NAME
DECLARE_MODULE —
kernel module declaration
macro
SYNOPSIS
#include
<sys/param.h>
#include <sys/kernel.h>
#include <sys/module.h>
DECLARE_MODULE(name,
moduledata_t data,
sub,
order);
DECLARE_MODULE_TIED(name,
moduledata_t data,
sub,
order);
DESCRIPTION
TheDECLARE_MODULE()
macro declares a generic kernel module. It is used to register the module with
the system, using the SYSINIT() macro.
DECLARE_MODULE() is usually used within other macros,
such as
DRIVER_MODULE(9),
DEV_MODULE(9) and
SYSCALL_MODULE(9). Of course, it can also be called directly,
for example in order to implement dynamic sysctls.
A module declared with
DECLARE_MODULE_TIED()
will load only if the running kernel version (as specified by
__FreeBSD_version) is identical to that on which it
was built. This declaration should be used by modules which depend on
interfaces beyond the stable kernel KBI (such as ABI emulators or
hypervisors that rely on internal kernel structures).
DECLARE_MODULE() will behave like
DECLARE_MODULE_TIED() when compiled with modules
built with the kernel. This allows locks and other synchronization
primitives to be inlined safely.
The arguments are:
- name
- The module name, which will be used in the
SYSINIT() call to identify the module. - data
- A moduledata_t structure, which contains two main items, the official name of the module name, which will be used in the module_t structure and a pointer to the event handler function of type modeventhand_t.
- sub
- An argument directed to the
SYSINIT() macro. Valid values for this are contained in the sysinit_sub_id enumeration (see<sys/kernel.h>) and specify the type of system startup interfaces. The DRIVER_MODULE(9) macro uses a value ofSI_SUB_DRIVERShere for example, since these modules contain a driver for a device. For kernel modules that are loaded at runtime, a value ofSI_SUB_EXECis common. - order
- An argument for
SYSINIT(). It represents the KLDs order of initialization within the subsystem. Valid values are defined in the sysinit_elem_order enumeration (<sys/kernel.h>).
SEE ALSO
DEV_MODULE(9), DRIVER_MODULE(9), module(9), SYSCALL_MODULE(9)
/usr/include/sys/kernel.h, /usr/share/examples/kld
AUTHORS
This manual page was written by Alexander Langer <alex@FreeBSD.org>, inspired by the KLD Facility Programming Tutorial by Andrew Reiter <arr@watson.org>.