What is the difference between rtos and normal os

Priority inversion is a situation where a low priority thread uses a resource and delays the execution of a high priority thread when both are competing for the same resources. Additionally, one of the primary provisions of an RTOS is that interrupt latency is predictable.

RTOS developers must have detailed information about the system interrupt levels, system calls, and timing. Developers need to know the maximum time during which the OS and device drivers mask interrupts. The interrupt latency, which is the time from when an interrupt first occurs to when the interrupt task runs, must be predictable and consistent with application requirements.

Hard real-time guarantees tasks will be performed within set deadlines. Hard real-time is typically required when loss of life is a possibility if processing deadlines are not met.

An example of hard real time is a nuclear plant shutdown system or flight control system. Using the wrong RTOS, particularly one that does not provide sufficient real time capability, will severely compromise the design and viability of the final product.

The RTOS needs to be of high quality and easy to use. Developing embedded projects is difficult and time consuming — the developer does not want to be struggling with RTOS related problems as well. The RTOS must be a trusted component that the developer can rely on, supported by in-depth training and good, responsive support. What is an RTOS? Tasks and Priorities In a pre-emptive system each Task is given an individual priority value.

Download Centre. Why use an RTOS? These include: Priority Based Scheduling: The ability to separate critical processing from non-critical is a powerful tool.

What should be considered when choosing an RTOS? Trust, quality of product, and quality of support is everything. How does the RTOS affect the development of the design? By selecting an appropriate RTOS the developer gains: A Task based design that enhances modularity, simplifies testing and encourages code reuse; An environment that makes it easier for engineering teams to develop together; Abstraction of timing behaviour from functional behaviour, which should result in smaller code size and more efficient use of available resources.

High accuracy Resource allocation 3. Configurable Kernel 4. BSP support for external dependancy to another system 5. Mostly used in Embedded systems Normal OS: 1.

It may or may not be time deterministic Eg Hard OS is time - deterministic 2. General level Resource allocation 3. Configurable may or may not be Kernel e. Package support is available here 5. Mostly used in general purpose systems.

The resources are explicitly managed for the purpose of operating in real time. But OS is process based. In an RTOS how many task at least a ceiling of max. Former will fail while second will just slow down! Here time becomes significant. Similar threads M. Rtos and Normal OS Difference.. Such a library is linked with application code to produce a single executable that your system boots directly or via a bootloader. Most RTOS do not directly support the loading and unloading of code dynamically from a file system.

Normal Linux Kernel is intended for full OS and is a preemptive kernel but not real time. In most multithreading environments aka multitasking , a preemptive kernel allows the thread that has higher priority to receive longer time on the processor and a lower priority thread will have less time with the processor.

In the normal kernel, no particular thread can monopolize the services of the resident processor all the time, no matter what its priority. So, the programs will never hang up even if an arbitrary thread of the program goes into a forever loop. Here is a good PDF on the topic :. Shopping is Not Easy than it Sounds.