INTRODUCTION OF EMBEDDED SYSTEM:
The embedded system is a dedicated computer system embedded in another larger system that may be mechanical or electrical. An embedded system performs pre-defined tasks, usually with very specific requirements based on single or multi cores processors in form of microcontrollers or digital signal processors and FPGA. These processing components are integrated with components dedicated to handle electrical and mechanical interfacing. Most Embedded systems include operating system, but this operating system is simple enough to be written as single program and is called embedded operating systems, Linux is an example of emerging operating system in market of embedded operating system.
EMBEDDED OPERATIONG SYSTEM / REAL TIME OPERATING SYSTEM
This field of research crosses the barriers because the embedded system designer usually has control over both the hardware design and the software design, unlike general-purpose computing. Many embedded systems have real time requirements. A real time requirements is one that specifies the embedded system must respond to a certain event within a strictly defined time(the deadline).real time operating system provide basic support for scheduling, resource management, synchronization, precise timings and input output. Like embedded systems RTOS’s evolved from single use specialized system to wide variety of general purpose operating system such as real time Linux.
A RTOS monitors, responds to, and controls an external environment, which is connected to the computer system through sensors, actuators, or other input-output (I/O) devices. In a real-time system in general and an RTOS in particular, the correctness of system behaviors depends not only on the logical ...
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Process scheduling in RTOS a process has to be in one of three states:
waiting
ready
executing.
In a uni-processor system, only one process can be executed at any time. Some processes may be waiting for input output or other interrupts. Processes which are not waiting for external events and also are not currently executing are considered to be ready queue. This switching of process execution from one process to another is called a context switching. To execute a context switch, the RTOS must save the state of the old process, determine what process will next obtain the CPU, and then set the CPU state to that process’s state. Context switch overhead is non-trivial but often not a major factor in performance; scheduling policies, process partitioning, memory performance, and other factors are often more critical I in obtaining good performance.
The Linux operating system is the catchall term for the dozens of software stacks built around the free and open source Linux kernel. Clumped into distribution...
Controlled Requirement Expression (CORE) was developed for the British Aerospace programs while the UK Ministry of Defence was carrying out a requirement analysis (Hull et al., 2010). The fundamental component of the CORE methodology is viewpoints as different users see systems in different ways. There are many different stakeholders involved in a system; using CORE methodology involves finding all the different viewpoints of those stakeholders that have an interest in the system whether it’s a person, role or organisation ext.… (Sommerville and Sawyer, 2000). By organising viewpoints hierarchy it assists experts to read the scope and supports the analysis process. CORE Methodology is extensively used for real time system requirements specification.
The table above shows what this ordering of instructions may look like in action. Over 8 instruction steps, the operations required by Process0 and Process1 are fully completed by sharing the single CPU resource efficiently. Normally, modern desktop computers are capable of
Kleinjohann, B. (2001). Architecture and Design of Distributed Embedded Systems: IFIP WG10.3/WG10.4/WG10.5 International Workshop on Distributed and Parallel Embedded Systems (DIPES 2000) October 18-19, 2000, Schloﾀ Eringerfeld, Germany. Boston, MA: Springer US.
Instruction fetch is done via small and fast memory block known as Instruction cache. The reason for using small and fast memory is to reduce latency. Instruction cache also stores recently executed instructions making the instruction fetch more efficient. All the instructions to be fetched are stored in this memory and are fetched by the program counter. Program counter is used to search the instructions. If the desired instruction is found, then it is termed as cache hit or else it is a cache miss. We all are familiar that superscalar processors execute multiple instructions per cycle. Hence the fetch should be fast enough to fetch multiple instructions from the cache. As a solution to this we separate data cache and instruction cache. Number of instructions fetch should be higher than instructions executed per cycle in order to compensate for cache miss.
Because of the robust Linux programmer community, several “flavour’s” of Linux (known as “vendors”) are available, and each is specialized in a slightly different way. This robust operating system is being widely adopted by IT professionals in growing businesses because of its high quality, reliability, and price.
Terminal Operating Systems often utilize other technologies such as internet, EDI processing, mobile computers, wireless LANs and Radio-frequency identification (RFID) to efficiently monitor the flow of products in, out and around the terminal. Data is either a batch synchronization with, or a real-time wireless transmission to a central database. The database can then provide useful reports about the status of goods, locations and machines in the terminal. The objective of a Terminal Operating System is to provide a set of computerized procedures to manage cargo, machines and people within the facility to enable a seamless link to efficiently and effectively manage the facility. Terminal operating systems can be stand-alone systems, managed as a service or
Operating system design goals and requirements are divided into two groups. What are these two groups?
The central unit is the basic part of the computer and includes all the main computer parts. It is the heart of the computer system. It is responsible for executing, or running the software. The software programs are translated into a series of codes made up of 1s to 0s that the CPU can understand. Every code means a certain operation should take place.
An Operating system is system software that controls the system’s hardware that interacts with users and the application software. As we all may know, Windows Microsoft has always been a commercial high-level sale in the retail industry and an in domain operating system used today. But there are more operating systems than just Windows Microsoft than the general population may assume. Linux is another well-known operating systems, which is free and open-source software. Linux is also used in companies we would have never thought of like Google, NASA, USPS, Amazon and many more companies. Linux and Microsoft operating systems have been in competition to see which one is the best operating system in the market. There are so many resemblances
Computers are very complex and have many different uses. This makes for a very complex system of parts that work together to do what the user wants from the computer. The purpose of this paper is to explain a few main components of the computer. The components covered are going to be system units, Motherboards, Central Processing Units, and Memory. Many people are not familiar with these terms and their meaning. These components are commonly mistaken for one and other.
The operating system is a remarkably complex set of instructions that schedules the series of jobs (user applications) to be performed by the computer and allocates them to the various hardware systems of a computer, such as the central processing unit, main memory, and peripheral systems. It is the master program based on which all other program work. Popular operating systems are Microsoft Desk Operating System (MS-DOS), Microsoft Windows, Red Hat Linux, Apple Mackintosh, etc.
Smartphone’s, PADs, tablet computers and other handheld devices that are used to run over operating system are called mobile operating system (Mobile OS). A specified data and programs that run over the mobile devices are referred as mobile operating system. It handles all the hardware and optimizes the performance of the application software in the device. Mobile multimedia functions, Internet connectivity and many other applications are handled by mobile operating system. Base infrastructure software inherent of a computerized system is operating system. It controls all primitive operations of the computer such as PDA and Smartphone. To install and execute the third party applications (known as apps) by users are allowed in the operating system devices. It enumerates new functionalities of the devices. Today mobile devices with a desired OS are called Smartphone’s and a wide range of applications for instances games, apps,communication or social media apps, digital maps, etc are used by users.
In designing a computer system, architects consider five major elements that make up the system's hardware: the arithmetic/logic unit, control unit, memory, input, and output. The arithmetic/logic unit performs arithmetic and compares numerical values. The control unit directs the operation of the computer by taking the user instructions and transforming them into electrical signals that the computer's circuitry can understand. The combination of the arithmetic/logic unit and the control unit is called the central processing unit (CPU). The memory stores instructions and data.
Truth to be said, a vast number of applications used by OS are primary being developed on Linux since of its cross functional module type. Linux has a bright future shining upon that operating system because of the compatibility and user-oriented environment that supports ever-lasting changes and improvisation so that the applications and usage of Linux with its variants can be found in each segment of today’s and future exploitation of PC and other “smart” machines destined to be Linux-supported.