EmulatorPkg/Library/PeiServicesTablePointerLib/PeiServicesTablePointer.c

   1 /** @file
   2   PEI Services Table Pointer Library.
   3
   4   This library is used for PEIM which does executed from flash device directly but
   5   executed in memory.
   6
   7   Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
   8   Portiions copyrigth (c) 2011, Apple Inc. All rights reserved.
   9   This program and the accompanying materials
  10   are licensed and made available under the terms and conditions of the BSD License
  11   which accompanies this distribution.  The full text of the license may be found at
  12   http://opensource.org/licenses/bsd-license.php.
  13
  14   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  15   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  16
  17 **/
  18
  19 #include <PiPei.h>
  20 #include <Library/PeiServicesTablePointerLib.h>
  21 #include <Library/DebugLib.h>
  22
  23 #include <Ppi/MemoryDiscovered.h>
  24
  25
  26 CONST EFI_PEI_SERVICES  **gPeiServices = NULL;
  27
  28 /**
  29   Caches a pointer PEI Services Table.
  30
  31   Caches the pointer to the PEI Services Table specified by PeiServicesTablePointer
  32   in a CPU specific manner as specified in the CPU binding section of the Platform Initialization
  33   Pre-EFI Initialization Core Interface Specification.
  34
  35   If PeiServicesTablePointer is NULL, then ASSERT().
  36
  37   @param    PeiServicesTablePointer   The address of PeiServices pointer.
  38 **/
  39 VOID
  40 EFIAPI
  41 SetPeiServicesTablePointer (
  42   IN CONST EFI_PEI_SERVICES ** PeiServicesTablePointer
  43   )
  44 {
  45   ASSERT (PeiServicesTablePointer != NULL);
  46   ASSERT (*PeiServicesTablePointer != NULL);
  47   gPeiServices = PeiServicesTablePointer;
  48 }
  49
  50 /**
  51   Retrieves the cached value of the PEI Services Table pointer.
  52
  53   Returns the cached value of the PEI Services Table pointer in a CPU specific manner
  54   as specified in the CPU binding section of the Platform Initialization Pre-EFI
  55   Initialization Core Interface Specification.
  56
  57   If the cached PEI Services Table pointer is NULL, then ASSERT().
  58
  59   @return  The pointer to PeiServices.
  60
  61 **/
  62 CONST EFI_PEI_SERVICES **
  63 EFIAPI
  64 GetPeiServicesTablePointer (
  65   VOID
  66   )
  67 {
  68   ASSERT (gPeiServices != NULL);
  69   ASSERT (*gPeiServices != NULL);
  70   return gPeiServices;
  71 }
  72
  73
  74
  75 /**
  76   Notification service to be called when gEmuThunkPpiGuid is installed.
  77
  78   @param  PeiServices                 Indirect reference to the PEI Services Table.
  79   @param  NotifyDescriptor          Address of the notification descriptor data structure. Type
  80           EFI_PEI_NOTIFY_DESCRIPTOR is defined above.
  81   @param  Ppi                             Address of the PPI that was installed.
  82
  83   @retval   EFI_STATUS                This function will install a PPI to PPI database. The status
  84                                                   code will be the code for (*PeiServices)->InstallPpi.
  85
  86 **/
  87 EFI_STATUS
  88 EFIAPI
  89 PeiServicesTablePointerNotifyCallback (
  90   IN EFI_PEI_SERVICES              **PeiServices,
  91   IN EFI_PEI_NOTIFY_DESCRIPTOR     *NotifyDescriptor,
  92   IN VOID                          *Ppi
  93   )
  94 {
  95   gPeiServices = (CONST EFI_PEI_SERVICES  **)PeiServices;
  96
  97   return EFI_SUCCESS;
  98 }
  99
 100
 101 EFI_PEI_NOTIFY_DESCRIPTOR mNotifyOnThunkList = {
 102   (EFI_PEI_PPI_DESCRIPTOR_NOTIFY_CALLBACK | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST),
 103   &gEfiPeiMemoryDiscoveredPpiGuid,
 104   PeiServicesTablePointerNotifyCallback
 105 };
 106
 107
 108 /**
 109   Constructor register notification on when PPI updates. If PPI is
 110   alreay installed registering the notify will cause the handle to
 111   run.
 112
 113   @param  FileHandle   The handle of FFS header the loaded driver.
 114   @param  PeiServices  The pointer to the PEI services.
 115
 116   @retval EFI_SUCCESS  The constructor always returns EFI_SUCCESS.
 117
 118 **/
 119 EFI_STATUS
 120 EFIAPI
 121 PeiServicesTablePointerLibConstructor (
 122   IN EFI_PEI_FILE_HANDLE        FileHandle,
 123   IN CONST EFI_PEI_SERVICES     **PeiServices
 124   )
 125 {
 126   EFI_STATUS              Status;
 127
 128   gPeiServices = (CONST EFI_PEI_SERVICES  **)PeiServices;
 129
 130   // register to be told when PeiServices pointer is updated
 131   Status = (*PeiServices)->NotifyPpi (PeiServices, &mNotifyOnThunkList);
 132   ASSERT_EFI_ERROR (Status);
 133   return Status;
 134 }
 135
 136 /**
 137   Perform CPU specific actions required to migrate the PEI Services Table
 138   pointer from temporary RAM to permanent RAM.
 139
 140   For IA32 CPUs, the PEI Services Table pointer is stored in the 4 bytes
 141   immediately preceding the Interrupt Descriptor Table (IDT) in memory.
 142   For X64 CPUs, the PEI Services Table pointer is stored in the 8 bytes
 143   immediately preceding the Interrupt Descriptor Table (IDT) in memory.
 144   For Itanium and ARM CPUs, a the PEI Services Table Pointer is stored in
 145   a dedicated CPU register.  This means that there is no memory storage
 146   associated with storing the PEI Services Table pointer, so no additional
 147   migration actions are required for Itanium or ARM CPUs.
 148
 149 **/
 150 VOID
 151 EFIAPI
 152 MigratePeiServicesTablePointer (
 153   VOID
 154   )
 155 {
 156   //
 157   //  PEI Services Table pointer is cached in the global variable. No additional
 158   //  migration actions are required.
 159   //
 160   return;
 161 }
 162