Other POSIX-based systems use getrlimit(RLIMIT_NOFILE) to derive
maxDescriptor.
ulimit(4, nn) should also work but is old and obsolete (/like me ;)/ ).
https://man7.org/linux/man-pages/man3/ulimit.3.html
In terms of "POSIX compliant", the same system calls could be used for
a clean implementation, but NuttX currently returns a fixed value of 0.
----
/* This is a dummy realization to make the compiler happy */
memset(rlp, 0, sizeof(*rlp));
----
Is it possible to add an implementation within this systemcall?
(For starters, returning 128 as suggested by alan would be good.)
Sounds like a good, small project and a good contribution to the OS