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   SPDX-License-Identifier: BSD-2-Clause-Patent
  10
  11 **/
  12
  13 #include <PiPei.h>
  14 #include <Library/PeiServicesTablePointerLib.h>
  15 #include <Library/DebugLib.h>
  16
  17 #include <Ppi/MemoryDiscovered.h>
  18
  19
  20 CONST EFI_PEI_SERVICES  **gPeiServices = NULL;
  21
  22 /**
  23   Caches a pointer PEI Services Table.
  24
  25   Caches the pointer to the PEI Services Table specified by PeiServicesTablePointer
  26   in a CPU specific manner as specified in the CPU binding section of the Platform Initialization
  27   Pre-EFI Initialization Core Interface Specification.
  28
  29   If PeiServicesTablePointer is NULL, then ASSERT().
  30
  31   @param    PeiServicesTablePointer   The address of PeiServices pointer.
  32 **/
  33 VOID
  34 EFIAPI
  35 SetPeiServicesTablePointer (
  36   IN CONST EFI_PEI_SERVICES ** PeiServicesTablePointer
  37   )
  38 {
  39   ASSERT (PeiServicesTablePointer != NULL);
  40   ASSERT (*PeiServicesTablePointer != NULL);
  41   gPeiServices = PeiServicesTablePointer;
  42 }
  43
  44 /**
  45   Retrieves the cached value of the PEI Services Table pointer.
  46
  47   Returns the cached value of the PEI Services Table pointer in a CPU specific manner
  48   as specified in the CPU binding section of the Platform Initialization Pre-EFI
  49   Initialization Core Interface Specification.
  50
  51   If the cached PEI Services Table pointer is NULL, then ASSERT().
  52
  53   @return  The pointer to PeiServices.
  54
  55 **/
  56 CONST EFI_PEI_SERVICES **
  57 EFIAPI
  58 GetPeiServicesTablePointer (
  59   VOID
  60   )
  61 {
  62   ASSERT (gPeiServices != NULL);
  63   ASSERT (*gPeiServices != NULL);
  64   return gPeiServices;
  65 }
  66
  67
  68
  69 /**
  70   Notification service to be called when gEmuThunkPpiGuid is installed.
  71
  72   @param  PeiServices                 Indirect reference to the PEI Services Table.
  73   @param  NotifyDescriptor          Address of the notification descriptor data structure. Type
  74           EFI_PEI_NOTIFY_DESCRIPTOR is defined above.
  75   @param  Ppi                             Address of the PPI that was installed.
  76
  77   @retval   EFI_STATUS                This function will install a PPI to PPI database. The status
  78                                                   code will be the code for (*PeiServices)->InstallPpi.
  79
  80 **/
  81 EFI_STATUS
  82 EFIAPI
  83 PeiServicesTablePointerNotifyCallback (
  84   IN EFI_PEI_SERVICES              **PeiServices,
  85   IN EFI_PEI_NOTIFY_DESCRIPTOR     *NotifyDescriptor,
  86   IN VOID                          *Ppi
  87   )
  88 {
  89   gPeiServices = (CONST EFI_PEI_SERVICES  **)PeiServices;
  90
  91   return EFI_SUCCESS;
  92 }
  93
  94
  95 EFI_PEI_NOTIFY_DESCRIPTOR mNotifyOnThunkList = {
  96   (EFI_PEI_PPI_DESCRIPTOR_NOTIFY_CALLBACK | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST),
  97   &gEfiPeiMemoryDiscoveredPpiGuid,
  98   PeiServicesTablePointerNotifyCallback
  99 };
 100
 101
 102 /**
 103   Constructor register notification on when PPI updates. If PPI is
 104   alreay installed registering the notify will cause the handle to
 105   run.
 106
 107   @param  FileHandle   The handle of FFS header the loaded driver.
 108   @param  PeiServices  The pointer to the PEI services.
 109
 110   @retval EFI_SUCCESS  The constructor always returns EFI_SUCCESS.
 111
 112 **/
 113 EFI_STATUS
 114 EFIAPI
 115 PeiServicesTablePointerLibConstructor (
 116   IN EFI_PEI_FILE_HANDLE        FileHandle,
 117   IN CONST EFI_PEI_SERVICES     **PeiServices
 118   )
 119 {
 120   EFI_STATUS              Status;
 121
 122   gPeiServices = (CONST EFI_PEI_SERVICES  **)PeiServices;
 123
 124   // register to be told when PeiServices pointer is updated
 125   Status = (*PeiServices)->NotifyPpi (PeiServices, &mNotifyOnThunkList);
 126   ASSERT_EFI_ERROR (Status);
 127   return Status;
 128 }
 129
 130 /**
 131   Perform CPU specific actions required to migrate the PEI Services Table
 132   pointer from temporary RAM to permanent RAM.
 133
 134   For IA32 CPUs, the PEI Services Table pointer is stored in the 4 bytes
 135   immediately preceding the Interrupt Descriptor Table (IDT) in memory.
 136   For X64 CPUs, the PEI Services Table pointer is stored in the 8 bytes
 137   immediately preceding the Interrupt Descriptor Table (IDT) in memory.
 138   For Itanium and ARM CPUs, a the PEI Services Table Pointer is stored in
 139   a dedicated CPU register.  This means that there is no memory storage
 140   associated with storing the PEI Services Table pointer, so no additional
 141   migration actions are required for Itanium or ARM CPUs.
 142
 143 **/
 144 VOID
 145 EFIAPI
 146 MigratePeiServicesTablePointer (
 147   VOID
 148   )
 149 {
 150   //
 151   //  PEI Services Table pointer is cached in the global variable. No additional
 152   //  migration actions are required.
 153   //
 154   return;
 155 }
 156