Logging

Detailed Description

The Logging Subsystem.

The logging system is made up of two parts. The upper layer provides message formatting, and discards log messages that are less than the current log level.

The bottom layer is the logging transport. This can be

• Via LOG messages using the vendor class USB device.
• Over a CDC class USB device (serial console)

The low level implementation is determined by the callback function passed to SysLog_Initialize (or via PIPELINE_LOG_WRITE).

To log messages to the console, use SysLog_Message() and SysLog_Print(). This should not be called within interrupt context.

Files
file	syslog.h
	The upper layer of the Logging subsystem.
file	usb_console.h
	A logging transport that uses a USB serial console.

Typedefs
typedef void(*	SysLogWriteFn )(const char *)
	A function pointer to log a message. More...

Enumerations
enum	SysLogLevel {   SYSLOG_DEBUG, SYSLOG_INFO, SYSLOG_WARN, SYSLOG_ERROR,   SYSLOG_FATAL, SYSLOG_ALWAYS }
	The system log levels. More...

Functions
void	SysLog_Initialize (SysLogWriteFn write_fn)
	Initialize the System Logging module. More...
void	SysLog_Message (SysLogLevel level, const char *msg)
	Log a message. More...
void	SysLog_Print (SysLogLevel level, const char *format,...)
	Format and log a message. More...
SysLogLevel	SysLog_GetLevel ()
	Return the current log level. More...
void	SysLog_SetLevel (SysLogLevel level)
	Set the log level. More...
void	SysLog_Increment ()
	Increase the verbosity of the logging.
void	SysLog_Decrement ()
	Decrease the verbosity of the logging.
const char *	SysLog_LevelToString (SysLogLevel level)
	Return the string description of a log level. More...
void	USBConsole_Initialize ()
	Initialize the USB Console module.
void	USBConsole_Log (const char *message)
	Write a message to the console. More...
void	USBConsole_Tasks ()
	Perform the housekeeping tasks for the USB Console.

Typedef Documentation

typedef void(* SysLogWriteFn)(const char *)

A function pointer to log a message.

Parameters

msg	The message to log, must be NULL terminated.

Enumeration Type Documentation

enum SysLogLevel

The system log levels.

Enumerator
SYSLOG_DEBUG	Debug messages.
SYSLOG_INFO	Info messages.
SYSLOG_WARN	Warnings.
SYSLOG_ERROR	Errors.
SYSLOG_FATAL	Fatal events.
SYSLOG_ALWAYS	Always logged regardless of log level.

Function Documentation

SysLogLevel SysLog_GetLevel

(

)

Return the current log level.

Returns

The current log level.

void SysLog_Initialize

(

SysLogWriteFn

write_fn

)

Initialize the System Logging module.

Parameters

write_fn

The function to use for logging messages.

If PIPELINE_LOG_WRITE is defined in app_pipeline.h, the macro will override the write_fn argument.

const char* SysLog_LevelToString

(

SysLogLevel

level

)

Return the string description of a log level.

Parameters

level

The log level.

Returns

A statically allocated string which contains the text description of the log level.

void SysLog_Message	(	SysLogLevel	level,
		const char *	msg
	)

Log a message.

Parameters

level	the log level of the message
msg	the message to log.

Note

This should not be called within interrupt context.

void SysLog_Print	(	SysLogLevel	level,
		const char *	format,
			...
	)

Format and log a message.

Parameters

level	the log level of the message
format	The format string.

Note

This should not be called within interrupt context.

void SysLog_SetLevel

(

SysLogLevel

level

)

Set the log level.

Parameters

level

the new log level.

void USBConsole_Log

(

const char *

message

)

Write a message to the console.

Parameters

message

a NULL terminated string.

We may not buffer the entire message if the log buffer is full. Since the messages are sent over a serial console, the NULL characters are replaced with
characters.