NAME

       DRIVER_MODULE,  DRIVER_MODULE_ORDERED,  EARLY_DRIVER_MODULE,  EARLY_DRIVER_MODULE_ORDERED — kernel driver
       declaration macro

SYNOPSIS

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

       DRIVER_MODULE(name, busname, driver_t driver, devclass_t devclass, modeventhand_t evh, void *arg);

       DRIVER_MODULE_ORDERED(name, busname, driver_t driver, devclass_t devclass, modeventhand_t evh, void *arg,
           int order);

       EARLY_DRIVER_MODULE(name, busname, driver_t driver, devclass_t devclass, modeventhand_t evh,  void  *arg,
           enum sysinit_elem_order order, int pass);

       EARLY_DRIVER_MODULE_ORDERED(name,  busname,  driver_t  driver,  devclass_t  devclass, modeventhand_t evh,
           void *arg, enum sysinit_elem_order order, int pass);

DESCRIPTION

       The DRIVER_MODULE() macro  declares  a  kernel  driver.   DRIVER_MODULE()  expands  to  the  real  driver
       declaration,  where  the phrase name is used as the naming prefix for the driver and its functions.  Note
       that it is supplied as plain text, and not a char or char *.

       busname is the parent bus of the driver (PCI, ISA, PPBUS and others), e.g. ‘pci’, ‘isa’, or ‘ppbus’.

       The identifier used in DRIVER_MODULE() can be different from the driver  name.   Also,  the  same  driver
       identifier  can  exist on different buses, which is a pretty clean way of making front ends for different
       cards using the same driver on the same or different buses.  For example, the following is allowed:

       DRIVER_MODULE(foo, isa, foo_driver, foo_devclass, NULL, NULL);

       DRIVER_MODULE(foo, pci, foo_driver, foo_devclass, NULL, NULL);

       driver is the driver of type driver_t, which contains the information about the driver and  is  therefore
       one of the two most important parts of the call to DRIVER_MODULE().

       The  devclass  argument  contains  the  kernel-internal  information about the device, which will be used
       within the kernel driver module.

       The evh argument is the event handler which is called when the driver (or module) is loaded  or  unloaded
       (see module(9)).

       The arg is unused at this time and should be a NULL pointer.

       The  DRIVER_MODULE_ORDERED()  macro  allows  a  driver to be registered in a specific order.  This can be
       useful if a single kernel module contains multiple drivers that are inter-dependent.  The order  argument
       should  be one of the SYSINIT(9) initialization ordering constants (SI_ORDER_*).  The default order for a
       driver module is SI_ORDER_MIDDLE.  Typically a module will specify an order of SI_ORDER_ANY for a  single
       driver to ensure it is registered last.

       The  EARLY_DRIVER_MODULE()  macro  allows  a driver to be registered for a specific pass level.  The boot
       time probe and attach process makes multiple passes over the device tree.  Certain critical drivers  that
       provide  basic  services  needed  by  other devices are attached during earlier passes.  Most drivers are
       attached in a final general pass.  A driver that attaches during  an  early  pass  must  register  for  a
       specific  pass  level (BUS_PASS_*) via the pass argument.  Once a driver is registered it is available to
       attach to devices for all subsequent passes.

       The EARLY_DRIVER_MODULE_ORDERED() macro allows a driver to be registered both in a specific order and for
       a specific pass level.

SEE ALSO

       device(9), driver(9), module(9), MODULE_PNP_INFO(9), SYSINIT(9)

AUTHORS

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

Debian                                          February 12, 2018                               DRIVER_MODULE(9)