NAME

     SYSCALL_MODULE — syscall kernel module declaration macro

SYNOPSIS

     #include <sys/param.h>
     #include <sys/kernel.h>
     #include <sys/proc.h>
     #include <sys/module.h>
     #include <sys/sysent.h>

     SYSCALL_MODULE(name, int *offset, struct sysent *new_sysent, modeventhand_t evh, void *arg);

DESCRIPTION

     The SYSCALL_MODULE() macro declares a new syscall.  SYSCALL_MODULE() expands into a kernel
     module declaration with name ‘sys/name’.

     The rest of the arguments expected by this macro are:

     offset      A pointer to an int which saves the offset in struct sysent where the syscall is
                 allocated.  If the location pointed to by offset holds a non 0 number it will be
                 used if possible.  If it holds 0 then one will be assigned.

     new_sysent  is a pointer to a structure that specifies the function implementing the syscall
                 and the number of arguments this function needs (see <sys/sysent.h>).

     evh         A pointer to the kernel module event handler function with the argument arg.
                 Please refer to module(9) for more information.

     arg         The argument passed to the callback functions of the evh event handler when it
                 is called.

     The syscall number assigned to the module can be retrieved using the modstat(3) and
     modfind(3) library functions in libc.  The MACRO SYSCALL_MODULE_HELPER() includes
     SYSCALL_MODULE() and much of its boilerplate code.

EXAMPLES

     A minimal example for a syscall module can be found in
     /usr/share/examples/kld/syscall/module/syscall.c.

SEE ALSO

     module(9)

     /usr/share/examples/kld/syscall/module/syscall.c

AUTHORS

     This manual page was written by Alexander Langer <alex@FreeBSD.org>.