register_callback(9r)													     register_callback(9r)

NAME

       register_callback - General: Registers a configuration callback routine

SYNOPSIS

       int register_callback(
	       void (*function) (),
	       int point,
	       int order,
	       ulong argument );

ARGUMENTS

       Specifies  the name of the routine that you want called at a later time.  Specifies the dispatch point at which the kernel calls this call-
       back routine. The kernel passes the value associated with this dispatch point to the kernel module's callback routine  when  it	calls  it.
       Specifies  the order in which you want callback routines registered for the same dispatch point to be executed. The kernel passes the value
       associated with this order to the kernel module's callback routine when it calls it.  You use this argument to control the order of  execu-
       tion of multiple callback routine within each dispatch point. The register_callback routine executes a kernel module's callback routine for
       the same dispatch point in increasing numerical order of the value specified in the order argument.  Specifies an argument  that  you  want
       the  kernel  to pass to the kernel module'scallback routine when the kernel calls it. You pass the integer constant 0L to indicate that you
       do not want to pass an argument.

DESCRIPTION

       The register_callback routine registers a kernel module's callback routine. The kernel calls a kernel module's callback routine when execu-
       tion  reaches  the point specified in the point and order arguments. The kernel passes the values specified in the point and argument argu-
       ments to the kernel module's callback routine. Kernel modules implement one or more callback routines  to  handle  the  different  dispatch
       points in the boot path.

       The dispatch point constants you can pass to the point argument are defined in the /usr/sys/include/sys/sysconfig.h file. The following ta-
       ble lists the dispatch point constants that kernel modules can use: The dispatch point is hardware  preconfiguration.  Tasks  that  do  not
       require	completion  of	hardware configuration can be performed at this dispatch point.  The dispatch point is hardware postconfiguration.
       Tasks that require completion of hardware configuration can be performed at this dispatch point.  The dispatch point is	root  file  system
       available. Tasks that require completion of the root file system mount operation can be performed at this dispatch point.

       The  order constants you can pass to the order argument are defined in the /usr/sys/include/sys/sysconfig.h file. The following table lists
       the order constants that kernel modules can use: This callback routine is registered at the lowest priority.  Typically, you pass this con-
       stant  with an appropriate offset. The kernel executes callback routines registered at this priority last.  This callback routine is regis-
       tered at the highest priority.  Typically, you pass this constant with an appropriate offset. The kernel executes callback routines  regis-
       tered at this priority first.

NOTES

       The  kernel  maintains  an  internal callback list that stores the values you pass to the register_callback routine. These callbacks remain
       registered until the user removes them.

       Only statically configured kernel modules need to implement callback routines. Thus, only statically configured kernel modules need to call
       the register_callback routine.

       You  typically call the cfgmgr_get_state routine to determine if the kernel module is in the dynamic configuration state or the static con-
       figuration state.

RETURN VALUES

       Upon successful completion, the register_callback routine returns the value ESUCCESS.

       Otherwise, register_callback returns one of the following error constants defined in /usr/sys/include/sys/errno.h: The system limit on  the
       maximum	number	of  callback requests was exceeded. To change the maximum number of callback requests, set the new value for the boot-time
       tunable parameter max_callbacks in the cm subsystem (located in the /etc/sysconfigtab database) and reboot the  system.	You  can  use  the
       sysconfigdb utility to accomplish this task.  The value you passed to the point argument is outside the minimum and maximum range.

FILES

SEE ALSO

       Kernel routines: cfgmgr_get_state(9r), unregister_callback(9r)

															     register_callback(9r)