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OSEK
OSEK (''Offene Systeme und deren Schnittstellen für die Elektronik in Kraftfahrzeugen''; English: "''Open Systems and their Interfaces for the Electronics in Motor Vehicles''") is a standards body that has produced specifications for an embedded operating system, a communications stack, and a network management protocol for automotive embedded systems. It has produced related specifications, namely AUTOSAR. OSEK was designed to provide a reliable standard software architecture for the various electronic control units (ECUs) throughout a car. OSEK was founded in 1993 by a German automotive company consortium (BMW, Robert Bosch GmbH, DaimlerChrysler, Opel, Siemens, and Volkswagen Group) and the University of Karlsruhe. In 1994, the French cars manufacturers Renault and PSA Peugeot Citroën, which had a similar project called VDX (Vehicle Distributed eXecutive), joined the consortium. Therefore, the official name was OSEK/VDX and OSEK was registered trademark of Continental Automot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AUTOSAR
AUTOSAR (AUTomotive Open System ARchitecture) is a global development partnership founded in 2003 by automotive manufacturers, suppliers and other companies from the electronics, semiconductor and software industries. Its purpose is to develop and establish an open and standardized software architecture for automotive electronic control units (ECUs). The objectives are scalability to different vehicle and platform variants, transferability of software, consideration of availability and safety requirements, cooperation between different partners, sustainable use of natural resources and maintainability during the product lifecycle. History AUTOSAR was formed in July 2003 by Bavarian Motor Works (BMW), Robert Bosch GmbH, Continental AG, Mercedes-Benz Group AG, Siemens VDO and Volkswagen AG to develop and establish an open industry standard for the automotive electrical-electronic (E/E) architecture. In November 2003, the Ford Motor Company joined as a Core Partner. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comparison Of Real-time Operating Systems ...
This is a list of real-time operating systems (RTOSs). This is an operating system in which the time taken to process an input stimulus is less than the time lapsed until the next input stimulus of the same type. References External links 2024 RTOS Performance Report(FreeRTOS / ThreadX / PX5 / Zephyr) - Beningo Embedded Group 2013 RTOS Comparison(Nucleus / ThreadX / ucOS / Unison) - Embedded Magazine {{Real-time operating systems Embedded operating systems * Real-time operating systems A real-time operating system (RTOS) is an operating system (OS) for real-time computing applications that processes data and events that have critically defined time constraints. A RTOS is distinct from a time-sharing operating system, such as Unix ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operating System
An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for efficient use of the system and may also include accounting software for cost allocation of Scheduling (computing), processor time, mass storage, peripherals, and other resources. For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware, although the application code is usually executed directly by the hardware and frequently makes system calls to an OS function or is interrupted by it. Operating systems are found on many devices that contain a computerfrom cellular phones and video game consoles to web servers and supercomputers. , Android (operating system), Android is the most popular operating system with a 46% market share, followed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memory Management Unit
A memory management unit (MMU), sometimes called paged memory management unit (PMMU), is a computer hardware unit that examines all references to computer memory, memory, and translates the memory addresses being referenced, known as virtual memory addresses, into physical addresses in main memory. In modern systems, programs generally have addresses that access the theoretical maximum memory of the computer architecture, 32 or 64 bits. The MMU maps the addresses from each program into separate areas in physical memory, which is generally much smaller than the theoretical maximum. This is possible because programs rarely use large amounts of memory at any one time. Most modern operating systems (OS) work in concert with an MMU to provide virtual memory (VM) support. The MMU tracks memory use in fixed-size blocks known as ''pages''. If a program refers to a location in a page that is not in physical memory, the MMU sends an interrupt to the operating system. The OS selects a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carnegie Mellon University
Carnegie Mellon University (CMU) is a private research university in Pittsburgh, Pennsylvania, United States. The institution was established in 1900 by Andrew Carnegie as the Carnegie Technical Schools. In 1912, it became the Carnegie Institute of Technology and began granting four-year degrees. In 1967, it became Carnegie Mellon University through its merger with the Mellon Institute of Industrial Research, founded in 1913 by Andrew Mellon and Richard B. Mellon and formerly a part of the University of Pittsburgh. The university consists of seven colleges, including the College of Engineering, the School of Computer Science, and the Tepper School of Business. The university has its main campus located 5 miles (8 km) from downtown Pittsburgh. It also has over a dozen degree-granting locations in six continents, including campuses in Qatar, Silicon Valley, and Kigali, Rwanda ( Carnegie Mellon University Africa) and partnerships with universities nationally and glob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software Engineering Institute
Software Engineering Institute (SEI) is a Federally funded research and development centers, federally funded research and development center in Pittsburgh, Pennsylvania, United States. Founded in 1984, the institute is now sponsored by the United States Department of Defense and the Under Secretary of Defense for Research and Engineering, Office of the Under Secretary of Defense for Research and Engineering, and administrated by Carnegie Mellon University. The activities of the institute cover cybersecurity, software assurance, software engineering and acquisition, and component capabilities critical to the United States Department of Defense. Authority The Carnegie Mellon Software Engineering Institute is a federally funded research and development center headquartered on the campus of Carnegie Mellon University in Pittsburgh, Pennsylvania, United States. The SEI also has offices in Washington, DC; Arlington County, Virginia; and Los Angeles, California. The SEI operates wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Real-time Operating System
A real-time operating system (RTOS) is an operating system (OS) for real-time computing applications that processes data and events that have critically defined time constraints. A RTOS is distinct from a time-sharing operating system, such as Unix, which manages the sharing of system resources with a scheduler, data buffers, or fixed task prioritization in multitasking or multiprogramming environments. All operations must verifiably complete within given time and resource constraints or else fail safe. Real-time operating systems are event-driven and preemptive, meaning the OS can monitor the relevant priority of competing tasks, and make changes to the task priority. Characteristics A key characteristic of an RTOS is the level of its consistency concerning the amount of time it takes to accept and complete an application's task; the variability is "jitter". A "hard" real-time operating system (hard RTOS) has less jitter than a "soft" real-time operating system (soft RTOS); a l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scheduling (computing)
In computing, scheduling is the action of assigning resources to perform tasks. The resources may be processors, network links or expansion cards. The tasks may be threads, processes or data flows. The scheduling activity is carried out by a mechanism called a scheduler. Schedulers are often designed so as to keep all computer resources busy (as in load balancing), allow multiple users to share system resources effectively, or to achieve a target quality-of-service. Scheduling is fundamental to computation itself, and an intrinsic part of the execution model of a computer system; the concept of scheduling makes it possible to have computer multitasking with a single central processing unit (CPU). Goals A scheduler may aim at one or more goals, for example: * maximizing '' throughput'' (the total amount of work completed per time unit); * minimizing '' wait time'' (time from work becoming ready until the first point it begins execution); * minimizing '' latency'' o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Application Binary Interface
An application binary interface (ABI) is an interface exposed by software that is defined for in-process machine code access. Often, the exposing software is a library, and the consumer is a program. An ABI is at a relatively low-level of abstraction. Interface compatibility depends on the target hardware and the software build toolchain. In contrast, an application programming interface (API) defines access in source code which is a relatively high-level, hardware-independent, and human-readable format. An API defines interface at the source code level, before compilation, whereas an ABI defines an interface to compiled code. API compatibility is generally the concern for system design and of the toolchain. However, a programmer may have to deal with an ABI directly when writing a program in a multiple languages or compilers. A complete ABI enables a program that supports an ABI to run without modification on multiple operating systems that provide the ABI. The targe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Priority Inheritance
In real-time computing, priority inheritance is a method for eliminating unbounded priority inversion. Using this Computer programming, programming method, a process scheduling algorithm increases the priority of a process (A) to the maximum priority of any other process waiting for any resource (computer science), resource on which A has a Lock (computer science), resource lock (if it is higher than the original priority of A). The basic idea of the priority inheritance protocol is that when a job blocks one or more high-priority jobs, it ignores its original priority assignment and executes its critical section at an elevated priority level. After executing its critical section and releasing its locks, the process returns to its original priority level. Example Consider three jobs: Suppose that both H and L require some shared resource. If L acquires this shared resource (entering a critical section), and H subsequently requires it, H will block until L releases it (leaving its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Priority Ceiling
In real-time computing, the priority ceiling protocol is a synchronization protocol for shared resources to avoid unbounded priority inversion and mutual deadlock due to wrong nesting of critical sections. In this protocol each resource is assigned a priority ceiling, which is a priority equal to the highest priority of any task which may lock the resource. The protocol works by temporarily raising the priorities of tasks in certain situations, thus it requires a scheduler that supports dynamic priority scheduling. ICPP versus OCPP There are two variants of the protocol: Original Ceiling Priority Protocol (OCPP) and Immediate Ceiling Priority Protocol (ICPP). The worst-case behaviour of the two ceiling schemes is identical from a scheduling view point. Both variants work by temporarily raising the priorities of tasks. In OCPP, a task X's priority is raised when a higher-priority task Y tries to acquire a resource that X has locked. The task's priority is then raised to the high ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Priority Inversion
In computer science, priority inversion is a scenario in scheduling in which a high-priority task is indirectly superseded by a lower-priority task, effectively inverting the assigned priorities of the tasks. This violates the priority model that high-priority tasks can only be prevented from running by higher-priority tasks. Inversion occurs when there is a resource contention with a low-priority task that is then preempted by a medium-priority task. Formulation Consider two tasks ''H'' and ''L'', of high and low priority respectively, either of which can acquire exclusive use of a shared resource ''R''. If ''H'' attempts to acquire ''R'' after ''L'' has acquired it, then ''H'' becomes blocked until ''L'' relinquishes the resource. Sharing an exclusive-use resource (''R'' in this case) in a well-designed system typically involves ''L'' relinquishing ''R'' promptly so that ''H'' (a higher-priority task) does not stay blocked for excessive periods of time. Despite good design, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
