FOSDEM 2003 Presentation

Abstract

eCos is a highly configurable, portable, open source, royalty free Operating System for real time embedded applications. This presentation provides a brief, mainly technical, overview of eCos: its history, implementation, configuration system and future directions.

One of the key technological innovations in eCos is a highly sophisticated configuration system. The configuration system allows the application writer to impose their requirements on the run-time components, both in terms of their functionality and implementation. eCos provides both a graphical configuration tool that runs on both Windows and Linux, and a command line tool that can be used to automate the configuration process.

eCos is designed to be portable to a wide range of target architectures and target platforms including 16, 32, and 64 bit architectures, MPUs, MCUs and DSPs. The eCos kernel, libraries and runtime components are layered on the Hardware Abstraction Layer (HAL), and thus will run on any target once the HAL and relevant device drivers have been ported to he target's processor architecture and board. Currently eCos supports a large range of different target architectures (ARM, Intel StrongARM and XScale, Hitachi SH3/4, Intel x86, MIPS, Matsushita AM3x, NEC V850, Motorola PowerPC, SPARC and several others), including many of the popular variants of these architectures and evaluation boards.

eCos has been designed to support applications with real-time requirements, providing features such as full preemptability, minimal interrupt latencies, and all the necessary synchronization primitives, scheduling policies, and interrupt handling mechanisms needed for these type of applications. eCos also provides all the functionality required for general embedded application support including device drivers, memory management, exception handling, networking, file systems, standard C and math libraries, POSIX and uITRON compatibility etc.

To permit proprietary application code to be linked with eCos without itself being forced to be released under the GPL, eCos is distributed under the GPL license with an exception. It is also royalty and buyout free, making it an attractive alternative to license inhibited, closed source or commercial real-time operating systems.