Free RTOS G 23 9961256 9960114 9961217 1

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Free. RTOS G 23 9961256 9960114 9961217 王偉一  江哲維  洪心為 1

Free. RTOS G 23 9961256 9960114 9961217 王偉一  江哲維  洪心為 1

2 /23 Outline • PART 1 • Introduction • PART 2 • Architecture •

2 /23 Outline • PART 1 • Introduction • PART 2 • Architecture • PART 3 • Application • Future View • Conclusion 王偉一,江哲維,洪心為

PART  I Introduction 9961257 王偉一 3

PART  I Introduction 9961257 王偉一 3

4 /23 Free. RTOS • A Real Time Operating System • Written by Richard

4 /23 Free. RTOS • A Real Time Operating System • Written by Richard Barry & Free. RTOS Team • Owned by Real Time Engineers Ltd but free to use • Huge number of users all over the world • 6000 Download per month • Simple but very powerful 王偉一,江哲維,洪心為

5 /23 Real-Time Operating System ? • A type of an operating system •

5 /23 Real-Time Operating System ? • A type of an operating system • It’s all about scheduler : • multi user operating system(UNIX)- fair amount of the processing time • desk top operating system(Windows)- remain responsive to its user • …… • RTOS scheduler focuses on predictable execution pattern 王偉一,江哲維,洪心為

6 /23 Why using Free. RTOS • Abstract out timing information • Maintainability/Extensibility •

6 /23 Why using Free. RTOS • Abstract out timing information • Maintainability/Extensibility • Modularity • Cleaner interfaces • Easier testing (in some cases) • Code reuse • Improved efficiency? • Idle time  …. . .  …… 王偉一,江哲維,洪心為

7 /23 When to use Free. RTOS 王偉一,江哲維,洪心為

7 /23 When to use Free. RTOS 王偉一,江哲維,洪心為

8 /23 License of Free. RTOS l Modified GPL 王偉一,江哲維,洪心為

8 /23 License of Free. RTOS l Modified GPL 王偉一,江哲維,洪心為

9 /23 History of Free. RTOS v 1. 0. 1 Free. RTOS v 2.

9 /23 History of Free. RTOS v 1. 0. 1 Free. RTOS v 2. 0. 0 Free. RTOS v 3. 0. 0 Free. RTOS v 4. 0. 0 Free. RTOS v 5. 0. 0 +Scalability +New Task API +API Changes +Directory Names Changed +Changes in Kernel +Co-routines +API Changes 王偉一,江哲維,洪心為

10 /23 What is the current version? Free. RTOS v 7. 6. 0 +

10 /23 What is the current version? Free. RTOS v 7. 6. 0 + Tick Suppression + Queue sets + Port optimized task selection http: //www. freertos. org/History. txt 王偉一,江哲維,洪心為

PART  II Architecture 9961217 洪心為 11

PART  II Architecture 9961217 洪心為 11

12 /23 Architecture Overview • Tasks (50%) • task. c and task. h do

12 /23 Architecture Overview • Tasks (50%) • task. c and task. h do all the heavy lifting for creating, scheduling, and maintaining tasks. • Communication (40%) • queue. c and queue. h handle Free. RTOS communication. Tasks and interrupts use queues to send data to each other and to signal the use of critical resources using semaphores and mutexes. • Hardware Interfacing (6%) 王偉一,江哲維,洪心為

13 /23 Task States (1/3) • Running • Ready • Blocked • Suspended 王偉一,江哲維,洪心為

13 /23 Task States (1/3) • Running • Ready • Blocked • Suspended 王偉一,江哲維,洪心為

14 /23 Task Priorities (2/3) • Each task is assigned a priority from 0

14 /23 Task Priorities (2/3) • Each task is assigned a priority from 0 to ( config. MAX_PRIORITIES - 1 ). Low priority numbers denote low priority tasks. The idle task has priority zero (tsk. IDLE_PRIORITY). • The task placed into the Running state is always be the highest priority task that is able to run. • Ready state tasks of equal priority share the available processing time using a time sliced round robin scheduling scheme. 王偉一,江哲維,洪心為

15 /23 Idle Task (3/3) • Created automatically when the RTOS scheduler is started

15 /23 Idle Task (3/3) • Created automatically when the RTOS scheduler is started to ensure there is always at least one task that is able to run. • Responsible for freeing memory allocated by the RTOS to tasks that have since been deleted. • An idle task hook is a function that is called during each cycle of the idle task. 王偉一,江哲維,洪心為

16 /23 Communication & Synchronization • Queues • Binary Semaphores • Counting Semaphores •

16 /23 Communication & Synchronization • Queues • Binary Semaphores • Counting Semaphores • Mutexes • Recursive Mutexes 王偉一,江哲維,洪心為

17 /23 Hardware Interfacing • Hardware Independent • The same code runs whether Free.

17 /23 Hardware Interfacing • Hardware Independent • The same code runs whether Free. RTOS is running on the humble 8051 or the newest, shiniest ARM core. • Free. RTOS software layers 王偉一,江哲維,洪心為

PART  III Application & Future View 9960114 江哲維 18

PART  III Application & Future View 9960114 江哲維 18

19 /23 Applications & Future view • Because of the basic kernel of Free.

19 /23 Applications & Future view • Because of the basic kernel of Free. RTOS, it’s more flexible for users to attach other expanded modules on OS to get more applications. • New cloud managed service, file system API, TCP/IP, safety certified kernel… 王偉一,江哲維,洪心為

20 /23 Free. RTOS+Nabto • Free. RTOS+Nabto is a small piece of C code.

20 /23 Free. RTOS+Nabto • Free. RTOS+Nabto is a small piece of C code. • Each Internet of Things (Io. T) device has a unique URL over the Internet, and the technology allows secure, authenticated and extremely low bandwidth P 2 P connections. • accessible over a local network in the absence of Internet connectivity. • combined with Free. RTOS's special low power features, makes Free. RTOS a natural choice for implementing the Internet of Things. 王偉一,江哲維,洪心為

21 /23 Benefits • A resolvable URL for each device • Remote access over

21 /23 Benefits • A resolvable URL for each device • Remote access over the Internet from computer, tablet or smart phone • No firewall hassles • No embedded file system, TCP/IP stack necessary • Low bandwidth for enhanced performance • Increased privacy and security • Reduced hardware and software cost 王偉一,江哲維,洪心為

22 /23 Conclusion • An Free Real-Time OS with essential kernel of low power(Tick-less

22 /23 Conclusion • An Free Real-Time OS with essential kernel of low power(Tick-less kernel) & high efficiency. • Support many architecture. Ex. ARM, Altera, Xilinx, IBM, Intel, Cortus… • Co-routine – multitasking by coding • Open source, implantable, flexible and easy learning 王偉一,江哲維,洪心為

23 /23 Reference • The Architecture of Open Source Applications (Volume 2): Free. RTOS

23 /23 Reference • The Architecture of Open Source Applications (Volume 2): Free. RTOS http: //www. aosabook. org/en/freertos. html • Free. RTOS official Website http: //www. freertos. org/ 王偉一,江哲維,洪心為