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1 /** @file
2   This driver produces PEI_LOCK_PHYSICAL_PRESENCE_PPI to indicate
3   whether TPM need be locked or not. It can be replaced by a platform
4   specific driver.
5 
6 Copyright (c) 2005 - 2011, Intel Corporation. All rights reserved.<BR>
7 This program and the accompanying materials
8 are licensed and made available under the terms and conditions of the BSD License
9 which accompanies this distribution.  The full text of the license may be found at
10 http://opensource.org/licenses/bsd-license.php
11 
12 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
13 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
14 
15 **/
16 
17 #include <PiPei.h>
18 #include <Ppi/LockPhysicalPresence.h>
19 #include <Ppi/ReadOnlyVariable2.h>
20 #include <Guid/PhysicalPresenceData.h>
21 #include <Library/PcdLib.h>
22 #include <Library/PeiServicesLib.h>
23 
24 /**
25   This interface returns whether TPM physical presence needs be locked or not.
26 
27   @param[in]  PeiServices       The pointer to the PEI Services Table.
28 
29   @retval     TRUE              The TPM physical presence should be locked.
30   @retval     FALSE             The TPM physical presence cannot be locked.
31 
32 **/
33 BOOLEAN
34 EFIAPI
35 LockTpmPhysicalPresence (
36   IN CONST  EFI_PEI_SERVICES             **PeiServices
37   );
38 
39 //
40 // Gobal defintions for lock physical presence PPI and its descriptor.
41 //
42 PEI_LOCK_PHYSICAL_PRESENCE_PPI    mLockPhysicalPresencePpi = {
43   LockTpmPhysicalPresence
44 };
45 
46 EFI_PEI_PPI_DESCRIPTOR       mLockPhysicalPresencePpiList = {
47   EFI_PEI_PPI_DESCRIPTOR_PPI | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST,
48   &gPeiLockPhysicalPresencePpiGuid,
49   &mLockPhysicalPresencePpi
50 };
51 
52 /**
53   This interface returns whether TPM physical presence needs be locked or not.
54 
55   @param[in]  PeiServices       The pointer to the PEI Services Table.
56 
57   @retval     TRUE              The TPM physical presence should be locked.
58   @retval     FALSE             The TPM physical presence cannot be locked.
59 
60 **/
61 BOOLEAN
62 EFIAPI
LockTpmPhysicalPresence(IN CONST EFI_PEI_SERVICES ** PeiServices)63 LockTpmPhysicalPresence (
64   IN CONST  EFI_PEI_SERVICES             **PeiServices
65   )
66 {
67   EFI_STATUS                         Status;
68   EFI_PEI_READ_ONLY_VARIABLE2_PPI    *Variable;
69   UINTN                              DataSize;
70   EFI_PHYSICAL_PRESENCE              TcgPpData;
71 
72   //
73   // The CRTM has sensed the physical presence assertion of the user. For example,
74   // the user has pressed the startup button or inserted a USB dongle. The details
75   // of the implementation are vendor-specific. Here we read a PCD value to indicate
76   // whether operator physical presence.
77   //
78   if (!PcdGetBool (PcdTpmPhysicalPresence)) {
79     return TRUE;
80   }
81 
82   //
83   // Check the pending TPM requests. Lock TPM physical presence if there is no TPM
84   // request.
85   //
86   Status = PeiServicesLocatePpi (
87              &gEfiPeiReadOnlyVariable2PpiGuid,
88              0,
89              NULL,
90              (VOID **)&Variable
91              );
92   if (!EFI_ERROR (Status)) {
93     DataSize = sizeof (EFI_PHYSICAL_PRESENCE);
94     Status = Variable->GetVariable (
95                          Variable,
96                          PHYSICAL_PRESENCE_VARIABLE,
97                          &gEfiPhysicalPresenceGuid,
98                          NULL,
99                          &DataSize,
100                          &TcgPpData
101                          );
102     if (!EFI_ERROR (Status)) {
103       if (TcgPpData.PPRequest != 0) {
104         return FALSE;
105       }
106     }
107   }
108 
109   //
110   // Lock TPM physical presence by default.
111   //
112   return TRUE;
113 }
114 
115 /**
116   Entry point of this module.
117 
118   It installs lock physical presence PPI.
119 
120   @param[in] FileHandle   Handle of the file being invoked.
121   @param[in] PeiServices  Describes the list of possible PEI Services.
122 
123   @return                 Status of install lock physical presence PPI.
124 
125 **/
126 EFI_STATUS
127 EFIAPI
PeimEntry(IN EFI_PEI_FILE_HANDLE FileHandle,IN CONST EFI_PEI_SERVICES ** PeiServices)128 PeimEntry (
129   IN       EFI_PEI_FILE_HANDLE       FileHandle,
130   IN CONST EFI_PEI_SERVICES          **PeiServices
131   )
132 {
133   return PeiServicesInstallPpi (&mLockPhysicalPresencePpiList);
134 }
135