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<section xmlns="http://docbook.org/ns/docbook" 
         xmlns:xi="http://www.w3.org/2001/XInclude"
         xmlns:xlink="http://www.w3.org/1999/xlink" 
         version="5.0" 
         xml:id="Hot_Plug_Events">
         
  <title>Hot Plug Events</title>
  
  <para>Hot Plug Events, when implemented, are reported through 
  either the event-scan RTAS call or a hotplug interrupt.</para>

  <para>An OS that wants to be notified of hotplug events will need to 
  set the appropriate arch-vector bit.  Look for the hot-plug-events 
  node in the /event-sources node of the OF device tree (see 
  <xref linkend="LoPAR.DeviceTree" />), enable the interrupts listed 
  in its “interrupts” property and provide an interrupt handler to call 
  check-exception when one of those interrupts are received.</para>

  <para>When a hotplug event occurs, whether reported by check-exception 
  or event-scan, RTAS will directly pass back the Hotplug Event Log as 
  described in <xref linkend="table.error.hotplug" />.</para>
  
  <variablelist>
  
  	<varlistentry>
  		<term><emphasis role="bold">R1-<xref linkend="Hot_Plug_Events" 
			xrefstyle="select: labelnumber nopage"/>-1.</emphasis></term>
  			<listitem>
		      <para>If FRUs can be hot plugged in the system
		      without OS support, the Hot Plug Event mechanism must be provided for
		      signaling the OS about the event.</para>
  			</listitem>
  	</varlistentry>
  
  </variablelist>
  
</section>
