Embedded Linux

When Linus Torvalds, then a young student at the University of Helsinki, posted his first message on the Internet in July 1991 about the nascent development of his free UNIX kernel, he had no idea that, like other technology celebrities such as Steve Jobs and Bill Gates, he was about to change the world.

Linux is a multitasking operating system (actually a "kernel") from the UNIX family. Initially developed for Intel x86 (386 and 486) processors, it has since been adapted to a wide range of hardware architectures, including PowerPC, ARM, SH4 and now specialized industrial processors such as Nios II, MicroBlaze and Blackfin. In all, 31 architectures are currently supported by the official version of the Linux kernel.

Linux conforms to the POSIX standard (for Portable Operating System Interface for UNIX), which means that program sources developed under Linux can be easily compiled on other POSIX-compatible operating systems. Linux is also renowned for its high level of interoperability, meaning it can be easily integrated into complex computer systems using other proprietary operating systems. The Linux kernel source code is freely available on the Internet, in compliance with the GPL license defined for the GNU project.

Initially, embedded software was a "niche" market totally dominated by specialized publishers (such as Wind River, founded in 1981 and publisher of the VxWorks operating system), with very high licensing costs due to the low volume of production, which was limited to military, space and industrial applications in general. The constraints of embedded software are very different from those of conventional software, particularly with regard to the notion of software lifetime, which is much more important in the case of embedded software. For example, the Hubble Space Telescope, using the VRTX operating system, has been running –– since 1990.

In the early 2000s, Linux was already widely used in the server world, in direct competition with Microsoft solutions. Even back then, many Linux developers and users believed that Linux could be used for industrial and embedded solutions, thanks to its reliability, the availability of its source code and, of course, its zero redistribution cost. The evolution of embedded computing towards multimedia, thanks to widespread Internet access, has since enabled Linux to become a major player in the field, since proprietary embedded operating systems were not adapted to these functionalities. Internet access equipment such as gateways and set-top boxes mostly use Linux-based operating systems. These include Freebox, Bbox and Livebox.

The vast majority of smartphones (over 80% to date) also use the Linux kernel (rather than the full system) in Google's...