PX4 FMU启动流程 2. 一、 nsh_newconsole

野性酷女 2021-10-29 16:03 229阅读 0赞

## [PX4 FMU启动流程 2. 一、 nsh\_newconsole][PX4 FMU_ 2. _ nsh_newconsole] ##

**PX4 FMU启动流程 2. 一、 nsh\_newconsole**

-------- 转载请注明出处

-------- 2014-11-27.冷月追风

-------- email：[merafour@163.com][merafour_163.com]

这是一个 new函数。用来创建 stdio接口。

FAR **struct** console\_stdio\_s \*nsh\_newconsole(**void**)  
\{  
  **struct** console\_stdio\_s \*pstate = (**struct** console\_stdio\_s \*)zalloc(**sizeof**(**struct** console\_stdio\_s));  
  **if** (pstate)  
    \{  
      /\* Initialize the call table \*/  
  
\#**ifndef** CONFIG\_NSH\_DISABLEBG  
      pstate->cn\_vtbl.clone      = nsh\_consoleclone;  
      pstate->cn\_vtbl.release    = nsh\_consolerelease;  
\#**endif**  
      pstate->cn\_vtbl.write      = nsh\_consolewrite;  
      pstate->cn\_vtbl.output     = nsh\_consoleoutput;  
      pstate->cn\_vtbl.linebuffer = nsh\_consolelinebuffer;  
      pstate->cn\_vtbl.redirect   = nsh\_consoleredirect;  
      pstate->cn\_vtbl.undirect   = nsh\_consoleundirect;  
      pstate->cn\_vtbl.exit       = nsh\_consoleexit;  
  
      /\* (Re-) open the console input device \*/  
  
\#**ifdef** CONFIG\_NSH\_CONDEV  
      pstate->cn\_confd           = open(CONFIG\_NSH\_CONDEV, O\_RDWR);  
      **if** (pstate->cn\_confd < 0)  
        \{  
          free(pstate);  
          **return** NULL;  
        \}  
  
      /\* Create a standard C stream on the console device \*/  
  
      pstate->cn\_constream = fdopen(pstate->cn\_confd, "r+");  
      **if** (!pstate->cn\_constream)  
        \{  
          close(pstate->cn\_confd);  
          free(pstate);  
          **return** NULL;  
        \}  
\#**endif**  
  
      /\* Initialize the output stream \*/  
  
      pstate->cn\_outfd           = OUTFD(pstate);  
      pstate->cn\_outstream       = OUTSTREAM(pstate);  
    \}  
  **return** pstate;  
\}

其实也就是填充了结构 “**struct** console\_stdio\_s”。这些接口基本上都可以通过函数名大致了解其作用。除了函数指针外还有两个比较特殊的指针：输出流。

转载于:https://www.cnblogs.com/eastgeneral/p/10879671.html

[PX4 FMU_ 2. _ nsh_newconsole]: http://merafour.lofter.com/post/385dd8_40574cc
[merafour_163.com]: mailto:merafour@163.com