Create new cros_write_firmware tool based on write_tegra_bios.

host/cros_write_firmware

+#!/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 writes a firmware image to a tegra based board.
+
+# Include common CrOS utilities.
+. "/usr/lib/crosutils/common.sh"
+
+get_default_board
+
+# Command line options
+DEFINE_string board "${DEFAULT_BOARD}" "The name of the board to flash."
+DEFINE_string variant "" "Board variant."
+DEFINE_string firmware "" "Path to firmware image to write."
+DEFINE_string flasher "" "Path to flasher image to use."
+DEFINE_string bct "" "Path to bct image to write."
+DEFINE_string map "" "Path to System.map file to read for load address."
+DEFINE_string flash "" "Boot flash parameter file."
+DEFINE_string config "" "Directory for temporary configuration files."
+DEFINE_boolean sign $FLAGS_FALSE "Sign and append a BCT to the firmware image."
+
+# Parse command line.
+FLAGS "$@" || exit 1
+eval set -- "${FLAGS_ARGV}"
+
+# Die on errors.
+set -e
+
+CROS_LOG_PREFIX="cros_write_firmware"
+
+if [ -z "${FLAGS_board}" ]; then
+  error "--board required."
+  exit 1
+fi
+
+get_board_and_variant $FLAGS_board $FLAGS_variant
+
+# Display the U-Boot version string.
+function show_u_boot_info() {
+  local firmware=$1
+  local header=$(strings "${firmware}" | grep "U-Boot" | head -1 )
+
+  info "Using ${header}"
+}
+
+# Given two values in decimal format return the first value rounded up to a
+# multiple of the second value.  The second value must be a power of two.
+function round() {
+  awk "BEGIN { print and(($1 + $2 - 1), compl($2 - 1)) }"
+}
+
+# Given a value in decimal format return that value converted to hexidecimal
+# and formatted as 0xXXXXXXXX.
+function to_hex() {
+  awk "BEGIN { printf \"0x%x\", $1 }"
+}
+
+# Create the flashing script.  This script will be loaded and run by the flasher
+# build of U-Boot.  Most of the script is constant, we just need to append the
+# sizes and address of the payload.
+#
+# TODO(robotboy): Compute the address from the text_base (0xe08000) +
+# flasher image size (0x40000) + script block (0x1000)
+function make_flashing_script() {
+  local firmware=$1
+  local firmware_size=$(stat -c"%s" "${firmware}")
+
+  echo "setenv address       0xe49000"

[vb, 2011/03/04 00:58:31]

where does this number come from? Can it be derived from some common source?

Also, I looked at host/share/cros_write_firmware/spi.script
before this file, it seems to me now that the whole thing
would be better readable if the spi.script was incorporated
here, it's pretty short.

and since you generate it all here you could forgo defining the variables in
lines 71...73 and use the values in the
script directly instead.

[robotboy, 2011/03/04 16:58:57]

The TODO in the description of the function above explains in pretty good detail
where this number comes from.
While it is short, it is much less readable as a script when inlined because of
shell escapes required to prevent bash from interpreting the U-Boot variable
dereferences as shell dereferences.  Also, there will soon be a nand.script and
an emmc.script.  So including those here will end up bloating things more.
I explicitly didn't do this so that you can break into the boot delay sequence
once the flasher image has booted and change these values/run the _commands
manually.  If I substituted the values directly it would be much more difficult
to reuse the _commands.  Also, the above reasoning (nand and emmc scripts coming
soon) holds.

+  echo "setenv firmware_size $(to_hex ${firmware_size})"
+  echo "setenv length        $(to_hex $(round ${firmware_size} 4096))"
+
+  cat /usr/share/cros_write_firmware/spi.script
+}
+
+# Parse the System.map file generated by the U-Boot build to get the entry
+# point address.
+function get_text_base() {
+  local map=$1
+
+  grep -m1 -E "^[0-9a-fA-F]{8} T _start$" ${map} | cut -d " " -f 1
+}
+
+###############################################################################
+
+u_boot="/build/${BOARD_VARIANT}/u-boot"
+
+# Generate default values for the firmware, flasher, BCT, map and flash config
+# file paths from the board and variant information provided.
+firmware=${FLAGS_firmware:-"${u_boot}/image.bin"}
+flasher=${FLAGS_flasher:-"${u_boot}/u-boot-flasher.bin"}
+bct=${FLAGS_bct:-"${u_boot}/board.bct"}
+map=${FLAGS_map:-"${u_boot}/System.map"}
+flash=${FLAGS_flash:-"${u_boot}/flash.cfg"}
+
+# Extract the load and entry point for U-Boot.
+text_base="0x$(get_text_base "${map}")"
+
+# Verify that all of the files and tools we will need are present.
+check_for_file "firmware" " " "${firmware}"
+check_for_file "flasher" "  " "${flasher}"
+check_for_file "BCT" "      " "${bct}"
+check_for_file "map" "      " "${map}"
+check_for_file "flash" "    " "${flash}"
+
+check_for_tool "nvflash" "nvflash"
+
+show_u_boot_info "${firmware}"
+
+# If the user has not specified a config directory then create one on the fly
+# and remove it when we are done.
+if [ -z "${FLAGS_config}" ]; then
+  config=$(mktemp -d)
+
+  trap "rm -rf ${config}" EXIT
+else
+  mkdir -p "${FLAGS_config}"
+
+  config=${FLAGS_config}
+fi
+
+# Optionally sign the firmware.  This is usefull if you want to write a bare
+# U-Boot to SPI and boot with that instead of a fully build ChromiumOS firmware
+# image.
+if [ $FLAGS_sign -eq $FLAGS_TRUE ]; then
+  signed_firmware=${config}/signed.bin
+
+  cros_sign_bootstub \
+    --bct "${bct}" \
+    --flash "${flash}" \
+    --bootstub "${firmware}" \
+    --output "${signed_firmware}" \
+    --config "${config}" \
+    --text_base "${text_base}"
+else
+  signed_firmware=${firmware}
+fi
+
+# Create the flashing script and turn it into a U-Boot uImage.
+make_flashing_script "${signed_firmware}" > ${config}/script
+
+mkimage -A arm -T script -d ${config}/script ${config}/script.uimg > /dev/null
+
+# Construct RAM image of flasher + script + firmware.  The firmware should
+# already be signed by cbootimage.  The RAM image has a fixed 256K partition
+# for the flasher, followed by the script and payload to be written.
+dd if="${flasher}"            of="${config}/image"          &> /dev/null
+dd if="${config}/script.uimg" of="${config}/image" seek=512 &> /dev/null
+dd if="${signed_firmware}"    of="${config}/image" seek=520 &> /dev/null
+
+# Write the RAM image image to the board.  The flasher will write the payload
+# into the boot device.  The warning below about the failure is due to the
+# way that we are using nvflash.  It expects to be able to talk to the flashing
+# bootloader that is passed down, but U-Boot doesn't talk back the way
+# bootloader.bin did, and nvflash complains.
+sudo nvflash \
+  --configfile /usr/share/cros_write_firmware/nvflash-spi.cfg \
+  --bct "${bct}" \
+  --setbct \
+  --bl "${config}/image" \
+  --go \
+  --setentry "${text_base}" "${text_base}" ||
+  warn "The above 'command failure: go failed' can be ignored."
+
+# TODO(robotboy): Make a U-Boot tool that can compute the same checksum on
+# the host and display it here.  Unfortunately U-Boot uses a slightly different
+# crc32 than zlib, so it's not possible to use zlib's crc32 to do this.  It has
+# to be done by building a tool that uses U-Boots version.
+info "The serial terminal or LCD panel should show before and after CRCs of"
+info "the image written to the boot flash.  If these values match each other"
+info "your flash was probably successful."

[vb, 2011/03/04 00:58:31]

are you being too conservative here when you say 'probably'?

[robotboy, 2011/03/04 16:58:57]

Because there could have been a transmission failure when nvflash wrote the
combined flasher + script + payload to the device.  Thus even if the values
written match the values that were initially in RAM when the flasher started,
they may not match the values that are on the host file system.  The solution as
I point out in my TODO is to make a tool that can generate the same CRCs on the
host so that that CRC can be compared to the after CRC on the target.