Device I/O Support

This group contains the Device I/O Support API and implementation. More...

Files
file	cpukit/dev/ioprintf.c
	This source file contains the implementation of _IO_Printf().
file	cpukit/dev/iorelax.c
	This source file contains the implementation of _IO_Relax().
file	cpukit/dev/iovprintf.c
	This source file contains the implementation of _IO_Vprintf().
file	cpukit/include/rtems/dev/io.h
	This header file provides the interfaces of the Device I/O Support.

Typedefs
typedef void(*)	IO_Put_char(int c, void *arg)
	This type defines the put character handler.

Functions
int	_IO_Printf (IO_Put_char put_char, void *arg, char const *fmt,...) RTEMS_PRINTFLIKE(3
	Prints characters using the put character handler according to the format string.
int int	_IO_Vprintf (IO_Put_char put_char, void *arg, char const *fmt, va_list ap)
	Prints characters using the put character handler according to the format string.
void	_IO_Relax (void)
	Issues a couple of no-operation instructions.

Detailed Description

This group contains the Device I/O Support API and implementation.

Typedef Documentation

IO_Put_char

typedef void(*) IO_Put_char(int c, void *arg)

This type defines the put character handler.

Parameters

c	is the character to put.
arg	is the user-provided argument.

Function Documentation

_IO_Printf()

int _IO_Printf	(	IO_Put_char	put_char,
		void *	arg,
		char const *	fmt,
			... )

Prints characters using the put character handler according to the format string.

Parameters

put_char	is the put character handler.
arg	is the user-provided argument for the put character handler.
fmt	is the printf()-style format string.
...	is the list of parameters required by the format string.

Returns

Returns the count of put characters.

_IO_Relax()

void _IO_Relax

(

void

)

Issues a couple of no-operation instructions.

This function may be used to burn a couple of processor cycles with minimum impact on the system bus. It may be used in busy wait loops.

_IO_Vprintf()

int int _IO_Vprintf	(	IO_Put_char	put_char,
		void *	arg,
		char const *	fmt,
		va_list	ap )

Prints characters using the put character handler according to the format string.

Parameters

put_char	is the put character handler.
arg	is the user-provided argument for the put character handler.
fmt	is the printf()-style format string.
ap	is the argument list required by the format string.

Returns

Returns the count of put characters.