RTEMS Print Support

Files
file	print.h
	User print interface to the bspIO print plug in.
file	printer.h
	User print interface to the bspIO print plug in.
file	printk_plugin.c
	This source file contains the implementation of rtems_printk_printer() and rtems_print_printer_printk().

Data Structures
struct	rtems_printer
struct	rtems_printer_task_context

Typedefs
typedef int(*	rtems_print_printer) (void *, const char *format, va_list ap)

Functions
int	rtems_printf (const rtems_printer *printer, const char *format,...) RTEMS_PRINTFLIKE(2
	Print to the kernel plugin handler. This has to be a macro because there is no vprint version of the plug in handlers.
int int	rtems_vprintf (const rtems_printer *printer, const char *format, va_list ap)
	Print to the kernel plugin handler. This has to be a macro because there is no vprint version of the plug in handlers.
void	rtems_print_printer_printk (rtems_printer *printer)
	Initializes the printer to print via printk().
void	rtems_print_printer_printf (rtems_printer *printer)
	Initializes the printer to print via printf().
void	rtems_print_printer_fprintf (rtems_printer *printer, FILE *file)
	Initializes the printer to print via fprintf() using the specified file stream.
void	rtems_print_printer_fprintf_putc (rtems_printer *printer)
	Initializes the printer to print via fprintf() using an unbuffered FILE stream with output through rtems_putc().
int	rtems_print_printer_task (rtems_printer *printer, rtems_printer_task_context *context)
	Creates a printer task.
void	rtems_printer_task_drain (rtems_printer_task_context *context)
	Drains the work queue of the printer task.

Detailed Description

This module contains all methods and support related to providing the user with an interface to the kernel level print support.

Typedef Documentation

rtems_print_printer

typedef int(* rtems_print_printer) (void *, const char *format, va_list ap)

Type definition for function which can be plugged in to certain reporting routines to redirect the output.

Use the RTEMS Print interface to call these functions. Do not directly use them.

If the user provides their own printer, then they may redirect those reports as they see fit.

Function Documentation

rtems_print_printer_fprintf()

void rtems_print_printer_fprintf	(	rtems_printer *	printer,
		FILE *	file
	)

Initializes the printer to print via fprintf() using the specified file stream.

Parameters

[in]

printer

Pointer to the printer structure.

rtems_print_printer_fprintf_putc()

void rtems_print_printer_fprintf_putc

(

rtems_printer *

printer

)

Initializes the printer to print via fprintf() using an unbuffered FILE stream with output through rtems_putc().

Parameters

[in]

printer

Pointer to the printer structure.

rtems_print_printer_printf()

void rtems_print_printer_printf

(

rtems_printer *

printer

)

Initializes the printer to print via printf().

Parameters

[in]

printer

Pointer to the printer structure.

rtems_print_printer_printk()

void rtems_print_printer_printk

(

rtems_printer *

printer

)

Initializes the printer to print via printk().

Parameters

[in]

printer

Pointer to the printer structure.

rtems_print_printer_task()

int rtems_print_printer_task	(	rtems_printer *	printer,
		rtems_printer_task_context *	context
	)

Creates a printer task.

Print requests via rtems_printf() or rtems_vprintf() using a printer task printer are output to a buffer and then placed on a work queue in FIFO order. The work queue is emptied by the printer task. The printer task writes the buffer content to the file descriptor specified by the context. Buffers are allocated from a pool of buffers as specified by the context.

Parameters

[in]	printer	Pointer to the printer structure.
[in]	context	The initialized printer task context.

Return values

0	Successful operation.
EINVAL	Invalid context parameters.
ENOMEM	Not enough resources.

rtems_printer_task_drain()

void rtems_printer_task_drain

(

rtems_printer_task_context *

context

)

Drains the work queue of the printer task.

Waits until all output buffers in the work queue at the time of this function call are written to the file descriptor and an fsync() completed.

The printer task must be successfully started via rtems_print_printer_task() before this function can be used. Otherwise, the behaviour is undefined.

Parameters

[in]

context

The printer task context of a successfully started printer task.

rtems_printf()

int rtems_printf	(	const rtems_printer *	printer,
		const char *	format,
			...
	)

Print to the kernel plugin handler. This has to be a macro because there is no vprint version of the plug in handlers.

Parameters

[in]	printer	Pointer to the printer structure.
[in]	fmt	Print format string.
[in]	...	Print variable argument list.

Returns

int Number of characters printed.

rtems_vprintf()

int int rtems_vprintf	(	const rtems_printer *	printer,
		const char *	format,
		va_list	ap
	)

Print to the kernel plugin handler. This has to be a macro because there is no vprint version of the plug in handlers.

Parameters

[in]	printer	Pointer to the printer structure.
[in]	fmt	Print format string.
[in]	ap	Print variable argument list pointer.

Returns

int Number of characters printed.