RT-Thread-Studio/sdk-rt-thread-source-code: https://github.com/RT-Thread-Studio/sdk-rt-thread-source-code.git @ v4.0.3

yaxing.chen c0257098b9 release rt-thread v4.0.3		4 rokov pred
..
sys	c0257098b9 release rt-thread v4.0.3	4 rokov pred
SConscript	c0257098b9 release rt-thread v4.0.3	4 rokov pred
readme.md	c0257098b9 release rt-thread v4.0.3	4 rokov pred
termios.h	c0257098b9 release rt-thread v4.0.3	4 rokov pred
time.c	c0257098b9 release rt-thread v4.0.3	4 rokov pred
unistd.c	c0257098b9 release rt-thread v4.0.3	4 rokov pred

Attentions

This folder is "common" for armlibc newlibc and dlib. It's not "common" for minilibc.
If you want to add new .c files, please do not forget to fix SConscript file too. eg:
```
if GetDepend('RT_USING_POSIX') == False:
    SrcRemove(src, ['unistd.c'])
```