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.Dd January 6, 2005
.Dt DECLARE_MODULE 9
.Os
.Sh NAME
.Nm DECLARE_MODULE
.Nd kernel module declaration macro
.Sh SYNOPSIS
.In sys/param.h
.In sys/kernel.h
.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 .
Of course, it can also be called directly, for example in
order to implement dynamic sysctls.
.Pp
The arguments it expects are:
.Bl -tag -width indent
.It Fa name
The module name, which will be used in the
.Fn SYSINIT
call to identify the module.
.It Fa data
A
.Vt moduledata_t
structure, which contains two main items, the official name of the
module name, which will be used in the
.Vt module_t
structure and a pointer to the event handler function of type
.Vt modeventhand_t .
.It Fa sub
An argument directed to the
.Fn SYSINIT
macro.
Valid values for this are contained in the
.Vt sysinit_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.
.It Fa order
An 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
.Pq In sys/kernel.h .
.El
.Sh SEE ALSO
.Xr DEV_MODULE 9 ,
.Xr DRIVER_MODULE 9 ,
.Xr module 9 ,
.Xr SYSCALL_MODULE 9
.Pp
.Pa /usr/include/sys/kernel.h ,
.Pa /usr/share/examples/kld
.Sh AUTHORS
.An -nosplit
This manual page was written by
.An Alexander Langer Aq alex@FreeBSD.org ,
inspired by the KLD Facility Programming Tutorial by
.An Andrew Reiter Aq arr@watson.org .