Add Tper Reset Logic by using MOR bit.
[mirror_edk2.git] / SecurityPkg / Tcg / MemoryOverwriteControl / TcgMor.c
CommitLineData
0c18794e 1/** @file\r
2 TCG MOR (Memory Overwrite Request) Control Driver.\r
3\r
4 This driver initilize MemoryOverwriteRequestControl variable. It \r
5 will clear MOR_CLEAR_MEMORY_BIT bit if it is set.\r
6\r
504dfa9d 7Copyright (c) 2009 - 2012, Intel Corporation. All rights reserved.<BR>\r
0c18794e 8This program and the accompanying materials \r
9are licensed and made available under the terms and conditions of the BSD License \r
10which accompanies this distribution. The full text of the license may be found at \r
11http://opensource.org/licenses/bsd-license.php\r
12\r
13THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, \r
14WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
15\r
16**/\r
17\r
18#include "TcgMor.h"\r
19\r
504dfa9d 20UINT8 mMorControl;\r
21\r
22/**\r
23 Ready to Boot Event notification handler.\r
24\r
25 Sequence of OS boot events is measured in this event notification handler.\r
26\r
27 @param[in] Event Event whose notification function is being invoked\r
28 @param[in] Context Pointer to the notification function's context\r
29\r
30**/\r
31VOID\r
32EFIAPI\r
33OnReadyToBoot (\r
34 IN EFI_EVENT Event,\r
35 IN VOID *Context\r
36 )\r
37{\r
38 UINTN DataSize;\r
39 \r
40 if (MOR_CLEAR_MEMORY_VALUE (mMorControl) == 0x0) {\r
41 //\r
42 // MorControl is expected, directly return to avoid unnecessary variable operation\r
43 //\r
44 return ;\r
45 }\r
46 //\r
47 // Clear MOR_CLEAR_MEMORY_BIT\r
48 //\r
49 DEBUG ((EFI_D_INFO, "TcgMor: Clear MorClearMemory bit\n"));\r
50 mMorControl &= 0xFE; \r
51\r
52 DataSize = sizeof (mMorControl);\r
53 gRT->SetVariable (\r
54 MEMORY_OVERWRITE_REQUEST_VARIABLE_NAME, \r
55 &gEfiMemoryOverwriteControlDataGuid, \r
56 EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,\r
57 DataSize, \r
58 &mMorControl\r
59 );\r
60\r
61}\r
62\r
63\r
0c18794e 64/**\r
65 Entry Point for TCG MOR Control driver.\r
66\r
67 @param[in] ImageHandle Image handle of this driver.\r
68 @param[in] SystemTable A Pointer to the EFI System Table.\r
69\r
70 @retval EFI_SUCEESS \r
71 @return Others Some error occurs.\r
72**/\r
73EFI_STATUS\r
74EFIAPI\r
75MorDriverEntryPoint (\r
76 IN EFI_HANDLE ImageHandle,\r
77 IN EFI_SYSTEM_TABLE *SystemTable\r
78 )\r
79{\r
80 EFI_STATUS Status;\r
0c18794e 81 UINTN DataSize;\r
504dfa9d 82 EFI_EVENT Event;\r
0c18794e 83\r
84 ///\r
85 /// The firmware is required to create the MemoryOverwriteRequestControl UEFI variable.\r
86 ///\r
87\r
504dfa9d 88 DataSize = sizeof (mMorControl);\r
0c18794e 89 Status = gRT->GetVariable (\r
90 MEMORY_OVERWRITE_REQUEST_VARIABLE_NAME, \r
91 &gEfiMemoryOverwriteControlDataGuid, \r
92 NULL, \r
93 &DataSize, \r
504dfa9d 94 &mMorControl\r
0c18794e 95 );\r
96 if (EFI_ERROR (Status)) {\r
97 //\r
98 // Set default value to 0\r
99 //\r
504dfa9d 100 mMorControl = 0;\r
101 DEBUG ((EFI_D_INFO, "TcgMor: Create gEfiMemoryOverwriteControlDataGuid!\n"));\r
102 Status = gRT->SetVariable (\r
103 MEMORY_OVERWRITE_REQUEST_VARIABLE_NAME, \r
104 &gEfiMemoryOverwriteControlDataGuid, \r
105 EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,\r
106 DataSize, \r
107 &mMorControl\r
108 );\r
109 ASSERT_EFI_ERROR (Status);\r
110 \r
0c18794e 111 } else {\r
0c18794e 112 //\r
504dfa9d 113 // Create a Ready To Boot Event and Clear the MorControl bit in the call back function.\r
0c18794e 114 //\r
504dfa9d 115 DEBUG ((EFI_D_INFO, "TcgMor: Create ReadyToBoot Event for MorControl Bit cleanning!\n"));\r
116 Status = EfiCreateEventReadyToBootEx (\r
117 TPL_CALLBACK,\r
118 OnReadyToBoot,\r
119 NULL,\r
120 &Event\r
121 );\r
122 } \r
0c18794e 123 \r
0c18794e 124 return Status;\r
125}\r
126\r
127\r