B E L K Q u i c k S t a r t G u i d e
v . 1 . 0 . 9
2.2
Embedded Linux
When we talk in general about Embedded Linux
, we refer to
an embedded system running Linux operating system. As the
reader probably knows, Linux was first developed on the PC
platform, based on the famous x86 architecture. Typical
embedded systems using an operating system (O.S. for short),
are equipped with much lighter software. Recent hardware
advances made these systems so powerful that now they can
run a complex O.S. such as Linux. This choice has several
benefits:
●
the developer can count on a reliable and efficient
software, developed and maintained by a large
community all over the world
●
the software is open-source, so developers have
access to the whole source code
●
since Linux runs on many different platforms (x86,
PowerPC, ARM, SuperH, MIPS etc.), applications are
portable by definition
●
there are a lot of open-source applications running on
top of Linux that can easily be integrated in the
embedded system
●
last but not least, there are no license fees.
The typical Embedded Linux system is composed of:
●
the bootloader – this software is run by the processor
after exiting the reset state. It performs basic
hardware initialization, retrieves the Linux kernel
image (for example from a remote server via the TFTP
protocol) and launches it by passing the proper
arguments (command line and tags)
●
the Linux kernel
●
the root file system – this file system is mounted
(which means "made available", "attached") by the
kernel during the boot process on the root (“/”)
1
An exhaustive description of this topic is beyond the scope of this document. We recommend reading
specific documents, eg Building Embedded Linux Systems By Karim Yaghmour.
March, 2016
14/66
