The Secret Life of Embedded Linux
Mar 22, 2007 4:00 AM PT
Consumers and enterprise workers will not likely soon see cute marketing labels such as "Linux Inside" or images of penguins pasted on the outer casings of their favorite entertainment and communications products. Nor will products they buy be touted as using Linux in advertising campaigns.
Regardless of labels, unless the manufacturer is a proprietary partner with Microsoft, if the product's electronic circuits need a control system, more likely than not Linux will be doing the job.
"Linux is becoming very pervasive through the manufacturing industry. There is a huge number of products shipping with embedded Linux," Karim Yaghmour, CEO of e-mail security firm Kryptiva, told LinuxInsider. "There is no branding involved. Engineers decide to use it but don't advertise it."
The trend towards using Linux to drive consumer products has grown over the last decade, according to Yaghmour, author of "Building Embedded Linux Systems." Ten years ago there were fewer options with Linux, so about half of the manufacturers developed their own operating systems. The rest used well-known Linux distributions.
"Today, the roll-your-own option is more costly and time-consuming, so most manufacturers are now using an established distribution. Also, more silicon manufacturers are handing out Linux with their processors," he said.
Push and Pull
Intel had the same identity problem with its use in PCs. No one knew about Intel until the famous advertising campaign, according to Jim Ready, CTO of MontaVista Software, a Linux and proprietary OS developer. Products that are well built give no clue that Linux is embedded.
"Usually there is no interface, just a microprocessor and the OS," Ready told LinuxInsider.
Embedded Linux is a generic term. It is merely the commercial version of any Linux adaptation, according to Ready. Using an established distribution is usually a manufacturer's best bet, but others prefer to build the OS version themselves.
Generally vendors are not pushing the use of Linux in their products. It is the engineers developing the actual products that are pulling Linux in, Yaghmour noted.
"As a marketing hook there is no value to device makers in advertising the use of Linux. There is no advantage to do this. There is no competitive edge in advertising Linux," he added.
The list of products running Linux spans communications, entertainment, transportation and productivity markets. In fact, it is rapidly edging out proprietary operating systems, Inder Singh, chairman of LinuxWorks, a developer of real-time embedded Linux systems, told LinuxInsider.
Embedded Linux is widely used in networking products such as routers, gateways, firewalls and black boxes. Popular consumer items married to Linux include cell phones, TiVo, DVRs, HD televisions, set-top boxes, high-end printers and automobiles.
"Linux works best with those devices that are connected and those that have multifunction uses, added Bill Weinberg, an embedded Linux and open source analyst and consultant at Linuxpundit.com.
No Linux Here
Generally the Linux OS is not a good fit in aircraft equipment and high-level security devices whose certification requirements prohibit open source elements, according to Singh.
"FAA certification requires full documentation. In many cases, providing that documentation is not possible for all open source components," said LinuxWorks' Singh.
While Linux is safer than Windows, it is still highly complex. Some electronic devices are too simple to need a full-fledged operating system. Perhaps the biggest product area not well suited for Linux is the specialized applications hardware that requires real-time critical timing elements, Singh said.
Other poor uses for Linux include devices running low-end processors such as low-cost MP3 players and low memory devices, Weinberg told LinuxInsider.
Manufacturers achieve three major benefits for putting Linux inside: cost efficiency, flexibility and time to market. From Ready's view, Linux is very viable and will continue to grow in use because of these factors. He sees products based on running embedded Linux as being on pretty solid ground.
When MontaVista started, the typical Linux OS would take 90 seconds to boot up. An ARM processor would take only seconds, he said.
"We shrunk the Linux coding and speeded it up. This narrowed the gap and dramatically reduced the need to use other non-Linux solutions," Ready explained.
The industry is in a continuing cycle of development. Semiconductors get smaller, Linux gets smaller and faster and applications get a better fit, he said, adding that shrink-fitting Linux has become the biggest form of competition in the industry.
"Manufacturers are under tremendous pressure to get their products out quickly with lots of features," Ready said.
One of the biggest drawbacks to using Linux in a new product line is the lack of driver support, according to Weinberg of Linuxpundit.com. Another downside is that Linux and open source packages can increase the memory footprint. Depending on the size and scope of the product, that can hinder Linux's suitability.
Weinberg disagrees with the view that Linux can speed up the time to market, at least for first-generation products. Compared to Windows-based devices, products such as PDAs, cell phones and Symbian devices, Linux-based products can take longer to get to market, he argued.
There are also drawbacks with licensing and latency issues, Weinberg stated. Licensing issues may arise when a manufacture runs Linux on top of proprietary devices.
When a graphic interface is needed, putting Linux in a product can result in problems, warned Kriptiva's Yaghmour. Otherwise, devices that do not need a display pose few, if any, disadvantages.
"Sometimes using Linux can cost more than using WindowsCE. The GUI part is where Linux really stumbles," Yaghmour said. "Not much being done in simplifying the interface."
Manufacturers have to weigh sometimes competing factors when selecting Linux over Windows or a proprietary OS in consumer products. Often, the flexibility of Linux balances out those differences, sometimes it does not.
Clearly, though, Linux's freedom and flexibility are driving the trend to putting Linux inside consumer products that are not encumbered with hardware restrictions. Manufacturers are not dependent on a single vendor with Linux.
"Linux is a moving trend. More and more manufacturers are using it," concluded MontaVista's Ready.
Yaghmour concurs. "Every engineer adapts it and expands the user base," he said. "Anybody who wants to enter the market is using Linux due to its low cost. It is hard to justify changing for a proprietary OS."