DECLARE_MODULE(9)      FreeBSD Kernel Developer's Manual     DECLARE_MODULE(9)

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
     The DECLARE_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 of
             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 SI_SUB_EXEC is 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>.

FreeBSD 13.1-RELEASE-p6        February 13, 2018       FreeBSD 13.1-RELEASE-p6