module_depend(9) [freebsd man page]

MODULE_DEPEND(9)					   BSD Kernel Developer's Manual					  MODULE_DEPEND(9)

NAME

     MODULE_DEPEND -- set kernel module dependencies

SYNOPSIS

     #include <sys/param.h>
     #include <sys/module.h>

     MODULE_DEPEND(name, moddepend, int minversion, int prefversion, int maxversion);

DESCRIPTION

     The MODULE_DEPEND() macro sets a dependency on another kernel module with name moddepend, which has registered its version with
     MODULE_VERSION().

     The MODULE_DEPEND() macro provides hints to the kernel loader(8) and to the kernel linker to ensure that the named dependency is loaded prior
     to the existing module.  It does not change or dictate the order in which modules are initialized at runtime.

     Three versions must be specified for moddepend:

     minversion   The minimum version on which the current module can depend.

     maxversion   The maximum version on which the current module can depend.

     prefversion  The preferred version on which the current module can depend.

EXAMPLES

     MODULE_DEPEND(foo, bar, 1, 3, 4);

SEE ALSO

     DECLARE_MODULE(9), module(9), MODULE_VERSION(9)

AUTHORS

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

BSD
								 January 11, 2005							       BSD

MODULE(9)						   BSD Kernel Developer's Manual						 MODULE(9)

NAME

     module -- structure describing a kernel module

DESCRIPTION

     Each module in the kernel is described by a module_t structure.  The structure contains the name of the device, a unique ID number, a pointer
     to an event handler function and to an argument, which is given to the event handler, as well as some kernel internal data.

     The DECLARE_MODULE(9) macro registers the module with the system.

     When the module is loaded, the event handler function is called with the what argument set to MOD_LOAD.

     On unload it is first called with what set to MOD_QUIESCE.  If the unload was not forced, a non-zero return will prevent the unload from hap-
     pening.

     If the unload continues what is set to MOD_UNLOAD.  If the module returns non-zero to this, the unload will not happen.

     The difference between MOD_QUIESCE and MOD_UNLOAD is that the module should fail MOD_QUIESCE if it is currently in use, whereas MOD_UNLOAD
     should only fail if it is impossible to unload the module, for instance because there are memory references to the module which cannot be
     revoked.

     When the system is shutting down, what contains the value of MOD_SHUTDOWN.

     The module should return EOPNOTSUPP for unsupported and unrecognized values of what.

EXAMPLES

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

     static int foo_handler(module_t mod, int /*modeventtype_t*/ what,
			    void *arg);

     static moduledata_t mod_data= {
	     "foo",
	     foo_handler,
	     NULL
     };

     MODULE_VERSION(foo, 1);
     MODULE_DEPEND(foo, bar, 1, 3, 4);

     DECLARE_MODULE(foo, mod_data, SI_SUB_EXEC, SI_ORDER_ANY);

SEE ALSO

     DECLARE_MODULE(9), DEV_MODULE(9), DRIVER_MODULE(9), MODULE_DEPEND(9), MODULE_VERSION(9), SYSCALL_MODULE(9)

     /usr/share/examples/kld

AUTHORS

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

BSD
								   July 19, 2007							       BSD