MdePkg/Include/Protocol/LegacyRegion2.h

   1 /** @file
   2   The Legacy Region Protocol controls the read, write and boot-lock attributes for
   3   the region 0xC0000 to 0xFFFFF.
   4
   5   Copyright (c) 2009, Intel Corporation
   6   All rights reserved. This program and the accompanying materials
   7   are licensed and made available under the terms and conditions of the BSD License
   8   which accompanies this distribution.  The full text of the license may be found at
   9   http://opensource.org/licenses/bsd-license.php
  10
  11   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  12   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  13
  14   @par Revision Reference:
  15   This Protocol is defined in UEFI Platform Initialization Specification 1.2
  16   Volume 5: Standards
  17
  18   @attention This protocol appears to be 'EFI_LEGACY_REGION_PROTOCOL' in current PI 1.2
  19   public spec. Therefore, some names are different from public PI 1.2 spec and we should
  20   remove this attention when they appear in public PI 1.2 spec in the future.
  21
  22 **/
  23
  24 #ifndef __LEGACY_REGION2_H__
  25 #define __LEGACY_REGION2_H__
  26
  27
  28 #define EFI_LEGACY_REGION2_PROTOCOL_GUID \
  29 { \
  30   0x70101eaf, 0x85, 0x440c, {0xb3, 0x56, 0x8e, 0xe3, 0x6f, 0xef, 0x24, 0xf0 } \
  31 }
  32
  33 typedef struct _EFI_LEGACY_REGION2_PROTOCOL EFI_LEGACY_REGION2_PROTOCOL;
  34
  35 /**
  36   Modify the hardware to allow (decode) or disallow (not decode) memory reads in a region.
  37
  38   If the On parameter evaluates to TRUE, this function enables memory reads in the address range
  39   Start to (Start + Length - 1).
  40   If the On parameter evaluates to FALSE, this function disables memory reads in the address range
  41   Start to (Start + Length - 1).
  42
  43   @param  This[in]              Indicates the EFI_LEGACY_REGION2_PROTOCOL instance.
  44   @param  Start[in]             The beginning of the physical address of the region whose attributes
  45                                 should be modified.
  46   @param  Length[in]            The number of bytes of memory whose attributes should be modified.
  47                                 The actual number of bytes modified may be greater than the number
  48                                 specified.
  49   @param  Granularity[out]      The number of bytes in the last region affected. This may be less
  50                                 than the total number of bytes affected if the starting address
  51                                 was not aligned to a region's starting address or if the length
  52                                 was greater than the number of bytes in the first region.
  53   @param  On[in]                Decode / Non-Decode flag.
  54
  55   @retval EFI_SUCCESS           The region's attributes were successfully modified.
  56   @retval EFI_INVALID_PARAMETER If Start or Length describe an address not in the Legacy Region.
  57
  58 **/
  59 typedef
  60 EFI_STATUS
  61 (EFIAPI *EFI_LEGACY_REGION2_DECODE) (
  62  IN  EFI_LEGACY_REGION2_PROTOCOL  *This,
  63  IN  UINT32                       Start,
  64  IN  UINT32                       Length,
  65  OUT UINT32                       *Granularity,
  66  IN  BOOLEAN                      *On
  67  );
  68
  69
  70 /**
  71   Modify the hardware to disallow memory writes in a region.
  72
  73   This function changes the attributes of a memory range to not allow writes.
  74
  75   @param  This[in]              Indicates the EFI_LEGACY_REGION2_PROTOCOL instance.
  76   @param  Start[in]             The beginning of the physical address of the region whose
  77                                 attributes should be modified.
  78   @param  Length[in]            The number of bytes of memory whose attributes should be modified.
  79                                 The actual number of bytes modified may be greater than the number
  80                                 specified.
  81   @param  Granularity[out]      The number of bytes in the last region affected. This may be less
  82                                 than the total number of bytes affected if the starting address was
  83                                 not aligned to a region's starting address or if the length was
  84                                 greater than the number of bytes in the first region.
  85
  86   @retval EFI_SUCCESS           The region's attributes were successfully modified.
  87   @retval EFI_INVALID_PARAMETER If Start or Length describe an address not in the Legacy Region.
  88
  89 **/
  90 typedef
  91 EFI_STATUS
  92 (EFIAPI *EFI_LEGACY_REGION2_LOCK) (
  93  IN  EFI_LEGACY_REGION2_PROTOCOL   *This,
  94  IN  UINT32                        Start,
  95  IN  UINT32                        Length,
  96  OUT UINT32                        *Granularity
  97  );
  98
  99
 100 /**
 101   Modify the hardware to disallow memory attribute changes in a region.
 102
 103   This function makes the attributes of a region read only. Once a region is boot-locked with this
 104   function, the read and write attributes of that region cannot be changed until a power cycle has
 105   reset the boot-lock attribute. Calls to Decode(), Lock() and Unlock() will have no effect.
 106
 107   @param  This[in]              Indicates the EFI_LEGACY_REGION2_PROTOCOL instance.
 108   @param  Start[in]             The beginning of the physical address of the region whose
 109                                 attributes should be modified.
 110   @param  Length[in]            The number of bytes of memory whose attributes should be modified.
 111                                 The actual number of bytes modified may be greater than the number
 112                                 specified.
 113   @param  Granularity[out]      The number of bytes in the last region affected. This may be less
 114                                 than the total number of bytes affected if the starting address was
 115                                 not aligned to a region's starting address or if the length was
 116                                 greater than the number of bytes in the first region.
 117
 118   @retval EFI_SUCCESS           The region's attributes were successfully modified.
 119   @retval EFI_INVALID_PARAMETER If Start or Length describe an address not in the Legacy Region.
 120   @retval EFI_UNSUPPORTED       The chipset does not support locking the configuration registers in
 121                                 a way that will not affect memory regions outside the legacy memory
 122                                 region.
 123
 124 **/
 125 typedef
 126 EFI_STATUS
 127 (EFIAPI *EFI_LEGACY_REGION2_BOOT_LOCK)(
 128   IN  EFI_LEGACY_REGION2_PROTOCOL         *This,
 129   IN  UINT32                              Start,
 130   IN  UINT32                              Length,
 131   OUT UINT32                              *Granularity OPTIONAL
 132   );
 133
 134
 135 /**
 136   Modify the hardware to allow memory writes in a region.
 137
 138   This function changes the attributes of a memory range to allow writes.
 139
 140   @param  This[in]              Indicates the EFI_LEGACY_REGION2_PROTOCOL instance.
 141   @param  Start[in]             The beginning of the physical address of the region whose
 142                                 attributes should be modified.
 143   @param  Length[in]            The number of bytes of memory whose attributes should be modified.
 144                                 The actual number of bytes modified may be greater than the number
 145                                 specified.
 146   @param  Granularity[out]      The number of bytes in the last region affected. This may be less
 147                                 than the total number of bytes affected if the starting address was
 148                                 not aligned to a region's starting address or if the length was
 149                                 greater than the number of bytes in the first region.
 150
 151   @retval EFI_SUCCESS           The region's attributes were successfully modified.
 152   @retval EFI_INVALID_PARAMETER If Start or Length describe an address not in the Legacy Region.
 153
 154 **/
 155 typedef
 156 EFI_STATUS
 157 (EFIAPI *EFI_LEGACY_REGION2_UNLOCK) (
 158  IN  EFI_LEGACY_REGION2_PROTOCOL  *This,
 159  IN  UINT32                       Start,
 160  IN  UINT32                       Length,
 161  OUT UINT32                       *Granularity
 162  );
 163
 164
 165 typedef enum {
 166   LegacyRegionDecoded,         ///< This region is currently set to allow reads.
 167   LegacyRegionNotDecoded,      ///< This region is currently set to not allow reads.
 168   LegacyRegionWriteEnabled,    ///< This region is currently set to allow writes.
 169   LegacyRegionWriteDisabled,   ///< This region is currently set to write protected.
 170   LegacyRegionBootLocked,      ///< This region's attributes are locked, cannot be modified until
 171                                ///< after a power cycle.
 172   LegacyRegionNotLocked        ///< This region's attributes are not locked.
 173 } EFI_LEGACY_REGION_ATTRIBUTE;
 174
 175
 176 typedef struct {
 177   UINT32                      Start;       ///< The beginning of the physical address of this
 178                                            ///< region.
 179   UINT32                      Length;      ///< The number of bytes in this region.
 180   EFI_LEGACY_REGION_ATTRIBUTE Attribute;   ///< Attribute of the Legacy Region Descriptor that
 181                                            ///< describes the capabilities for that memory region.
 182   UINT32                      Granularity; ///< Describes the byte length programmability
 183                                            ///< associated with the Start address and the specified
 184                                            ///< Attribute setting.
 185 } EFI_LEGACY_REGION_DESCRIPTOR;
 186
 187
 188 /**
 189   Get region information for the attributes of the Legacy Region.
 190
 191   This function is used to discover the granularity of the attributes for the memory in the legacy
 192   region. Each attribute may have a different granularity and the granularity may not be the same
 193   for all memory ranges in the legacy region.
 194
 195   @param  This[in]              Indicates the EFI_LEGACY_REGION2_PROTOCOL instance.
 196   @param  DescriptorCount[out]  The number of region descriptor entries returned in the Descriptor
 197                                 buffer.
 198   @param  Descriptor[out]       A pointer to a pointer used to return a buffer where the legacy
 199                                 region information is deposited. This buffer will contain a list of
 200                                 DescriptorCount number of region descriptors.  This function will
 201                                 provide the memory for the buffer.
 202
 203   @retval EFI_SUCCESS           The information structure was returned.
 204   @retval EFI_UNSUPPORTED       This function is not supported.
 205
 206 **/
 207 typedef
 208 EFI_STATUS
 209 (EFIAPI *EFI_LEGACY_REGION_GET_INFO) (
 210   IN  EFI_LEGACY_REGION2_PROTOCOL   *This,
 211   OUT UINT32                        *DescriptorCount,
 212   OUT EFI_LEGACY_REGION_DESCRIPTOR  **Descriptor
 213   );
 214
 215
 216 /**
 217   Abstracts the hardware control of the physical address region 0xC0000-0xFFFFF.
 218
 219   The EFI_LEGACY_REGION2_PROTOCOL is used to abstract the hardware control of the memory
 220   attributes of the Option ROM shadowing region, 0xC0000 to 0xFFFFF.
 221
 222   There are three memory attributes that can be modified through this protocol: read, write and
 223   boot-lock. These protocols may be set in any combination.
 224
 225 **/
 226 struct _EFI_LEGACY_REGION2_PROTOCOL {
 227   EFI_LEGACY_REGION2_DECODE     Decode;     ///< Modify the read attribute of a memory region. See
 228                                             ///< the Decode() function description.
 229   EFI_LEGACY_REGION2_LOCK       Lock;       ///< Modify the write attribute of a memory region to
 230                                             ///< prevent writes. See the Lock() function description.
 231   EFI_LEGACY_REGION2_BOOT_LOCK  BootLock;   ///< Modify the boot-lock attribute of a memory region to
 232                                             ///< prevent future changes to the memory attributes for
 233                                             ///< this region. See the BootLock() function description.
 234   EFI_LEGACY_REGION2_UNLOCK     UnLock;     ///< Modify the write attribute of a memory region to
 235                                             ///< allow writes. See the Unlock() function description.
 236   EFI_LEGACY_REGION_GET_INFO    GetInfo;    ///< Modify the write attribute of a memory region to
 237                                             ///< allow writes. See the GetInfo() function description.
 238 };
 239
 240 extern EFI_GUID gEfiLegacyRegion2ProtocolGuid;
 241
 242 #endif