This files are required for compiling newlib for fool os.
they go into this dir or similar..

~/Downloads/newlib-foolos/newlib/libc/sys/foolos 

configure.in
Makefile.am

syscall.h
syscall.s

syscalls.h
syscalls.c

crt0.h
crt0.s

this should to /usr/include/sys
fs.h -> sys/dirent.h  !! required by kernel/userspace and maybe clibrary