/SmBios.h>
  23
  24 #include <Library/BaseMemoryLib.h>
  25 #include <Library/DebugLib.h>
  26 #include <Library/PcdLib.h>
  27 #include <Library/QemuFwCfgLib.h>
  28
  29
  30 /**
  31   Set the SMBIOS entry point version for the generic SmbiosDxe driver.
  32 **/
  33 STATIC
  34 VOID
  35 SmbiosVersionInitialization (
  36   VOID
  37   )
  38 {
  39   FIRMWARE_CONFIG_ITEM     Anchor;
  40   UINTN                    AnchorSize;
  41   SMBIOS_TABLE_ENTRY_POINT QemuAnchor;
  42   UINT16                   SmbiosVersion;
  43
  44   if (RETURN_ERROR (QemuFwCfgFindFile ("etc/smbios/smbios-anchor", &Anchor,
  45                       &AnchorSize)) ||
  46       AnchorSize != sizeof QemuAnchor) {
  47     return;
  48   }
  49
  50   QemuFwCfgSelectItem (Anchor);
  51   QemuFwCfgReadBytes (AnchorSize, &QemuAnchor);
  52   if (CompareMem (QemuAnchor.AnchorString, "_SM_", 4) != 0 ||
  53       CompareMem (QemuAnchor.IntermediateAnchorString, "_DMI_", 5) != 0) {
  54     return;
  55   }
  56
  57   SmbiosVersion = (UINT16)(QemuAnchor.MajorVersion << 8 |
  58                            QemuAnchor.MinorVersion);
  59   DEBUG ((EFI_D_INFO, "%a: SMBIOS version from QEMU: 0x%04x\n", __FUNCTION__,
  60     SmbiosVersion));
  61   PcdSet16 (PcdSmbiosVersion, SmbiosVersion);
  62 }
  63
  64 EFI_STATUS
  65 EFIAPI
  66 ParseQemuFwCfgToPcd (
  67   IN EFI_HANDLE       ImageHandle,
  68   IN EFI_SYSTEM_TABLE *SystemTable
  69   )
  70 {
  71   SmbiosVersionInitialization ();
  72   return EFI_SUCCESS;
  73 }