about header files used in score

[chrisj at rtems.org (Chris Johns)]

Zhongjie wrote:
> thanks for reply.
> I am just beginning studying RTEMS, the newlib depends on a limited 
> number of low level functions.

Welcome.

> In fact, we do not need any C library to build gcc as a cross complier, 
> like arm-elf-gcc, only enable the c
> language. what I concerns is that some part of RTEMS should can be 
> compiled using those compiler.

If you look in libgcc2.c you will see an include for stdio.h. I have always 
needed some libc headers to build gcc.

> Of course, with newlib support, RTEMS works well, it just a little 
> confused logically for a beginner like me.
> as my understanding, it is a c library depends on a os, not a os depends 
> a c library.
> I think we could define those types in rtems, then included by gcc and 
> newlib, but not use those types directly in
> a c library header files. it will make the architecture more clearly.

GCC and newlib have all the types defined for a specific target and RTEMS uses 
them.

Regards
Chris