EmbeddedPkg/Library/PrePiHobListPointerLib/PrePiHobListPointer.c

   1 /** @file
   2 *
   3 *  Copyright (c) 2011, ARM Limited. All rights reserved.
   4 *
   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 <PiPei.h>
  16 #include <Library/PrePiHobListPointerLib.h>
  17 #include <Library/DebugLib.h>
  18 #include <Library/PcdLib.h>
  19
  20 //
  21 // Have to use build system to set the original value in case we are running
  22 // from FLASH and globals don't work. So if you do a GetHobList() and gHobList
  23 // and gHobList is NULL the PCD default values are used.
  24 //
  25 VOID *gHobList = NULL;
  26
  27
  28 /**
  29   Returns the pointer to the HOB list.
  30
  31   This function returns the pointer to first HOB in the list.
  32
  33   @return The pointer to the HOB list.
  34
  35 **/
  36 VOID *
  37 EFIAPI
  38 PrePeiGetHobList (
  39   VOID
  40   )
  41 {
  42   if (gHobList == NULL) {
  43     return (VOID *)*(UINTN*)PcdGet32 (PcdPrePiHobBase);
  44   } else {
  45     return gHobList;
  46   }
  47 }
  48
  49
  50
  51 /**
  52   Updates the pointer to the HOB list.
  53
  54   @param  HobList       Hob list pointer to store
  55
  56 **/
  57 EFI_STATUS
  58 EFIAPI
  59 PrePeiSetHobList (
  60   IN  VOID      *HobList
  61   )
  62 {
  63   gHobList = HobList;
  64
  65   //
  66   // If this code is running from ROM this could fail
  67   //
  68   return (gHobList == HobList) ? EFI_SUCCESS: EFI_UNSUPPORTED;
  69 }