USING PERL IN EMBEDDED SOFTWARE DEVELOPMENT

THE MAGAZINE FOR COMPUTER APPLICATIONS
Circuit Cellar Online offers articles illustrating creative solutions
and unique applications through complete projects, practical
tutorials, and useful design techniques.

USING PERL IN EMBEDDED SOFTWARE DEVELOPMENT

Lessons from the Trenches by Liu Kai

Start ı Sales Front-End Online ı Custom Software Service Online ı Software Engineering ı Documentation ı Utilities for Debugging and Production ı GUI and OLE ı The Benefits ı Sources and PDF

Using Perl in embedded software development was not originally my idea. I was inspired by Bruce Lightnerıs PicoWeb design, which consisted of a small web server in a microcontroller. Perl is used with a DOS batch file and some other utilities to transfer the know-how and whole design to other designers. This led me to survey Perl in embedded software development. After reading a lot about Perl applications in a book and on several web sites, I found that Perl is a good tool for assisting in embedded software development.

Embedded software is a term that covers a large spectrum, ranging from embedded computing to small microcontroller applications. In this article, I will talk about the software (or firmware) developed on low-end microcontrollers. Although development tools continually increase in power, embedded software engineers always work in a worse environment than those creating desktop applications. A poor toolchain could be a simple ROM-monitor running in a target controller with no source-level debugger, simple assembler, or programmer. And, sometimes itıs worse, like when only a simulator or programmer is available. That means that you have to key in a lot of commands in the debug session. And, itıs hard to identify the bugs and the process is slowed down.

Most of the source code has to be written in assembly, and the architecture is hardly kept clear. I tried to find some tools to save me from doing the same thing everyday. Thatıs where Perl came in. Because Perl is open-source, any developer can get the code and modify it for his or her own purposes. In fact, I am writing some Perl scripts to generate custom make files, assembly converters, code templates, and other utilities.

Perl is a language developed in UNIX and is popular as a CGI script for web applications. One advantage of Perl is in its text handling. It is a powerful script language, which can operate in UNIX, Linux, Windows32, OS/2, and Mac. Many attractive features include networking, object-oriented programming, GUI, OLE, and more. Table 1 is a review of a typical development process for (embedded) software development, identifying potential replacements and improvements with the help of Perl.

Without Perl	With Perl
The sales team would get the customersı inquiries.	Perl can handle the inquiries from the web siteıs customer form.
The sales team would forward the inquiries to the software engineers or project manager.	Perl can do it through an intranet.
The developer would send the specifications back to the customers or sales team for approval and further negotiation.	Perl can generate documentation based on templates and the customersı demands and forward it on to everyone involved.
The developer would start to develop the project based on the specification.	Perl can help retrieve software modules from existing code databases, generate make files, and make custom code. The customer can retrieve the code via e-mail after sending the inquires, providing no additional error occurs.
Documentation is a key issue in keeping the software architecture.	Perl has its own method to help the programmer write, code, and document into one file and then generate the required documentation format specified.
Table 1ıHere you can see how Perl could potentially improve the development process, making it faster.

Perl can also be used as an agent to browse the whole software catalog and then compose an abstract of software modules, easing the learning curve of a new software module.

During debugging, Perl can help the developer debug the code and keep track of the process. And during production, Perl can help the manufacturer test and program the devices. Because Perl is open-source, the whole toolset is constantly changed and updated. And seeing that it has its own GUI, Perl is useful for setting up a Windows version in development and making a graphic device driver (LCD, OSD).

Teamwork is important in developing a project, and because Perl is a language of networks, it can be easily achieved based on the Perl script. You will find that all the processes will run faster because your database is increasing in size during the processes.

Using Perl is not a new idea, but it has not been popular in embedded software industries. However, Perl will help embedded engineers in the areas of software engineering, automation in definition, documentation, coding, debugging, production, and almost every other session of development. It really makes the development easier and faster.

Now, letıs follow the development process and see how Perl can help.

Circuit Cellar provides up-to-date information for engineers. Visit www.circuitcellar.com for more information and additional articles.
For subscription information, call (860) 875-2199, subscribe@circuitcellar.com or subscribe online. ıCircuit Cellar, the Magazine for Computer Applications. Posted with permission.