diff --git a/vppapigen/ylwrap b/vppapigen/ylwrap
new file mode 100755
index 0000000..8f072a8
--- /dev/null
+++ b/vppapigen/ylwrap
@@ -0,0 +1,247 @@
+#! /bin/sh
+# ylwrap - wrapper for lex/yacc invocations.
+
+scriptversion=2013-01-12.17; # UTC
+
+# Copyright (C) 1996-2013 Free Software Foundation, Inc.
+#
+# Written by Tom Tromey <tromey@cygnus.com>.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# As a special exception to the GNU General Public License, if you
+# distribute this file as part of a program that contains a
+# configuration script generated by Autoconf, you may include it under
+# the same distribution terms that you use for the rest of that program.
+
+# This file is maintained in Automake, please report
+# bugs to <bug-automake@gnu.org> or send patches to
+# <automake-patches@gnu.org>.
+
+get_dirname ()
+{
+  case $1 in
+    */*|*\\*) printf '%s\n' "$1" | sed -e 's|\([\\/]\)[^\\/]*$|\1|';;
+    # Otherwise,  we want the empty string (not ".").
+  esac
+}
+
+# guard FILE
+# ----------
+# The CPP macro used to guard inclusion of FILE.
+guard ()
+{
+  printf '%s\n' "$1"                                                    \
+    | sed                                                               \
+        -e 'y/abcdefghijklmnopqrstuvwxyz/ABCDEFGHIJKLMNOPQRSTUVWXYZ/'   \
+        -e 's/[^ABCDEFGHIJKLMNOPQRSTUVWXYZ]/_/g'                        \
+        -e 's/__*/_/g'
+}
+
+# quote_for_sed [STRING]
+# ----------------------
+# Return STRING (or stdin) quoted to be used as a sed pattern.
+quote_for_sed ()
+{
+  case $# in
+    0) cat;;
+    1) printf '%s\n' "$1";;
+  esac \
+    | sed -e 's|[][\\.*]|\\&|g'
+}
+
+case "$1" in
+  '')
+    echo "$0: No files given.  Try '$0 --help' for more information." 1>&2
+    exit 1
+    ;;
+  --basedir)
+    basedir=$2
+    shift 2
+    ;;
+  -h|--h*)
+    cat <<\EOF
+Usage: ylwrap [--help|--version] INPUT [OUTPUT DESIRED]... -- PROGRAM [ARGS]...
+
+Wrapper for lex/yacc invocations, renaming files as desired.
+
+  INPUT is the input file
+  OUTPUT is one file PROG generates
+  DESIRED is the file we actually want instead of OUTPUT
+  PROGRAM is program to run
+  ARGS are passed to PROG
+
+Any number of OUTPUT,DESIRED pairs may be used.
+
+Report bugs to <bug-automake@gnu.org>.
+EOF
+    exit $?
+    ;;
+  -v|--v*)
+    echo "ylwrap $scriptversion"
+    exit $?
+    ;;
+esac
+
+
+# The input.
+input=$1
+shift
+# We'll later need for a correct munging of "#line" directives.
+input_sub_rx=`get_dirname "$input" | quote_for_sed`
+case $input in
+  [\\/]* | ?:[\\/]*)
+    # Absolute path; do nothing.
+    ;;
+  *)
+    # Relative path.  Make it absolute.
+    input=`pwd`/$input
+    ;;
+esac
+input_rx=`get_dirname "$input" | quote_for_sed`
+
+# Since DOS filename conventions don't allow two dots,
+# the DOS version of Bison writes out y_tab.c instead of y.tab.c
+# and y_tab.h instead of y.tab.h. Test to see if this is the case.
+y_tab_nodot=false
+if test -f y_tab.c || test -f y_tab.h; then
+  y_tab_nodot=true
+fi
+
+# The parser itself, the first file, is the destination of the .y.c
+# rule in the Makefile.
+parser=$1
+
+# A sed program to s/FROM/TO/g for all the FROM/TO so that, for
+# instance, we rename #include "y.tab.h" into #include "parse.h"
+# during the conversion from y.tab.c to parse.c.
+sed_fix_filenames=
+
+# Also rename header guards, as Bison 2.7 for instance uses its header
+# guard in its implementation file.
+sed_fix_header_guards=
+
+while test $# -ne 0; do
+  if test x"$1" = x"--"; then
+    shift
+    break
+  fi
+  from=$1
+  # Handle y_tab.c and y_tab.h output by DOS
+  if $y_tab_nodot; then
+    case $from in
+      "y.tab.c") from=y_tab.c;;
+      "y.tab.h") from=y_tab.h;;
+    esac
+  fi
+  shift
+  to=$1
+  shift
+  sed_fix_filenames="${sed_fix_filenames}s|"`quote_for_sed "$from"`"|$to|g;"
+  sed_fix_header_guards="${sed_fix_header_guards}s|"`guard "$from"`"|"`guard "$to"`"|g;"
+done
+
+# The program to run.
+prog=$1
+shift
+# Make any relative path in $prog absolute.
+case $prog in
+  [\\/]* | ?:[\\/]*) ;;
+  *[\\/]*) prog=`pwd`/$prog ;;
+esac
+
+dirname=ylwrap$$
+do_exit="cd '`pwd`' && rm -rf $dirname > /dev/null 2>&1;"' (exit $ret); exit $ret'
+trap "ret=129; $do_exit" 1
+trap "ret=130; $do_exit" 2
+trap "ret=141; $do_exit" 13
+trap "ret=143; $do_exit" 15
+mkdir $dirname || exit 1
+
+cd $dirname
+
+case $# in
+  0) "$prog" "$input" ;;
+  *) "$prog" "$@" "$input" ;;
+esac
+ret=$?
+
+if test $ret -eq 0; then
+  for from in *
+  do
+    to=`printf '%s\n' "$from" | sed "$sed_fix_filenames"`
+    if test -f "$from"; then
+      # If $2 is an absolute path name, then just use that,
+      # otherwise prepend '../'.
+      case $to in
+        [\\/]* | ?:[\\/]*) target=$to;;
+        *) target=../$to;;
+      esac
+
+      # Do not overwrite unchanged header files to avoid useless
+      # recompilations.  Always update the parser itself: it is the
+      # destination of the .y.c rule in the Makefile.  Divert the
+      # output of all other files to a temporary file so we can
+      # compare them to existing versions.
+      if test $from != $parser; then
+        realtarget=$target
+        target=tmp-`printf '%s\n' "$target" | sed 's|.*[\\/]||g'`
+      fi
+
+      # Munge "#line" or "#" directives.  Don't let the resulting
+      # debug information point at an absolute srcdir.  Use the real
+      # output file name, not yy.lex.c for instance.  Adjust the
+      # include guards too.
+      sed -e "/^#/!b"                           \
+          -e "s|$input_rx|$input_sub_rx|"       \
+          -e "$sed_fix_filenames"               \
+          -e "$sed_fix_header_guards"           \
+        "$from" >"$target" || ret=$?
+
+      # Check whether files must be updated.
+      if test "$from" != "$parser"; then
+        if test -f "$realtarget" && cmp -s "$realtarget" "$target"; then
+          echo "$to is unchanged"
+          rm -f "$target"
+        else
+          echo "updating $to"
+          mv -f "$target" "$realtarget"
+        fi
+      fi
+    else
+      # A missing file is only an error for the parser.  This is a
+      # blatant hack to let us support using "yacc -d".  If -d is not
+      # specified, don't fail when the header file is "missing".
+      if test "$from" = "$parser"; then
+        ret=1
+      fi
+    fi
+  done
+fi
+
+# Remove the directory.
+cd ..
+rm -rf $dirname
+
+exit $ret
+
+# Local Variables:
+# mode: shell-script
+# sh-indentation: 2
+# eval: (add-hook 'write-file-hooks 'time-stamp)
+# time-stamp-start: "scriptversion="
+# time-stamp-format: "%:y-%02m-%02d.%02H"
+# time-stamp-time-zone: "UTC"
+# time-stamp-end: "; # UTC"
+# End: