EdkCompatibilityPkg/Foundation/Protocol/LegacyBiosThunk/LegacyBiosThunk.h

   1 /*++
   2
   3 Copyright (c) 2006, Intel Corporation
   4 All rights reserved. This program and the accompanying materials
   5 are licensed and made available under the terms and conditions of the BSD License
   6 which accompanies this distribution.  The full text of the license may be found at
   7 http://opensource.org/licenses/bsd-license.php
   8
   9 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11
  12 Module Name:
  13
  14   LegacyBiosThunk.h
  15
  16 Abstract:
  17
  18   The EFI Legacy BIOS Thunk Protocol is used to abstract Thunk16 call.
  19
  20   Note: The names for EFI_IA32_REGISTER_SET elements were picked to follow
  21   well known naming conventions.
  22
  23   Thunk - A thunk is a transition from one processor mode to another. A Thunk
  24           is a transition from native EFI mode to 16-bit mode. A reverse thunk
  25           would be a transition from 16-bit mode to native EFI mode.
  26
  27
  28   Note: Note: Note: Note: Note: Note: Note:
  29
  30   You most likely should not use this protocol! Find the EFI way to solve the
  31   problem to make your code portable
  32
  33   Note: Note: Note: Note: Note: Note: Note:
  34
  35 Revision History
  36
  37 --*/
  38
  39 #ifndef _EFI_LEGACY_BIOS_THUNK_H_
  40 #define _EFI_LEGACY_BIOS_THUNK_H_
  41
  42 #include EFI_PROTOCOL_DEFINITION (LegacyBios)
  43
  44 #define EFI_LEGACY_BIOS_THUNK_PROTOCOL_GUID \
  45   { \
  46     0x4c51a7ba, 0x7195, 0x442d, 0x87, 0x92, 0xbe, 0xea, 0x6e, 0x2f, 0xf6, 0xec \
  47   }
  48
  49 EFI_FORWARD_DECLARATION (EFI_LEGACY_BIOS_THUNK_PROTOCOL);
  50
  51 typedef
  52 BOOLEAN
  53 (EFIAPI *EFI_LEGACY_BIOS_THUNK_INT86) (
  54   IN EFI_LEGACY_BIOS_THUNK_PROTOCOL   * This,
  55   IN  UINT8                           BiosInt,
  56   IN OUT  EFI_IA32_REGISTER_SET       * Regs
  57   )
  58 /*++
  59
  60   Routine Description:
  61     Thunk to 16-bit real mode and execute a software interrupt with a vector
  62     of BiosInt. Regs will contain the 16-bit register context on entry and
  63     exit.
  64
  65   Arguments:
  66     This    - Protocol instance pointer.
  67     BiosInt - Processor interrupt vector to invoke
  68     Reg     - Register contexted passed into (and returned) from thunk to
  69               16-bit mode
  70
  71   Returns:
  72     FALSE   - Thunk completed, and there were no BIOS errors in the target code.
  73               See Regs for status.
  74     TRUE    - There was a BIOS erro in the target code.
  75
  76 --*/
  77 ;
  78
  79 typedef
  80 BOOLEAN
  81 (EFIAPI *EFI_LEGACY_BIOS_THUNK_FARCALL86) (
  82   IN EFI_LEGACY_BIOS_THUNK_PROTOCOL   * This,
  83   IN  UINT16                          Segment,
  84   IN  UINT16                          Offset,
  85   IN  EFI_IA32_REGISTER_SET           * Regs,
  86   IN  VOID                            *Stack,
  87   IN  UINTN                           StackSize
  88   )
  89 /*++
  90
  91   Routine Description:
  92     Thunk to 16-bit real mode and call Segment:Offset. Regs will contain the
  93     16-bit register context on entry and exit. Arguments can be passed on
  94     the Stack argument
  95
  96   Arguments:
  97     This      - Protocol instance pointer.
  98     Segment   - Segemnt of 16-bit mode call
  99     Offset    - Offset of 16-bit mdoe call
 100     Reg       - Register contexted passed into (and returned) from thunk to
 101                 16-bit mode
 102     Stack     - Caller allocated stack used to pass arguments
 103     StackSize - Size of Stack in bytes
 104
 105   Returns:
 106     FALSE     - Thunk completed, and there were no BIOS errors in the target code.
 107                 See Regs for status.
 108     TRUE      - There was a BIOS erro in the target code.
 109
 110 --*/
 111 ;
 112
 113 typedef struct _EFI_LEGACY_BIOS_THUNK_PROTOCOL {
 114   EFI_LEGACY_BIOS_THUNK_INT86                 Int86;
 115   EFI_LEGACY_BIOS_THUNK_FARCALL86             FarCall86;
 116 } EFI_LEGACY_BIOS_THUNK_PROTOCOL;
 117
 118 extern EFI_GUID gEfiLegacyBiosThunkProtocolGuid;
 119
 120 #endif