Lab40: Scheduling (2015q1 Week #4)

預期目標

• 分析 FreeRTOS</embedded/freertos>_ 排程行為
• 學習 ARM Cortex-M3 架構並且理解 SysTick<http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dai0179b/ar01s02s08.html>_
• 設計出一個具體而微的 FreeRTOS 視覺化機制

Grasp

• Understanding and validating the timing behavior of real-time systems is not trivial.

• Many real-time operating systems and their development environments do not provide tracing support, and provide only limited visualization, measurements and analysis tools.

• Grasp<http://www.win.tue.nl/san/grasp/>_ is a tool for tracing, visualizing and measuring the behavior of real-time systems. It provides a simple plugin infrastructure for extending Grasp with custom visualization and measurement methods.

• PDF: Grasp: Tracing, Visualizing and Measuring the Behavior of Real-Time Systems<http://www.win.tue.nl/~mholende/publications/Holenderski2010.pdf>_

• mutex 視覺化輸出

.. image:: /embedded/Lab12/mutex.png

• RTOS scheduling 視覺化輸出

.. image:: /embedded/Lab12/hsf.png

Grasp 安裝

• 抓取預先編譯的程式碼 (x86/linux): 假設和 Lab-39</embedded/Lab39>_ 的工作目錄一樣是 workspace

.. code-block:: prettyprint

sudo apt-get install zip
wget http://www.win.tue.nl/san/grasp/grasp_linux.zip
unzip grasp_linux.zip

• 如果你的系統是 x86_64，需要額外安裝以下套件才能執行 Grasp

.. code-block:: prettyprint

sudo apt-get install libxft2:i386

• 執行 Grasp、點選 examples 目錄並且挑選副檔名為 .grasp 的檔案，之後觀察視覺化輸出