Linus Torvalds gives the military a new secret weapon

April 1, 2000
Linux is gaining market share and momentum, while a real-time version of the open-source operating system is hitting the industry and causing real-time stalwarts VxWorks and LynxOS, to take notice. Meanwhile VenturCom continues to market real-time extensions to WindowsNT as a viable option for military platforms

By John McHale

Click here to enlarge image

Linux is gaining market share and momentum, while a real-time version of the open-source operating system is hitting the industry and causing real-time stalwarts VxWorks and LynxOS, to take notice. Meanwhile VenturCom continues to market real-time extensions to WindowsNT as a viable option for military platforms

Linux is no longer just an academic project, but has become a mainstream operating system competing with Microsoft Corp. in Redmond, Wash., that offers traditional users of Windows an inexpensive alternative. Now, the open-source brainchild of software developer Linus Torvalds is generating unprecedented buzz and hype among systems designers - particularly those involved with the military. The excitement surrounding Linux has spread from the server community, to workstation developers, and is moving quickly into real-time embedded applications.

Yet as the hype builds to a crescendo, Linux developers and their wealthy backers are under terrific pressure to build bulletproof, ultra-reliable systems that can perform under the most harsh and demanding conditions. One of those who says Linux is up to the task is Victor Yodaiken, chief executive officer of FSMLabs in Soccoro, N.M., and inventor of RTLinux, the FSMLabs real-time version of Linux.

RTLinux enables computers to execute real-time functions quickly and predictably, while offering all the networking and price advantages of non-deterministic versions of Linux, Yodaiken claims.

Measurements of a dual Pentium II processor running RTLinux version 2.0 show no timing delays of more than 25 microseconds on periodically scheduled tasks, FSMLabs officials claim.

RTLinux 2.0 supports a POSIX pthread-style application program interface (API), symmetric multiprocessing, POSIX-style device drivers, and optimized timing code, Yodaiken explains. The new version offers a stripped-down version of the POSIX pthreads API, a powerful shared memory utility, and solid support for symmetric multiprocessing.

The use of POSIX interfaces makes RTLinux compatible with a wider range of applications that it would be without POSIX, Yodaiken says. Not only does the 2.2 version of RTLinux add support for pthreads mutex, but it also includes early support for signal handling as the RTLinux API moves closer to the POSIX 1003.13 PE51 profile.

"By combining the well-known POSIX API with our model of connecting simple real-time components to Linux processes, RTLinux is now becoming an easy-to-learn tool, while remaining at the performance edge," Yodaiken says.

RTLinux runs a real-time version of the Linux kernel - which some call a real-time extension - side-by-side with a traditional non-real-time Linux kernel. The two Linux kernels connect by a POSIX thread. Its kernel modifications provide the hard real-time functionality that is necessary for machine control, yet make the full power of the Linux kernel available, Yodaiken says. The multithreaded RTLinux real-time kernel runs close to the bare machine, and executes the non-real-time Linux kernel and operating system files as threads. RTLinux functionally decouples the mechanisms of the real-time kernel from those of the Linux kernel, which optimizes them independently for the most efficient performance possible.

An industrial application in Germany, which he would not name, ran RTLinux for a year and a half without rebooting until a power device failed, Yodaiken says. The hardware broke down but the operating system never did, he claims.

RTLinux 1.0, which customers traditionally used in industry and research laboratories, today is part of an instrumentation application aboard NASA's KC-135 zero-gravity training aircraft popularly known as the "Vomit Comet," and also for NASA weather instrumentation applications, Yodaiken says.

FSMLabs also recently signed a contract with officials at Compaq Computer Corp. in Houston to port Linux to their computer based on the Alpha microprocessor, Yodaiken says.

Linux runs on many different computers, and with a wide variety of software packages - including key military hardware technologies such as VME and CompactPCI - says Bill Weinberg, director of marketing at MontaVista Software in

Sunnyvale, Calif. MontaVista officials are offering RTLinux as a real-time acceleration extension to their Hard Hat embedded version of Linux.

MontaVista officials offer Hard Hat Linux free to their customers, yet make money by selling subscriptions for support. Linux may be open source, but it is never free, points out Jim Ready, MontaVista's president and founder. MontaVista's model, however, avoids long licensing agreements and other business requirements, which makes life easier for the customer, Ready claims.

Military designers are performing a "bakeoff" with Linux to see what they like best, Weinberg says. RTLinux is performing well for simple real-time applications and, like Linux, is in its adolescence and will improve with time, Weinberg adds.

Many military customers are expressing an interest in Linux, says Ron Marcus, director of marketing at Synergy Microsystems in San Diego. "Mostly, the military is just tire-kicking Linux right now," he explains. Synergy officials will be offering RTLinux on their entire line of PowerPC-based boards in the next few months.

"Our customers have certainly taken notice of Linux," says Tom Powell, Synergy Microsystems chief executive officer. "We're getting an increasing amount of inquiries about the availability of PowerPC single-board computers running Linux. These customers would like to leverage their familiarity and comfort with a UNIX-like operating system as well as the open-source nature of Linux."

Linux will lend itself well to digital battlefield applications because of its ability to work with high-bandwidth connections such as Ethernet, Weinberg says.

"We find many customers only desire real-time performance with about 10 to 20 percent of each application," says Duncan Young director of marketing at DY 4 Systems Inc. of Kanata, Ontario. The other 80 to 90 percent deals with graphical user interfaces and data transmission for which Linux is ideal, he continues. Plus Linux is certainly cheaper than other operating systems, Young adds.

DY 4 officials have joined hands with experts at Amirix Systems Inc. in Halifax, Nova Scotia, to bring embedded Linux to DY 4's PowerPC and Pentium-based single-board computers for military/aerospace and telecommunications applications.

Embedded Linux technologies will enable DY 4 engineers to reduce software maintenance overhead through productivity gains and cost-efficiencies while accelerating time to market, DY 4 officials claim.

The embedded Linux technology is "tailored to support embedded applications," says Doug Pincock, president and chief executive officer of Amirix. "It will offer headless operation, network install and operation, backplane communication, and diskless operation through Flash file system support, and a small memory footprint - all backed by our professional support team."

Paradigm shift

The software industry is facing a paradigm shift with the advent of Linux, says Ray Alderman, executive director of the VME International Trade Association (VITA) in Scottsdale, Ariz. Historically, it has been a sellers market; those using products such as Wind River's VxWorks pay for a particular seat, Alderman says. Linux and open source has turned it around to a buyers market, he explains.

"With the Linux model the best will float to the top and the doggies will be available, but the doggies will stay at the bottom," Alderman says

VxWorks from Wind River Systems in Alameda, Calif., is the fundamental run-time component the company's Tornado II embedded development platform and is part of many defense applications including advanced avionics, fire control, sonar/radar, navigation and guidance, command and control, simulation, space, and missile systems.

VxWorks continues to be the most popular operating system among military designers, Synergy's Marcus says. Synergy officials say they appreciate Linux, but point out that about 90 percent of their customers still ask for VxWorks, he explains.

Customer support and software upgrades are one area that illustrates how Linux is fundamentally different from more-established software packages, Alderman says. Linux is more dynamic with price control and rapid availability of upgrades, he says. Engineers are working on improvements and putting them out overnight, Alderman adds. Yet with more established companies such as Wind River customers receive upgrades "when by god Wind River thinks you need one," Alderman says.

Linux also has brought a dynamic energy to the real-time software business that industry observers say they have not seen a long time. For essentially 20 years nothing had changed, says Ready, a veteran of the software industry for more than two decades. "It had all been done, then along came Linux and it's springtime again. Linux came in like a rabid penguin," Ready quips. "It's better software at a lower cost. Linux is real open source."

The open-source model

The Linux open-source operating system is just entering its adolescence and in three to five years should be a dominating force among real-time operating systems, Ready says.

Microsoft leaders may someday open up their Windows source code, but it would not be the same, Ready explains. The whole movement is supporting a technology community, not putting money in one company's pocket, he says.

Ready has a strong model that is an example of how the software industry will go in the future, Alderman says. Software will become a commodity and people will make money off of it by providing services and support, he explains.

"There are more people writing code for Linux out of a labor of love than there are engineers writing code for VxWorks, LynxOS, and Windows NT combined," Alderman claims.

Still, the open-source approach to software development does have its skeptics. The labor of love notion is patently ridiculous - eventually you have to put food on the table - charges Curt Schacker, vice president of corporate marketing for Wind River.

It is too early to tell where Linux will head, Schacker says. People today are mostly using it with standard PC hardware in Internet appliance applications, he continues.

Linux started out with a figurehead in Linus Torvalds, and represented a movement against Microsoft, Schacker says. They went after PCs with Intel technology with the huge amount of anti-Microsoft sentiment fueling the movement, Schacker explains.

However, there is a danger that the Linux market will become fragmented, Schacker warns. As soon as someone tweaks a version of Linux for their application, it will become a proprietary operating system like all the others out there, he explains.

Real-time Linux has many pros and cons, observes Myron Zimmerman, chief technology officer for VenturCom of Cambridge, Mass., the provider of real-time Windows NT. "However, it can be dangerous to muck around with source code if you don't know what it will do to the overall system," he cautions.

Messing with source code can also cause reliability problems, and "the military is all about reliability," Schacker warns.


While traditional real-time operating system developers VenturCom and Wind River have yet to embrace Linux, engineers at Lynx Real-Time Systems in San Jose, Calif., are jumping on the Linux bandwagon with their BlueCat Linux, release 1.0. The product is Lynx's version of Linux for high-availability, high-reliability embedded applications. BlueCat is binary compatible with Linux applications, system and development tools, and drivers for embedded deployment.

BlueCat Linux is part of the company's LynuxWorks suite that enables systems designers to use BlueCat Linux and the LynxOS real-time operating system with a common compatible toolset. Through LynuxWorks, BlueCat designers can integrate applications with LynxOS applications to provide a choice of real-time performance and reliability that matches the schedule, market, and features for embedded development.

The new product enables vendors to get software from the same vendor under a common development environment, says Indir Singh, chief executive officer of Lynx.

Lynx customers can use LynxOS for their real-time functions, then switch to BlueCat to run graphics on displays and other non-real-time functions, Singh explains. LynxOS is POSIX-based and comes with memory protection, Singh says. Every task runs on its own address. One failure does not affect the others, which continue to run, he explains.

Lynx is currently partnering with Radstone Technology in Towcester, England, to provide BlueCat on Radstone's PPCx family of rugged PowerPC based single-board computers.

The toolset and code compatibility between BlueCat and the Lynx LynxOS real-time operating system, enable designers to build systems containing non real-time and critical real-time elements from Radstone's hardware.

"This is the best of both worlds," says Andy West, software product manager for Radstone's processor group. "Our customers are attracted to the open-source model, yet want to retain the kind of backup for critical programs they have been used to from Radstone and the mainstream [operating system] vendors. BlueCat provides an embedded Linux backed by the same partnership that is already supplying highly successful, rugged PowerPC/real-time LynxOS solutions."

Linux is generating momentum due to the growing number of vendors porting their products to Linux, Singh says. Lynx officials say they are seeing more BlueCat customers in the military than they expected, Singh says. "I thought most of the customers would come from telecommunications," he explains.

Singh insists that Lynx's main competitor, Wind River, must eventually address Linux because of the third-party advantages it has over VxWorks. Linux has the potential to develop a large market capacity, he adds.

It makes a lot of sense for Lynx to embrace Linux since Lynx OS and Linux are Unix based, Wind River's Schacker admits. However, Wind River officials will wait and see where it heads in the real-time world, Schacker says. Meanwhile, Wind River engineers are currently running

Tornado tools on a Linux host to develop applications targeting VxWorks, he notes.

Windows NT

Engineers at VenturCom are continuing to improve their real-time extensions to Windows NT and claim it is a viable option for mission-critical military applications, VenturCom's Zimmerman claims. However, as applications grow in complexity, their testing and validation will also become more demanding, he explains. Currently Windows NT is running on rocket launchers and in telemetry applications on U.S. Navy warships, he says. Zimmerman says he cannot go into more detail on the applications.

Engineers at VenturCom are tracking the development of Windows 2000 for use with their RTX products. Windows 2000 and Windows NT version 4 have the same underlying kernel, Zimmerman says. The scheduling algorithms are the same, he adds.

Most failures with Windows NT occur because of hardware problems such as a disk drive failure or because a new device driver is not configured correctly, Zimmerman claims. However, when failures occur the real-time environment continues to run and is not affected by the failure, Zimmerman says.

The configuration problem results from the use of third-party drivers, Zimmerman says. If those drivers are bad it can cause a system to blue-screen, which is the shutting down of non-real-time functions signified by the infamous Windows "blue screen of death" on the computer monitor.

Real-time Windows NT is more difficult to configure than VxWorks because it so much larger and more complex, he explains. Zimmerman notes that Windows NT and VxWorks do not even compete. They operate at different ends of the market - Windows NT at the high end and VxWorks at the low end.

The real-time Windows NT extension may protect the real-time functions but the system will still lose valuable tools such as an Ethernet connection, VITA's Alderman claims. Zimmerman counters that if experts configure the system correctly this will not be a problem. It can be a complicated tasks because of the large number of drivers associated with an operating system as complex as Windows NT.

The RTX extensions use a WIN32 API and switch to Windows NT when the real-time functions are completed, Zimmerman explains. VenturCom's RTX version 4.3 improves the latency response time of multiprocessor-based real-time Windows NT systems, compared with the response time experienced with uniprocessor systems, typically by a factor of two or more, VenturCom officials claim.

RTX 4.3 also works with the standard Windows NT HAL (hardware abstraction layer), as well as with a wide variety of custom-designed original equipment manufacturers HAL configurations. "RTX 4.3 further enhances the performance of real-time applications by providing technology which significantly reduces the size of the run-time environment," claims Rob David, RTX product manager at VenturCom.

The new version's functionality will enable users to add a digital signal processor (DSP) without spending extra money on a DSP developmental software program, Zimmerman says. It provides real-time determinism in one standard box, he says. Zimmerman says he believes these features and real-time Windows NT's compatibility with commercial technology make the operating system a viable option for the military.

For more information VenturCom's RTX products contact the company by phone at 617-661-1230 or on the World Wide Web at

Real-Time Innovations releases ScopeTools 2.0

SUNNYVALE, Calif., - Engineers at Real-Time Innovations (RTI) have designed developmental tools that provide instant analysis for the Tornado II embedded development environment from Wind River Systems in Alameda, Calif.

The ScopeTools 2.0 suite consists of visualization tools for data monitoring, execution tracing, performance tuning, and memory analysis. All four tools in the suite feature 'instant analysis,' providing simple, one-touch operation without code instrumentation or recompilation, RTI officials claim.

Most advanced visualization tools have a relatively high barrier to usage, RTI officials say. Programmers often avoid using tools because of the extensive instrumentation or recompilation required, they explain. 'Instant analysis' delivers greater productivity and to provide it, RTI tools implement automatic configuration detection, automated tool loading and initialization, on-line symbol table analysis, tight debugger and Tornado integration, and on-the-fly code patching, RTI officials say.

The ScopeTools from Real-Time Innovations are visualization tools to help embedded system designers working with Tornado II development environment from Wind River Systems.
Click here to enlarge image

Scopetools is currently used in a radar test bed and simulation system from Northrop Grumman Electronic Systems and sensors in Baltimore.

"As a member of our WindLink partner program, RTI helps extend the Tornado environment by bringing high-productivity tools to real-time developers," says Dave Sheaffer, director of corporate product marketing at Wind River.

"Embedded developers face huge challenges working with systems that require small footprints, speed, reliability, and short development schedules," says Stan Schneider, president and chief executive officer of RTI in Sunnyvale, Calif. "Tools have come a long way, but they are still underutilized. ScopeTools new 'Instant analysis' capability realizes the productivity promised by visualization tools. When you need the tool, 'one click' is all it takes to see what's going on.

"The ScopeTools analyze data activities, CPU performance, memory usage, and function traces on production code running at full speed with virtually no impact," Schneider adds.

ScopeTools 2.0 is a suite of four tools for real-time visualization. The tools give users the visibility needed to understand a real-time system and make it work, RTI officials claim. Each tool offers simple, one-touch operation without code instrumentation or recompilation, and each is built for minimal intrusion and impact on system performance.

The tools include StethoScope, a real-time data monitor; TraceScope, an execution-flow-tracing tool; ProfileScope, a CPU execution profiler; and MemScope, an instant memory analyzer.

The ScopeTools are available through Wind River Systems as part of the WindPower Tools bundled with Tornado. For more information, contact Real-Time Innovations by phone at 408-734-4200 or on the World Wide Web at - J.M.



Web site provides embedded Linux info

A new World Wide Web site, launched late last year by Rick Lehrbaum - co-founder of Ampro computers and originator of the PC/104 specification - aims to provide a high concentration of information regarding the use of Linux in embedded applications.

"It is a commercial site funded by me," Lehrbaum says. "Revenues are derived from sponsorships of leading companies in the embedded Linux market." accomplishes its task by enabling users, to share information with others in a free and open manner.

The portal site features a broad spectrum of embedded Linux topics including news, articles, events, links, jobs, polls, an interactive forum, and product information - all targeted to Linux-based embedded system developers. carries up-to-date information about Linux-related single-board computers, chips, tools, and support, and highlights a variety of embedded, real-time, and small-footprint Linux implementations, including commercial distributions and open-source projects.

Sponsors include Motorola Computer Group in Tempe, Ariz., Synergy Microsystems in San Diego, Lynx Real-Time Systems in San Jose, Calif., and MontaVista Software in Sunnyvale, Calif., among others.

"The feedback on the site has been unbelievable," Lehrbaum boasts. "Really much more positive than I ever dreamed."

For more information, visit the site on the World Wide Web at - J.M.

Wind River completes acquisition of ISI, and merges product lines together


ALAMEDA, Calif., - Wind River Systems has broadened its share of the military real-time operating system market by completing the acquisition of Integrated Systems, Inc. (ISI) in Sunnyvale, Calif., and has announced plans to merge the two companies' product lines.

Wind River officials plan to combine all of ISI's products and with their own on to a single development and operating system platform, says Curt Schacker, vice president of corporate marketing for Wind River. The convergence will be accomplished over the next 12 -24 months. During that time, users of VxWorks and pSOS - ISI's real-time operating system - will receive additional releases.

Wind River officials have organized the company into five business units to ease the transition and provide targeted solutions for a number of vertical markets. The units are Wind River Platforms, Wind River Services, Wind River Networks, Wind River Consumer, and Wind River Transportation/Defense/Industrial.

Wind River officials will also offer their tools for use with non-Wind River operating systems. This policy was executed effectively at ISI and enabled customers using multiple operating systems to standardize on a single-tools environment, Wind River officials claim. Wind River will also continue to support the GNU and Diab compilers.

"It is not unusual to find large companies using multiple commercial operating systems as well as in-house proprietary systems," Schacker says. "By offering the Wind River tools independent of the operating system, these customers can more easily share code and engineering resources across multiple projects within their organizations."

The pSOS real-time operating system, developed by engineers at ISI and now owned by Wind River Systems, is flying on the U.S. Air force F-15 fighter aircraft.
Click here to enlarge image

The Platforms business unit will introduce a new release of the VxWorks and pSOS real-time operating systems. Wind River will also support the Tornado and the pRISM integrated development environments with a new release of each product. Following those releases, Wind River will introduce a single real-time operating system / IDE platform with advanced features.

The next version of the Tornado development environment and VxWorks, code-named project "Cirrus," will be available by the fall of 2000 and will form the foundation of Wind River's operating system and IDE platform. It will support all leading host systems, including Linux. Cirrus will also include protection domain technology for memory protection and application isolation as well as features for high availability.

The next generations of the pRISM IDE and pSOS real-time operating system will be code-named project "Stratus" and will also be available by the fall of 2000. Stratus will feature runtime enhancements including memory protection and compatibility with the latest Diab / SDS releases.

Following Stratus and Cirrus, Wind River officials plan to merge the products into one real-time operating system that combines the best of both operating systems, called "Cumulus". It will be available in 2001 and will include all the features of Cirrus as well as advanced high availability, enhanced connectivity for distributed computing, increased Java programmability, and enhanced features from the SNIFF+ development tool. In addition, Cumulus will include support for the pSOS application programming interface and other characteristics unique to the pSOS operating system.

ISI is a provider of embedded systems software for a range of industries that telecom/datacom, consumer electronics, automotive, and aerospace. ISI's pSOS real-time operating system is flying on U.S. Air Force F-15 fighter aircraft.

Based on Wind River's closing price of $41.50, the stock-for-stock merger is valued at $930 million. The companies began operating as one integrated organization on February 16, 2000.

About 20 percent of Wind River's business in 1999 was military, Schacker says, and he says he expects that to grow with the ISI acquisition. Wind River's total revenue in 1999 was about $310 million, he adds.

For more information on the merger contact Wind River Systems by phone at 510-748-4100 or on the World Wide Web at - J.M.

Voice your opinion!

To join the conversation, and become an exclusive member of Military Aerospace, create an account today!