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 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 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 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 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 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 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
