How to implement a syscall in Haiku

Hi,

as the subject suggest, the question is very simple.
What are the steps in order to implement a syscall in Haiku?

I had a look at the _user_realtime_sem_open for example and I found
that they are declare in syscall_dispatcher.h and syscall_table.h, but
both of them are found in the "generated" directory, which reminds me
that there is something to do with the build system.

The only document I found on the website is from 2002 and I guess
it's pretty outdated? Is it?
http://www.haiku-os.org/documents/dev/hello_kernel_you_have_a_syscall_from_userland

Anyhow, the syscall_info structures, requires that the second field to
be the amount
of the parameter size. What if one of the parameter it's a union? Is
it that allowed?

Regards,
-- 
Salvatore Benedetto (a.k.a. emitrax)
Student of Computer Engineer
University of Pisa
www.haiku-os.it

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