Notes for uc/OS-III User Guide

Posted 2021-03-18 qiyuexin

1. Architecture

 

F2-1(1) The application code consists of project or product files. For convenience, these are simply called app.c and app.h, however an application can contain any number of files that do not have to be called app.*. The application code is typically where one would find the main().

F2-1(2) Semiconductor manufacturers often provide library functions in source form for accessing the peripherals on their CPU or MCU. These libraries are quite useful and often save valuable time. Since there is no naming convention for these files, *.c and *.h are assumed.

F2-1(3) The Board Support Package (BSP) is code that is typically written to interface to peripherals on a target board. For example such code can turn on and off LEDs, turn on and off relays, or read switches, temperature sensors, and more.

F2-1(4) This is the μC/OS-III processor-independent code. This code is written in highly portable ANSI C.

F2-1(5) This is the μC/OS-III code that is adapted to a specific CPU architecture and is called a port. μC/OS-III has its roots in μC/OS-II and benefits from being able to use most of the 45 or so ports available for μC/OS-II. μC/OS-II ports, however, will require small changes to work with μC/OS-III. These changes are  described in Appendix C, “Migrating from μC/OS-II to μC/OS-III” on page 697.

F2-1(6) At Micriμm, we encapsulate CPU functionality. These files define functions to disable and enable interrupts, CPU_??? data types to be independent of the CPU and compiler used, and many more functions.

F2-1(7) μC/LIB is of a series of source files that provide common functions such as memory copy, string, and ASCII-related functions. Some are occasionally used to replace stdlib functions provided by the compiler. The files are provided to ensure that they are fully portable from application to application and especially, from compiler to compiler. μC/OS-III does not use these files, but μC/CPU does.

F2-1(8) Configuration files are used to define μC/OS-III features (os_cfg.h) to include in the application, specify the size of certain variables and data structures expected by μC/OS-III (os_cfg_app.h), such as idle task stack size, tick rate, size of the message pool, configure the μC/CPU features available to the application programmer (cpu_cfg.h) and also configure μC/LIB options (lib_cfg.h).