diff --git a/tools/build_usb_boot.sh b/tools/build_usb_boot.sh
index 332c869..c79cf2b 100755
--- a/tools/build_usb_boot.sh
+++ b/tools/build_usb_boot.sh
@@ -1,17 +1,11 @@
 #!/bin/bash -e
 # build_usb_boot.sh - Create a syslinux boot environment
 #
-# build_usb_boot.sh [-k kernel-version] destdev
+# build_usb_boot.sh destdev
 #
 # Assumes syslinux is installed
 # Needs to run as root
 
-KVER=`uname -r`
-if [ "$1" = "-k" ]; then
-    KVER=$2
-    shift;shift
-fi
-
 DEST_DIR=${1:-/tmp/syslinux-boot}
 PXEDIR=${PXEDIR:-/var/cache/devstack/pxe}
 OPWD=`pwd`
@@ -20,7 +14,7 @@ PROGDIR=`dirname $0`
 if [ -b $DEST_DIR ]; then
     # We have a block device, install syslinux and mount it
     DEST_DEV=$DEST_DIR
-    DEST_DIR=`mktemp -d mntXXXXXX`
+    DEST_DIR=`mktemp -d --tmpdir mntXXXXXX`
     mount $DEST_DEV $DEST_DIR
 
     if [ ! -d $DEST_DIR/syslinux ]; then
@@ -57,20 +51,41 @@ mkdir -p $DEST_DIR/ubuntu
 if [ ! -d $PXEDIR ]; then
     mkdir -p $PXEDIR
 fi
-if [ ! -r $PXEDIR/vmlinuz-${KVER} ]; then
-    sudo chmod 644 /boot/vmlinuz-${KVER}
-    if [ ! -r /boot/vmlinuz-${KVER} ]; then
-        echo "No kernel found"
-    else
-        cp -p /boot/vmlinuz-${KVER} $PXEDIR
-    fi
-fi
-cp -p $PXEDIR/vmlinuz-${KVER} $DEST_DIR/ubuntu
-if [ ! -r $PXEDIR/stack-initrd.gz ]; then
+
+# Get image into place
+if [ ! -r $PXEDIR/stack-initrd.img ]; then
     cd $OPWD
-    sudo $PROGDIR/build_ramdisk.sh $PXEDIR/stack-initrd.gz
+    $PROGDIR/build_ramdisk.sh $PXEDIR/stack-initrd.img
 fi
-cp -p $PXEDIR/stack-initrd.gz $DEST_DIR/ubuntu
+if [ ! -r $PXEDIR/stack-initrd.gz ]; then
+    gzip -1 -c $PXEDIR/stack-initrd.img >$PXEDIR/stack-initrd.gz
+fi
+#cp -p $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 $MNTDIR
+        if [ -n "$DEST_DEV" ]; then
+            umount $DEST_DIR
+            rmdir $DEST_DIR
+        fi
+        exit 1
+    else
+        cp -p $MNTDIR/boot/vmlinuz-*-generic $PXEDIR
+    fi
+    umount $MNTDIR
+    rmdir $MNTDIR
+fi
+
+# Get generic kernel version
+KNAME=`basename $PXEDIR/vmlinuz-*-generic`
+KVER=${KNAME#vmlinuz-}
+cp -p $PXEDIR/vmlinuz-$KVER $DEST_DIR/ubuntu
 cat >>$CFG <<EOF
 
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