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 #define EMU_IO_THUNK_PROTOCOL_DATA_SIGNATURE  SIGNATURE_32('E','m','u','T')
  20
  21 typedef struct {
  22   UINTN                    Signature;
  23   EMU_IO_THUNK_PROTOCOL    Data;
  24   BOOLEAN                  EmuBusDriver;
  25   LIST_ENTRY               Link;
  26 } EMU_IO_THUNK_PROTOCOL_DATA;
  27
  28 LIST_ENTRY  mThunkList = INITIALIZE_LIST_HEAD_VARIABLE (mThunkList);
  29
  30 EFI_STATUS
  31 EFIAPI
  32 AddThunkProtocol (
  33   IN  EMU_IO_THUNK_PROTOCOL  *ThunkIo,
  34   IN  CHAR16                 *ConfigString,
  35   IN  BOOLEAN                EmuBusDriver
  36   )
  37 {
  38   UINTN                       Size;
  39   CHAR16                      *StartString;
  40   CHAR16                      *SubString;
  41   UINTN                       Instance;
  42   EMU_IO_THUNK_PROTOCOL_DATA  *Private;
  43
  44   if (ThunkIo == NULL) {
  45     return EFI_INVALID_PARAMETER;
  46   }
  47
  48   Instance    = 0;
  49   Size        = StrSize (ConfigString);
  50   StartString = AllocatePool (Size);
  51   if (StartString == NULL) {
  52     return EFI_OUT_OF_RESOURCES;
  53   }
  54
  55   StrCpyS (StartString, Size / sizeof (CHAR16), ConfigString);
  56   while (*StartString != '\0') {
  57     //
  58     // Find the end of the sub string
  59     //
  60     SubString = StartString;
  61     while (*SubString != '\0' && *SubString != '!') {
  62       SubString++;
  63     }
  64
  65     if (*SubString == '!') {
  66       //
  67       // Replace token with '\0' to make sub strings. If this is the end
  68       //  of the string SubString will already point to NULL.
  69       //
  70       *SubString = '\0';
  71       SubString++;
  72     }
  73
  74     Private = AllocatePool (sizeof (EMU_IO_THUNK_PROTOCOL_DATA));
  75     if (Private == NULL) {
  76       return EFI_OUT_OF_RESOURCES;
  77     }
  78
  79     Private->Signature    = EMU_IO_THUNK_PROTOCOL_DATA_SIGNATURE;
  80     Private->EmuBusDriver = EmuBusDriver;
  81
  82     CopyMem (&Private->Data, ThunkIo, sizeof (EMU_IO_THUNK_PROTOCOL));
  83     Private->Data.Instance     = (UINT16)Instance++;
  84     Private->Data.ConfigString = StartString;
  85
  86     InsertTailList (&mThunkList, &Private->Link);
  87
  88     //
  89     // Parse Next sub string. This will point to '\0' if we are at the end.
  90     //
  91     StartString = SubString;
  92   }
  93
  94   return EFI_SUCCESS;
  95 }
  96
  97 EFI_STATUS
  98 EFIAPI
  99 GetNextThunkProtocol (
 100   IN  BOOLEAN                EmuBusDriver,
 101   OUT EMU_IO_THUNK_PROTOCOL  **Instance  OPTIONAL
 102   )
 103 {
 104   LIST_ENTRY                  *Link;
 105   EMU_IO_THUNK_PROTOCOL_DATA  *Private;
 106
 107   if (mThunkList.ForwardLink == &mThunkList) {
 108     // Skip parsing an empty list
 109     return EFI_NOT_FOUND;
 110   }
 111
 112   for (Link = mThunkList.ForwardLink; Link != &mThunkList; Link = Link->ForwardLink) {
 113     Private = CR (Link, EMU_IO_THUNK_PROTOCOL_DATA, Link, EMU_IO_THUNK_PROTOCOL_DATA_SIGNATURE);
 114     if (EmuBusDriver & !Private->EmuBusDriver) {
 115       continue;
 116     } else if (*Instance == NULL) {
 117       // Find 1st match in list
 118       *Instance = &Private->Data;
 119       return EFI_SUCCESS;
 120     } else if (*Instance == &Private->Data) {
 121       // Matched previous call so look for valid next entry
 122       Link = Link->ForwardLink;
 123       if (Link == &mThunkList) {
 124         return EFI_NOT_FOUND;
 125       }
 126
 127       Private   = CR (Link, EMU_IO_THUNK_PROTOCOL_DATA, Link, EMU_IO_THUNK_PROTOCOL_DATA_SIGNATURE);
 128       *Instance = &Private->Data;
 129       return EFI_SUCCESS;
 130     }
 131   }
 132
 133   return EFI_NOT_FOUND;
 134 }