--- a/packages/fs/yaffs/current/doc/yaffs.sgml
+++ b/packages/fs/yaffs/current/doc/yaffs.sgml
@@ -232,6 +232,14 @@ improve performance.
 Set to 0 to disable these caches altogether. 
 <emphasis>This setting is a global default and may be
 changed by a mount-time option.</emphasis></para></listitem></varlistentry>
+<varlistentry><term><constant>CYGNUM_FS_YAFFS_TEMP_BUFFERS</constant></term>
+<listitem><para>
+YAFFS requires temporary buffers in many places throughout the code.
+To avoid the overhead of a dynamic malloc every time, a number of
+buffers are preallocated at mount time. This setting controls how many;
+should it not prove enough, YAFFS will call maloc on demand as required.
+The default setting is 6; most users will not need to change it.
+</para></listitem></varlistentry>
 <varlistentry><term><constant>CYGNUM_FS_YAFFS_TRACEMASK</constant></term><listitem><para>This
 is a 32-bit bitfield which controls diagnostic output. The bit definitions
 are found in <filename>yportenv.h</filename>; changing this setting tends to only be useful