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MODULE(9) | 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 toMOD_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 happening.
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/kldAUTHORS¶
This manual page was written by Alexander Langer ⟨alex@FreeBSD.org⟩.July 19, 2007 | Debian |