LINUX IN EMBEDDED SYSTEMS

The embedded system is a combination of computer hardware, software and, perhaps, additional mechanical parts, designed to perform a specific function. A good example is an automatic washing machine or a microwave oven. Embedded systems need only the basic functionalities of an operating system in real-time environment-a scaled down version of an RTOS. They demand extremely high reliability plus the ability to customize the OS to match an application’s unique requirements. However, commercial RTOSes, while designed to satisfy the reliability and configuration flexibility requirements of embedded applications, are increasingly less desirable due to their lack of standardization and their inability to keep pace with the rapid evolution of technology. The alternative is: open-source Linux. Linux offers powerful and sophisticated system management facilities, a rich cadre of device support, a superb reputation for reliability and robustness, and extensive documentation. Also, Linux is inherently modular and can be easily scaled into compact configurations.

INTRODUCTION

Computers have evolved from a few, huge mainframes shared by many people, to today’s PCs -millions in number, miniscule in size compared to the mainframes, and used by only one person at a time. The next generation could be invisible, with billions being around and each of us using more than one at a time. Welcome to the world of embedded systems, of computers that will not look like computers and won’t function like anything we’re familiar with. An embedded computing system uses microprocessors to implement parts of functionality of non-general-purpose computers. Early microprocessor-based design emphasized input and output. Modern high performance embedded processors are capable of a great deal of computation in addition to I/O task. Microprocessors that were once prized centerpieces of desktop computers are now being used in automobiles, televisions and telephones. The huge increase in computational power can be harnessed only by applying structured design methodologies to the design of embedded computing systems.  Historically, Linux was developed specifically as an operating system for the desktop/server environment. More recently, there has been a growing interest in tailoring Linux to a very different hardware and software needs of the embedded applications environment.

Linux now spans the spectrum of computing applications, including IBM’s tiny Linux wrist watch, hand-held devices (PDAs and cell phones), Internet appliances, thin clients, firewalls, industrial robotics, telephony infrastructure equipment, and even cluster-based supercomputers. Let’s take a look at what Linux has to offer as anembedded system, and why it’s the most attractive option currently available.