1 /** @file
2 Dummy implementation of Legacy Region 2 Protocol.
3
4 This generic implementation of the Legacy Region 2 Protocol does not actually
5 perform any lock/unlock operations. This module may be used on platforms
6 that do not provide HW locking of the legacy memory regions. It can also
7 be used as a template driver for implementing the Legacy Region 2 Protocol on
8 a platform that does support HW locking of the legacy memory regions.
9
10 Copyright (c) 2009 - 2010, Intel Corporation. All rights reserved.<BR>
11 This program and the accompanying materials
12 are licensed and made available under the terms and conditions of the BSD License
13 which accompanies this distribution. The full text of the license may be found at
14 http://opensource.org/licenses/bsd-license.php
15
16 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
17 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
18
19 **/
20
21 #include <LegacyRegion2.h>
22
23 EFI_HANDLE mLegacyRegion2Handle = NULL;
24
25 EFI_LEGACY_REGION2_PROTOCOL mLegacyRegion2 = {
26 LegacyRegion2Decode,
27 LegacyRegion2Lock,
28 LegacyRegion2BootLock,
29 LegacyRegion2Unlock,
30 LegacyRegionGetInfo
31 };
32
33 /**
34 Modify the hardware to allow (decode) or disallow (not decode) memory reads in a region.
35
36 If the On parameter evaluates to TRUE, this function enables memory reads in the address range
37 Start to (Start + Length - 1).
38 If the On parameter evaluates to FALSE, this function disables memory reads in the address range
39 Start to (Start + Length - 1).
40
41 @param This[in] Indicates the EFI_LEGACY_REGION_PROTOCOL instance.
42 @param Start[in] The beginning of the physical address of the region whose attributes
43 should be modified.
44 @param Length[in] The number of bytes of memory whose attributes should be modified.
45 The actual number of bytes modified may be greater than the number
46 specified.
47 @param Granularity[out] The number of bytes in the last region affected. This may be less
48 than the total number of bytes affected if the starting address
49 was not aligned to a region's starting address or if the length
50 was greater than the number of bytes in the first region.
51 @param On[in] Decode / Non-Decode flag.
52
53 @retval EFI_SUCCESS The region's attributes were successfully modified.
54 @retval EFI_INVALID_PARAMETER If Start or Length describe an address not in the Legacy Region.
55
56 **/
57 EFI_STATUS
58 EFIAPI
LegacyRegion2Decode(IN EFI_LEGACY_REGION2_PROTOCOL * This,IN UINT32 Start,IN UINT32 Length,OUT UINT32 * Granularity,IN BOOLEAN * On)59 LegacyRegion2Decode (
60 IN EFI_LEGACY_REGION2_PROTOCOL *This,
61 IN UINT32 Start,
62 IN UINT32 Length,
63 OUT UINT32 *Granularity,
64 IN BOOLEAN *On
65 )
66 {
67 if ((Start < 0xC0000) || ((Start + Length - 1) > 0xFFFFF)) {
68 return EFI_INVALID_PARAMETER;
69 }
70
71 ASSERT (Granularity != NULL);
72 *Granularity = 0;
73 return EFI_SUCCESS;
74 }
75
76 /**
77 Modify the hardware to disallow memory writes in a region.
78
79 This function changes the attributes of a memory range to not allow writes.
80
81 @param This[in] Indicates the EFI_LEGACY_REGION_PROTOCOL instance.
82 @param Start[in] The beginning of the physical address of the region whose
83 attributes should be modified.
84 @param Length[in] The number of bytes of memory whose attributes should be modified.
85 The actual number of bytes modified may be greater than the number
86 specified.
87 @param Granularity[out] The number of bytes in the last region affected. This may be less
88 than the total number of bytes affected if the starting address was
89 not aligned to a region's starting address or if the length was
90 greater than the number of bytes in the first region.
91
92 @retval EFI_SUCCESS The region's attributes were successfully modified.
93 @retval EFI_INVALID_PARAMETER If Start or Length describe an address not in the Legacy Region.
94
95 **/
96 EFI_STATUS
97 EFIAPI
LegacyRegion2Lock(IN EFI_LEGACY_REGION2_PROTOCOL * This,IN UINT32 Start,IN UINT32 Length,OUT UINT32 * Granularity)98 LegacyRegion2Lock (
99 IN EFI_LEGACY_REGION2_PROTOCOL *This,
100 IN UINT32 Start,
101 IN UINT32 Length,
102 OUT UINT32 *Granularity
103 )
104 {
105 if ((Start < 0xC0000) || ((Start + Length - 1) > 0xFFFFF)) {
106 return EFI_INVALID_PARAMETER;
107 }
108
109 ASSERT (Granularity != NULL);
110 *Granularity = 0;
111 return EFI_SUCCESS;
112 }
113
114 /**
115 Modify the hardware to disallow memory attribute changes in a region.
116
117 This function makes the attributes of a region read only. Once a region is boot-locked with this
118 function, the read and write attributes of that region cannot be changed until a power cycle has
119 reset the boot-lock attribute. Calls to Decode(), Lock() and Unlock() will have no effect.
120
121 @param This[in] Indicates the EFI_LEGACY_REGION_PROTOCOL instance.
122 @param Start[in] The beginning of the physical address of the region whose
123 attributes should be modified.
124 @param Length[in] The number of bytes of memory whose attributes should be modified.
125 The actual number of bytes modified may be greater than the number
126 specified.
127 @param Granularity[out] The number of bytes in the last region affected. This may be less
128 than the total number of bytes affected if the starting address was
129 not aligned to a region's starting address or if the length was
130 greater than the number of bytes in the first region.
131
132 @retval EFI_SUCCESS The region's attributes were successfully modified.
133 @retval EFI_INVALID_PARAMETER If Start or Length describe an address not in the Legacy Region.
134 @retval EFI_UNSUPPORTED The chipset does not support locking the configuration registers in
135 a way that will not affect memory regions outside the legacy memory
136 region.
137
138 **/
139 EFI_STATUS
140 EFIAPI
LegacyRegion2BootLock(IN EFI_LEGACY_REGION2_PROTOCOL * This,IN UINT32 Start,IN UINT32 Length,OUT UINT32 * Granularity)141 LegacyRegion2BootLock (
142 IN EFI_LEGACY_REGION2_PROTOCOL *This,
143 IN UINT32 Start,
144 IN UINT32 Length,
145 OUT UINT32 *Granularity
146 )
147 {
148 if ((Start < 0xC0000) || ((Start + Length - 1) > 0xFFFFF)) {
149 return EFI_INVALID_PARAMETER;
150 }
151
152 return EFI_UNSUPPORTED;
153 }
154
155 /**
156 Modify the hardware to allow memory writes in a region.
157
158 This function changes the attributes of a memory range to allow writes.
159
160 @param This[in] Indicates the EFI_LEGACY_REGION_PROTOCOL instance.
161 @param Start[in] The beginning of the physical address of the region whose
162 attributes should be modified.
163 @param Length[in] The number of bytes of memory whose attributes should be modified.
164 The actual number of bytes modified may be greater than the number
165 specified.
166 @param Granularity[out] The number of bytes in the last region affected. This may be less
167 than the total number of bytes affected if the starting address was
168 not aligned to a region's starting address or if the length was
169 greater than the number of bytes in the first region.
170
171 @retval EFI_SUCCESS The region's attributes were successfully modified.
172 @retval EFI_INVALID_PARAMETER If Start or Length describe an address not in the Legacy Region.
173
174 **/
175 EFI_STATUS
176 EFIAPI
LegacyRegion2Unlock(IN EFI_LEGACY_REGION2_PROTOCOL * This,IN UINT32 Start,IN UINT32 Length,OUT UINT32 * Granularity)177 LegacyRegion2Unlock (
178 IN EFI_LEGACY_REGION2_PROTOCOL *This,
179 IN UINT32 Start,
180 IN UINT32 Length,
181 OUT UINT32 *Granularity
182 )
183 {
184 if ((Start < 0xC0000) || ((Start + Length - 1) > 0xFFFFF)) {
185 return EFI_INVALID_PARAMETER;
186 }
187
188 ASSERT (Granularity != NULL);
189 *Granularity = 0;
190 return EFI_SUCCESS;
191 }
192
193 /**
194 Get region information for the attributes of the Legacy Region.
195
196 This function is used to discover the granularity of the attributes for the memory in the legacy
197 region. Each attribute may have a different granularity and the granularity may not be the same
198 for all memory ranges in the legacy region.
199
200 @param This[in] Indicates the EFI_LEGACY_REGION2_PROTOCOL instance.
201 @param DescriptorCount[out] The number of region descriptor entries returned in the Descriptor
202 buffer.
203 @param Descriptor[out] A pointer to a pointer used to return a buffer where the legacy
204 region information is deposited. This buffer will contain a list of
205 DescriptorCount number of region descriptors. This function will
206 provide the memory for the buffer.
207
208 @retval EFI_SUCCESS The information structure was returned.
209 @retval EFI_UNSUPPORTED This function is not supported.
210
211 **/
212 EFI_STATUS
213 EFIAPI
LegacyRegionGetInfo(IN EFI_LEGACY_REGION2_PROTOCOL * This,OUT UINT32 * DescriptorCount,OUT EFI_LEGACY_REGION_DESCRIPTOR ** Descriptor)214 LegacyRegionGetInfo (
215 IN EFI_LEGACY_REGION2_PROTOCOL *This,
216 OUT UINT32 *DescriptorCount,
217 OUT EFI_LEGACY_REGION_DESCRIPTOR **Descriptor
218 )
219 {
220 return EFI_UNSUPPORTED;
221 }
222
223 /**
224 The user Entry Point for module LegacyRegionDxe. The user code starts with this function.
225
226 @param[in] ImageHandle The firmware allocated handle for the EFI image.
227 @param[in] SystemTable A pointer to the EFI System Table.
228
229 @retval EFI_SUCCESS The entry point is executed successfully.
230
231 **/
232 EFI_STATUS
233 EFIAPI
LegacyRegion2Install(IN EFI_HANDLE ImageHandle,IN EFI_SYSTEM_TABLE * SystemTable)234 LegacyRegion2Install (
235 IN EFI_HANDLE ImageHandle,
236 IN EFI_SYSTEM_TABLE *SystemTable
237 )
238 {
239 EFI_STATUS Status;
240
241 //
242 // Make sure the Legacy Region 2 Protocol is not already installed in the system
243 //
244 ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gEfiLegacyRegion2ProtocolGuid);
245
246 //
247 // Install the protocol on a new handle.
248 //
249 Status = gBS->InstallMultipleProtocolInterfaces (
250 &mLegacyRegion2Handle,
251 &gEfiLegacyRegion2ProtocolGuid, &mLegacyRegion2,
252 NULL
253 );
254 ASSERT_EFI_ERROR (Status);
255
256 return EFI_SUCCESS;
257 }
258