描述

On SDK 14.4 from an empty workspace, select File -> New -> Application Project and choose the lwip Echo Server example. The following error occurs when building:

"../src/echo.c:22:22: fatal error: lwip/err.h: No such file or directory"

解决方案

This error occurs because the auto-generated BSP for the example does not contain the lwip library.

To work around this issue, follow these steps:

1. Right-click on the LwIP BSP and select Board Support Package Setting.
   
2. Select the lwip140 library and click OK.
   
3. Right-click on the LwIP application.
4. Select C/C++ Build Settings.
   
5. In the pop-up GUI, click Apply.