<imgsrc="../pic/wingdorothy.gif"alt="gif"align="left"><ahref="http://www.eecis.udel.edu/%7emills/pictures.html">from <i>The Wizard of Oz</i>, L. Frank Baum</a>
<p>Last update: <csobjformat="ShortTime"h="25"locale="00000409"region="0"t="DateTime"w="99">12:56 AM</csobj> UTC <csobjformat="LongDate"h="25"locale="00000409"region="0"t="DateTime"w="266">Saturday, March 20, 2004</csobj></p>
<p>NOTE: The following procedures have been replaced by GNU <tt>automake</tt> and <tt>autoconfigure</tt>. This page is to be updated in the next release.</p>
<p>Porting to a new machine or operating system ordinarily requires updating the <tt>./machines</tt> directory and the <tt>./compilers</tt> directories in order to define the build environment and autoconfigure means. You will probably have to modify the <tt>ntp_machines.h</tt> file and <tt>"l_stdlib.h"</tt> files as well. The two most famous trouble spots are the I/O code in <tt>./ntpd/ntp_io.c</tt> and the clock adjustment code in <tt>./ntpd/ntp_unixclock.c</tt>.</p>
<p>These are the rules so that older bsd systems and the POSIX standard system can coexist together.</p>
<ol>
<li>If you use <tt>select</tt> then include <tt>"ntp_select.h"</tt>. <tt>select</tt> is not standard, since it is very system dependent as to where it is defined. The logic to include the right system dependent include file is in <tt>"ntp_select.h"</tt>.
<li>Always use POSIX definition of strings. Include <tt>"ntp_string.h"</tt> instead of <tt><string.h></tt>.
<li>Always include <tt>"ntp_malloc.h"</tt> if you use <tt>malloc</tt>.
<li>Always include <tt>"ntp_io.h"</tt> instead of <tt><sys/file.h></tt> or <tt><fnctl.h></tt> to get <tt>O_*</tt> flags.
<li>Always include <tt>"ntp_if.h"</tt> instead of <tt><net/if.h></tt>.
<li>Always include <tt>"ntp_stdlib.h"</tt> instead of <tt><stdlib.h></tt>.
<li>Define any special defines needed for a system in <tt>./include/ntp_machine.h</tt> based on system identifier. This file is included by the <tt>"ntp_types.h"</tt> file and should always be placed first after the <tt><></tt> defines.
<li>Define any special library prototypes left over from the system library and include files in the <tt>"l_stdlib.h"</tt> file. This file is included by the <tt>"ntp_stdlib.h"</tt> file and should ordinarily be placed last in the includes list.
<li>Don't define a include file by the same name as a system include file.
</ol>
<p><tt>"l_stdlib.h"</tt> can contain any extra definitions that are needed so that <tt>gcc</tt> will shut up. They should be controlled by a system identifier and there should be a separate section for each system. Really this will make it easier to maintain.</p>
<p>See <tt>include/ntp_machines.h</tt> for the various compile time options.</p>
<p>When you are satisfied the port works and that other ports are not adversely affected, please send <ahref="patches.html">patches</a> for the system files you have changed, as well as any documentation that should be updated, including the advice herein.</p>
