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/*++
Copyright (c) 2006, Intel Corporation
All rights reserved. This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
Module Name:
LegacyBiosThunk.h
Abstract:
The EFI Legacy BIOS Thunk Protocol is used to abstract Thunk16 call.
Note: The names for EFI_IA32_REGISTER_SET elements were picked to follow
well known naming conventions.
Thunk - A thunk is a transition from one processor mode to another. A Thunk
is a transition from native EFI mode to 16-bit mode. A reverse thunk
would be a transition from 16-bit mode to native EFI mode.
Note: Note: Note: Note: Note: Note: Note:
You most likely should not use this protocol! Find the EFI way to solve the
problem to make your code portable
Note: Note: Note: Note: Note: Note: Note:
Revision History
--*/
#ifndef _EFI_LEGACY_BIOS_THUNK_H_
#define _EFI_LEGACY_BIOS_THUNK_H_
#define EFI_LEGACY_BIOS_THUNK_PROTOCOL_GUID \
{ \
0x4c51a7ba, 0x7195, 0x442d, 0x87, 0x92, 0xbe, 0xea, 0x6e, 0x2f, 0xf6, 0xec \
}
typedef struct _EFI_LEGACY_BIOS_THUNK_PROTOCOL EFI_LEGACY_BIOS_THUNK_PROTOCOL;
typedef
BOOLEAN
(EFIAPI *EFI_LEGACY_BIOS_THUNK_INT86) (
IN EFI_LEGACY_BIOS_THUNK_PROTOCOL * This,
IN UINT8 BiosInt,
IN OUT EFI_IA32_REGISTER_SET * Regs
)
/*++
Routine Description:
Thunk to 16-bit real mode and execute a software interrupt with a vector
of BiosInt. Regs will contain the 16-bit register context on entry and
exit.
Arguments:
This - Protocol instance pointer.
BiosInt - Processor interrupt vector to invoke
Reg - Register contexted passed into (and returned) from thunk to
16-bit mode
Returns:
FALSE - Thunk completed, and there were no BIOS errors in the target code.
See Regs for status.
TRUE - There was a BIOS erro in the target code.
--*/
;
typedef
BOOLEAN
(EFIAPI *EFI_LEGACY_BIOS_THUNK_FARCALL86) (
IN EFI_LEGACY_BIOS_THUNK_PROTOCOL * This,
IN UINT16 Segment,
IN UINT16 Offset,
IN EFI_IA32_REGISTER_SET * Regs,
IN VOID *Stack,
IN UINTN StackSize
)
/*++
Routine Description:
Thunk to 16-bit real mode and call Segment:Offset. Regs will contain the
16-bit register context on entry and exit. Arguments can be passed on
the Stack argument
Arguments:
This - Protocol instance pointer.
Segment - Segemnt of 16-bit mode call
Offset - Offset of 16-bit mdoe call
Reg - Register contexted passed into (and returned) from thunk to
16-bit mode
Stack - Caller allocated stack used to pass arguments
StackSize - Size of Stack in bytes
Returns:
FALSE - Thunk completed, and there were no BIOS errors in the target code.
See Regs for status.
TRUE - There was a BIOS erro in the target code.
--*/
;
struct _EFI_LEGACY_BIOS_THUNK_PROTOCOL {
EFI_LEGACY_BIOS_THUNK_INT86 Int86;
EFI_LEGACY_BIOS_THUNK_FARCALL86 FarCall86;
};
extern EFI_GUID gEfiLegacyBiosThunkProtocolGuid;
#endif
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