FreeBSD kernel system call

[Alexandru Goia]

Greetings !

I am trying to write the code to a Unix system call, on the
FreeBSD 12.0 system. I managed to do that on Linux :

http://romania-acknowledges-stars.blogspot.com/2018/10/angel-call-in-kernel.html

but I find hard, without proper documentation, to implement it
on FreeBSD.

I am in trouble understanding the presence of SYSCALL_MODULE(9), and
its meaning and usage.

Please help.
Thank you.
Alexander Goia