Someone pointed out that cpu_to_XXX is not included in the Unreliable
Guide to Kernel Hacking.
Being aimed as a "fast background to kernel coding", it's a definite
hole.
Cheers,
Rusty.
diff -urN -I \$.*\$ --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.4.16-uml/Documentation/DocBook/kernel-hacking.tmpl working-2.4.16-uml-proc/Documentation/DocBook/kernel-hacking.tmpl
--- linux-2.4.16-uml/Documentation/DocBook/kernel-hacking.tmpl Thu Oct 25 11:29:46 2001
+++ working-2.4.16-uml-proc/Documentation/DocBook/kernel-hacking.tmpl Thu Dec 20 12:31:41 2001
@@ -18,8 +18,8 @@
</authorgroup>
<copyright>
- <year>2000</year>
- <holder>Paul Russell</holder>
+ <year>2001</year>
+ <holder>Rusty Russell</holder>
</copyright>
<legalnotice>
@@ -651,6 +651,28 @@
</para>
</sect1>
+ <sect1 id="routines-endian">
+ <title><function>cpu_to_be32()</function>/<function>be32_to_cpu()</function>/<function>cpu_to_le32()</function>/<function>le32_to_cpu()</function>
+ <filename class=headerfile>include/asm/byteorder.h</filename>
+ </title>
+
+ <para>
+ The <function>cpu_to_be32()</function> family (where the "32" can
+ be replaced by 64 or 16, and the "be" can be replaced by "le") are
+ the general way to do endian conversions in the kernel: they
+ return the converted value.
+ </para>
+
+ <para>
+ There are two major variations of these functions: the pointer
+ variation, such as <function>cpu_to_be32p()</function>, which take
+ a pointer to the given type, and return the converted value. The
+ other variation is the "in-situ" family, such as
+ <function>cpu_to_be32s()</function>, which convert value referred
+ to by the pointer, and return void.
+ </para>
+ </sect1>
+
<sect1 id="routines-local-irqs">
<title><function>local_irq_save()</function>/<function>local_irq_restore()</function>
<filename class=headerfile>include/asm/system.h</filename>
-- Anyone who quotes me in their sig is an idiot. -- Rusty Russell. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Sun Dec 23 2001 - 21:00:20 EST