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 - 2018, 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   CHAR16                      *StartString;
  41   CHAR16                      *SubString;
  42   UINTN                       Instance;
  43   EMU_IO_THUNK_PROTOCOL_DATA  *Private;
  44
  45   if (ThunkIo == NULL) {
  46     return EFI_INVALID_PARAMETER;
  47   }
  48
  49   Instance = 0;
  50   StartString = AllocatePool (StrSize (ConfigString));
  51   StrCpy (StartString, ConfigString);
  52   while (*StartString != '\0') {
  53
  54     //
  55     // Find the end of the sub string
  56     //
  57     SubString = StartString;
  58     while (*SubString != '\0' && *SubString != '!') {
  59       SubString++;
  60     }
  61
  62     if (*SubString == '!') {
  63       //
  64       // Replace token with '\0' to make sub strings. If this is the end
  65       //  of the string SubString will already point to NULL.
  66       //
  67       *SubString = '\0';
  68       SubString++;
  69     }
  70
  71     Private = AllocatePool (sizeof (EMU_IO_THUNK_PROTOCOL_DATA));
  72     if (Private == NULL) {
  73       return EFI_OUT_OF_RESOURCES;
  74     }
  75     Private->Signature          = EMU_IO_THUNK_PROTOCOL_DATA_SIGNATURE;
  76     Private->EmuBusDriver       = EmuBusDriver;
  77
  78     CopyMem (&Private->Data, ThunkIo, sizeof (EMU_IO_THUNK_PROTOCOL));
  79     Private->Data.Instance      = (UINT16)Instance++;
  80     Private->Data.ConfigString  = StartString;
  81
  82     InsertTailList (&mThunkList, &Private->Link);
  83
  84     //
  85     // Parse Next sub string. This will point to '\0' if we are at the end.
  86     //
  87     StartString = SubString;
  88   }
  89
  90   return EFI_SUCCESS;
  91 }
  92
  93
  94 EFI_STATUS
  95 EFIAPI
  96 GetNextThunkProtocol (
  97   IN  BOOLEAN                 EmuBusDriver,
  98   OUT EMU_IO_THUNK_PROTOCOL   **Instance  OPTIONAL
  99   )
 100 {
 101   LIST_ENTRY                   *Link;
 102   EMU_IO_THUNK_PROTOCOL_DATA   *Private;
 103
 104   if (mThunkList.ForwardLink == &mThunkList) {
 105     // Skip parsing an empty list
 106     return EFI_NOT_FOUND;
 107   }
 108
 109   for (Link = mThunkList.ForwardLink; Link != &mThunkList; Link = Link->ForwardLink) {
 110     Private = CR (Link, EMU_IO_THUNK_PROTOCOL_DATA, Link, EMU_IO_THUNK_PROTOCOL_DATA_SIGNATURE);
 111     if (EmuBusDriver & !Private->EmuBusDriver) {
 112       continue;
 113     } else if (*Instance == NULL) {
 114       // Find 1st match in list
 115       *Instance = &Private->Data;
 116       return EFI_SUCCESS;
 117     } else if (*Instance == &Private->Data) {
 118       // Matched previous call so look for valid next entry
 119       Link = Link->ForwardLink;
 120       if (Link == &mThunkList) {
 121         return EFI_NOT_FOUND;
 122       }
 123       Private = CR (Link, EMU_IO_THUNK_PROTOCOL_DATA, Link, EMU_IO_THUNK_PROTOCOL_DATA_SIGNATURE);
 124       *Instance = &Private->Data;
 125       return EFI_SUCCESS;
 126     }
 127   }
 128
 129
 130   return EFI_NOT_FOUND;
 131 }
 132