Create bootstub signing utility.

host/cros_sign_bootstub

+#!/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.
+
+# This utility uses cbootimage to signs a bootstub so that the Tegra boot ROM
+# will load and run it.
+
+# Include common CrOS utilities.
+. "/usr/lib/crosutils/common.sh"
+
+# Command line options
+DEFINE_string bct "" "DDR memory timing BCT file."
+DEFINE_string flash "" "Boot flash parameter file."
+DEFINE_string bootstub "" "Bootstub firmware image to sign."
+DEFINE_string output "bootstub.bin" "Signed bootstub + BCT output file."
+DEFINE_string text_base "0xe08000" "Load address and entry point for bootstub."
+DEFINE_string config "" "Directory for temporary configuration files."
+
+# Parse command line.
+FLAGS "$@" || exit 1
+eval set -- "${FLAGS_ARGV}"
+
+# Die on errors.
+set -e
+
+CROS_LOG_PREFIX="cros_sign_bootstub"
+
+function construct_config() {
+  local flash_file="$1"
+  local bct_file="$2"
+  local bootstub="$3"
+  local text_base="$4"
+
+  #
+  # First we output the boot flash configuration file.
+  #
+  cat ${flash_file}
+
+  #
+  # The cbootimage config file format is not yet documented.  Below is
+  # a minimal config file that merges a BCT file and bootloader; in
+  # this case our stub U-Boot image.  We do not use the Version, but it
+  # needs to be set.
+  #
+  # Currently a bug in cbootimage prevents us from setting Redundancy to
+  # 0.  Redundancy controls how many instances of the BCT should be
+  # written to the signed image.  A value of 1 causes two instances to
+  # be written.
+  #
+  # The BootLoader parameter specifies the bootloader image to use.  It
+  # also specifies the load address for the bootloader in RAM and the
+  # entry point of the resulting image.  For U-Boot these are the same
+  # value (TEXT_BASE).
+  #
+  echo ""
+  echo "Bctfile=${bct_file};"
+  echo "Version=1;"
+  echo "Redundancy=1;"
+  echo "BootLoader=${bootstub},${text_base},${text_base},Complete;"
+}
+
+###############################################################################
+
+check_for_file "boot flash device config" "..." "${FLAGS_flash}"
+check_for_file "BCT" "........................" "${FLAGS_bct}"
+check_for_file "bootstub image" "............." "${FLAGS_bootstub}"
+
+check_for_tool "cbootimage" "cbootimage"
+
+if [ -z "${FLAGS_config}" ]; then
+  config=$(mktemp -d)
+
+  trap "rm -rf ${config}" EXIT
+else
+  mkdir -p "${FLAGS_config}"

[vb, 2011/02/28 23:54:44]

It would be cleaner to remove the directory on exit if it did not exist on
entry.

OTOH it would be good to be able to request to keep the config file.

[robotboy, 2011/03/01 00:03:40]

Yup, the intent here is that if you don't specify anything on the command line
(no --config option) then the config is generated in a /tmp/tmp.XXXXXXX
directory and cleaned up after the run.  If you do pass a --config option on the
command line then the config file is retained in that directory.

+
+  config=${FLAGS_config}
+fi
+
+construct_config \
+  "${FLAGS_flash}" \
+  "${FLAGS_bct}" \
+  "${FLAGS_bootstub}" \
+  "${FLAGS_text_base}" > "${config}/boot.cfg"
+
+cbootimage "${config}/boot.cfg" "${FLAGS_output}"