diff --git a/build_library/create_legacy_bootloader_templates.sh b/build_library/create_legacy_bootloader_templates.sh
index ed05c5f5b1..c4dd64a08b 100755
--- a/build_library/create_legacy_bootloader_templates.sh
+++ b/build_library/create_legacy_bootloader_templates.sh
@@ -46,45 +46,32 @@ if [[ "${FLAGS_arch}" = "x86" || "${FLAGS_arch}" = "amd64"  ]]; then
   ROOTB="PARTUUID=$(get_uuid base ROOT-B)"
 
   # Build configuration files for pygrub/pvgrub
-  GRUB_DIR="${FLAGS_to}/boot/grub"
+  GRUB_DIR="${FLAGS_to}/grub"
   sudo mkdir -p "${GRUB_DIR}"
 
   # Add hvc0 for hypervisors
   grub_args="${common_args} console=hvc0"
 
-  cat <<EOF | sudo dd of="${GRUB_DIR}/menu.lst.A" 2>/dev/null
+  sudo_clobber "${GRUB_DIR}/menu.lst.A" <<EOF
 timeout         0
 
-title           CoreOS A Kernel
-root            (hd0,0)
-kernel          /syslinux/vmlinuz.A ${grub_args} root=gptprio:
-
-title           CoreOS B Kernel
-root            (hd0,0)
-kernel          /syslinux/vmlinuz.B ${grub_args} root=gptprio:
-
-title           CoreOS bootengine
-root            (hd0,0)
-kernel          /syslinux/vmlinuz-boot_kernel ${grub_args} root=gptprio:
-
-title           CoreOS A Root Rescue
+title           CoreOS A Root
 root            (hd0,0)
 kernel          /syslinux/vmlinuz.A ${grub_args} root=${ROOTA}
 
-title           CoreOS B Root Rescue
+title           CoreOS B Root
 root            (hd0,0)
 kernel          /syslinux/vmlinuz.B ${grub_args} root=${ROOTB}
 EOF
   info "Emitted ${GRUB_DIR}/menu.lst.A"
 
-  cat <<EOF | sudo dd of="${GRUB_DIR}/menu.lst.B" 2>/dev/null
+  sudo_clobber "${GRUB_DIR}/menu.lst.B" <<EOF
 default         1
 EOF
-  sudo sh -c "cat ${GRUB_DIR}/menu.lst.A >> ${GRUB_DIR}/menu.lst.B"
+  sudo_append "${GRUB_DIR}/menu.lst.B" <"${GRUB_DIR}/menu.lst.A"
   info "Emitted ${GRUB_DIR}/menu.lst.B"
   sudo cp ${GRUB_DIR}/menu.lst.A ${GRUB_DIR}/menu.lst
 
-  # /boot/syslinux must be installed in partition 12 as /syslinux/.
   SYSLINUX_DIR="${FLAGS_to}/syslinux"
   sudo mkdir -p "${SYSLINUX_DIR}"
 
@@ -92,7 +79,7 @@ EOF
   # This leaves /dev/console mapped to tty0 (vga) which is reasonable default.
   syslinux_args="console=ttyS0,115200n8 ${common_args}"
 
-  cat <<EOF | sudo dd of="${SYSLINUX_DIR}/syslinux.cfg" 2>/dev/null
+  sudo_clobber "${SYSLINUX_DIR}/syslinux.cfg" <<EOF
 SERIAL 0 115200
 PROMPT 0
 TIMEOUT 0
@@ -111,14 +98,15 @@ EOF
   # Different files are used so that the updater can only touch the file it
   # needs to for a given change.  This will minimize any potential accidental
   # updates issues, hopefully.
-  cat <<EOF | sudo dd of="${SYSLINUX_DIR}/boot_kernel.cfg" 2>/dev/null
+  sudo_clobber "${SYSLINUX_DIR}/boot_kernel.cfg" <<EOF
 label boot_kernel
   menu label boot_kernel
   kernel vmlinuz-boot_kernel
   append ${syslinux_args} root=gptprio:
 EOF
   info "Emitted ${SYSLINUX_DIR}/boot_kernel.cfg"
-  cat <<EOF | sudo dd of="${SYSLINUX_DIR}/root.A.cfg" 2>/dev/null
+
+  sudo_clobber "${SYSLINUX_DIR}/root.A.cfg" <<EOF
 label coreos.A
   menu label coreos.A
   kernel vmlinuz.A
@@ -126,7 +114,7 @@ label coreos.A
 EOF
   info "Emitted ${SYSLINUX_DIR}/root.A.cfg"
 
-  cat <<EOF | sudo dd of="${SYSLINUX_DIR}/root.B.cfg" 2>/dev/null
+  sudo_clobber "${SYSLINUX_DIR}/root.B.cfg" <<EOF
 label coreos.B
   menu label coreos.B
   kernel vmlinuz.B
diff --git a/update_bootloaders.sh b/update_bootloaders.sh
index 24b2d6e9d9..41092cfd7a 100755
--- a/update_bootloaders.sh
+++ b/update_bootloaders.sh
@@ -19,9 +19,6 @@ assert_inside_chroot
 # Flags.
 DEFINE_string arch "x86" \
   "The boot architecture: arm or x86. (Default: x86)"
-# TODO(wad) once extlinux is dead, we can remove this.
-DEFINE_boolean install_syslinux ${FLAGS_TRUE} \
-  "Controls whether syslinux is run on 'to'. (Default: true)"
 DEFINE_string from "/tmp/boot" \
   "Path the legacy bootloader templates are copied from. (Default /tmp/boot)"
 DEFINE_string to "/tmp/esp.img" \
@@ -101,8 +98,8 @@ if [[ "${FLAGS_arch}" = "x86" || "${FLAGS_arch}" = "amd64" ]]; then
   # Copy over the grub configurations for cloud machines and the
   # kernel into both the A and B slot
   sudo mkdir -p "${ESP_FS_DIR}"/boot/grub
-  sudo cp -r "${FLAGS_from}"/boot/grub/. "${ESP_FS_DIR}"/boot/grub
-  sudo cp -r "${FLAGS_from}"/boot/grub/menu.lst.A "${ESP_FS_DIR}"/boot/grub/menu.lst
+  sudo cp -r "${FLAGS_from}"/grub/. "${ESP_FS_DIR}"/boot/grub
+  sudo cp -r "${FLAGS_from}"/grub/menu.lst.A "${ESP_FS_DIR}"/boot/grub/menu.lst
 
   # Prepopulate the syslinux directories too and update for verified boot values
   # after the rootfs work is done.
@@ -119,27 +116,12 @@ if [[ "${FLAGS_arch}" = "x86" || "${FLAGS_arch}" = "amd64" ]]; then
   sudo mkdir -p "${ESP_FS_DIR}"/EFI/boot
   sudo cp -f "${FLAGS_vmlinuz}" "${ESP_FS_DIR}"/EFI/boot/bootx64.efi
 
-  # Extract kernel flags
-  kernel_cfg="cros_debug"
-  old_root="%U+1"
-
-  # Install the syslinux loader on the ESP image (part 12) so it is ready when
-  # we cut over from rootfs booting (extlinux).
-  if [[ ${FLAGS_install_syslinux} -eq ${FLAGS_TRUE} ]]; then
-    safe_umount "${ESP_FS_DIR}"
-    sudo syslinux -d /syslinux "${ESP_DEV}"
-    # mount again for cleanup to free resource gracefully
-    sudo mount -o ro "${ESP_DEV}" "${ESP_FS_DIR}"
-  fi
-elif [[ "${FLAGS_arch}" = "arm" ]]; then
-  # Copy u-boot script to ESP partition
-  if [ -r "${FLAGS_from}/boot-A.scr.uimg" ]; then
-    sudo mkdir -p "${ESP_FS_DIR}/u-boot"
-    sudo cp "${FLAGS_from}/boot-A.scr.uimg" \
-      "${ESP_FS_DIR}/u-boot/boot.scr.uimg"
-    sudo cp -f "${FLAGS_from}"/vmlinuz "${ESP_FS_DIR}"/vmlinuz.uimg.A
-    sudo cp -f "${FLAGS_from}"/zImage "${ESP_FS_DIR}"/vmlinuz.A
-  fi
+  safe_umount "${ESP_FS_DIR}"
+  sudo syslinux -d /syslinux "${ESP_DEV}"
+  # mount again for cleanup to free resource gracefully
+  sudo mount -o ro "${ESP_DEV}" "${ESP_FS_DIR}"
+else
+  die "Unknown arch ${FLAGS_arch}"
 fi
 
 set +e