to develop the needed software components to deploy your embedded Linux-based system.
1.4. Standards and Relevant Bodies
As Linux continues to gain market share in the desktop, enterprise, and embedded market segments, new standards and organizations are emerging to help influence the use and acceptance of Linux. This section serves as a resource to introduce the standards that you might want to familiarize yourself with.
1.4.1. Linux Standard Base
Probably the single most relevant standard is the Linux Standard Base (LSB). The goal of the LSB is to establish a set of standards designed to enhance the interoperability of applications among different Linux distributions. Currently, the LSB spans several architectures, including IA32/64, PowerPC 32- and 64-bit, AMD64, and others. The standard is broken down into a core component and the individual architecture components.
The LSB specifies common attributes of a Linux distribution, including object format, standard library interfaces, minimum set of commands and utilities and their behavior, file system layout, system initialization, and so on.
You can learn more about the LSB at the link given in Section 1.5.1, 'Suggestions for Additional Reading,' section at the end of this chapter.
1.4.2. Open Source Development Labs
Open Source Development Labs (OSDL) was formed to help accelerate the acceptance of Linux in the general marketplace. According to its mission statement, OSDL currently provides enterprise-class testing facilities and other technical support to the Linux community. Of significance, OSDL has sponsored several working groups to define standards and participate in the development of features targeting three important market segments. The next three sections introduce these initiatives.
1.4.2.1. OSDL: Carrier Grade Linux
A significant number of the world's largest networking and telecommunications equipment manufacturers are either developing or shipping carrier-class equipment running Linux as the operating system. Significant features of carrier-class equipment include high reliability, high availability, and rapid serviceability. These vendors design products using redundant, hot-swap architectures, fault-tolerant features, clustering, and often real-time performance.
The OSDL Carrier Grade Linux working group has produced a specification defining a set of requirements for carrier-class equipment. The current version of the specification covers seven functional areas:
• Availability Requirements that provide enhanced availability, including online maintenance operations, redundancy, and status monitoring
• Clusters Requirements that facilitate redundant services, such as cluster membership management and data checkpointing
• Serviceability Requirements for remote servicing and maintenance, such as SNMP and diagnostic monitoring of fans and power supplies
• Performance Requirements to define performance and scalability, symmetric multiprocessing, latencies, and more
• Standards Requirements that define standards to which CGL-compliant equipment shall conform
• Hardware Requirements related to high-availability hardware, such as blade servers and hardware-management interfaces
• Security Requirements to improve overall system security from various threats
1.4.2.2. OSDL: Mobile Linux Initiative
As this book is written, several mobile handsets (cellular phones) are available on the worldwide market that have been built around embedded Linux. It has been widely reported that millions of handsets have been shipped based on Linux. The only certainty is that more are coming. This promises to be one of the most explosive market segments for what was formerly the role of a proprietary real-time operating system. This speaks volumes about the readiness of Linux for commercial embedded applications.
The OSDL sponsors a working group called Mobile Linux Initiative. Its purpose is to accelerate the adoption of Linux on next-generation mobile handsets and other converged voice/data portable devices, according to the OSDL website. The areas of focus for this working group include development tools, I/O and networking, memory management, multimedia, performance, power management, security, and storage.
1.4.2.3. Service Availability Forum
If you are engaged in building products for environments in which high reliability, availability, and serviceability (RAS) are important, you should be aware of the Service Availability Forum (SA Forum). This organization is playing a leading role in defining a common set of interfaces for use in carrier-grade and other commercial equipment for system management. The SA Forum website is www.saforum.org.
1.5. Chapter Summary
• Adoption of Linux among developers and manufacturers of embedded products continues to accelerate.
• Use of Linux in embedded devices continues to grow at an exciting pace.
• In this chapter, we present many of the factors driving the growth of Linux in the embedded market.
• Several standards and relevant organizations influencing embedded Linux were presented in this chapter.
