Singh was speaking to developers at the Embedded Systems Show in London last week.
The biggest competition for Linux--as for Windows CE--are the dozens of custom, proprietary operating systems developed and used by vendors for their own products. Proprietary systems have the advantage of being finely tuned for particular hardware and functionality, so they don't take much in the way of resources. On the down side, they usually are not flexible or powerful enough to handle complex applications like connecting to networks, and are often incompatible with open standards like Internet protocol (IP).
Singh dismissed Palm OS and Symbian OS as "also-rans," since they are focusing only on niche markets: handheld computers in the case of Palm, smart phones with Symbian.
"Symbian has good traction in cell phones, but it doesn't have broader traction in other kinds of applications like embedded routers and set-top boxes," Singh said. "Linux has broader applicability."
Microsoft has also been active in pitching its operating system for a wide range of devices. Singh framed the choice between Windows CE and Linux as a matter of freedom against outside control: Linux allows companies to make choices for themselves, while choosing Windows means companies must toe the Microsoft line. "With Windows CE you're stuck with Microsoft's choices, while Linux has an open-market mechanism," Singh said.
But that open market--which supplies vendors with choices for user interface and other components--can be a problem, since it's impossible to be sure whether a particular piece of software will work on all embedded versions of Linux.
Fragmentation particularly affects "real time" versions of Linux, where there is no response lag time, as Linux vendors have to modify the Linux kernel in various ways to make it perform in a real-time environment. "The solutions are not all identical," Singh said.
The Embedded Linux Consortium is working on a certification program that would ensure that any certified application works on any certified embedded Linux distribution. The program will involve a high-profile "Intel Inside"-type logo, Singh said.
The ELC counts among its members chipmakers such as Intel and Motorola and device makers like Sony and Sharp, as well as Linux distributors like Red Hat.
The compatibility issues are directly related to Linux's open-source nature, which is also one of its chief benefits for system designers. The software is distributed under the General Public Licence, which means anyone can acquire, modify and redistribute it, as long as the redistributed version carries the same conditions.
That means Linux can be used without license fees, but it also means no single vendor maintains control over all aspects of the software.
However, compatibility between different Linux distributions is generally very good because of the watchful eye of the open-source developer community, Singh said.
In the embedded industry, the software has gone from a lot of hot air two years ago to one of the three biggest embedded operating systems in use today, Singh said. The most popular embedded OS today is VxWorks, but in a survey of which system developers were planning to use in the next year, Linux came out on top by a wide margin, Singh said.
"There's never been an operating system that has grown at this rate in the embedded industry," Singh said.
Demand for complex embedded operating systems is growing as devices become more complex.
"It's hard to find things that don't have intelligence anymore. Go in to a store at Christmas and it's amazing all the things you'll see talking to you," Singh said. "Everything has a browser built into it. You hear about the intelligent fridge and the intelligent microwave. I don't know if those things are going to take off, but this is clearly the way things are heading."
