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 - 2018, Intel Corporation. All rights reserved.<BR>
   6   SPDX-License-Identifier: BSD-2-Clause-Patent
   7
   8   @par Revision Reference:
   9   This Protocol is defined in UEFI Platform Initialization Specification 1.2
  10   Volume 5: Standards
  11
  12 **/
  13
  14 #ifndef __LEGACY_REGION2_H__
  15 #define __LEGACY_REGION2_H__
  16
  17
  18 #define EFI_LEGACY_REGION2_PROTOCOL_GUID \
  19 { \
  20   0x70101eaf, 0x85, 0x440c, {0xb3, 0x56, 0x8e, 0xe3, 0x6f, 0xef, 0x24, 0xf0 } \
  21 }
  22
  23 typedef struct _EFI_LEGACY_REGION2_PROTOCOL EFI_LEGACY_REGION2_PROTOCOL;
  24
  25 /**
  26   Modify the hardware to allow (decode) or disallow (not decode) memory reads in a region.
  27
  28   If the On parameter evaluates to TRUE, this function enables memory reads in the address range
  29   Start to (Start + Length - 1).
  30   If the On parameter evaluates to FALSE, this function disables memory reads in the address range
  31   Start to (Start + Length - 1).
  32
  33   @param  This[in]              Indicates the EFI_LEGACY_REGION2_PROTOCOL instance.
  34   @param  Start[in]             The beginning of the physical address of the region whose attributes
  35                                 should be modified.
  36   @param  Length[in]            The number of bytes of memory whose attributes should be modified.
  37                                 The actual number of bytes modified may be greater than the number
  38                                 specified.
  39   @param  Granularity[out]      The number of bytes in the last region affected. This may be less
  40                                 than the total number of bytes affected if the starting address
  41                                 was not aligned to a region's starting address or if the length
  42                                 was greater than the number of bytes in the first region.
  43   @param  On[in]                Decode / Non-Decode flag.
  44
  45   @retval EFI_SUCCESS           The region's attributes were successfully modified.
  46   @retval EFI_INVALID_PARAMETER If Start or Length describe an address not in the Legacy Region.
  47
  48 **/
  49 typedef
  50 EFI_STATUS
  51 (EFIAPI *EFI_LEGACY_REGION2_DECODE)(
  52  IN  EFI_LEGACY_REGION2_PROTOCOL  *This,
  53  IN  UINT32                       Start,
  54  IN  UINT32                       Length,
  55  OUT UINT32                       *Granularity,
  56  IN  BOOLEAN                      *On
  57  );
  58
  59
  60 /**
  61   Modify the hardware to disallow memory writes in a region.
  62
  63   This function changes the attributes of a memory range to not allow writes.
  64
  65   @param  This[in]              Indicates the EFI_LEGACY_REGION2_PROTOCOL instance.
  66   @param  Start[in]             The beginning of the physical address of the region whose
  67                                 attributes should be modified.
  68   @param  Length[in]            The number of bytes of memory whose attributes should be modified.
  69                                 The actual number of bytes modified may be greater than the number
  70                                 specified.
  71   @param  Granularity[out]      The number of bytes in the last region affected. This may be less
  72                                 than the total number of bytes affected if the starting address was
  73                                 not aligned to a region's starting address or if the length was
  74                                 greater than the number of bytes in the first region.
  75
  76   @retval EFI_SUCCESS           The region's attributes were successfully modified.
  77   @retval EFI_INVALID_PARAMETER If Start or Length describe an address not in the Legacy Region.
  78
  79 **/
  80 typedef
  81 EFI_STATUS
  82 (EFIAPI *EFI_LEGACY_REGION2_LOCK)(
  83  IN  EFI_LEGACY_REGION2_PROTOCOL   *This,
  84  IN  UINT32                        Start,
  85  IN  UINT32                        Length,
  86  OUT UINT32                        *Granularity
  87  );
  88
  89
  90 /**
  91   Modify the hardware to disallow memory attribute changes in a region.
  92
  93   This function makes the attributes of a region read only. Once a region is boot-locked with this
  94   function, the read and write attributes of that region cannot be changed until a power cycle has
  95   reset the boot-lock attribute. Calls to Decode(), Lock() and Unlock() will have no effect.
  96
  97   @param  This[in]              Indicates the EFI_LEGACY_REGION2_PROTOCOL instance.
  98   @param  Start[in]             The beginning of the physical address of the region whose
  99                                 attributes should be modified.
 100   @param  Length[in]            The number of bytes of memory whose attributes should be modified.
 101                                 The actual number of bytes modified may be greater than the number
 102                                 specified.
 103   @param  Granularity[out]      The number of bytes in the last region affected. This may be less
 104                                 than the total number of bytes affected if the starting address was
 105                                 not aligned to a region's starting address or if the length was
 106                                 greater than the number of bytes in the first region.
 107
 108   @retval EFI_SUCCESS           The region's attributes were successfully modified.
 109   @retval EFI_INVALID_PARAMETER If Start or Length describe an address not in the Legacy Region.
 110   @retval EFI_UNSUPPORTED       The chipset does not support locking the configuration registers in
 111                                 a way that will not affect memory regions outside the legacy memory
 112                                 region.
 113
 114 **/
 115 typedef
 116 EFI_STATUS
 117 (EFIAPI *EFI_LEGACY_REGION2_BOOT_LOCK)(
 118   IN  EFI_LEGACY_REGION2_PROTOCOL         *This,
 119   IN  UINT32                              Start,
 120   IN  UINT32                              Length,
 121   OUT UINT32                              *Granularity OPTIONAL
 122   );
 123
 124
 125 /**
 126   Modify the hardware to allow memory writes in a region.
 127
 128   This function changes the attributes of a memory range to allow writes.
 129
 130   @param  This[in]              Indicates the EFI_LEGACY_REGION2_PROTOCOL instance.
 131   @param  Start[in]             The beginning of the physical address of the region whose
 132                                 attributes should be modified.
 133   @param  Length[in]            The number of bytes of memory whose attributes should be modified.
 134                                 The actual number of bytes modified may be greater than the number
 135                                 specified.
 136   @param  Granularity[out]      The number of bytes in the last region affected. This may be less
 137                                 than the total number of bytes affected if the starting address was
 138                                 not aligned to a region's starting address or if the length was
 139                                 greater than the number of bytes in the first region.
 140
 141   @retval EFI_SUCCESS           The region's attributes were successfully modified.
 142   @retval EFI_INVALID_PARAMETER If Start or Length describe an address not in the Legacy Region.
 143
 144 **/
 145 typedef
 146 EFI_STATUS
 147 (EFIAPI *EFI_LEGACY_REGION2_UNLOCK)(
 148  IN  EFI_LEGACY_REGION2_PROTOCOL  *This,
 149  IN  UINT32                       Start,
 150  IN  UINT32                       Length,
 151  OUT UINT32                       *Granularity
 152  );
 153
 154
 155 typedef enum {
 156   LegacyRegionDecoded,         ///< This region is currently set to allow reads.
 157   LegacyRegionNotDecoded,      ///< This region is currently set to not allow reads.
 158   LegacyRegionWriteEnabled,    ///< This region is currently set to allow writes.
 159   LegacyRegionWriteDisabled,   ///< This region is currently set to write protected.
 160   LegacyRegionBootLocked,      ///< This region's attributes are locked, cannot be modified until
 161                                ///< after a power cycle.
 162   LegacyRegionNotLocked        ///< This region's attributes are not locked.
 163 } EFI_LEGACY_REGION_ATTRIBUTE;
 164
 165
 166 typedef struct {
 167   ///
 168   /// The beginning of the physical address of this
 169   /// region.
 170   ///
 171   UINT32                      Start;
 172   ///
 173   /// The number of bytes in this region.
 174   ///
 175   UINT32                      Length;
 176   ///
 177   /// Attribute of the Legacy Region Descriptor that
 178   /// describes the capabilities for that memory region.
 179   ///
 180   EFI_LEGACY_REGION_ATTRIBUTE Attribute;
 181   ///
 182   /// Describes the byte length programmability
 183   /// associated with the Start address and the specified
 184   /// Attribute setting.
 185   UINT32                      Granularity;
 186 } EFI_LEGACY_REGION_DESCRIPTOR;
 187
 188
 189 /**
 190   Get region information for the attributes of the Legacy Region.
 191
 192   This function is used to discover the granularity of the attributes for the memory in the legacy
 193   region. Each attribute may have a different granularity and the granularity may not be the same
 194   for all memory ranges in the legacy region.
 195
 196   @param  This[in]              Indicates the EFI_LEGACY_REGION2_PROTOCOL instance.
 197   @param  DescriptorCount[out]  The number of region descriptor entries returned in the Descriptor
 198                                 buffer.
 199   @param  Descriptor[out]       A pointer to a pointer used to return a buffer where the legacy
 200                                 region information is deposited. This buffer will contain a list of
 201                                 DescriptorCount number of region descriptors.  This function will
 202                                 provide the memory for the buffer.
 203
 204   @retval EFI_SUCCESS           The information structure was returned.
 205   @retval EFI_UNSUPPORTED       This function is not supported.
 206
 207 **/
 208 typedef
 209 EFI_STATUS
 210 (EFIAPI *EFI_LEGACY_REGION_GET_INFO)(
 211   IN  EFI_LEGACY_REGION2_PROTOCOL   *This,
 212   OUT UINT32                        *DescriptorCount,
 213   OUT EFI_LEGACY_REGION_DESCRIPTOR  **Descriptor
 214   );
 215
 216
 217 ///
 218 /// The EFI_LEGACY_REGION2_PROTOCOL is used to abstract the hardware control of the memory
 219 /// attributes of the Option ROM shadowing region, 0xC0000 to 0xFFFFF.
 220 /// There are three memory attributes that can be modified through this protocol: read, write and
 221 /// boot-lock. These protocols may be set in any combination.
 222 ///
 223 struct _EFI_LEGACY_REGION2_PROTOCOL {
 224   EFI_LEGACY_REGION2_DECODE     Decode;
 225   EFI_LEGACY_REGION2_LOCK       Lock;
 226   EFI_LEGACY_REGION2_BOOT_LOCK  BootLock;
 227   EFI_LEGACY_REGION2_UNLOCK     UnLock;
 228   EFI_LEGACY_REGION_GET_INFO    GetInfo;
 229 };
 230
 231 extern EFI_GUID gEfiLegacyRegion2ProtocolGuid;
 232
 233 #endif