1 /** @file
2 PEI Services Table Pointer Library for IA-32 and x64.
3
4 According to PI specification, the peiservice pointer is stored prior at IDT
5 table in IA32 and x64 architecture.
6
7 Copyright (c) 2006 - 2014, Intel Corporation. All rights reserved.<BR>
8 This program and the accompanying materials
9 are licensed and made available under the terms and conditions of the BSD License
10 which accompanies this distribution. The full text of the license may be found at
11 http://opensource.org/licenses/bsd-license.php.
12
13 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
14 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
15
16 **/
17
18 #include <PiPei.h>
19
20 #include <Library/BaseLib.h>
21 #include <Library/PeiServicesTablePointerLib.h>
22 #include <Library/DebugLib.h>
23 #include <Library/BaseMemoryLib.h>
24
25 /**
26 Retrieves the cached value of the PEI Services Table pointer.
27
28 Returns the cached value of the PEI Services Table pointer in a CPU specific manner
29 as specified in the CPU binding section of the Platform Initialization Pre-EFI
30 Initialization Core Interface Specification.
31
32 If the cached PEI Services Table pointer is NULL, then ASSERT().
33
34 @return The pointer to PeiServices.
35
36 **/
37 CONST EFI_PEI_SERVICES **
38 EFIAPI
GetPeiServicesTablePointer(VOID)39 GetPeiServicesTablePointer (
40 VOID
41 )
42 {
43 CONST EFI_PEI_SERVICES **PeiServices;
44 IA32_DESCRIPTOR Idtr;
45
46 AsmReadIdtr (&Idtr);
47 PeiServices = (CONST EFI_PEI_SERVICES **) (*(UINTN*)(Idtr.Base - sizeof (UINTN)));
48 ASSERT (PeiServices != NULL);
49 return PeiServices;
50 }
51
52 /**
53 Caches a pointer PEI Services Table.
54
55 Caches the pointer to the PEI Services Table specified by PeiServicesTablePointer
56 in a CPU specific manner as specified in the CPU binding section of the Platform Initialization
57 Pre-EFI Initialization Core Interface Specification.
58 The function set the pointer of PEI services immediately preceding the IDT table
59 according to PI specification.
60
61 If PeiServicesTablePointer is NULL, then ASSERT().
62
63 @param PeiServicesTablePointer The address of PeiServices pointer.
64 **/
65 VOID
66 EFIAPI
SetPeiServicesTablePointer(IN CONST EFI_PEI_SERVICES ** PeiServicesTablePointer)67 SetPeiServicesTablePointer (
68 IN CONST EFI_PEI_SERVICES ** PeiServicesTablePointer
69 )
70 {
71 IA32_DESCRIPTOR Idtr;
72
73 ASSERT (PeiServicesTablePointer != NULL);
74 AsmReadIdtr (&Idtr);
75 (*(UINTN*)(Idtr.Base - sizeof (UINTN))) = (UINTN)PeiServicesTablePointer;
76 }
77
78 /**
79 Perform CPU specific actions required to migrate the PEI Services Table
80 pointer from temporary RAM to permanent RAM.
81
82 For IA32 CPUs, the PEI Services Table pointer is stored in the 4 bytes
83 immediately preceding the Interrupt Descriptor Table (IDT) in memory.
84 For X64 CPUs, the PEI Services Table pointer is stored in the 8 bytes
85 immediately preceding the Interrupt Descriptor Table (IDT) in memory.
86 For Itanium and ARM CPUs, a the PEI Services Table Pointer is stored in
87 a dedicated CPU register. This means that there is no memory storage
88 associated with storing the PEI Services Table pointer, so no additional
89 migration actions are required for Itanium or ARM CPUs.
90
91 If The cached PEI Services Table pointer is NULL, then ASSERT().
92 If the permanent memory is allocated failed, then ASSERT().
93 **/
94 VOID
95 EFIAPI
MigratePeiServicesTablePointer(VOID)96 MigratePeiServicesTablePointer (
97 VOID
98 )
99 {
100 EFI_STATUS Status;
101 IA32_DESCRIPTOR Idtr;
102 EFI_PHYSICAL_ADDRESS IdtBase;
103 CONST EFI_PEI_SERVICES **PeiServices;
104
105 //
106 // Get PEI Services Table pointer
107 //
108 AsmReadIdtr (&Idtr);
109 PeiServices = (CONST EFI_PEI_SERVICES **) (*(UINTN*)(Idtr.Base - sizeof (UINTN)));
110 ASSERT (PeiServices != NULL);
111 //
112 // Allocate the permanent memory.
113 //
114 Status = (*PeiServices)->AllocatePages (
115 PeiServices,
116 EfiBootServicesCode,
117 EFI_SIZE_TO_PAGES(Idtr.Limit + 1 + sizeof (UINTN)),
118 &IdtBase
119 );
120 ASSERT_EFI_ERROR (Status);
121 //
122 // Idt table needs to be migrated into memory.
123 //
124 CopyMem ((VOID *) (UINTN) IdtBase, (VOID *) (Idtr.Base - sizeof (UINTN)), Idtr.Limit + 1 + sizeof (UINTN));
125 Idtr.Base = (UINTN) IdtBase + sizeof (UINTN);
126 AsmWriteIdtr (&Idtr);
127
128 return;
129 }
130
131
132