DuetPkg/FSVariable/MemStorage.c

   1 /*++
   2
   3 Caution: This file is used for Duet platform only, do not use them in real platform.
   4 All variable code, variable metadata, and variable data used by Duet platform are on
   5 disk. They can be changed by user. BIOS is not able to protoect those.
   6 Duet trusts all meta data from disk. If variable code, variable metadata and variable
   7 data is modified in inproper way, the behavior is undefined.
   8
   9 Copyright (c) 2006 - 2014, Intel Corporation. All rights reserved.<BR>
  10 This program and the accompanying materials
  11 are licensed and made available under the terms and conditions of the BSD License
  12 which accompanies this distribution.  The full text of the license may be found at
  13 http://opensource.org/licenses/bsd-license.php
  14
  15 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  16 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  17
  18 Module Name:
  19
  20     MemStorage.c
  21
  22 Abstract:
  23
  24     handles variable store/reads with emulated memory
  25
  26 Revision History
  27
  28 --*/
  29 #include "FSVariable.h"
  30
  31 VOID
  32 EFIAPI
  33 OnVirtualAddressChangeMs (
  34   IN EFI_EVENT            Event,
  35   IN VOID                 *Context
  36   );
  37
  38 EFI_STATUS
  39 EFIAPI
  40 MemEraseStore(
  41   IN VARIABLE_STORAGE   *This
  42   );
  43
  44 EFI_STATUS
  45 EFIAPI
  46 MemWriteStore (
  47   IN VARIABLE_STORAGE   *This,
  48   IN UINTN                Offset,
  49   IN UINTN                BufferSize,
  50   IN VOID                 *Buffer
  51   );
  52
  53 EFI_STATUS
  54 MemStorageConstructor (
  55   OUT VARIABLE_STORAGE          **VarStore,
  56   OUT EFI_EVENT_NOTIFY          *GoVirtualEvent,
  57   IN  UINTN                     Size
  58   )
  59 {
  60   EFI_STATUS                  Status;
  61   VS_DEV                      *Dev;
  62
  63   Status = gBS->AllocatePool (EfiRuntimeServicesData, sizeof(VS_DEV), (VOID **) &Dev);
  64   ASSERT_EFI_ERROR (Status);
  65
  66   ZeroMem (Dev, sizeof(VS_DEV));
  67
  68   Dev->Signature   = VS_DEV_SIGNATURE;
  69   Dev->Size        = Size;
  70
  71   Dev->VarStore.Erase    = MemEraseStore;
  72   Dev->VarStore.Write    = MemWriteStore;
  73
  74   Status = gBS->AllocatePool (EfiRuntimeServicesData, Size, (VOID **) &VAR_DATA_PTR (Dev));
  75   ASSERT_EFI_ERROR (Status);
  76
  77   DEBUG ((EFI_D_ERROR, "VStorage: Size = 0x%x\n", Size));
  78
  79   *VarStore       = &Dev->VarStore;
  80   *GoVirtualEvent = OnVirtualAddressChangeMs;
  81
  82   return EFI_SUCCESS;
  83 }
  84
  85 VOID
  86 EFIAPI
  87 OnVirtualAddressChangeMs (
  88   IN EFI_EVENT            Event,
  89   IN VOID                 *Context
  90   )
  91 {
  92   VS_DEV                  *Dev;
  93
  94   Dev = DEV_FROM_THIS (Context);
  95
  96   EfiConvertPointer (0, (VOID **)&VAR_DATA_PTR (Dev));
  97   EfiConvertPointer (0, (VOID **)&Dev->VarStore.Erase);
  98   EfiConvertPointer (0, (VOID **)&Dev->VarStore.Write);
  99 }
 100
 101 EFI_STATUS
 102 EFIAPI
 103 MemEraseStore(
 104   IN VARIABLE_STORAGE   *This
 105   )
 106 {
 107   VS_DEV              *Dev;
 108
 109   Dev = DEV_FROM_THIS(This);
 110   SetMem (VAR_DATA_PTR (Dev), Dev->Size, VAR_DEFAULT_VALUE);
 111   return EFI_SUCCESS;
 112 }
 113
 114
 115 EFI_STATUS
 116 EFIAPI
 117 MemWriteStore (
 118   IN VARIABLE_STORAGE     *This,
 119   IN UINTN                Offset,
 120   IN UINTN                BufferSize,
 121   IN VOID                 *UserBuffer
 122   )
 123 {
 124   VS_DEV              *Dev;
 125
 126   Dev = DEV_FROM_THIS(This);
 127
 128   ASSERT (Offset + BufferSize < Dev->Size);
 129
 130   // For better performance
 131   if (VAR_DATA_PTR (Dev) + Offset != UserBuffer) {
 132     CopyMem (VAR_DATA_PTR (Dev) + Offset, UserBuffer, BufferSize);
 133   }
 134   return EFI_SUCCESS;
 135 }