DebugCommunicationLib.h File Reference

Typedefs
typedef VOID *	DEBUG_PORT_HANDLE
typedef VOID(EFIAPI *	DEBUG_PORT_CONTINUE )(IN VOID *Context, IN DEBUG_PORT_HANDLE DebugPortHandle)

Functions
DEBUG_PORT_HANDLE EFIAPI	DebugPortInitialize (IN VOID *Context, IN DEBUG_PORT_CONTINUE Function)
UINTN EFIAPI	DebugPortReadBuffer (IN DEBUG_PORT_HANDLE Handle, IN UINT8 *Buffer, IN UINTN NumberOfBytes, IN UINTN Timeout)
UINTN EFIAPI	DebugPortWriteBuffer (IN DEBUG_PORT_HANDLE Handle, IN UINT8 *Buffer, IN UINTN NumberOfBytes)
BOOLEAN EFIAPI	DebugPortPollBuffer (IN DEBUG_PORT_HANDLE Handle)

Detailed Description

Debug Communication Library definitions.

Copyright (c) 2010 - 2018, Intel Corporation. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent

Typedef Documentation

typedef VOID(EFIAPI * DEBUG_PORT_CONTINUE)(IN VOID *Context, IN DEBUG_PORT_HANDLE DebugPortHandle)

Caller provided function to be invoked at the end of DebugPortInitialize().

Refer to the description for DebugPortInitialize() for more details.

Parameters

[in]	Context	The first input argument of DebugPortInitialize().
[in]	DebugPortHandle	Debug port handle created by Debug Communication Library.

typedef VOID* DEBUG_PORT_HANDLE

Function Documentation

DEBUG_PORT_HANDLE EFIAPI DebugPortInitialize	(	IN VOID *	Context,
		IN DEBUG_PORT_CONTINUE	Function
	)

Initialize the debug port.

This function will initialize debug port to get it ready for data transmission. If certain Debug Communication Library instance has to save some private data in the stack, this function must work on the mode that doesn't return to the caller, then the caller needs to wrap up all rest of logic after DebugPortInitialize() into one function and pass it into DebugPortInitialize(). DebugPortInitialize() is responsible to invoke the passing-in function at the end of DebugPortInitialize().

If the parameter Function is not NULL, Debug Communication Library instance will invoke it by passing in the Context to be the first parameter. Debug Communication Library instance could create one debug port handle to be the second parameter passing into the Function. Debug Communication Library instance also could pass NULL to be the second parameter if it doesn't create the debug port handle.

If the parameter Function is NULL, and Context is not NULL. At this time, Context is the debug port handle created by the previous Debug Communication Library instance. a) If the instance can understand and continue use the private data of the previous instance, it could return the same handle as passed in (as Context parameter). b) If the instance does not understand, or does not want to continue use the private data of the previous instance, it could ignore the input Context parameter and create the new handle to be returned.

If Function() is NULL and Context is NULL, Debug Communication Library could create a new handle and return it. NULL is also a valid handle to be returned.

Parameters

[in]	Context	Context needed by callback function; it was optional.
[in]	Function	Continue function called by Debug Communication library; it was optional.

Returns

The debug port handle created by Debug Communication Library if Function is not NULL.

BOOLEAN EFIAPI DebugPortPollBuffer

(

IN DEBUG_PORT_HANDLE

Handle

)

Polls a debug device to see if there is any data waiting to be read.

Polls a debug device to see if there is any data waiting to be read. If there is data waiting to be read from the debug device, then TRUE is returned. If there is no data waiting to be read from the debug device, then FALSE is returned.

Parameters

Handle

Debug port handle.

Return values

TRUE	Data is waiting to be read from the debug device.
FALSE	There is no data waiting to be read from the debug device.

UINTN EFIAPI DebugPortReadBuffer	(	IN DEBUG_PORT_HANDLE	Handle,
		IN UINT8 *	Buffer,
		IN UINTN	NumberOfBytes,
		IN UINTN	Timeout
	)

Read data from debug device and save the datas in buffer.

Reads NumberOfBytes data bytes from a debug device into the buffer specified by Buffer. The number of bytes actually read is returned. If the return value is less than NumberOfBytes, then the rest operation failed. If NumberOfBytes is zero, then return 0.

Parameters

Handle	Debug port handle.
Buffer	Pointer to the data buffer to store the data read from the debug device.
NumberOfBytes	Number of bytes which will be read.
Timeout	Timeout value for reading from debug device. Its unit is Microsecond.

Return values

0	Read data failed, no data is to be read.
>0	Actual number of bytes read from debug device.

UINTN EFIAPI DebugPortWriteBuffer	(	IN DEBUG_PORT_HANDLE	Handle,
		IN UINT8 *	Buffer,
		IN UINTN	NumberOfBytes
	)

Write data from buffer to debug device.

Writes NumberOfBytes data bytes from Buffer to the debug device. The number of bytes actually written to the debug device is returned. If the return value is less than NumberOfBytes, then the write operation failed. If NumberOfBytes is zero, then return 0.

Parameters

Handle	Debug port handle.
Buffer	Pointer to the data buffer to be written.
NumberOfBytes	Number of bytes to written to the debug device.

Return values

0	NumberOfBytes is 0.
>0	The number of bytes written to the debug device. If this value is less than NumberOfBytes, then the write operation failed.