Linux on embedded systems

Embedded Linux is the designation for Linux-based operating systems that are used as embedded operating systems in cell phones, personal digital assistants, media player handsets and other consumer electronics devices. Linux is also suitable for other embedded applications such as networking equipment, machine control, industrial automation, navigation equipment, and medical instruments.

Embedded Linux can be characterized as different from desktop and server versions of Linux in that embedded Linux is designed for devices with comparably limited resources, such as smaller sizes of RAM and much more limited secondary storage. Embedded Linux based devices frequently involve flash memory based secondary storage instead of a hard disk.(The read time of a flash memory is uniform as compared to that of a hard disk). It also interesting to note that Embedded Linux is tailor made for the required application and target hardware. One can consider Embedded Linux to be the optimized form of the linux kernel for that application. Most optimizations are done in order to make the OS RTOS (Real Time Operating System).

Further, embedded Linux has been ported to a variety of processors not suited for use as the processor of desktop or server computers.

It is an alternative to the—usually proprietary—bespoke assembler or C software largely used in embedded development. Advantages compared to other embedded operating systems include: the source code can be modified and redistributed; relatively small footprint (a typical installation may require less than two megabytes of memory); no royalty or licensing costs; mature and stable; and a large support base. Embedded Linux systems combine the Linux kernel with a small set of free software utilities. The glibc is often replaced as the C standard library by less resource-consuming alternatives such as dietlibc, uClibc or Newlib.

Several industry groups have formed to foster use of Linux in embedded applications. These include: the CE Linux Forum, founded in 2003 to aid the inclusion of embedded features in the main Linux kernel branch; the Linux Foundation (formerly Open Source Development Labs); the Linux Phone Standards Forum, created in 2004 to pursue a standard applications environment for Linux-based mobile phones and "converged devices"; the LiMo Foundation, founded in 2006 by Motorola, NEC, Panasonic, Samsung, DoCoMo, and Vodafone to establish a set of interfaces and standard reference components to improve the third-party mobile phone developer base; and the San Francisco, California-based Embedded Linux Consortium, which, until its 2005 closure and transfer of operations to the Linux Foundation, included IBM, Intel, LynuxWorks, and others, and focused on application programming interface standardization. The Embedded Linux Consortium produced the ELCPS which was intended as a guide to developers of embedded Linux devices as to what functionality should be included in order to provide a standard platform supporting application portability.

Providers of commercial Linux distributions specifically targeting embedded Linux development include MontaVista Software, LynuxWorks, SysGo, and TimeSys. Some commercial embedded hardware known to use Linux is: Motorola mobile telephones including the A760, A780, E680, A1200, and others; the Panasonic P901i and NEC N901ic telephones; FIC's Neo1973; the Philips LPC3180; and a variety of single board computers.

See also

• MontaVista Software
• Access Co.
• Wind River Systems
• T2 SDE
• Qtopia
• Soekris
• Picotux
• OpenMoko
• Maemo
• μClinux
• TimeSys

External links

• Template:Dmoz
• Embedded Linux wiki - A wiki for developers using Embedded Linux
• Embedded Linux and the Law
• Embedded Linux Tools (French)
• News and technical articles concerning embedded Linux
• Community Support for Colibri board with embedded Linux