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.\" $FreeBSD: src/share/man/man9/DECLARE_MODULE.9,v 1.2.2.3 2001/12/17 11:30:18 ru Exp $
.\"
.Dd March 3, 2001
.Dt DECLARE_MODULE 9
.Os
.Sh NAME
.Nm DECLARE_MODULE
.Nd kernel module declaration macro
.Sh SYNOPSIS
.In sys/module.h
.Fn DECLARE_MODULE "name" "moduledata_t data" "sub" "order"
.Sh DESCRIPTION
The
.Fn DECLARE_MODULE
macro declares a generic kernel module.
It is used to register the module with the system, using the
.Fn SYSINIT
macro.
.Fn DECLARE_MODULE
is usually used within other macros, such as
.Xr DRIVER_MODULE 9 ,
.Xr DEV_MODULE 9
and
.Xr SYSCALL_MODULE 9 .
However, it can be called directly of course, for example in
order to implement dynamic sysctls.
.Pp
The arguments to
.Fn DECLARE_MODULE :
.Pp
.Fa name
is the name of the module, which will be used in the
.Fn SYSINIT
call to identify the module.
.Pp
.Fa data
is a pointer to the
.Vt moduledata_t
structure, which contains two main items, the official name of the
module, which will be used in the
.Vt module
structure and a pointer to the event handler function of type
.Vt modeventhand_t .
.Pp
.Fa sub
is an argument directed to the
.Fn SYSINIT
macro.
Valid values for this are contained in the
.Vt sysstem_sub_id
enumeration
(see
.In sys/kernel.h )
and specify the type of system startup interfaces.
The
.Xr DRIVER_MODULE 9
macro uses a value of
.Dv SI_SUB_DRIVERS
here for example, since these modules contain a driver for a device.
For kernel modules that are loaded at runtime, a value of
.Dv SI_SUB_EXEC
is common.
.Pp
The
.Fa order
value is another argument for
.Fn SYSINIT .
It represents the KLDs order of initialization within the subsystem.
Valid values are defined in the
.Vt sysinit_elem_order
enumeration (see
.In sys/kernel.h ) .
.Sh SEE ALSO
.Xr DEV_MODULE 9 ,
.Xr DRIVER_MODULE 9 ,
.Xr module 9 ,
.Xr SYSCALL_MODULE 9
.Pp
.In sys/kernel.h ,
.Pa /usr/share/examples/kld
.Sh AUTHORS
.An -nosplit
This manual page was written by
.An Alexander Langer Aq Mt alex@FreeBSD.org ,
inspired by the KLD Facility Programming Tutorial by
.An Andrew Reiter Aq Mt arr@watson.org .