Kernel +Trace Tool Variant Device Driver Overview

Intended audience

This document is intended to be +used by Symbian platform developers implementing a kernel side trace handler.

Kernel Trace tool variant device driver library details

The +DLL that provides the functionality and the library to which kernel.exe must +link is identified below.

+ + + +DLL +LIB +Short Description + + + + +

btracex.ldd

No export library

Kernel side implementation of BTraceC

+ + + +

Architectural +Relationship

The kernel trace tool variant device driver implements +the handler function of the kernel side BTrace class. It is the kernel side +implementation of BTraceC.

Description

The kernel trace tool variant device +driver is a kernel side component which reads trace data from a buffer.

Kernel Trace tool variant device driver functionality

The +kernel trace tool variant device driver exists purely to implement kernel +side trace handling functionality.

Trace handling

The kernel trace tool +variant device driver exists to handle trace data generated kernel side by +the BTrace framework.

Key Kernel +Trace tool variant device driver classes

The key classes that make +up the kernel trace tool variant device driver module are as follows:

TBTraceBufferK

A +class representing the buffer to which trace data is written.
DBTraceFactory

A +factory class for trace channels.
DBTraceChannel

A +class representing trace channels.

Using Kernel +Trace tool variant device driver

The kernel trace tool variant +device driver is a kernel side executable and thus not called directly from +user side. BTraceC communicates with it by passing members of its TControl enumeration +to the DoControl function. Its function Trace_Impl implements +the handler function of the BTrace kernel class.