freertos book

The Task Creation API function Xtaskcreate () is described in the FreeRTOS Basic series "FreeRTOS series 10th---freertos task creation and deletion ", and we'll review the declaration of this function here: basetype_t xtaskcreate ( taskfunction_tp vtaskcode, const char * constpcname,

new features have been introduced in FreeRTOS version V8.2.0: task notifications. In most cases, task notifications can replace binary semaphores, Count semaphores, event groups, and can replace queues of length 1 (which can hold a 32-bit integer or pointer value), and task notifications are faster and use less RAM! I in the "FreeRTOS series 14th---freertos task

The FreeRTOS kernel Scheduler uses a data structure that lists (list) extensively. If we want to explore the operating mechanism behind FreeRTOS, the first stumbling block is the list. For the FreeRTOS kernel, the list is the most basic part of it. In this chapter we focus on the structure of lists and list items, as well as the operation functions, and the knowl

Original: http://blog.csdn.net/zhzht19861011/article/details/51606068 Memory management is important for both the application and the operating system. Now many of the program vulnerabilities and run crashes are related to memory allocation using errors. The FreeRTOS operating system implements the kernel and memory management separately, and the operating system kernel only prescribes the necessary memory management function prototypes, rather th

The FreeRTOS semaphore includes a binary semaphore, a count semaphore, a mutex (hereafter referred to as a mutex), and a recursive mutex (hereafter referred to as a recursive mutex). The difference between them can be referred to in the article " FreeRTOS series 19th---freertos semaphore ". Semaphore API functions are actually macros, which use the existing queue

This article introduces the basic knowledge of memory management, detailed source analysis See " FreeRTOS Advanced Chapter 7---freertos Memory management analysis " FreeRTOS provides several memory heap management schemes, with complex and simple ones. One of the simplest management strategies can also meet the requirements of many applications, such as security-

FreeRTOS Task Control API function mainly realizes the functions of task delay, task suspending, lifting task suspending, task priority acquiring and setting.1. Relative delay1.1 Function Descriptionvoid Vtaskdelay (Portticktypextickstodelay)When the Vtaskdelay () function is called, the task goes into a blocking state, and the duration is specified by the parameter xtickstodelay of the Vtaskdelay () function, which is the system tick clock cycle. The

beat counter must be adjusted to enter a low-power time offset.If the macro portsuppress_ticks_and_sleep () entity is defined in the FreeRTOS migration file, the function Vtasksteptick is used in this macro portsuppress_ticks_and_sleep () The system beat counter is adjusted inside the entity. The function Vtasksteptick is a global function, so you can also override the function in the macro portsuppress_ticks_and_sleep () entity.In file FreeRTOSConfi

This paper introduces the basic knowledge of semaphore, detailed source analysis see "FreeRTOS Advanced 6---freertos analysis of the signal volume" 1. Signal Volume Introduction The FreeRTOS semaphore includes a binary semaphore, a count semaphore, a mutex (hereafter referred to as a mutex), and a recursive mutex (hereafter referred to as a recursive mutex). We

Using FreeRTOS, one of the most basic program architectures is as follows:int main (void) { necessary initialization work; Create task 1; Create Task 2; ... Vtaskstartscheduler (); /* Start Scheduler * /while (1); }when the task is created, the static variable pointer PXCURRENTTCB (see section 7th, "FreeRTOS advanced 2---freertos Task creati

Reference documents: Understanding the FreeRTOS directory structure. The FreeRTOS source package downloaded from the official website has a demo application for each processor that has been ported to it for reference. Beginners are strongly advised to start with the demo to learn how to use FreeRTOS. Basic directory Structure For each

--turn from: http://bbs.armfly.com/read.php?tid=1552 before you know FreeRTOS, be sure to figure out the relationship between FreeRTOS, Safertos and Openrtos. 1. First say FreeRTOS and Openrtos FreeRTOS and Openrtos share the same source code, just openrtos for FreeRTOS drap

The FreeRTOS is highly configurable. All the configurable items are in the FreeRTOSConfig.h file. Each demo program contains a well-configured FreeRTOSConfig.h file that can be modified based on the FreeRTOSConfig.h file in the demo program as a template.A typical FreeRTOSConfig.h file is given below, which is then described in one item./* FreeRTOS v8.2.3-copyright (C) Real time Engineers Ltd. All rights

Translated from FreeRTOS official website document, original website: http://www.freertos.org/RTOS-Cortex-M3-M4.htmlReprint: Original source: Http://bbs.ednchina.com/BLOG_ARTICLE_3009240.HTMThousands of FreeRTOS applications run on the arm cortex-m core. Surprisingly, the RTOs is used in combination with the Cortex-m kernel, making the request for technical support so much less. Most of the problem points a

Recently just re-review of these several OS, in the mind has always had a question, clearly these several rtos is so like, why still have to make so many come, the final conclusion is, tube him, anyway which use of the handy with which.This blog will be to count the characteristics of these several rtos. 　 The following are from the official website or the official manual feature Google Translate added some of my adjustments, without any subjective elements. 1.

: Preemption Priority (Group priority) and sub-priority (sub-priority), a register in Nvic is "Application interrupt and reset control register (AIRCR)", the AIRCR register has a single-digit segment named "Priority Group". [10:8] Prigroup priority grouping The STM32 uses 4-bit, so there are up to 5 groups of priority grouping settings. Nvic_prioritygroup_4 If you choose Nvic_prioritygroup_4, then the 4-bit priority is all preemption priority, no sub-priority , then there are 0-15 to

1. PrefaceIn embedded operating system, the two-valued signal is an important means to synchronize between tasks and interrupts. FreeRTOS's two-value signal is easy to use, with a specific example below to illustrate how the two-value semaphore in FreeRTOS is used."Related blog posts""FreeRTOS STM32 Transplant Notes""FreeRTOS Learning Notes – Using queues to sync

The priority of the cortex kernel is that the smaller the number, the higher the priority, i.e. 0 is the highest priority. FreeRTOS on the contrary, in order to meet the needs of some applications for real-time interrupt demand, so that the interrupt priority above a certain value, the operating system can not invoke kernel functions to improve real-time. The common mistake we make is to set the priority of the interrupt above this value, but also to

A background There are a lot of configuration data on FreeRTOS interrupt priorities on the web, but individual configuration items have changed in v10.0, and the entire priority management configuration scenario is described in detail in this article.ARM chip priority for 0~255, different chip manufacturers use different priorities, not all use, here with Arm CORTEX-M3 series as an example. The priorities of the CM3 kernel are grouped as follows:In or

Freertos is a hard real-time kernel that supports a wide range of microprocessor architectures. From its official website (www. freertos. download its sourcecode. At the same time, we can see that it supports dozens of microprocessor architectures. The reason why I chose to study this is to always make every bottom-layer software developer's wish to look into the inside story of the RTOS kernel. I have chos