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 } 162 163
