hal

[tangke]

hi all, I am a beginner of this field, now i am looking some documents 
about the hal.
but when i use lshal,
udi = '/org/freedesktop/Hal/devices/computer'
   5   info.addons = {'hald-addon-cpufreq', 'hald-addon-acpi'} (string list)
   6   info.callouts.add = {'hal-acl-tool --remove all', 
'hal-storage-cleanup-all-mountpoints'} (string list)
   7   info.callouts.session_active = {'hal-acl-tool --reconfigure'} 
(string list)
   8   info.callouts.session_add = {'hal-acl-tool --reconfigure'} 
(string list)
   9   info.callouts.session_inactive = {'hal-acl-tool --reconfigure'} 
(string list)
  10   info.callouts.session_remove = {'hal-acl-tool --reconfigure'} 
(string list)
  11   info.capabilities = {'cpufreq_control'} (string list)
  12   info.interfaces = 
{'org.freedesktop.Hal.Device.SystemPowerManagement', 
'org.freedesktop.Hal.Device.CPUFreq'} (string l     ist)
  13   info.product = 'Computer'  (string)


i don't know what's means of info.addons, info.callouts.add etc.

 info.{bus,udi,persistent,capabilities,product,vendor,parent,locked}
  usb_device.{device_class,speed_bcd,serial,product,vendor}
  scsi.{host,bus,target,lun}
  block.{device,major,minor,is_volume,no_partitions}
  volume.{is_mounted,fstype,label,uuid,block_size,size,is_partition}
  storage.{drive_type,removable,hotpluggable,requires_eject}
  storage.cdrom.{cdr,cdrw,dvd,dvdr,read_speed,write_speed}

  storage.policy.default.{mount_option,mount_root}


thanks
best regards