IntelFrameworkPkg/Library/FrameworkUefiLib/Acpi.c

   1 /** @file
   2   This module provides help function for finding ACPI table.
   3
   4   Copyright (c) 2018, Intel Corporation. All rights reserved.<BR>
   5   This program and the accompanying materials
   6   are licensed and made available under the terms and conditions of the BSD License
   7   which accompanies this distribution.  The full text of the license may be found at
   8   http://opensource.org/licenses/bsd-license.php.
   9
  10   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13 **/
  14
  15 #include "UefiLibInternal.h"
  16 #include <IndustryStandard/Acpi.h>
  17
  18 /**
  19   This function locates next ACPI table in XSDT/RSDT based on Signature and
  20   previous returned Table.
  21
  22   If PreviousTable is NULL:
  23   This function will locate the first ACPI table in XSDT/RSDT based on
  24   Signature in gEfiAcpi20TableGuid system configuration table first, and then
  25   gEfiAcpi10TableGuid system configuration table.
  26   This function will locate in XSDT first, and then RSDT.
  27   For DSDT, this function will locate XDsdt in FADT first, and then Dsdt in
  28   FADT.
  29   For FACS, this function will locate XFirmwareCtrl in FADT first, and then
  30   FirmwareCtrl in FADT.
  31
  32   If PreviousTable is not NULL:
  33   1. If it could be located in XSDT in gEfiAcpi20TableGuid system configuration
  34      table, then this function will just locate next table in XSDT in
  35      gEfiAcpi20TableGuid system configuration table.
  36   2. If it could be located in RSDT in gEfiAcpi20TableGuid system configuration
  37      table, then this function will just locate next table in RSDT in
  38      gEfiAcpi20TableGuid system configuration table.
  39   3. If it could be located in RSDT in gEfiAcpi10TableGuid system configuration
  40      table, then this function will just locate next table in RSDT in
  41      gEfiAcpi10TableGuid system configuration table.
  42
  43   It's not supported that PreviousTable is not NULL but PreviousTable->Signature
  44   is not same with Signature, NULL will be returned.
  45
  46   @param Signature          ACPI table signature.
  47   @param PreviousTable      Pointer to previous returned table to locate next
  48                             table, or NULL to locate first table.
  49
  50   @return Next ACPI table or NULL if not found.
  51
  52 **/
  53 EFI_ACPI_COMMON_HEADER *
  54 EFIAPI
  55 EfiLocateNextAcpiTable (
  56   IN UINT32                     Signature,
  57   IN EFI_ACPI_COMMON_HEADER     *PreviousTable OPTIONAL
  58   )
  59 {
  60   ASSERT (FALSE);
  61   return NULL;
  62 }
  63
  64 /**
  65   This function locates first ACPI table in XSDT/RSDT based on Signature.
  66
  67   This function will locate the first ACPI table in XSDT/RSDT based on
  68   Signature in gEfiAcpi20TableGuid system configuration table first, and then
  69   gEfiAcpi10TableGuid system configuration table.
  70   This function will locate in XSDT first, and then RSDT.
  71   For DSDT, this function will locate XDsdt in FADT first, and then Dsdt in
  72   FADT.
  73   For FACS, this function will locate XFirmwareCtrl in FADT first, and then
  74   FirmwareCtrl in FADT.
  75
  76   @param Signature          ACPI table signature.
  77
  78   @return First ACPI table or NULL if not found.
  79
  80 **/
  81 EFI_ACPI_COMMON_HEADER *
  82 EFIAPI
  83 EfiLocateFirstAcpiTable (
  84   IN UINT32                     Signature
  85   )
  86 {
  87   return EfiLocateNextAcpiTable (Signature, NULL);
  88 }