Comprehensive Real-World Guidance for Every Embedded Developer and Engineer
This book brings together indispensable knowledge for building efficient, high-value, Linux-based embedded products: information that has never been assembled in one place before. Drawing on years of experience as an embedded Linux consultant and field application engineer, Christopher Hallinan offers solutions for the specific technical issues you're most likely to face, demonstrates how to build an effective embedded Linux environment, and shows how to use it as productively as possible.
Hallinan begins by touring a typical Linux-based embedded system, introducing key concepts and components, and calling attention to differences between Linux and traditional embedded environments. Writing from the embedded developer's viewpoint, he thoroughly addresses issues ranging from kernel building and initialization to bootloaders, device drivers to file systems.
Hallinan thoroughly covers the increasingly popular BusyBox utilities; presents a step-by-step walkthrough of porting Linux to custom boards; and introduces real-time configuration via CONFIG_RT--one of today's most exciting developments in embedded Linux. You'll find especially detailed coverage of using development tools to analyze and debug embedded systems--including the art of kernel debugging.
• Compare leading embedded Linux processors
• Understand the details of the Linux kernel initialization process
• Learn about the special role of bootloaders in embedded Linux systems, with specific emphasis on U-Boot
• Use embedded Linux file systems, including JFFS2--with detailed guidelines for building Flash-resident file system images
• Understand the Memory Technology Devices subsystem for flash (and other) memory devices
• Master gdb, KGDB, and hardware JTAG debugging
• Learn many tips and techniques for debugging within the Linux kernel
• Maximize your productivity in cross-development environments
• Prepare your entire development environment, including TFTP, DHCP, and NFS target servers
• Configure, build, and initialize BusyBox to support your unique requirements
3.2.13. Other Architectures
3.2.13. Other Architectures
We have covered the major architectures in widespread use in embedded Linux systems. However, for completeness, you should be aware of other architectures for which support exists in Linux. A recent Linux snapshot revealed 25 architecture branches (subdirectories). In some instances, the 64-bit implementation of an architecture is separated from its 32-bit counterpart. In other cases, ports are not current or are no longer maintained.
The Linux source tree contains ports for Sun Sparc and Sparc64, the Xtensa from Tensilica, and the v850 from NEC, to name a few. Spend a few minutes looking through the architecture branches of the Linux kernel to see the range of architectures for which Linux has been ported. Beware, however, that not all these architectures might be up-to-date in any given snapshot. You can be reasonably certain that the major architectures are fairly current, but the only way to be certain is to follow the development in the Linux community or consult with your favorite embedded Linux vendor. Appendix E, "Open Source Resources," contains a list of resources you can consult to help you stay current with Linux developments.
