Chapter 24. CDL Concepts

Table of Contents
About this chapter
Component Repository
Component Definition Language
Packages
Configuration Items
Conflicts
Templates

About this chapter

This chapter serves as a brief introduction to the concepts involved in eCos (Embedded Configurable Operating System). It describes the configuration architecture and the underlying technology to a level required for the embedded systems developer to configure eCos. It does not describe in detail aspects such as how to write reusable components for eCos: this information is given in the Component Writer’s Guide.

Background

Software solutions for the embedded space place particularly stringent demands on the developer, typically represented as requirements for small memory footprint, high performance and robustness. These demands are addressed in eCos by providing the ability to perform compile-time specialization: the developer can tailor the operating system to suit the needs of the application. In order to make this process manageable, eCos is built in the context of a Configuration Infrastructure: a set of tools including a Configuration Tool and a formal description of the process of configuration by means of a Component Definition Language.

Configurations

eCos is tailored at source level (that is, before compilation or assembly) in order to create an eCos configuration. In concrete terms, an eCos configuration takes the form of a configuration save file (with extension .ecc) and set of files used to build user applications (including, when built, a library file against which the application is linked).