Exactly When Do You Need an RTOS?

Introduction

Do most embedded projects still need an RTOS? It’s a good question, given the speed of today’s high-performance processors and the availability of realtime patches ...

RTOSs Aren't "Fair"

The need for "hard" real time — and for the RTOSs that enable it — remains prevalent in the embedded industry. The question is ...

Preemptible Kernel

In most GPOSs, the OS kernel isn’t preemptible. Consequently, a high-priority user thread can never preempt a kernel call, but must instead wait for the entire call to complete ...

Mechanisms to Avoid Priority Inversion

In a GPOS, and even in an RTOS, a lower-priority thread can inadvertently prevent a higher-priority thread from accessing the CPU — a condition known as priority inversion ...

Partitioning Schedulers for Guaranteed CPU Availability

For many systems, guaranteeing resource availability is critical. If a key subsystem is deprived of, say, CPU cycles, the services provided by that subsystem becomes unavailable ...

"Dualing" Kernels

GPOSs — including Linux, Windows, and various flavors of Unix — typically lack the realtime mechanisms discussed thus far. In an attempt to fill the gap ...

Extending the RTOS for Application-specific Requirements

Whatever their shortcomings in deterministic environments, there are, nonetheless, benefits to using GPOSs. These benefits include ...

A Strategic Decision

An RTOS can help make complex applications both predictable and reliable; in fact, the precise control over timing ...