Five years ago, it was little more than a technical curiosity.
Embraced only by open-source enthusiasts and by a disgruntled anti-Windows brigade, Linux initially received a lukewarm welcome from pragmatists in the embedded world. Most of those engineers, concerned with issues of security and real-time operation, merely kept a watchful eye, waiting to see if there was a fire amid all the smoke.
Now it appears the wait is over. The fire is real, and it's spreading across the embedded industry in a way that even the most feverish Linux supporters didn't foresee a few years ago. The biggest mainstream semiconductor manufacturers have ported the upstart operating system to their hardware and product designers around the world are considering it for future projects.
"In the last 24 months, the activity around Linux has gone up dramatically," notes Glenn Beck, director of marketing for high-performance PowerPC processors at Freescale Semiconductor. "Every customer we're talking to is looking at it."
To meet the growing demand for Linux, chip manufacturers are making their products compatible with Linux. At the Embedded Systems Conference in San Francisco in March, Freescale announced that it has ported MontaVista Linux to its PowerQUICC II processor. Freescale's announcement came on the heels of news, days earlier, that it is working with the Chinese Ministry of Information Industry to evaluate embedded systems based on Linux and the Freescale family of PowerPC processors. Similarly, Analog Devices said earlier this year that it has rolled out a board incorporating its Blackfin processor and the open-source uCLinux operating system.
While significant for product developers, those latest announcements merely scratched the surface of a powerful trend that's sweeping the embedded industry now.
Beck and others in the embedded community say they've recently seen an extraordinary increase in the number of applications using Linux. Whereas a few years ago, Linux use was mainly in routers, switches, firewalls, and other forms of networking infrastructure, its applications are broader today. Vendors of commercial Linux systems say their Linux products are playing a role in televisions, MP3 players, refrigerators, dishwashers, tanks, aircraft, automotive dashboards, and industrial control systems. "One of our customers ships 80 percent of its digital TVs with MontaVista Linux," notes Peder Ulander, vice president of marketing for MontaVista Software.
A 'Port for Every Processor'
After nearly a decade in the shadow of more prominent embedded operating systems, such as Wind River Systems' industry-leading VxWorks, Linux is now gaining momentum for a number of good reasons. Key among those is the ever present desire of product developers to gain access to, and control over, all the software code that goes into their products. With Linux, unlike some proprietary operating systems, development engineers can view—and make changes to—all the code.
IDC predicts that revenues for Linux hardware (purple) and software (green) will reach $35.7 billion by 2008.
Equally important is the growing pervasiveness of Linux. Increasingly, Linux is bubbling up into the mainstream of the embedded world. "There's so much available on Linux," notes Inder Singh, chairman and CEO of LynuxWorks Inc., a supplier of Linux-based operating systems. "There's a port of Linux on every conceivable processor and hardware device. And just about every embedded software product now has a Linux version."
MontaVista Linux, for example, is now available on eight processor architectures, 30 different chip sets, and 150 types of processor-based printed circuit boards. Freescale, meanwhile, claims that all of its PowerPC-based processors offer Linux ports, as well as many of its non-PowerPC-based processors.
In February, Freescale proved its growing allegiance to Linux when the company announced it is teaming with the China Software and Integrated Circuit Promotion Center to build a technology lab for research and development of computing platforms based on Linux and PowerPC processors. Freescale says that the joint effort is founded on the common desire of both parties to promote open, flexible technology solutions.
Similarly, Analog Devices (ADI) is supporting noncommercial projects in its own community (http://blackfin.uclinux.org) by encouraging engineering teams to share coding ideas for uClinux, an open- source operating system for low-cost microcontrollers that have no memory management. Like Freescale, ADI has made one of its own key products available for such applications by enabling uClinux to run on Blackfin, an Analog Devices DSP core with traditional microcontroller architecture.
LynuxWorks LynxOS will serve as the operating system for Verifone point-of-sale machines employed in convenience stores and gas stations.
The move toward Linux in the embedded community has grown so strong that even the most strident anti-Linux voices have deserted their old arguments. Wind River Systems, a company built atop the success of proprietary embedded operating systems, conceded to the Linux movement last year, announcing that it is teaming with Red Hat Inc. to develop a Linux-based software platform. The partnership calls for Red Hat to supply the operating system while Wind River offers development tools for the platform.
Industry analysts say that such corporate moves are a reaction to the tidal wave of user interest in Linux and, at the same time, are adding to the Linux phenomenon by rolling out products that bring Linux closer to the mainstream. Gartner Dataquest, an industry analyst based in San Jose, CA, says that North American Linux usage has climbed steadily in the past three years, jumping from 7 percent in 2002 to 14 percent in 2003 to 20 percent in 2004. Similarly, a December 2004 forecast by IDC predicts that revenues for Linux hardware and software will reach $35.7 billion by 2008, an increase of more than 300 percent over 2003 figures.
Vendors say that Linux offers a level of standardization that can't be attained through the so-called "roll-your-own" approach, in which the product developer writes its own operating system code.
"Developers have to get over the do-it-yourself mentality," says Ken Klein, CEO of Wind River. "The work they do today is too critical to spend their precious bandwidth reinventing the wheel."
Wind River, LynuxWorks, MontaVista Software, and Metrowerks serve as suppliers of Linux-based operating systems and software tools. Because publicly available Linux kernels can be downloaded at no cost to users, such vendors draw revenues, not on the sale of the operating system itself, but on the sale of software tools and support services for their brand of Linux-based products.
Industry analysts say that vendor-supplied versions of Linux serve an important purpose, especially for engineering teams that are cash-strapped or shorthanded.
"If you go with a publicly available kernel, as opposed to a commercial Linux distribution, you have to make sure you have enough knowledge in-house to deploy and maintain the kernel," notes Daya Nadamuni, principal analyst for Gartner Dataquest.
Most experts stress that cost is not one of the key reasons for Linux's emergence during the past two years. Although the operating system is royalty-free, Linux's costs can be as much or more than those of its commercial counterparts, they say.
"The original premise of Linux is that it's cheap and there are no royalties," Nadamuni says. "But price alone isn't a sufficient reason to pick Linux anymore. It's wrong to assume that Linux will automatically be cheaper."
Nadamuni and other industry experts argue that bug-fixing, patch development, and other forms of operating system maintenance end up costing money for the product developer when they have no vendor support.
"If you're a project manager, you have to ask, 'Do I have the in-house expertise to support the kernel?'" Nadamuni says. "If, two years down the road, your star programmer leaves, and you want to come up with the second generation of your product, will you be able to do it?"
Real-Time or Not?
The other primary reason for not choosing Linux is that it is inherently a non-real-time system. In a 2004 study performed by Venture Development Corp., engineers described real-time limitations as the most important factor inhibiting the growth of Linux. Up to now, Linux has not been regarded as a true, hard real-time system because it has not had the precise timing and ability to meet prescribed deadlines. That means certain applications in factory automation, machine design, defense, and aerospace have always been out of bounds for Linux.
Nonetheless, MontaVista announced last year that it is developing a real-time Linux kernel. Also, real-time extensions, such as those made by FSMLabs Inc., which run Linux as a non-real-time thread of a real-time operating system, have enabled Linux to increasingly serve in applications that must meet prescribed deadlines.
Some suppliers, such as LynuxWorks and MontaVista, have also developed Linux-compatible, open source operating systems for use in highly secure and reliable applications. LynuxWorks' open-source LynxOS-178 is being employed as the software backbone for the U.S. Army's communication-centric Future Combat System.
Linux has also made in-roads in industrial and commercial applications. MontaVista executives say that their company is working with an unnamed manufacturer on a "connected" refrigerator that will employ MontaVista Linux. LynuxWorks says it is teaming with numerous makers of point-of-sale machines, including one such convenience store machine from Verifone Inc. that will employ the LynxOS.
Experts say that the migration of such applications to Linux is a natural offshoot of the extraordinary number of non-PC-based products that are gaining network connectivity. While desktop technology stagnates, they say, embedded technology is burgeoning.
"Five years from now, there will be 14 billion integrated devices connected in ways we can't even imagine now," noted Klein of Wind River in a recent keynote address at the Embedded Systems Conference.
Clearly, not all of the 14 billion devices will be candidates for Linux. Some applications, particularly those with hard real-time requirements and maximum security needs, will not use open source. For many applications, however, engineers will find the de facto standard status of Linux to be an advantage.
"Will we see a Linux operating system on the front end of a F16 jet fighter? Probably not," says Beck of Freescale. "But we haven't talked to anyone lately who isn't at least considering Linux."
Reach Senior Editor Chuck Murray at firstname.lastname@example.org.