Dr.Dobb’s Journal: Why Embedded Linux?

[ Thanks to LinuxDevices.com for this link.

“Intelligent dedicated systems used in interface, monitoring,
communications, and control applications increasingly demand the
services of a sophisticated, state-of-the-art operating system.
Additionally, the pace of hardware and chipset innovation continues
to accelerate. These two trends present an enormous challenge for
commercial RTOS vendors trying to keep up with the constant
churning of hardware devices. … Fortunately, a new and exciting
alternative has emerged: open-source Linux. Linux offers powerful
and sophisticated system management facilities, a rich cadre of
device support, a superb reputation for reliability and robustness,
and extensive documentation. Best of all, Linux is available at no
charge — and with completely free source code.”

“The main challenge in embedded Linux is minimizing system
resource requirements in order to fit within constraints such as
RAM, solid state disk (SSD) capacity, processor speed, and power
consumption. Embedded operation may require booting from (and
fitting within) a DiskOnChip or CompactFlash SSD; or booting and
running without a display and keyboard (‘headless’ operation); or
loading the application from a remote device via an Ethernet LAN
connection. There are many sources of ready-made
small-footprint Linux. Among these are a growing number of
application-oriented Linux configurations and distributions that
are tuned to specific applications. Some examples are routers,
firewalls, internet/network appliances, network servers,
, and so on.”

“Many embedded systems require predictable and bounded responses
to real-world events. Such ‘real-time’ systems include factory
automation, data acquisition and control systems, audio/video
applications, and many other computerized products and devices. The
commonly accepted definition of ‘real-time’ performance is that
real-world events must be responded to within a defined,
predicable, and relatively short time interval. Although Linux is
not a real-time operating system (the Linux kernel does not provide
the required event prioritization and preemption functions), there
are currently several add-on options available that can bring
real-time capabilities to Linux-based systems.”