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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 | |
7 | Copyright (c) 2009 - 2011, Intel Corporation. All rights reserved.<BR>\r | |
8 | This program and the accompanying materials \r | |
9 | are licensed and made available under the terms and conditions of the BSD License \r | |
10 | which accompanies this distribution. The full text of the license may be found at \r | |
11 | http://opensource.org/licenses/bsd-license.php\r | |
12 | \r | |
13 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, \r | |
14 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r | |
15 | \r | |
16 | **/\r | |
17 | \r | |
18 | #include "TcgMor.h"\r | |
19 | \r | |
20 | /**\r | |
21 | Entry Point for TCG MOR Control driver.\r | |
22 | \r | |
23 | @param[in] ImageHandle Image handle of this driver.\r | |
24 | @param[in] SystemTable A Pointer to the EFI System Table.\r | |
25 | \r | |
26 | @retval EFI_SUCEESS \r | |
27 | @return Others Some error occurs.\r | |
28 | **/\r | |
29 | EFI_STATUS\r | |
30 | EFIAPI\r | |
31 | MorDriverEntryPoint (\r | |
32 | IN EFI_HANDLE ImageHandle,\r | |
33 | IN EFI_SYSTEM_TABLE *SystemTable\r | |
34 | )\r | |
35 | {\r | |
36 | EFI_STATUS Status;\r | |
37 | UINT8 MorControl;\r | |
38 | UINTN DataSize;\r | |
39 | \r | |
40 | ///\r | |
41 | /// The firmware is required to create the MemoryOverwriteRequestControl UEFI variable.\r | |
42 | ///\r | |
43 | \r | |
44 | DataSize = sizeof (MorControl);\r | |
45 | Status = gRT->GetVariable (\r | |
46 | MEMORY_OVERWRITE_REQUEST_VARIABLE_NAME, \r | |
47 | &gEfiMemoryOverwriteControlDataGuid, \r | |
48 | NULL, \r | |
49 | &DataSize, \r | |
50 | &MorControl\r | |
51 | );\r | |
52 | if (EFI_ERROR (Status)) {\r | |
53 | //\r | |
54 | // Set default value to 0\r | |
55 | //\r | |
56 | MorControl = 0;\r | |
57 | } else {\r | |
58 | if (MOR_CLEAR_MEMORY_VALUE (MorControl) == 0x0) {\r | |
59 | //\r | |
60 | // MorControl is expected, directly return to avoid unnecessary variable operation\r | |
61 | //\r | |
62 | return EFI_SUCCESS;\r | |
63 | }\r | |
64 | //\r | |
65 | // Clear MOR_CLEAR_MEMORY_BIT\r | |
66 | //\r | |
67 | DEBUG ((EFI_D_INFO, "TcgMor: Clear MorClearMemory bit\n"));\r | |
68 | MorControl &= 0xFE;\r | |
69 | }\r | |
70 | \r | |
71 | Status = gRT->SetVariable (\r | |
72 | MEMORY_OVERWRITE_REQUEST_VARIABLE_NAME, \r | |
73 | &gEfiMemoryOverwriteControlDataGuid, \r | |
74 | EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,\r | |
75 | DataSize, \r | |
76 | &MorControl\r | |
77 | );\r | |
78 | ASSERT_EFI_ERROR (Status);\r | |
79 | return Status;\r | |
80 | }\r | |
81 | \r | |
82 | \r |