As Britton Kerin wrote: > at least it doesn't show up on > https://www.nongnu.org/avr-libc/user-manual/modules.html
Well, it's part of the compiler suite, not avr-libc. There are some more files in this group: j@uriah 63% ls /usr/local/lib/gcc/avr/9.1.0/include /usr/local/lib/gcc/avr/9.1.0/include: float.h stdarg.h stdfix-gcc.h stdnoreturn.h gcov.h stdatomic.h stdfix.h unwind.h iso646.h stdbool.h stdint-gcc.h varargs.h stdalign.h stddef.h stdint.h -- cheers, Joerg .-.-. --... ...-- -.. . DL8DTL http://www.sax.de/~joerg/ Never trust an operating system you don't have sources for. ;-)