1. Task Scheduling FreeRTOS is a lightweight real-time operating system kernel, and one of its core functions is task scheduling. Task scheduling is the core mechanism of FreeRTOS, determining which task runs at any given moment, when to switch tasks, and how to handle task priorities. 1.1. Task Definition Task “Task” is the basic execution … Read more
1. Interrupt Priority <span>Cortex-M</span> series cores (such as <span>M3/M4/M7</span>) use the <span>NVIC</span> (Nested Vectored Interrupt Controller) to support interrupt nesting and priority management. It employs a grouping mechanism that divides interrupt priority into two parts: Preemption Priority: Determines whether the current interrupt can interrupt other interrupts. Subpriority: Determines the response order when preemption priorities are … Read more
Core Value of Priority Queue The <span>priority_queue</span> container adapter in the C++ Standard Library provides an efficient way to maintain a priority data structure. This article will delve into its core features and demonstrate its applications in system design and algorithm optimization through practical examples. Basic Usage Analysis #include <iostream> #include <queue> int main() { … Read more
<span>at</span> is a command-line tool used to automatically execute various commands or scripts at a specified time and date. Tasks created with <span>at</span> are executed only once, making it an ideal tool for managing one-time tasks at precise time points. This article will introduce how to use <span>at</span> along with its companion tools <span>batch</span>, <span>atq</span>, … Read more
Follow andstar our public account to not miss exciting content Readers have been asking various questions about RTOS, such as: Should I learn RTOS now? What are the benefits of learning RTOS? Should my project run on RTOS? …and other questions regarding RTOS. Ultimately, it boils down to your insufficient understanding of RTOS and lack … Read more
Continuing from the previous article, we have already learned about the porting and startup process of FreeRTOS. Today, we will continue to study the task management part of FreeRTOS, starting with understanding what a task is. 1. Task 1.1 Introduction to Tasks (1) In bare-metal systems, we generally use a front-and-back system for development. If … Read more
Tasks are the smallest units of execution competing for system resources. Multiple tasks with the same priority can share the same priority level. In FreeRTOS, if configUSE_TIME_SLICING is defined as 1, then multiple ready tasks with the same priority will share the processor in a time-slicing manner, where one time slice equals one tick. Task … Read more
Have you ever wondered why your HarmonyOS device can do so many things at once? You can receive calls while gaming, and reply to messages while watching videos. The secret behind this is the task scheduling mechanism. This “traffic control system” determines who goes first and who goes later, directly affecting user experience! What is … Read more
In-Depth Analysis of FreeRTOS Kernel Source Code: From Task Scheduling to Interrupt Handling Introduction As a representative of embedded real-time operating systems, FreeRTOS has an elegant and efficient kernel implementation. This article will delve into the key implementations of the FreeRTOS kernel, including task scheduling, memory management, interrupt handling, and other core mechanisms. Task Management … Read more
<span>FreeRTOS</span> configuration is implemented through macro definitions to control the behavior of the FreeRTOS kernel, with parameters designed in <span>FreeRTOSConfig.h</span>. Below is a detailed explanation of commonly used configurations. Scheduling Method Whether to enable preemptive scheduling <span>#define configUSE_PREEMPTION 1</span> : Enables preemptive scheduling (<span>preemptive scheduling</span>), allowing higher priority tasks to interrupt lower priority tasks. <span>#define … Read more