LJ Archive

Embedded Linux and Java—Wave of the Future?

Rick Lehrbaum

Issue #94, February 2002

Rick contemplates the coming exponential proliferation of smart devices using Java + Linux.

Focus on Embedded Systems

Embedded Linux and Java—Wave of the Future?

Rick contemplates the coming exponential proliferation of smart devices using Java + Linux.

by Rick Lehrbaum

The world of intelligent devices is changing dramatically. The computerized devices around us are getting smarter; they're increasingly connected and interdependent, and they're becoming vastly more numerous. And, all this is happening at an ever-increasing rate.

Blame it on Moore's Law, but it's now practical to embed moderately high-performance computing and connectivity in just about everything that runs on electricity—whether tethered or mobile. This trend is fueled by powerful and highly integrated system-on-chip processors, coupled with large-capacity system and storage memories (both disk and silicon), and empowered by wired and wireless communications interfaces (Ethernet, IrDA, 802.11, Bluetooth).

Another important phenomenon is that as both embedded computing and connectivity proliferate, the intelligence within tomorrow's devices is becoming less localized. Increasingly, the precise location of the software running on these devices is blurring, and eventually we're unlikely actually to know where the programs we use are located. Is the application running inside the device? Is it based on some remote server (e.g., a home services gateway)? Is it located at an internet-based application service provider? Is it a combination of all three?

Call it distributed intelligence or distributed computing. Call it .NET. Call it the post-PC era. Whatever you call it, one thing's certain: the era of isolated, autonomous desktop PCs running nothing but localized software is coming to an end, like the mammoths of the Ice Age.

Welcome to the Post-PC Era

As the boundaries of the traditional computing paradigm blur and a new reality based on distributed, interconnected, pervasive computing devices dawns, a few important attributes of the coming era draw into focus:

  • The number of smart devices (i.e., products with embedded operating systems inside) will grow exponentially, reaching numbers in the billions.

  • The choice of CPU will be more a matter of cost than technology or architecture.

  • Nearly all devices will have connectivity, whether wired or wireless.

  • Most devices will have the ability to be upgraded or repaired remotely, by downloading new firmware or software.

  • Most devices will have specific rather than general-purpose functionality, so their application software will be defined by their manufacturers (rather than loaded by their users).

In general, most computing devices in this new era will not be PCs. Instead, they'll be smart appliances of various shapes and capabilities, used for information, entertainment, control and other purposes. Think of things like smart wristwatches (with built-in mobile phone and PIM functions), advanced cell phone/PDAs, audio/video systems, security systems, automobile infotronics, smart kitchen appliances and PC-like desktop terminals. The list goes on and on.

A Fertile Field for Linux

As the number and variety of devices with embedded intelligence grow exponentially, the need to minimize cost and maximize specialization increases correspondingly. Hence, embedded Linux becomes a highly desirable technology for the operating system due to its scalability, configurability and affordability.

It's worth noting that until recently, the cost penalty associated with the CPU and memory resources necessary to run Linux had been a somewhat limiting factor, relative to using it in cost-sensitive devices. Now, however, the baseline needs of embedding Linux—roughly 2MB Flash and 4MB RAM memory and a moderate speed processor—have become reasonably inexpensive, thanks in large measure to Moore's Law.

And Java

Another important challenge in this new era in which we'll be surrounded by billions of increasingly intelligent devices, all communicating with one another, is the obvious need to simplify and quicken the process of application development, deployment and maintenance. In this regard, Java appears postured to play an increasingly significant role.

Although Java failed to hit the target for which it was initially developed (which was, ironically, to serve as an embedded operating system within smart devices), Java ended up providing a convenient means to enable moving applications around among computing devices—propelled to this position by the dramatic emergence of the Web.

Today, despite its early failure as an embedded operating system, Java is showing promise in the role of providing a device-independent application platform, running on top of the embedded operating system. In this case, rather than serving as the operating system itself, Java provides the benefit of masking the unique aspects of the underlying device and providing an array of services beyond those offered by the embedded OS.

In the context of an exponential proliferation of smart devices, Java is emerging as a handy way to minimize device-specific development and to allow developers to focus on the truly unique aspects of their projects. Increasingly, Java is providing a means to obtain functionality like GUIs, web browsers, protocol stacks, handwriting and speech recognition, wireless communications, multimedia support, database management and a wide range of remote services.

A Couple of High-Profile Examples

One interesting example of a product based on a combination of embedded Java + Linux is a consumer entertainment system that was recently announced by Hewlett-Packard. The HP Digital Entertainment Center is basically a home-entertainment appliance that brings digital music and information via broadband and home networks into the living room, without a PC. The system connects like an audio component to a normal home stereo system and can be used to burn custom CDs, create/store/organize MP3 files on its large internal hard disk, transfer music to digital music players and listen to internet radio.

The HP Digital Entertainment Center

“HP embraced Linux for consumer appliances because of its open-source and community support”, explains William Woo, general manager of Hewlett-Packard's Embedded Software Operation. He adds:

We have customized Linux for use as an HP embedded OS and combined it with our HP Chai technology to create an embedded software solution with a Java application environment and web connectivity. HP Chai supports Java applications for delivering e-services to create a rich consumer experience.

Another high-profile, Linux-based device that makes a point of its support for Java applications, of course, is Sharp's new Zaurus PDA. “The Zaurus SL-5000D offers incredible potential for the developer community”, said Steve Petix, associate vice president of Sharp's Mobile & IT Solutions Group. “We are excited to support both Linux and Java developers as they create next-generation mobile applications for this powerful new platform.”

Wave of the Future?

In the exciting new post-PC world of pervasive computing, we'll be surrounded by an exponentially growing number and variety of intelligent, interconnected devices. But the challenges associated with developing, maintaining and supporting increasingly sophisticated system architectures and protocols also will grow exponentially.

Looked at from this perspective, the emerging popularity of Java technology as a well-supported application and services framework for devices, offers an enticing possibility of ready-to-use software components that can be used along with embedded Linux, to speed and simplify device development and to enhance the capabilities of the end product.


Rick Lehrbaum (rick@linuxdevices.com) created the LinuxDevices.com “embedded Linux portal”. Rick has worked in the field of embedded systems since 1979. He cofounded Ampro Computers, founded the PC/104 Consortium and was instrumental in creating and launching the Embedded Linux Consortium.

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