While I know this is similar to my other thread, I really want that thread to focus on which C Standard Libraries people are using, and why. I'd like to focus here on the compatibility issue I found in a web search with reentrant newlib and Yagarto. Is this an incompatibility that prevents Yagarto from shipping with fully reentrant newlib to this day? Is it not possible to use a fully reentrant C Standard Library with Free RTOS?

An example of the issue in question is here: https://sourceforge.net/projects/freertos/forums/forum/382005/topic/3234440

I don't think the link you provided has anything to do with reentrancy as such, it is more to do with the application dependent functions that newlib expects you to provide yourself. With reference to reentrancy, I was referring more to newlibs use of struct _reent, as described here: http://vmlinux.org/crash/mirror/www.objsw.com/docs/libc_127.html

If you search this forum, or the web, you will (maybe) find some modifications to FreeRTOS done by a third party to add the necessary pointer into the FreeRTOS task TCB.

Regards.

Your answers are a bit too subtle for me. Are you saying that standard FreeRTOS is incompatible with standard reentrant newlib? Are there other fully reentrant C Standard Libraries that don’t have this problem?