1 /** @file
2 PEI Services Table Pointer Library.
3
4 Store PEI Services Table pointer via gEmulatorPkgTokenSpaceGuid.PcdPeiServicesTablePage.
5 This emulates a platform SRAM. The PI mechaism does not work in the emulator due to
6 lack of privledge.
7
8 Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
9 Portiions copyrigth (c) 2011, Apple Inc. All rights reserved.
10 This program and the accompanying materials
11 are licensed and made available under the terms and conditions of the BSD License
12 which accompanies this distribution. The full text of the license may be found at
13 http://opensource.org/licenses/bsd-license.php.
14
15 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
16 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
17
18 **/
19
20 #include <PiPei.h>
21 #include <Library/PeiServicesTablePointerLib.h>
22 #include <Library/DebugLib.h>
23 #include <Library/EmuMagicPageLib.h>
24
25
26 /**
27 Caches a pointer PEI Services Table.
28
29 Caches the pointer to the PEI Services Table specified by PeiServicesTablePointer
30 in a CPU specific manner as specified in the CPU binding section of the Platform Initialization
31 Pre-EFI Initialization Core Interface Specification.
32
33 If PeiServicesTablePointer is NULL, then ASSERT().
34
35 @param PeiServicesTablePointer The address of PeiServices pointer.
36 **/
37 VOID
38 EFIAPI
SetPeiServicesTablePointer(IN CONST EFI_PEI_SERVICES ** PeiServicesTablePointer)39 SetPeiServicesTablePointer (
40 IN CONST EFI_PEI_SERVICES ** PeiServicesTablePointer
41 )
42 {
43 ASSERT (PeiServicesTablePointer != NULL);
44 ASSERT (*PeiServicesTablePointer != NULL);
45 EMU_MAGIC_PAGE()->PeiServicesTablePointer = PeiServicesTablePointer;
46 }
47
48 /**
49 Retrieves the cached value of the PEI Services Table pointer.
50
51 Returns the cached value of the PEI Services Table pointer in a CPU specific manner
52 as specified in the CPU binding section of the Platform Initialization Pre-EFI
53 Initialization Core Interface Specification.
54
55 If the cached PEI Services Table pointer is NULL, then ASSERT().
56
57 @return The pointer to PeiServices.
58
59 **/
60 CONST EFI_PEI_SERVICES **
61 EFIAPI
GetPeiServicesTablePointer(VOID)62 GetPeiServicesTablePointer (
63 VOID
64 )
65 {
66 CONST EFI_PEI_SERVICES **PeiServicesTablePointer;
67
68 PeiServicesTablePointer = EMU_MAGIC_PAGE()->PeiServicesTablePointer;
69 ASSERT (PeiServicesTablePointer != NULL);
70 ASSERT (*PeiServicesTablePointer != NULL);
71 return PeiServicesTablePointer;
72 }
73
74 /**
75 Perform CPU specific actions required to migrate the PEI Services Table
76 pointer from temporary RAM to permanent RAM.
77
78 For IA32 CPUs, the PEI Services Table pointer is stored in the 4 bytes
79 immediately preceding the Interrupt Descriptor Table (IDT) in memory.
80 For X64 CPUs, the PEI Services Table pointer is stored in the 8 bytes
81 immediately preceding the Interrupt Descriptor Table (IDT) in memory.
82 For Itanium and ARM CPUs, a the PEI Services Table Pointer is stored in
83 a dedicated CPU register. This means that there is no memory storage
84 associated with storing the PEI Services Table pointer, so no additional
85 migration actions are required for Itanium or ARM CPUs.
86
87 **/
88 VOID
89 EFIAPI
MigratePeiServicesTablePointer(VOID)90 MigratePeiServicesTablePointer (
91 VOID
92 )
93 {
94 //
95 // PEI Services Table pointer is cached in SRAM. No additional
96 // migration actions are required.
97 //
98 return;
99 }
100
101
102