Porting Linux to Set-Tops Is New Alliance's Challenge

Linux, the up-and-coming Unix-based operating system, received a major endorsement from a diverse group of cable software, silicon and service providers when the TV Linux Alliance was launched.

Although the alliance — launched earlier this month at the National Show in Chicago — comprises a number of strong cable-technology players, porting Linux to set-tops will be difficult, some industry participants noted.

The group's goal is to "create an industry standard API [application-programming interface] for digital TV" that's based on Linux, said Bryan Sparks, CEO of Lineo Inc., a developer of Linux-based embedded systems-reference designs.

Among the 24 founding member companies in the alliance: Liberate Technologies Inc., Broadcom Corp., Conexant Systems Corp., Excite@Home Corp., Sun Microsystems Inc., TiVo Inc., OpenTV Inc., WorldGate Communications Inc., Pace Micro Technology plc, Diva Systems Corp. and Motorola Broadband Communications Sector.

Notably absent from the alliance are Scientific-Atlanta Inc. and Microsoft Corp., the creator of Windows, Linux's dominant competitor.

The alliance hopes to leverage Linux's open-source nature, which has "created a [developer] community involvement that is unparalleled," said Sparks. The Linux developer community has gained near-cult status, thanks to its battle with commercial operating systems, most notably Windows.

The Linux kernel is freely available to developers who conform to the operating system's licensing agreements. The kernel serves as the core of the operating system, handling typical housekeeping duties with the PC hardware.

One analyst said the introduction of Linux to the set-top environment will help cable operators avoid more delays for rich interactive-television features and applications.

"A common solution built around a single framework will reduce the integration issues that result in lengthy deployment time frames for advanced interactive applications, as well as middleware solutions and set-top boxes," said The Yankee Group analyst Adi Kishore.

Linux will become increasingly relevant as network-oriented set-tops and home controllers come to market, added Motorola Broadband's Digi- Cable division vice president and general manager Carl McGrath.

The alliance promised to create a royalty-free TV Linux API that will be available sometime next year.

While Linux has gained a strong foothold in the enterprise-server market — and has taken some market share away from Microsoft — the OS has yet to break into the set-top market in a significant way. An exception is TiVo Inc.'s use of a flavor of Linux for its personal video recorder software.

Alliance members are looking forward to the prospect of a more significant set-top presence.

"Linux is a great platform," said Open TV vice president of strategic and product marketing Anup Murarka, who cited the value of partnering with the Linux community with its set of application-development tools.

"We want to enable more and more hardware functionality for peripherals and network compatibility," he said, pointing out that Linux developers are moving quickly to create drivers to support new hardware, such as USB [universal serial bus] devices.

Still, Murarka said some challenges remain in moving Linux to a set-top environment, as "getting Linux in an embedded product … will take some time."

For example, the real-time behavior of Linux needs to be improved because the OS relies on virtual memory, a technique that "borrows" hard drive space, in lieu of available random access memory (RAM). That compromises performance for some functions that require real-time execution.

Designed to function in a workstation environment, Linux requires fairly significant processing power and memory to execute commands. That's because of its memory-use scheme, which has "zero control" over how many applications and threads can be open at any one time, according to Murarka.

"There's no consistent, lightweight, very fast graphics library available for Linux today," he said. A graphics library is central to TV applications, as it helps an operating system support colors at 8 bits or greater, draw on-screen graphics and render fonts.

Murarka said it will take a minimum of 12 months to develop a robust graphics library for Linux, and more likely will take as long as two years.

However, the TV Linux alliance represents such a broad range of players that the group will "get [Linux] to the state it needs to be" for set-top applications, said Diva vice president of corporate and business development Michael Rose.

Scientific-Atlanta has its own set-top OS via its PowerTV Inc. subsidiary, which explains why the company has not joined TV Linux.

"Our position is we have a product today that works and is supported by a wide range of developers," said PowerTV CTO and vice president of engineering Ken Morse.

Linux "has a long way to go" before it can prove itself as a robust, set-top OS, Morse said. "It takes deployments to find out [OS] issues."

Linux's open-source nature means that core changes to the kernel must be fed back to the development community. Morse also questioned how competitive, commercial software developers are going to work "when sharing their crown jewels."

Still, adding Linux to the set-top environment is "a noble effort," Morse added.

Thus far, only a handful of alliance founders have actually developed Linux-based products. In March, Lineo struck a deal to acquire Germany-based Convergence Integrated Media GmbH, a digital-TV software and applications developer that makes a Linux TV media streaming server.

Shortly after Lineo's announcement this spring, TV Linux founding member ATI Technologies Inc. — a developer of computer graphics, video and multimedia cards and technology — purchased SONICblue Inc.'s FGL graphics division, which targets Linux and Windows NT workstation users.

MontaVista Software Inc., another TV Linux founder, makes Linux embedded operating systems and development tools.