X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=MdePkg%2FLibrary%2FPeiServicesTablePointerLib%2FPeiServicesTablePointer.c;h=efcaac929fc0fcb8a3e66825b04fdbf2092e7c35;hb=da351bdbe2076e06ecde95c9f563784c8d53af46;hp=43293fb83c62941997e68ec2a40879cebc0b30e8;hpb=42eedea958591087603bbacd1c2227d2494026af;p=mirror_edk2.git

diff --git a/MdePkg/Library/PeiServicesTablePointerLib/PeiServicesTablePointer.c b/MdePkg/Library/PeiServicesTablePointerLib/PeiServicesTablePointer.c
index 43293fb83c..efcaac929f 100644
--- a/MdePkg/Library/PeiServicesTablePointerLib/PeiServicesTablePointer.c
+++ b/MdePkg/Library/PeiServicesTablePointerLib/PeiServicesTablePointer.c
@@ -1,11 +1,14 @@
 /** @file
   PEI Services Table Pointer Library.
+  
+  This library is used for PEIM which does executed from flash device directly but
+  executed in memory.
 
-  Copyright (c) 2006, Intel Corporation<BR>
-  All rights reserved. This program and the accompanying materials
+  Copyright (c) 2006 - 2014, Intel Corporation. All rights reserved.<BR>
+  This program and the accompanying materials
   are licensed and made available under the terms and conditions of the BSD License
   which accompanies this distribution.  The full text of the license may be found at
-  http://opensource.org/licenses/bsd-license.php
+  http://opensource.org/licenses/bsd-license.php.
 
   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
@@ -16,35 +19,43 @@
 #include <Library/PeiServicesTablePointerLib.h>
 #include <Library/DebugLib.h>
 
-#include "PeiServicesTablePointerInternal.h"
-
-STATIC EFI_PEI_SERVICES  **gPeiServices;
+CONST EFI_PEI_SERVICES  **gPeiServices;
 
 /**
-  The function set the pointer of PEI services immediately preceding the IDT table
-  according to PI specification.
+  Caches a pointer PEI Services Table. 
+ 
+  Caches the pointer to the PEI Services Table specified by PeiServicesTablePointer 
+  in a CPU specific manner as specified in the CPU binding section of the Platform Initialization 
+  Pre-EFI Initialization Core Interface Specification. 
   
-  @param    PeiServices   The address of PeiServices pointer.
+  If PeiServicesTablePointer is NULL, then ASSERT().
+  
+  @param    PeiServicesTablePointer   The address of PeiServices pointer.
 **/
 VOID
 EFIAPI
 SetPeiServicesTablePointer (
-  EFI_PEI_SERVICES  **PeiServices
+  IN CONST EFI_PEI_SERVICES ** PeiServicesTablePointer
   )
 {
-  gPeiServices = PeiServices;
+  ASSERT (PeiServicesTablePointer != NULL);
+  gPeiServices = PeiServicesTablePointer;
 }
 
 /**
-  The function returns the pointer to PEI services.
+  Retrieves the cached value of the PEI Services Table pointer.
 
-  The function returns the pointer to PEI services.
-  It will ASSERT() if the pointer to PEI services is NULL.
+  Returns the cached value of the PEI Services Table pointer in a CPU specific manner 
+  as specified in the CPU binding section of the Platform Initialization Pre-EFI 
+  Initialization Core Interface Specification.
+  
+  If the cached PEI Services Table pointer is NULL, then ASSERT().
 
-  @retval  The pointer to PeiServices.
+  @return  The pointer to PeiServices.
 
 **/
-EFI_PEI_SERVICES **
+CONST EFI_PEI_SERVICES **
+EFIAPI
 GetPeiServicesTablePointer (
   VOID
   )
@@ -60,21 +71,46 @@ GetPeiServicesTablePointer (
   The constructor function caches the pointer to PEI services.
   It will always return EFI_SUCCESS.
 
-  @param  FileHandle   Handle of FFS header the loaded driver.
-  @param  PeiServices Pointer to the PEI services.
+  @param  FileHandle   The handle of FFS header the loaded driver.
+  @param  PeiServices  The pointer to the PEI services.
 
-  @retval EFI_SUCCESS   The constructor always returns EFI_SUCCESS.
+  @retval EFI_SUCCESS  The constructor always returns EFI_SUCCESS.
 
 **/
 EFI_STATUS
 EFIAPI
 PeiServicesTablePointerLibConstructor (
-  IN EFI_PEI_FILE_HANDLE  FileHandle,
-  IN EFI_PEI_SERVICES     **PeiServices
+  IN EFI_PEI_FILE_HANDLE        FileHandle,
+  IN CONST EFI_PEI_SERVICES     **PeiServices
   )
 {
   gPeiServices = PeiServices;
   return EFI_SUCCESS;
 }
 
+/**
+  Perform CPU specific actions required to migrate the PEI Services Table 
+  pointer from temporary RAM to permanent RAM.
+
+  For IA32 CPUs, the PEI Services Table pointer is stored in the 4 bytes 
+  immediately preceding the Interrupt Descriptor Table (IDT) in memory.
+  For X64 CPUs, the PEI Services Table pointer is stored in the 8 bytes 
+  immediately preceding the Interrupt Descriptor Table (IDT) in memory.
+  For Itanium and ARM CPUs, a the PEI Services Table Pointer is stored in
+  a dedicated CPU register.  This means that there is no memory storage 
+  associated with storing the PEI Services Table pointer, so no additional 
+  migration actions are required for Itanium or ARM CPUs.
 
+**/
+VOID
+EFIAPI
+MigratePeiServicesTablePointer (
+  VOID
+  )
+{
+  //
+  //  PEI Services Table pointer is cached in the global variable. No additional 
+  //  migration actions are required.
+  //
+  return;
+}