1 /** @file
2 SMM Access2 Protocol on SMM Access Protocol Thunk driver.
3
4 Copyright (c) 2009 - 2010, Intel Corporation. All rights reserved.<BR>
5 This program and the accompanying materials
6 are licensed and made available under the terms and conditions of the BSD License
7 which accompanies this distribution. The full text of the license may be found at
8 http://opensource.org/licenses/bsd-license.php
9
10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
12
13 **/
14
15 #include "SmmAccess2OnSmmAccessThunk.h"
16
17 EFI_SMM_ACCESS2_PROTOCOL gSmmAccess2 = {
18 SmmAccess2Open,
19 SmmAccess2Close,
20 SmmAccess2Lock,
21 SmmAccess2GetCapabilities,
22 FALSE,
23 FALSE
24 };
25
26 EFI_SMM_ACCESS_PROTOCOL *mSmmAccess;
27 UINTN mSmramRegionNumber;
28
29 /**
30 Opens the SMRAM area to be accessible by a boot-service driver.
31
32 This function "opens" SMRAM so that it is visible while not inside of SMM. The function should
33 return EFI_UNSUPPORTED if the hardware does not support hiding of SMRAM. The function
34 should return EFI_DEVICE_ERROR if the SMRAM configuration is locked.
35
36 @param[in] This The EFI_SMM_ACCESS2_PROTOCOL instance.
37
38 @retval EFI_SUCCESS The operation was successful.
39 @retval EFI_UNSUPPORTED The system does not support opening and closing of SMRAM.
40 @retval EFI_DEVICE_ERROR SMRAM cannot be opened, perhaps because it is locked.
41 **/
42 EFI_STATUS
43 EFIAPI
SmmAccess2Open(IN EFI_SMM_ACCESS2_PROTOCOL * This)44 SmmAccess2Open (
45 IN EFI_SMM_ACCESS2_PROTOCOL *This
46 )
47 {
48 EFI_STATUS Status;
49 UINTN DescriptorIndex;
50
51 ///
52 /// Open all SMRAM regions via SMM Access Protocol
53 ///
54
55 Status = EFI_SUCCESS;
56 for (DescriptorIndex = 0; DescriptorIndex < mSmramRegionNumber && !EFI_ERROR (Status); DescriptorIndex++) {
57 Status = mSmmAccess->Open (mSmmAccess, DescriptorIndex);
58 }
59 if (!EFI_ERROR (Status)) {
60 gSmmAccess2.OpenState = TRUE;
61 }
62 return Status;
63 }
64
65 /**
66 Inhibits access to the SMRAM.
67
68 This function "closes" SMRAM so that it is not visible while outside of SMM. The function should
69 return EFI_UNSUPPORTED if the hardware does not support hiding of SMRAM.
70
71 @param [in] This The EFI_SMM_ACCESS2_PROTOCOL instance.
72
73 @retval EFI_SUCCESS The operation was successful.
74 @retval EFI_UNSUPPORTED The system does not support opening and closing of SMRAM.
75 @retval EFI_DEVICE_ERROR SMRAM cannot be closed.
76 **/
77 EFI_STATUS
78 EFIAPI
SmmAccess2Close(IN EFI_SMM_ACCESS2_PROTOCOL * This)79 SmmAccess2Close (
80 IN EFI_SMM_ACCESS2_PROTOCOL *This
81 )
82 {
83 EFI_STATUS Status;
84 UINTN DescriptorIndex;
85
86 ///
87 /// Close all SMRAM regions via SMM Access Protocol
88 ///
89
90 Status = EFI_SUCCESS;
91 for (DescriptorIndex = 0; DescriptorIndex < mSmramRegionNumber && !EFI_ERROR (Status); DescriptorIndex++) {
92 Status = mSmmAccess->Close (mSmmAccess, DescriptorIndex);
93 }
94 if (!EFI_ERROR (Status)) {
95 gSmmAccess2.OpenState = FALSE;
96 }
97 return Status;
98 }
99
100 /**
101 Inhibits access to the SMRAM.
102
103 This function prohibits access to the SMRAM region. This function is usually implemented such
104 that it is a write-once operation.
105
106 @param[in] This The EFI_SMM_ACCESS2_PROTOCOL instance.
107
108 @retval EFI_SUCCESS The device was successfully locked.
109 @retval EFI_UNSUPPORTED The system does not support locking of SMRAM.
110 **/
111 EFI_STATUS
112 EFIAPI
SmmAccess2Lock(IN EFI_SMM_ACCESS2_PROTOCOL * This)113 SmmAccess2Lock (
114 IN EFI_SMM_ACCESS2_PROTOCOL *This
115 )
116 {
117 EFI_STATUS Status;
118 UINTN DescriptorIndex;
119
120 ///
121 /// Lock all SMRAM regions via SMM Access Protocol
122 ///
123
124 Status = EFI_SUCCESS;
125 for (DescriptorIndex = 0; DescriptorIndex < mSmramRegionNumber && !EFI_ERROR (Status); DescriptorIndex++) {
126 Status = mSmmAccess->Lock (mSmmAccess, DescriptorIndex);
127 }
128 if (!EFI_ERROR (Status)) {
129 gSmmAccess2.LockState = TRUE;
130 }
131 return Status;
132 }
133
134 /**
135 Queries the memory controller for the possible regions that will support SMRAM.
136
137 @param[in] This The EFI_SMM_ACCESS2_PROTOCOL instance.
138 @param[in, out] SmramMapSize A pointer to the size, in bytes, of the SmramMemoryMap buffer.
139 @param[in, out] SmramMap A pointer to the buffer in which firmware places the current memory map.
140
141 @retval EFI_SUCCESS The chipset supported the given resource.
142 @retval EFI_BUFFER_TOO_SMALL The SmramMap parameter was too small. The current buffer size
143 needed to hold the memory map is returned in SmramMapSize.
144 **/
145 EFI_STATUS
146 EFIAPI
SmmAccess2GetCapabilities(IN CONST EFI_SMM_ACCESS2_PROTOCOL * This,IN OUT UINTN * SmramMapSize,IN OUT EFI_SMRAM_DESCRIPTOR * SmramMap)147 SmmAccess2GetCapabilities (
148 IN CONST EFI_SMM_ACCESS2_PROTOCOL *This,
149 IN OUT UINTN *SmramMapSize,
150 IN OUT EFI_SMRAM_DESCRIPTOR *SmramMap
151 )
152 {
153 return mSmmAccess->GetCapabilities (mSmmAccess, SmramMapSize, SmramMap);
154 }
155
156 /**
157 Entry Point for SMM Access2 On SMM Access Thunk driver.
158
159 @param[in] ImageHandle Image handle of this driver.
160 @param[in] SystemTable A Pointer to the EFI System Table.
161
162 @retval EFI_SUCCESS The entry point is executed successfully.
163 @retval other Some error occurred when executing this entry point.
164 **/
165 EFI_STATUS
166 EFIAPI
SmmAccess2ThunkMain(IN EFI_HANDLE ImageHandle,IN EFI_SYSTEM_TABLE * SystemTable)167 SmmAccess2ThunkMain (
168 IN EFI_HANDLE ImageHandle,
169 IN EFI_SYSTEM_TABLE *SystemTable
170 )
171 {
172 EFI_STATUS Status;
173 UINTN SmramMapSize;
174
175 ///
176 /// Locate SMM Access Protocol
177 ///
178 Status = gBS->LocateProtocol (&gEfiSmmAccessProtocolGuid, NULL, (VOID **)&mSmmAccess);
179 ASSERT_EFI_ERROR (Status);
180
181 ///
182 /// Calculate number of SMRAM regions
183 ///
184 SmramMapSize = 0;
185 Status = mSmmAccess->GetCapabilities (mSmmAccess, &SmramMapSize, NULL);
186 ASSERT (Status == EFI_BUFFER_TOO_SMALL);
187
188 mSmramRegionNumber = SmramMapSize/sizeof (EFI_SMRAM_DESCRIPTOR);
189 ASSERT (mSmramRegionNumber > 0);
190
191 ///
192 /// Assume all SMRAM regions have consistent OPEN and LOCK states
193 ///
194 gSmmAccess2.OpenState = mSmmAccess->OpenState;
195 gSmmAccess2.LockState = mSmmAccess->LockState;
196
197 ///
198 /// Publish PI SMM Access2 Protocol
199 ///
200 Status = gBS->InstallProtocolInterface (
201 &ImageHandle,
202 &gEfiSmmAccess2ProtocolGuid,
203 EFI_NATIVE_INTERFACE,
204 &gSmmAccess2
205 );
206 return Status;
207 }
208
209