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.

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.