build pxe env tweaks
diff --git a/tools/build_pxe_env.sh b/tools/build_pxe_env.sh
new file mode 100755
index 0000000..1ab51f8
--- /dev/null
+++ b/tools/build_pxe_env.sh
@@ -0,0 +1,112 @@
+#!/bin/bash -e
+# build_pxe_env.sh - Create a PXE boot environment
+#
+# build_pxe_env.sh destdir
+#
+# Requires Ubuntu Oneiric
+#
+# Only needs to run as root if the destdir permissions require it
+
+dpkg -l syslinux || apt-get install -y syslinux
+
+DEST_DIR=${1:-/tmp}/tftpboot
+PXEDIR=${PXEDIR:-/var/cache/devstack/pxe}
+OPWD=`pwd`
+PROGDIR=`dirname $0`
+
+# Clean up any resources that may be in use
+cleanup() {
+    set +o errexit
+
+    # Mop up temporary files
+    if [ -n "$MNTDIR" -a -d "$MNTDIR" ]; then
+        umount $MNTDIR
+        rmdir $MNTDIR
+    fi
+
+    # Kill ourselves to signal any calling process
+    trap 2; kill -2 $$
+}
+
+trap cleanup SIGHUP SIGINT SIGTERM
+
+mkdir -p $DEST_DIR/pxelinux.cfg
+cd $DEST_DIR
+for i in memdisk menu.c32 pxelinux.0; do
+    cp -pu /usr/lib/syslinux/$i $DEST_DIR
+done
+
+CFG=$DEST_DIR/pxelinux.cfg/default
+cat >$CFG <<EOF
+default menu.c32
+prompt 0
+timeout 0
+
+MENU TITLE PXE Boot Menu
+
+EOF
+
+# Setup devstack boot
+mkdir -p $DEST_DIR/ubuntu
+if [ ! -d $PXEDIR ]; then
+    mkdir -p $PXEDIR
+fi
+
+# Get image into place
+if [ ! -r $PXEDIR/stack-initrd.img ]; then
+    cd $OPWD
+    $PROGDIR/build_ramdisk.sh $PXEDIR/stack-initrd.img
+fi
+if [ ! -r $PXEDIR/stack-initrd.gz ]; then
+    gzip -1 -c $PXEDIR/stack-initrd.img >$PXEDIR/stack-initrd.gz
+fi
+cp -pu $PXEDIR/stack-initrd.gz $DEST_DIR/ubuntu
+
+if [ ! -r $PXEDIR/vmlinuz-*-generic ]; then
+    MNTDIR=`mktemp -d --tmpdir mntXXXXXXXX`
+    mount -t ext4 -o loop $PXEDIR/stack-initrd.img $MNTDIR
+
+    if [ ! -r $MNTDIR/boot/vmlinuz-*-generic ]; then
+        echo "No kernel found"
+        umount $MNTDIR
+        rmdir $MNTDIR
+        exit 1
+    else
+        cp -pu $MNTDIR/boot/vmlinuz-*-generic $PXEDIR
+    fi
+    umount $MNTDIR
+    rmdir $MNTDIR
+fi
+
+# Get generic kernel version
+KNAME=`basename $PXEDIR/vmlinuz-*-generic`
+KVER=${KNAME#vmlinuz-}
+cp -pu $PXEDIR/vmlinuz-$KVER $DEST_DIR/ubuntu
+cat >>$CFG <<EOF
+
+LABEL devstack
+    MENU LABEL ^devstack
+    MENU DEFAULT
+    KERNEL ubuntu/vmlinuz-$KVER
+    APPEND initrd=ubuntu/stack-initrd.gz ramdisk_size=2109600 root=/dev/ram0
+EOF
+
+# Get Ubuntu
+if [ -d $PXEDIR -a -r $PXEDIR/natty-base-initrd.gz ]; then
+    cp -pu $PXEDIR/natty-base-initrd.gz $DEST_DIR/ubuntu
+    cat >>$CFG <<EOF
+
+LABEL ubuntu
+    MENU LABEL ^Ubuntu Natty
+    KERNEL ubuntu/vmlinuz-$KVER
+    APPEND initrd=ubuntu/natty-base-initrd.gz ramdisk_size=419600 root=/dev/ram0
+EOF
+fi
+
+# Local disk boot
+cat >>$CFG <<EOF
+
+LABEL local
+    MENU LABEL ^Local disk
+    LOCALBOOT 0
+EOF