EmulatorPkg/Library/ThunkProtocolList/ThunkProtocolList.c

   1 /** @file
   2   Emulator Thunk to abstract OS services from pure EFI code
   3
   4   Copyright (c) 2008 - 2011, Apple Inc. All rights reserved.<BR>
   5   Copyright (c) 2011 - 2019, Intel Corporation. All rights reserved.<BR>
   6
   7   SPDX-License-Identifier: BSD-2-Clause-Patent
   8
   9 **/
  10
  11 #include <Uefi.h>
  12 #include <Library/BaseLib.h>
  13 #include <Library/BaseMemoryLib.h>
  14 #include <Library/DebugLib.h>
  15 #include <Library/MemoryAllocationLib.h>
  16
  17 #include <Protocol/EmuIoThunk.h>
  18
  19
  20 #define EMU_IO_THUNK_PROTOCOL_DATA_SIGNATURE SIGNATURE_32('E','m','u','T')
  21
  22 typedef struct {
  23   UINTN                 Signature;
  24   EMU_IO_THUNK_PROTOCOL Data;
  25   BOOLEAN               EmuBusDriver;
  26   LIST_ENTRY            Link;
  27 } EMU_IO_THUNK_PROTOCOL_DATA;
  28
  29 LIST_ENTRY  mThunkList = INITIALIZE_LIST_HEAD_VARIABLE (mThunkList);
  30
  31
  32 EFI_STATUS
  33 EFIAPI
  34 AddThunkProtocol (
  35   IN  EMU_IO_THUNK_PROTOCOL   *ThunkIo,
  36   IN  CHAR16                  *ConfigString,
  37   IN  BOOLEAN                 EmuBusDriver
  38   )
  39 {
  40   UINTN                       Size;
  41   CHAR16                      *StartString;
  42   CHAR16                      *SubString;
  43   UINTN                       Instance;
  44   EMU_IO_THUNK_PROTOCOL_DATA  *Private;
  45
  46   if (ThunkIo == NULL) {
  47     return EFI_INVALID_PARAMETER;
  48   }
  49
  50   Instance = 0;
  51   Size = StrSize (ConfigString);
  52   StartString = AllocatePool (Size);
  53   if (StartString == NULL) {
  54     return EFI_OUT_OF_RESOURCES;
  55   }
  56   StrCpyS (StartString, Size / sizeof (CHAR16), ConfigString);
  57   while (*StartString != '\0') {
  58
  59     //
  60     // Find the end of the sub string
  61     //
  62     SubString = StartString;
  63     while (*SubString != '\0' && *SubString != '!') {
  64       SubString++;
  65     }
  66
  67     if (*SubString == '!') {
  68       //
  69       // Replace token with '\0' to make sub strings. If this is the end
  70       //  of the string SubString will already point to NULL.
  71       //
  72       *SubString = '\0';
  73       SubString++;
  74     }
  75
  76     Private = AllocatePool (sizeof (EMU_IO_THUNK_PROTOCOL_DATA));
  77     if (Private == NULL) {
  78       return EFI_OUT_OF_RESOURCES;
  79     }
  80     Private->Signature          = EMU_IO_THUNK_PROTOCOL_DATA_SIGNATURE;
  81     Private->EmuBusDriver       = EmuBusDriver;
  82
  83     CopyMem (&Private->Data, ThunkIo, sizeof (EMU_IO_THUNK_PROTOCOL));
  84     Private->Data.Instance      = (UINT16)Instance++;
  85     Private->Data.ConfigString  = StartString;
  86
  87     InsertTailList (&mThunkList, &Private->Link);
  88
  89     //
  90     // Parse Next sub string. This will point to '\0' if we are at the end.
  91     //
  92     StartString = SubString;
  93   }
  94
  95   return EFI_SUCCESS;
  96 }
  97
  98
  99 EFI_STATUS
 100 EFIAPI
 101 GetNextThunkProtocol (
 102   IN  BOOLEAN                 EmuBusDriver,
 103   OUT EMU_IO_THUNK_PROTOCOL   **Instance  OPTIONAL
 104   )
 105 {
 106   LIST_ENTRY                   *Link;
 107   EMU_IO_THUNK_PROTOCOL_DATA   *Private;
 108
 109   if (mThunkList.ForwardLink == &mThunkList) {
 110     // Skip parsing an empty list
 111     return EFI_NOT_FOUND;
 112   }
 113
 114   for (Link = mThunkList.ForwardLink; Link != &mThunkList; Link = Link->ForwardLink) {
 115     Private = CR (Link, EMU_IO_THUNK_PROTOCOL_DATA, Link, EMU_IO_THUNK_PROTOCOL_DATA_SIGNATURE);
 116     if (EmuBusDriver & !Private->EmuBusDriver) {
 117       continue;
 118     } else if (*Instance == NULL) {
 119       // Find 1st match in list
 120       *Instance = &Private->Data;
 121       return EFI_SUCCESS;
 122     } else if (*Instance == &Private->Data) {
 123       // Matched previous call so look for valid next entry
 124       Link = Link->ForwardLink;
 125       if (Link == &mThunkList) {
 126         return EFI_NOT_FOUND;
 127       }
 128       Private = CR (Link, EMU_IO_THUNK_PROTOCOL_DATA, Link, EMU_IO_THUNK_PROTOCOL_DATA_SIGNATURE);
 129       *Instance = &Private->Data;
 130       return EFI_SUCCESS;
 131     }
 132   }
 133
 134
 135   return EFI_NOT_FOUND;
 136 }
 137