15-06-2012, 12:14 PM
Embedded system using Linux
[attachment=24537]
What is embedded system?
An embedded system is a special-purpose computer system that is designed to perform very small sets of designated activities.
some examples are :
Network equipment such as firewall, router, switch, and so on
Consumer equipment such as MP3 players, cell phones, PDAs, digital
cameras, camcorders, home entertainment systems, and so on
Household appliances such as microwaves, washing machines, televisions, and so on
Mission-critical systems such as satellites and flight control
OS for Embedded system
More complex embedded systems started emerging and along with that a growing list of features that an embedded system should support.
All of these requirements mandated use of an operating system in embedded systems that should at least provide multitasking/multithreading, process and memory management, inter process communication, timers, and so on.
The companies started enhancing their in-house developed software so that they could have a minimal but a full featured operating system running on their embedded platform.
Today we have a multitude of embedded operating systems
Why Embedded Linux?
Why choose embedded Linux as an operating system in the target?”- every newbie.
Vendor Independence: Vendors of all embedded Linux distributions have more or less the same business model.
Time to Market For embedded Linux, a rich set of toolsets and utilities is available free of cost. Consequently you will spend time only in writing applications without worrying about the Linux port for the hardware or device driver for a high-performance I/O card that is part of your system. If it works on the host then the only effort required is to cross-compile it for your target
Varied Hardware Support If the product demands high-end hardware, customers may not be able to use it because their proprietary embedded OS vendor may not support it. Linux is also a preferred bring-up platform for hardware manufacturers.
Low Cost Embedded Linux brings minimal cost for development (licenses, free tools), training, and hiring needs.
Runtime Royalty Lack of runtime royalties reduces the BOM (Bill Of Materials) of the product
Open Source There are thousands of developers around the world, global support during your development. It has a rich set of features with superior software and a rich talent pool across the world reviews every feature that goes in the kernel. This makes Linux robust and reliable. Availability of source code and also tools source code.
Linux types in Embedded system
Some of the small-footprint embedded Linux efforts
include the following.
uClinux, a Linux port for no-MMU platforms such as Motorola 68k, ARM7™,and so on has a full-featured version with minimum SDRAM and FLASH requirement.
ELKS (Embedded Linux Kernel Subset) plans to put embedded Linux in the Palm Pilot.
ThinLinux is yet another small-footprint distribution targeted at digital cameras, MP3 players, and similar embedded applications.
The hardware abstraction layer
The hardware abstraction layer (HAL) virtualizes the platform
Hardware so that the different drivers can be ported easily on any
hardware. The HAL has support for the following hardware
components. It is at arch folder.
Processor, cache, and MMU
Setting up the memory map
Exception and interrupt handling support
DMA
Timers
System console
Bus management
Power management
[attachment=24537]
What is embedded system?
An embedded system is a special-purpose computer system that is designed to perform very small sets of designated activities.
some examples are :
Network equipment such as firewall, router, switch, and so on
Consumer equipment such as MP3 players, cell phones, PDAs, digital
cameras, camcorders, home entertainment systems, and so on
Household appliances such as microwaves, washing machines, televisions, and so on
Mission-critical systems such as satellites and flight control
OS for Embedded system
More complex embedded systems started emerging and along with that a growing list of features that an embedded system should support.
All of these requirements mandated use of an operating system in embedded systems that should at least provide multitasking/multithreading, process and memory management, inter process communication, timers, and so on.
The companies started enhancing their in-house developed software so that they could have a minimal but a full featured operating system running on their embedded platform.
Today we have a multitude of embedded operating systems
Why Embedded Linux?
Why choose embedded Linux as an operating system in the target?”- every newbie.
Vendor Independence: Vendors of all embedded Linux distributions have more or less the same business model.
Time to Market For embedded Linux, a rich set of toolsets and utilities is available free of cost. Consequently you will spend time only in writing applications without worrying about the Linux port for the hardware or device driver for a high-performance I/O card that is part of your system. If it works on the host then the only effort required is to cross-compile it for your target
Varied Hardware Support If the product demands high-end hardware, customers may not be able to use it because their proprietary embedded OS vendor may not support it. Linux is also a preferred bring-up platform for hardware manufacturers.
Low Cost Embedded Linux brings minimal cost for development (licenses, free tools), training, and hiring needs.
Runtime Royalty Lack of runtime royalties reduces the BOM (Bill Of Materials) of the product
Open Source There are thousands of developers around the world, global support during your development. It has a rich set of features with superior software and a rich talent pool across the world reviews every feature that goes in the kernel. This makes Linux robust and reliable. Availability of source code and also tools source code.
Linux types in Embedded system
Some of the small-footprint embedded Linux efforts
include the following.
uClinux, a Linux port for no-MMU platforms such as Motorola 68k, ARM7™,and so on has a full-featured version with minimum SDRAM and FLASH requirement.
ELKS (Embedded Linux Kernel Subset) plans to put embedded Linux in the Palm Pilot.
ThinLinux is yet another small-footprint distribution targeted at digital cameras, MP3 players, and similar embedded applications.
The hardware abstraction layer
The hardware abstraction layer (HAL) virtualizes the platform
Hardware so that the different drivers can be ported easily on any
hardware. The HAL has support for the following hardware
components. It is at arch folder.
Processor, cache, and MMU
Setting up the memory map
Exception and interrupt handling support
DMA
Timers
System console
Bus management
Power management