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An RTOS real time operating system is software that has deterministic behavior. Events are handled within a time constraint. I think Wind River Intel ships a version of this.
The question is clearly not "about general computing hardware and software", I am voting to reopen despite its age. Clifford someday I would like to see these forceful closing and negative votes because the question if off-topic go away! It is immediately capable of providing a guaranteed hard real-time environment for appropriately written applications within a Linux environment.
A fundamentally different approach is to add non-real-time services to a basic real-time kernel. An RTOS provides a real-time kernel that interleaves the execution of multiple tasks employing a scheduling algorithm.
The scheduler determines which task will own the CPU time and by default runs a preemptive algorithm to guarantee that the highest priority task preempts a lower priority task.
It also uses a single common address space for all tasks, avoiding virtual-to-physical memory mapping. Historically, RTOSes have only offered kernel mode tasks, trading abstraction and protection of kernel components for direct access to hardware to give much higher responsiveness and performance.
This trade-off requires that kernel development operates at a more sophisticated programming level, where the developer is more aware of subtle interactions with the hardware and the risk of hitting unrecoverable fault conditions. This creates a user mode application environment without eliminating the traditional model of RTOS programming and allows memory protection without compromising performance for traditional applications in the kernel space. Applications based on the RTP model benefit from the high-performance RTOS kernel, with the addition of reliable resource reclamation and memory protection.
The RTP model also greatly increases the facilities available to the application programmer. User mode applications run in memory contexts even without memory management unit support and run in protected memory contexts with MMU support. Applications that link into the microkernel will get hard real-time for interrupt and context switching.
For other services, the application must pass over to a Linux non-real-time task that will do the work. With an RTOS where the whole system is built to be real-time, the application may have more capabilities at its disposal in real-time mode.
All of this depends on how independent the applications actually are. The traditional RTOS still creates a much smaller footprint than the real-time core, and because Linux runs as a low-priority process alongside the real-time core, there are still footprint constraints.
There is also performance degradation for any non-real-time processes that may run in user mode in Linux. The user mode RTPs will have much better performance than standard Linux processes but probably about the same as Linux applications running in the real-time core executive in the Linux kernel space. The size of the Linux operating system makes it very difficult and costly to certify.
Other considerations in determining the right solution are the availability of the third-party software for the application, the overall costs and the availability of the right hardware support. The increasing diversity of real-time development tools and device application requirements has made life more complicated for developers.
Determining whether to use an RTOS or Linux to meet real-time requirements should not be an additional source of risk. The changeover procedure is so quick in RTOS that it seems to users as real-time.
Some RTOS utilize this architecture as well, albeit with a considerably lower task density to guarantee that the CPU is never overloaded, which might slow reaction times. OS or an operating system is a software application that serves as a conduit between the hardware of a computer and the operator.
To execute other applications, every system software must have at least one bootloader coupled with an OS. Web browser, MS Exchange, Notepad , executable files, and other applications require a certain environment in order to run and fulfill their functions.
The operating system OS on your laptop or pc or even phone controls all of the applications and technology that revolves around your hardware and software.
All of this is coordinated by the operating system to ensure that each software receives the resources it requires. Any computer you buy will typically come with an operating system pre-installed. It is a compact version of Linux that offers features and services in line with the operating and application requirement of the embedded system. FreeRTOS is a real-time operating system kernel for embedded devices that has been ported to 35 microcontroller platforms.
It is distributed under the MIT License. Although Linux is not a real-time operating system the Linux kernel does not provide the required event prioritization and preemption functions , several add-on options are available that can bring real-time capabilities to Linux-based systems.
The most common method is the dual-kernel approach. Real-time Linux: Installation on Ubuntu. Real-time operating systems are also known as multitasking operating systems.
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