Index for Section 9

Alphabetical listing for R

Bottom of page

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
  function
      Specifies the name of the routine that you want called at a later time.

  point
      Specifies the dispatch point at which the kernel calls this callback
      routine. The kernel passes the value associated with this dispatch
      point to the kernel module's callback routine when it calls it.

  order
      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 execution
      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.

  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 execution reaches
  the point specified in the point and order arguments. The kernel passes the
  values specified in the point and argument arguments 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 table lists the
  dispatch point constants that kernel modules can use:

  CFG_PT_PRECONFIG
	      The dispatch point is hardware preconfiguration. Tasks that do
	      not require completion of hardware configuration can be
	      performed at this dispatch point.

  CFG_PT_POSTCONFIG
	      The dispatch point is hardware postconfiguration. Tasks that
	      require completion of hardware configuration can be performed
	      at this dispatch point.

  CFG_PT_ROOTFS_AVAIL
	      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:

  CFG_ORD_NOMINAL
	      This callback routine is registered at the lowest priority.
	      Typically, you pass this constant with an appropriate offset.
	      The kernel executes callback routines registered at this
	      priority last.

  CFG_ORD_MAXIMUM
	      This callback routine is registered at the highest priority.
	      Typically, you pass this constant with an appropriate offset.
	      The kernel executes callback routines registered 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 configuration
  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:

  ENOMEM  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.

  EINVAL  The value you passed to the point argument is outside the minimum
	  and maximum range.








FILES
  <sysconfig.h>



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

Index for Section 9

Alphabetical listing for R

Top of page