TinyOS 代码分析

1.Basestation案例   位于/opt/tinyos-main-master/apps/Basetation

1.1本例的顶层结构图：

1.2软件实现流程

1) uartIn,uartOut 指向uartQueue的首尾位置。

2) TinyOS中ONE、ONE_NOK、TCAST释义

在TinyOS的许多程序中都可以见到ONE或者ONE_NOK等修饰符，这些修饰符用于标注变量使得编译器能适当地进行静态和动态的检查。在NesC程序中，这些标注用于接口文件或者全局变量/局部变量。

ONE

A pointer that always refers to a single object, similar to a C++ reference.

ONE_NOK 

Same as ONE but may be NULL.

COUNT(n) 

A pointer that always refers to a block of at least n objects.

COUNT_NOK(n) 

Same as COUNT but may be NULL.

BND(n,m) 

A pointer p such that n≤p<m, and that is aligned with respect to n and m.

BND_NOK(n,m) 

Same as BND but may be NULL.

TCAST(type,expr) 

A trusted cast, which tells Deputy to just trust the programmer. This is needed to perform casts that are safe, but are beyond the reach of Deputy's type system. Pointer casts in the network stack (e.g. getHeader() and getFooter() code) tend to fall into this category.

TRUSTEDBLOCK 

Code that is completely trusted (i.e., ignored by Deputy). This is used in very few places, and should be avoided when possible.

2.Tinyos启动

1) 调度器初始化

系统调用第一个命令是platform_bootstrap();用于将系统至于运行状态。实现配置内存系统，处理器工作模式。

2) 组件初始化  SoftwareInit()

我们将需要初始化的服务组件绑定到SoftwareInit(),在系统初始化时会自动完成初始化工作。

3.资源仲裁

1) 资源类型

专用资源:用户对象可以对某种资源一直拥有独占的访问权。可以使用AsyncControl，StdControl，SplitControl来控制。

共享资源：采用多路复用技术，实现多用户精确控制。

虚拟资源：指在单一的资源基础上虚拟出多个资源实例。没有提供直接控制电源状态的接口，由系统自动处理。无法精确控制底层资源。

2) 共享资源一般结构