svn commit: r53471 - head/en_US.ISO8859-1/books/porters-handbook/porting-dads

[Mark Linimon]

Author: linimon
Date: Tue Oct  8 07:46:18 2019
New Revision: 53471
URL: https://svnweb.freebsd.org/changeset/doc/53471

Log:
  Add a sect2 for "General Notes on Architectures".
  
  I had assumed that everyone was aware of these considerations, but,
  based on a conversation on ports-svn-commits, this is not the case.
  
  This text does not change policy; it merely documents existing
  technology.

Modified:
  head/en_US.ISO8859-1/books/porters-handbook/porting-dads/chapter.xml

Modified: head/en_US.ISO8859-1/books/porters-handbook/porting-dads/chapter.xml
==============================================================================
--- head/en_US.ISO8859-1/books/porters-handbook/porting-dads/chapter.xml	Tue Oct  8 06:48:45 2019	(r53470)
+++ head/en_US.ISO8859-1/books/porters-handbook/porting-dads/chapter.xml	Tue Oct  8 07:46:18 2019	(r53471)
@@ -520,6 +520,26 @@ cc -o someprogram source1.o source2.o -L/usr/local/lib
   <sect1 xml:id="dads-arch">
     <title>Architectural Considerations</title>
 
+    <sect2 xml:id="dads-arch-general">
+      <title>General Notes on Architectures</title>
+
+      <para>&os; runs on many more processor architectures than
+	just the well-known x86-based ones.  Some ports have
+	constraints which are particular to one or more of these
+	architectures.</para>
+
+      <para>For the list of supported architectures, run:</para>
+
+      <programlisting>cd ${SRCDIR}; make targets</programlisting>
+
+      <para>The values are shown in the form
+	<literal>TARGET</literal>/<literal>TARGET_ARCH</literal>.
+	The ports read-only makevar <literal>ARCH</literal> is set
+	based on the value of <literal>TARGET_ARCH</literal>.
+	Port <filename>Makefile</filename>s should test the value
+	of this Makevar.</para>
+    </sect2>
+
     <sect2 xml:id="dads-arch-neutral">
       <title>Marking a Port as Architecture Neutral</title>