overlay-nocturne/chromeos-base/chromeos-bsp-nocturne/files/init/generate_rdc_update.conf

# Copyright 2018 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.

description     "Job to generate rdc_update.bin"
author          "chromium-os-dev@chromium.org"

start on starting cras
task

env CRAS_RUN_DIR="/run/cras"
# Note: cannot use ${CRAS_RUN_DIR}, will not expand.
# Known issue: https://bugs.launchpad.net/upstart/+bug/328366
env DIST_FILE="/run/cras/rdc_update.bin"
env DEFAULT_RDC_FILE="/opt/google/dsm/rdc_update.default"
env VALID_FROM="0x045F202C"
env VALID_TO="0x15DBA0DF"

script
  dlog() {
    logger -t generate_rdc_update -p debug "$1"
  }

  use_default() {
    dlog "something went wrong, using default rdc_update.bin"
    cp "${DEFAULT_RDC_FILE}" "${DIST_FILE}"
    chown cras:cras "${DIST_FILE}"
    chmod 440 "${DIST_FILE}"
    exit 0
  }

  set +e

  # cras.conf will do this again.
  mkdir -p -m 1770 "${CRAS_RUN_DIR}"
  chown cras:cras "${CRAS_RUN_DIR}"

  dlog "reading dsm_calib from VPD..."
  calib=$(vpd_get_value dsm_calib)
  if [ "$?" -ne 0 ]; then
    use_default
  fi
  dlog "reading dsm_calib from VPD...ok, dsm_calib=${calib}"

  dlog "checking format..."
  echo "${calib}" | awk '{
    if (NF != 6)
      exit 1

    if (length($1) != 7 && length($1) != 8)
      exit 1

    for (i = 2; i <= NF; ++i)
      if (length($i) != 8)
        exit 1

    # check for hex-string characters
    if (match($0, /[^0-9a-fA-F ]/))
      exit 1
  }'
  if [ "$?" -ne 0 ]; then
    use_default
  fi
  dlog "checking format...ok"

  dlog "checking boundary..."
  valid_from=$(printf "%d" "${VALID_FROM}")
  valid_to=$(printf "%d" "${VALID_TO}")
  left=$(printf "%d" "0x$(echo "${calib}" | awk '{print $4}')")
  right=$(printf "%d" "0x$(echo "${calib}" | awk '{print $6}')")
  if [ "${left}" -lt "${valid_from}" -o "${left}" -gt "${valid_to}" -o \
       "${right}" -lt "${valid_from}" -o "${right}" -gt "${valid_to}" ]; then
    use_default
  fi
  dlog "checking boundary...ok"

  dlog "generating little endian byte sequence for each dword..."
  bs=$(echo "${calib}" | awk '{
    # Prepend "0" if the first sequence has only 7 characters.
    if (length($1) == 7)
      $1 = "0" $1

    for (i = 1; i <= NF; ++i) {
      # the index for substr start from 1
      high = substr($i, 1, 4)
      high_1 = substr(high, 1, 2)
      high_2 = substr(high, 3, 2)
      low = substr($i, 5, 4)
      low_1 = substr(low, 1, 2)
      low_2 = substr(low, 3, 2)

      printf "\\x%s\\x%s\\x%s\\x%s", low_2, low_1, high_2, high_1
    }
  }')
  if [ "$?" -ne 0 ]; then
    use_default
  fi
  dlog "generating little endian byte sequence for each dword...ok, \
byte sequence=${bs}"

  # Built-in printf of /bin/sh does not support \x, use the external one.
  /usr/bin/printf "%b" "${bs}" > "${DIST_FILE}"
  chown cras:cras "${DIST_FILE}"
  chmod 440 "${DIST_FILE}"
end script