Add support for using separate developer firmware keyblock while signing.

scripts/keygeneration/make_keyblock.sh

+#!/bin/bash
+# Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+#
+# Generates a keyblock containing a public key and signed using the given
+# signing key.
+
+# Load common constants and functions.
+. "$(dirname "$0")/common.sh"
+
+if [ $# -ne 4 ]; then
+  cat <<EOF
+Usage: $0 <in_public_key> <in_signing_key> <flags> <out_keyblock>
+
+Emits <out_keyblock>.keyblock containing <in_public_key>.vbpubk signed with
+<in_signing_key>.vbprivk with the given keyblock <flags>.
+EOF
+  exit 1
+fi
+
+in_pubkey=$1
+in_signkey=$2
+keyblock_flags=$3
+out_keyblock=$4
+
+make_keyblock $out_keyblock $keyblock_flags $in_pubkey $in_signkey