<HTML ><HEAD ><TITLE >Special kerneld uses</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.52"><LINK REL="HOME" TITLE="Linux kerneld mini-HOWTO" HREF="index.html"><LINK REL="PREVIOUS" TITLE="Spying on kerneld" HREF="spying.html"><LINK REL="NEXT" TITLE="Common problems and things that make you wonder" HREF="commonproblems.html"></HEAD ><BODY CLASS="SECT1" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#840084" ALINK="#0000FF" ><DIV CLASS="NAVHEADER" ><TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >Linux kerneld mini-HOWTO</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="spying.html" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="commonproblems.html" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="SECT1" ><H1 CLASS="SECT1" ><A NAME="GOODIES" >Special kerneld uses</A ></H1 ><P >I knew you would ask about how to setup the screen-saver module!</P ><P >The <TT CLASS="FILENAME" >kerneld/GOODIES</TT > directory in modules package has a couple of kernel patches for screen-saver and console-beep support in kerneld; these are not yet part of the official kernel, so you will need to install the kernel-patches and rebuild the kernel. </P ><P >To install a patch, you use the patch command: </P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" WIDTH="100%" ><TR ><TD ><PRE CLASS="SCREEN" > cd /usr/src/linux patch -s -p1 /usr/src/modules-*/kerneld/GOODIES/blanker_patch</PRE ></TD ></TR ></TABLE ><P >Then rebuild and install the new kernel. </P ><P >When the screen-saver triggers, kerneld will run the command <TT CLASS="FILENAME" >/sbin/screenblanker</TT >; this file may be anything you like, for example, a shell script that runs your favorite screen-saver. </P ><P >When the kernel wants to unblank the screen, it sends a <SPAN CLASS="TOKEN" >SIGQUIT</SPAN > signal to the process running <TT CLASS="FILENAME" >/sbin/screenblanker</TT >. Your shell script or screen-saver should trap this, and terminate. Remember to restore the screen to the original text mode! </P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="spying.html" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="commonproblems.html" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Spying on kerneld</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" > </TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Common problems and things that make you wonder</TD ></TR ></TABLE ></DIV ></BODY ></HTML >