OcLegacyThunkLib.h File Reference

#include <Protocol/Legacy8259.h>

Go to the source code of this file.

Macros
#define	LEGACY_REGION_BASE   0x0C0000
#define	LEGACY_REGION_SIZE   0x10000
#define	EFI_SEGMENT(_Adr)
#define	EFI_OFFSET(_Adr)

Functions
EFI_STATUS	OcLegacyThunkInitializeBiosIntCaller (IN OUT THUNK_CONTEXT *ThunkContext)
EFI_STATUS	OcLegacyThunkInitializeInterruptRedirection (IN EFI_LEGACY_8259_PROTOCOL *Legacy8259)
VOID	OcLegacyThunkDisconnectEfiGraphics (VOID)
BOOLEAN EFIAPI	OcLegacyThunkBiosInt86 (IN THUNK_CONTEXT *ThunkContext, IN EFI_LEGACY_8259_PROTOCOL *Legacy8259, IN UINT8 BiosInt, IN IA32_REGISTER_SET *Regs)
BOOLEAN EFIAPI	OcLegacyThunkFarCall86 (IN THUNK_CONTEXT *ThunkContext, IN EFI_LEGACY_8259_PROTOCOL *Legacy8259, IN UINT16 Segment, IN UINT16 Offset, IN IA32_REGISTER_SET *Regs, IN VOID *Stack, IN UINTN StackSize)

Detailed Description

This library implements thunking to legacy 16-bit environment.

Copyright (c) 2023, Goldfish64. All rights reserved.
Copyright (c) 2006 - 2007, Intel Corporation. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause

Definition in file OcLegacyThunkLib.h.

Macro Definition Documentation

EFI_OFFSET

#define EFI_OFFSET

(

_Adr

)

Value:

(UINT16) (((UINT16) ((UINTN) (_Adr))) & 0xffff)

Definition at line 21 of file OcLegacyThunkLib.h.

EFI_SEGMENT

#define EFI_SEGMENT

(

_Adr

)

Value:

(UINT16) ((UINT16) (((UINTN) (_Adr)) >> 4) & 0xf000)

Definition at line 20 of file OcLegacyThunkLib.h.

LEGACY_REGION_BASE

#define LEGACY_REGION_BASE   0x0C0000

Definition at line 17 of file OcLegacyThunkLib.h.

LEGACY_REGION_SIZE

#define LEGACY_REGION_SIZE   0x10000

Definition at line 18 of file OcLegacyThunkLib.h.

Function Documentation

OcLegacyThunkBiosInt86()

BOOLEAN EFIAPI OcLegacyThunkBiosInt86	(	IN THUNK_CONTEXT *	ThunkContext,
		IN EFI_LEGACY_8259_PROTOCOL *	Legacy8259,
		IN UINT8	BiosInt,
		IN IA32_REGISTER_SET *	Regs )

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.

Parameters

ThunkContext	The instance pointer of THUNK_CONTEXT.
Legacy8259	Instance pointer for EFI_LEGACY_8259_PROTOCOL.
BiosInt	Processor interrupt vector to invoke
Reg	Register contexted passed into (and returned) from thunk to 16-bit mode

Return values

TRUE	Thunk completed, and there were no BIOS errors in the target code. See Regs for status.
FALSE	There was a BIOS error in the target code.

Definition at line 241 of file OcLegacyThunkLib.c.

OcLegacyThunkDisconnectEfiGraphics()

VOID OcLegacyThunkDisconnectEfiGraphics

(

VOID

)

Disconnect all EFI graphics device handles in preparation for calling to legacy mode.

Definition at line 168 of file OcLegacyThunkLib.c.

OcLegacyThunkFarCall86()

BOOLEAN EFIAPI OcLegacyThunkFarCall86	(	IN THUNK_CONTEXT *	ThunkContext,
		IN EFI_LEGACY_8259_PROTOCOL *	Legacy8259,
		IN UINT16	Segment,
		IN UINT16	Offset,
		IN IA32_REGISTER_SET *	Regs,
		IN VOID *	Stack,
		IN UINTN	StackSize )

Definition at line 328 of file OcLegacyThunkLib.c.

OcLegacyThunkInitializeBiosIntCaller()

EFI_STATUS OcLegacyThunkInitializeBiosIntCaller

(

IN OUT THUNK_CONTEXT *

ThunkContext

)

Initialize legacy environment for BIOS INI caller.

Parameters

ThunkContext

The instance pointer of THUNK_CONTEXT.

OcLegacyThunkInitializeInterruptRedirection()

EFI_STATUS OcLegacyThunkInitializeInterruptRedirection

(

IN EFI_LEGACY_8259_PROTOCOL *

Legacy8259

)

Initialize interrupt redirection code and entries, because IDT Vectors 0x68-0x6f must be redirected to IDT Vectors 0x08-0x0f. Or the interrupt will lost when we do thunk. NOTE: We do not reset 8259 vector base, because it will cause pending interrupt lost.

Parameters

Legacy8259

Instance pointer for EFI_LEGACY_8259_PROTOCOL.

Definition at line 105 of file OcLegacyThunkLib.c.