MdePkg/Library/PeiServicesTablePointerLibKr1/PeiServicesTablePointer.c

   1 /*++
   2
   3 Copyright (c) 2006 Intel Corporation. All rights reserved
   4 This software and associated documentation (if any) is furnished
   5 under a license and may only be used or copied in accordance
   6 with the terms of the license. Except as permitted by such
   7 license, no part of this software or documentation may be
   8 reproduced, stored in a retrieval system, or transmitted in any
   9 form or by any means without the express written consent of
  10 Intel Corporation.
  11
  12
  13 Module Name:
  14
  15   PeiServicesTablePointer.c
  16
  17 Abstract:
  18
  19   PEI Services Table Pointer Library.
  20
  21 --*/
  22
  23
  24 /**
  25   Reads the current value of Kr1.
  26
  27   @return The current value of Kr1.
  28
  29 **/
  30 UINT64
  31 EFIAPI
  32 AsmReadKr1 (
  33   VOID
  34   );
  35
  36 /**
  37   Writes the current value of Kr1.
  38
  39   @param  Value The 64-bit value to write to Kr1.
  40
  41 **/
  42 VOID
  43 EFIAPI
  44 AsmWriteKr1 (
  45   IN      UINT64                    Value
  46   );
  47
  48 /**
  49   The function returns the pointer to PeiServices.
  50
  51   The function returns the pointer to PeiServices.
  52   It will ASSERT() if the pointer to PeiServices is NULL.
  53
  54   @retval  The pointer to PeiServices.
  55
  56 **/
  57 EFI_PEI_SERVICES **
  58 EFIAPI
  59 GetPeiServicesTablePointer (
  60   VOID
  61   )
  62 {
  63   EFI_PEI_SERVICES  **PeiServices;
  64
  65   PeiServices = (EFI_PEI_SERVICES **)(UINTN)AsmReadKr1 ();
  66   ASSERT (PeiServices != NULL);
  67   return PeiServices;
  68 }
  69
  70 /**
  71   The constructor function caches the pointer to PEI services.
  72
  73   The constructor function caches the pointer to PEI services.
  74   It will always return EFI_SUCCESS.
  75
  76   @param  FfsHeader   Pointer to FFS header the loaded driver.
  77   @param  PeiServices Pointer to the PEI services.
  78
  79   @retval EFI_SUCCESS   The constructor always returns EFI_SUCCESS.
  80
  81 **/
  82 EFI_STATUS
  83 EFIAPI
  84 PeiServicesTablePointerLibConstructor (
  85   IN EFI_FFS_FILE_HEADER  *FfsHeader,
  86   IN EFI_PEI_SERVICES     **PeiServices
  87   )
  88 {
  89   AsmWriteKr1 ((UINT64)(UINTN)PeiServices);
  90   return EFI_SUCCESS;
  91 }