As there are many embedded systems that have functions which should start in a certain time frame, Embedded OS makes sure that there are no delays or premature executions. One of such examples is traffic light where the controller needs to send signals in a programmed order.
When it comes to real-time operation feature, it’s important to say that there are tasks that are triggered by an event while others could be time-dependable which means their activation is set for a specific point in time. Furthermore, it’s easy to differentiate two types of real-time operation features: Soft, which allows a certain delay, and the Hard for processes that require immediate execution. The core of the real-time operation feature is in the kernel which controls task scheduling and Standard Function Libraries.
This feature enables the system to react upon a preset input that user triggers when needed. The input could be released by a sensor or a switch. We can see the use of this feature with alarm systems that activate security procedures when a proximity sensor is activated. The Operating System handles this feature by receiving the signal and acting upon the input, which could include starting a new event or scheduling a task that will be executed in a certain time-frame. This is similar to situations when a writer at a paper writing service receives a new order that should be addressed immediately or scheduled for later depending on the status of the order.
The design and application of the hardware determine the Operating System configuration. This means that for each embedded system there is a custom embedded Operating system configuration. The configurability feature allows the developer the possibility to reconfigure the OS when a certain change is needed. Furthermore, thanks to the conditional compilation, the developer can change the parameters for different hardware options, which allows seamless control over different modules.
Direct use of interrupts
Unlike Operating Systems that have a general purpose, embedded OS provides direct use of interrupts to the user, which is important when an event requires immediate attention. This means that there is a more comprehensive control over the peripherals. Since embedded systems require control over individual hardware components, there is a demand for the use of interrupts. Preemptive OS solutions are in the center of attention when it comes to direct use of interrupts, they allow pause of a certain ongoing event when the scheduler receives interrupt. The result is the transfer of CPU resourcesCPU resources from paused event to another one which is indicated with the interrupt signal. It’s a lot like.
Low resource consumption
Due to the small amount of memory and low CPU power of most embedded systems, the embedded Operating systems are built in such a way that allows them to operate in such low-resource conditions. The customization of the OS is, therefore, of paramount importance so that every bit of memory space and CPU power is used optimally. This means that any unnecessary software components can be removed before the OS is compiled, to save as much memory as possible. This also provides faster execution and overall improved system performance despite the low resources which are available.
Embedded operating systems which require multitasking can keep track of all active events however only one event may remain active. When another task needs to become active, the operating system stops the current event and saves its state. In return, the newly activated process continues right from the last active state, without any loss of information during its wait period. Task scheduling is imperative for the performance of multitasking, as well as the elements that include switching and execution of tasks. The effectiveness of these components determines the overall quality of the embedded OS’s multitasking capabilities.
Google’s Android is probably the most commonly used embedded Operating System in the world these days. Its advantage over various other embedded OS solutions is that it’s free and owns a massive library of different device drivers and open source code. Other embedded OS include Linux, Windows CE, MS-DOS, VxWorks, and others that serve the purpose of controlling various types of embedded systems. Now that we know the main features of these software solutions it’s easy to understand their value and use. Whether you’re building an industrial machine, alarm system, or you plan on developing a home appliance, an embedded operating system is one of the key components of your project.