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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" SUCH DAMAGE. .\" SUCH DAMAGE.
.\" .\"
.\" $FreeBSD$ .\" $FreeBSD$
.\" .\"
.Dd December 1, 2010 .Dd June 7, 2023
.Dt SYSINIT 9 .Dt SYSINIT 9
.Os .Os
.Sh NAME .Sh NAME
.Nm SYSINIT , .Nm SYSINIT ,
.Nm SYSUNINIT .Nm SYSUNINIT
.Nd a framework for dynamic kernel initialization .Nd a framework for dynamic kernel initialization
.Sh SYNOPSIS .Sh SYNOPSIS
.In sys/param.h .In sys/param.h
.In sys/kernel.h .In sys/kernel.h
.Fn SYSINIT "uniquifier" "enum sysinit_sub_id subsystem" "enum sysinit_elem_order order" "sysinit_cfunc_t func" "const void *ident" .Fn SYSINIT "uniquifier" "enum sysinit_sub_id subsystem" "enum sysinit_elem_order order" "func" "args..."
.Fn SYSUNINIT "uniquifier" "enum sysinit_sub_id subsystem" "enum sysinit_elem_order order" "sysinit_cfunc_t func" "const void *ident" .Fn SYSUNINIT "uniquifier" "enum sysinit_sub_id subsystem" "enum sysinit_elem_order order" "func" "args..."
.Sh DESCRIPTION .Sh DESCRIPTION
.Nm .Nm
is a mechanism for scheduling the execution of initialization and teardown is a mechanism for scheduling the execution of initialization and teardown
routines. routines.
This is similar to init and fini routines with the addition of explicit This is similar to init and fini routines with the addition of explicit
ordering metadata. ordering metadata.
It allows runtime ordering of subsystem initialization in the kernel as well It allows runtime ordering of subsystem initialization in the kernel as well
as kernel modules (KLDs). as kernel modules (KLDs).
.Pp .Pp
The The
.Fn SYSINIT .Fn SYSINIT
and
.Fn SYSUNINIT
macros may not be used inside function blocks.
.Pp
The
.Fn SYSINIT
macro creates a macro creates a
.Vt struct sysinit .Vt struct sysinit
and stores it in a startup linker set. and stores it in a startup linker set.
The The
.Vt struct sysinit .Vt struct sysinit
type as well as the subsystem identifier constants type as well as the subsystem identifier constants
.Pq Dv SI_SUB_* .Pq Dv SI_SUB_*
and initialization ordering constants and initialization ordering constants
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.Fa uniquifier .Fa uniquifier
argument to identify the particular function dispatch data, argument to identify the particular function dispatch data,
the the
.Fa subsystem .Fa subsystem
type of startup interface, the subsystem element type of startup interface, the subsystem element
.Fa order .Fa order
of initialization within the subsystem, the of initialization within the subsystem, the
.Fa func .Fa func
function to call, function to call
and the data specified in and the arguments, if any, are given by the
.Fa ident .Fa args .
argument to pass the function.
.Pp .Pp
The The
.Fn SYSUNINIT .Fn SYSUNINIT
macro behaves similarly to the macro behaves similarly to the
.Fn SYSINIT .Fn SYSINIT
macro except that it adds the data to a shutdown linker set. macro except that it adds the data to a shutdown linker set.
.Pp .Pp
The startup linker set for the kernel is scanned during boot to build a The startup linker set for the kernel is scanned during boot to build a
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The shutdown linker set for a kernel module is scanned, sorted, and executed The shutdown linker set for a kernel module is scanned, sorted, and executed
when a kernel module is unloaded. when a kernel module is unloaded.
The teardown routines are sorted in the reverse order of the initialization The teardown routines are sorted in the reverse order of the initialization
routines. routines.
The teardown routines of the kernel and any loaded modules are The teardown routines of the kernel and any loaded modules are
.Sy not .Sy not
executed during shutdown. executed during shutdown.
.Sh EXAMPLES .Sh EXAMPLES
This example shows the SYSINIT which displays the copyright notice during boot: How to create a SYSINIT() passing no arguments to a callback function:
.Bd -literal -offset indent .Bd -literal -offset indent
static void static void
print_caddr_t(void *data) print_notice(void)
{ {
printf("%s", (char *)data); printf("This is a 2-clause-BSD licensed system\n");
} }
SYSINIT(announce, SI_SUB_COPYRIGHT, SI_ORDER_FIRST, print_caddr_t, SYSINIT(announce, SI_SUB_COPYRIGHT, SI_ORDER_FIRST, print_notice, NULL);
copyright); .Pp
How to create a SYSINIT() passing a single argument to a callback function:
.Bd -literal -offset indent
static const char notice[] = "This is a 2-clause-BSD licensed system\n";
static void
print_notice(const char *data)
{
printf("%s", notice);
}
SYSINIT(announce, SI_SUB_COPYRIGHT, SI_ORDER_FIRST, print_notice, notice);
.Ed .Ed
.Sh SEE ALSO .Sh SEE ALSO
.Xr kld 4 , .Xr kld 4 ,
.Xr DECLARE_MODULE 9 , .Xr DECLARE_MODULE 9 ,
.Xr DEV_MODULE 9 , .Xr DEV_MODULE 9 ,
.Xr DRIVER_MODULE 9 , .Xr DRIVER_MODULE 9 ,
.Xr MTX_SYSINIT 9 , .Xr MTX_SYSINIT 9 ,
.Xr SYSCALL_MODULE 9 .Xr RM_SYSINIT 9 ,
.Xr RW_SYSINIT 9 ,
.Xr SX_SYSINIT 9 ,
.Xr SYSCALL_MODULE 9 ,
.Xr VNET_SYSINIT 9
.Sh HISTORY .Sh HISTORY
The The
.Nm .Nm
framework first appeared in framework first appeared in
.Fx 2.2 . .Fx 2.2 .
.Sh AUTHORS .Sh AUTHORS
.An -nosplit .An -nosplit
The The
.Nm .Nm
framework was written by framework was written by
.An Terrence Lambert Aq Mt terry@FreeBSD.org . .An Terrence Lambert Aq Mt terry@FreeBSD.org .
.Pp .Pp
This manual page was written by This manual page was written by
.An Hiten Pandya Aq Mt hmp@FreeBSD.org . .An Hiten Pandya Aq Mt hmp@FreeBSD.org .