IoLibGcc.c File Reference

#include "BaseIoLibIntrinsicInternal.h"
#include "IoLibTdx.h"

Go to the source code of this file.

Functions
UINT8 EFIAPI	IoRead8 (IN UINTN Port)
UINT8 EFIAPI	IoWrite8 (IN UINTN Port, IN UINT8 Value)
UINT16 EFIAPI	IoRead16 (IN UINTN Port)
UINT16 EFIAPI	IoWrite16 (IN UINTN Port, IN UINT16 Value)
UINT32 EFIAPI	IoRead32 (IN UINTN Port)
UINT32 EFIAPI	IoWrite32 (IN UINTN Port, IN UINT32 Value)

Detailed Description

I/O Library. This file has compiler specifics for GCC as there is no ANSI C standard for doing IO.

GCC - uses EFIAPI assembler. asm calls GAS. volatile makes sure the compiler puts the assembler in this exact location. The complex GNUC operations are not optimzed. It would be possible to also write these with EFIAPI assembler.

We don't advocate putting compiler specifics in libraries or drivers but there is no other way to make this work.

Copyright (c) 2006 - 2021, Intel Corporation. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent

Definition in file IoLibGcc.c.

Function Documentation

IoRead16()

UINT16 EFIAPI IoRead16

(

IN UINTN

Port

)

Reads a 16-bit I/O port.

Reads the 16-bit I/O port specified by Port. The 16-bit read value is returned. This function must guarantee that all I/O read and write operations are serialized.

If 16-bit I/O port operations are not supported, then ASSERT(). If Port is not aligned on a 16-bit boundary, then ASSERT().

For Td guest TDVMCALL_IO is invoked to read I/O port.

Parameters

Port	The I/O port to read.

Returns

The value read.

Definition at line 119 of file IoLibGcc.c.

IoRead32()

UINT32 EFIAPI IoRead32

(

IN UINTN

Port

)

Reads a 32-bit I/O port.

Reads the 32-bit I/O port specified by Port. The 32-bit read value is returned. This function must guarantee that all I/O read and write operations are serialized.

If 32-bit I/O port operations are not supported, then ASSERT(). If Port is not aligned on a 32-bit boundary, then ASSERT().

For Td guest TDVMCALL_IO is invoked to read I/O port.

Parameters

Port	The I/O port to read.

Returns

The value read.

Definition at line 204 of file IoLibGcc.c.

IoRead8()

UINT8 EFIAPI IoRead8

(

IN UINTN

Port

)

Reads an 8-bit I/O port.

Reads the 8-bit I/O port specified by Port. The 8-bit read value is returned. This function must guarantee that all I/O read and write operations are serialized.

If 8-bit I/O port operations are not supported, then ASSERT()

For Td guest TDVMCALL_IO is invoked to read I/O port.

Parameters

Port	The I/O port to read.

Returns

The value read.

Definition at line 39 of file IoLibGcc.c.

IoWrite16()

UINT16 EFIAPI IoWrite16	(	IN UINTN	Port,
		IN UINT16	Value
	)

Writes a 16-bit I/O port.

Writes the 16-bit I/O port specified by Port with the value specified by Value and returns Value. This function must guarantee that all I/O read and write operations are serialized.

If 16-bit I/O port operations are not supported, then ASSERT(). If Port is not aligned on a 16-bit boundary, then ASSERT().

For Td guest TDVMCALL_IO is invoked to write I/O port.

Parameters

Port	The I/O port to write.
Value	The value to write to the I/O port.

Returns

The value written the I/O port.

Definition at line 162 of file IoLibGcc.c.

IoWrite32()

UINT32 EFIAPI IoWrite32	(	IN UINTN	Port,
		IN UINT32	Value
	)

Writes a 32-bit I/O port.

Writes the 32-bit I/O port specified by Port with the value specified by Value and returns Value. This function must guarantee that all I/O read and write operations are serialized.

If 32-bit I/O port operations are not supported, then ASSERT(). If Port is not aligned on a 32-bit boundary, then ASSERT().

For Td guest TDVMCALL_IO is invoked to write I/O port.

Parameters

Port	The I/O port to write.
Value	The value to write to the I/O port.

Returns

The value written the I/O port.

Definition at line 247 of file IoLibGcc.c.

IoWrite8()

UINT8 EFIAPI IoWrite8	(	IN UINTN	Port,
		IN UINT8	Value
	)

Writes an 8-bit I/O port.

Writes the 8-bit I/O port specified by Port with the value specified by Value and returns Value. This function must guarantee that all I/O read and write operations are serialized.

If 8-bit I/O port operations are not supported, then ASSERT().

For Td guest TDVMCALL_IO is invoked to write I/O port.

Parameters

Port	The I/O port to write.
Value	The value to write to the I/O port.

Returns

The value written the I/O port.

Definition at line 79 of file IoLibGcc.c.