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CpuIo2.h File Reference

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Data Structures

struct  EFI_CPU_IO_PROTOCOL_ACCESS
 
struct  _EFI_CPU_IO2_PROTOCOL
 

Macros

#define EFI_CPU_IO2_PROTOCOL_GUID
 

Typedefs

typedef struct _EFI_CPU_IO2_PROTOCOL EFI_CPU_IO2_PROTOCOL
 
typedef EFI_STATUS(EFIAPIEFI_CPU_IO_PROTOCOL_IO_MEM) (IN EFI_CPU_IO2_PROTOCOL *This, IN EFI_CPU_IO_PROTOCOL_WIDTH Width, IN UINT64 Address, IN UINTN Count, IN OUT VOID *Buffer)
 

Enumerations

enum  EFI_CPU_IO_PROTOCOL_WIDTH {
  EfiCpuIoWidthUint8 , EfiCpuIoWidthUint16 , EfiCpuIoWidthUint32 , EfiCpuIoWidthUint64 ,
  EfiCpuIoWidthFifoUint8 , EfiCpuIoWidthFifoUint16 , EfiCpuIoWidthFifoUint32 , EfiCpuIoWidthFifoUint64 ,
  EfiCpuIoWidthFillUint8 , EfiCpuIoWidthFillUint16 , EfiCpuIoWidthFillUint32 , EfiCpuIoWidthFillUint64 ,
  EfiCpuIoWidthMaximum
}
 

Variables

EFI_GUID gEfiCpuIo2ProtocolGuid
 

Detailed Description

This files describes the CPU I/O 2 Protocol.

This protocol provides an I/O abstraction for a system processor. This protocol is used by a PCI root bridge I/O driver to perform memory-mapped I/O and I/O transactions. The I/O or memory primitives can be used by the consumer of the protocol to materialize bus-specific configuration cycles, such as the transitional configuration address and data ports for PCI. Only drivers that require direct access to the entire system should use this protocol.

Note: This is a boot-services only protocol and it may not be used by runtime drivers after ExitBootServices(). It is different from the Framework CPU I/O Protocol, which is a runtime protocol and can be used by runtime drivers after ExitBootServices().

Copyright (c) 2007 - 2018, Intel Corporation. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent

Revision Reference:
This Protocol is defined in UEFI Platform Initialization Specification 1.2 Volume 5: Standards

Definition in file CpuIo2.h.

Macro Definition Documentation

◆ EFI_CPU_IO2_PROTOCOL_GUID

#define EFI_CPU_IO2_PROTOCOL_GUID
Value:
{ \
0xad61f191, 0xae5f, 0x4c0e, {0xb9, 0xfa, 0xe8, 0x69, 0xd2, 0x88, 0xc6, 0x4f} \
}

Definition at line 27 of file CpuIo2.h.

Typedef Documentation

◆ EFI_CPU_IO2_PROTOCOL

Definition at line 32 of file CpuIo2.h.

◆ EFI_CPU_IO_PROTOCOL_IO_MEM

typedef EFI_STATUS(EFIAPI * EFI_CPU_IO_PROTOCOL_IO_MEM) (IN EFI_CPU_IO2_PROTOCOL *This, IN EFI_CPU_IO_PROTOCOL_WIDTH Width, IN UINT64 Address, IN UINTN Count, IN OUT VOID *Buffer)

Enables a driver to access registers in the PI CPU I/O space.

The Io.Read() and Io.Write() functions enable a driver to access PCI controller registers in the PI CPU I/O space.

The I/O operations are carried out exactly as requested. The caller is responsible for satisfying any alignment and I/O width restrictions that a PI System on a platform might require. For example on some platforms, width requests of EfiCpuIoWidthUint64 do not work. Misaligned buffers, on the other hand, will be handled by the driver.

If Width is EfiCpuIoWidthUint8, EfiCpuIoWidthUint16, EfiCpuIoWidthUint32, or EfiCpuIoWidthUint64, then both Address and Buffer are incremented for each of the Count operations that is performed.

If Width is EfiCpuIoWidthFifoUint8, EfiCpuIoWidthFifoUint16, EfiCpuIoWidthFifoUint32, or EfiCpuIoWidthFifoUint64, then only Buffer is incremented for each of the Count operations that is performed. The read or write operation is performed Count times on the same Address.

If Width is EfiCpuIoWidthFillUint8, EfiCpuIoWidthFillUint16, EfiCpuIoWidthFillUint32, or EfiCpuIoWidthFillUint64, then only Address is incremented for each of the Count operations that is performed. The read or write operation is performed Count times from the first element of Buffer.

Parameters
[in]ThisA pointer to the EFI_CPU_IO2_PROTOCOL instance.
[in]WidthSignifies the width of the I/O or Memory operation.
[in]AddressThe base address of the I/O operation.
[in]CountThe number of I/O operations to perform. The number of bytes moved is Width size * Count, starting at Address.
[in,out]BufferFor read operations, the destination buffer to store the results. For write operations, the source buffer from which to write data.
Return values
EFI_SUCCESSThe data was read from or written to the PI system.
EFI_INVALID_PARAMETERWidth is invalid for this PI system.
EFI_INVALID_PARAMETERBuffer is NULL.
EFI_UNSUPPORTEDThe Buffer is not aligned for the given Width.
EFI_UNSUPPORTEDThe address range specified by Address, Width, and Count is not valid for this PI system.

Definition at line 96 of file CpuIo2.h.

Enumeration Type Documentation

◆ EFI_CPU_IO_PROTOCOL_WIDTH

Enumeration that defines the width of the I/O operation.

Definition at line 37 of file CpuIo2.h.