generate-squashfs

#!/bin/bash
set -eo pipefail

help=$'Generate Tarball with PNOR SquashFS image and MANIFEST Script

Generates a PNOR SquashFS image from the PNOR image
Creates a MANIFEST for image verification and recreation
Packages the SquashFS image and MANIFEST together in a tarball

usage: generate-squashfs [OPTION] <PNOR FILE>...

Options:
   -f, --file <file>      Specify destination file. Defaults to
                          `pwd`/<PNOR FILE>.pnor.squashfs.tar if unspecified.
                          (For example, "generate-squashfs my.pnor" would
                          generate `pwd`/my.pnor.squashfs.tar output.)
   -s, --sign <path>      Sign the image. The optional path argument specifies
                          the private key file. Defaults to the bash variable
                          PRIVATE_KEY_PATH if available, or else uses the
                          open-source private key in this script.
   -h, --help             Display this help text and exit.
'

private_key=$'-----BEGIN PRIVATE KEY-----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-----END PRIVATE KEY-----
'

# Reference the ffs structures at:
# https://github.com/open-power/hostboot/blob/master/src/usr/pnor/common/ffs_hb.H
# https://github.com/open-power/hostboot/blob/master/src/usr/pnor/ffs.h
let ffs_entry_size=128
let vercheck_offset=112
do_sign=false
private_key_path="${PRIVATE_KEY_PATH}"
outfile=""
declare -a partitions=()
tocfile="pnor.toc"

while [[ $# -gt 0 ]]; do
  key="$1"
  case $key in
    -f|--file)
      outfile="$2"
      shift 2
      ;;
    -s|--sign)
      do_sign=true
      if [[ ! -z "${2}"  && "${2}" != -* ]]; then
        private_key_path="$2"
        shift 2
      else
        shift 1
      fi
      ;;
    -h|--help)
      echo "$help"
      exit
      ;;
    *)
      pnorfile="$1"
      shift 1
      ;;
  esac
done

if [ ! -f "${pnorfile}" ]; then
  echo "Please enter a valid PNOR file."
  echo "$help"
  exit 1
fi

if [[ -z $outfile ]]; then
    if [[ ${pnorfile##*.} == "pnor" ]]; then
        outfile=`pwd`/${pnorfile##*/}.squashfs.tar
    else
        outfile=`pwd`/${pnorfile##*/}.pnor.squashfs.tar
    fi
else
    if [[ $outfile != /* ]]; then
        outfile=`pwd`/$outfile
    fi
fi

scratch_dir=`mktemp -d`

if [[ "${do_sign}" == true ]]; then
  if [[ -z "${private_key_path}" ]]; then
    private_key_path=${scratch_dir}/OpenBMC.priv
    echo "${private_key}" > "${private_key_path}"
    echo "Image is NOT secure!! Signing with the open private key!"
  else
    if [[ ! -f "${private_key_path}" ]]; then
      echo "Couldn't find private key ${private_key_path}."
      exit 1
    fi

    echo "Signing with ${private_key_path}."
  fi

  public_key_file=publickey
  public_key_path=${scratch_dir}/$public_key_file
  openssl pkey -in "${private_key_path}" -pubout -out ${public_key_path}
fi

echo "Parsing PNOR TOC..."

pflash --partition=part --read=${scratch_dir}/part -F ${pnorfile}
pflash --partition=VERSION --read=${scratch_dir}/VERSION -F ${pnorfile}
version_size=$(du -k ${scratch_dir}/VERSION | head -1 | cut -f 1)
magic_number=$(xxd -p -l 4 ${scratch_dir}/VERSION)
# Check if VERSION is signed. A signed version partition will have an extra
# 4K header starting with the magic number 0x17082011, see:
# https://github.com/open-power/skiboot/blob/master/libstb/container.h#L47
if [ "$version_size" == "8" -a "$magic_number" == "17082011" ]; then
  # Advance past the STB header (4K, indexed from 1)
  cp ${scratch_dir}/VERSION ${scratch_dir}/VERSION_FULL
  tail --bytes=+4097 ${scratch_dir}/VERSION_FULL > ${scratch_dir}/VERSION
fi
{
  version=$(head -n 1 ${scratch_dir}/VERSION)
  echo "version=$version"
  extended_version=$(echo $(tail -n +2 ${scratch_dir}/VERSION)|tr ' ' ',')
  echo "extended_version=$extended_version"
  while read line; do
    if [[ $line == "ID="* ]]; then
        # This line looks like
        # "ID=05 MVPD 000d9000..00169000 (actual=00090000) [ECC]"
        read -r -a fields <<< "$line"

        id=${fields[0]##*=}
        offset=$((${ffs_entry_size} * 10#${id} + ${vercheck_offset}))
        vercheck=$(xxd -p -l  0x1 -seek ${offset} ${scratch_dir}/part)
        export flags=$(pflash --detail=$((10#$id)) -F ${pnorfile} | grep "\[" |
                sed 's/....$//' | tr '\n' ',' | sed 's/.$//')
        if [[ $flags != "" ]]; then
            flags=,$flags
        fi

        if [[ $(echo $flags | grep "READONLY") == "" &&
              $(echo $flags | grep "PRESERVED") == "" ]]; then
            flags=$flags,READWRITE
        fi

        # Need the partition ID, name, start location, end location, and flags
        echo  "partition${id}=${fields[1]},${fields[2]/../,},${vercheck}${flags}"

        # Save the partition name
        partitions+=(${fields[1]})
    fi
  # Don't need the BACKUP_PART partition
  done < <(pflash --info -F ${pnorfile} | grep -v "BACKUP")
} > ${scratch_dir}/${tocfile}

for partition in "${partitions[@]}"; do
  echo "Reading ${partition}..."
  pflash --partition=${partition} \
    --read=${scratch_dir}/${partition} \
    -F ${pnorfile}
done

echo "Creating SquashFS image..."
cd "${scratch_dir}"
mksquashfs ${tocfile} ${partitions[*]} pnor.xz.squashfs

echo "Creating MANIFEST for the image"
manifest_location="MANIFEST"
echo -e "purpose=xyz.openbmc_project.Software.Version.VersionPurpose.Host\nversion=$version\n\
extended_version=$extended_version" >> $manifest_location

if [[ "${do_sign}" == true ]]; then
  private_key_name=$(basename "${private_key_path}")
  key_type="${private_key_name%.*}"
  echo KeyType="${key_type}" >> $manifest_location
  echo HashType="RSA-SHA256" >> $manifest_location

  for file in pnor.xz.squashfs $manifest_location $public_key_file; do
    openssl dgst -sha256 -sign ${private_key_path} -out "${file}.sig" $file
  done

  additional_files="${public_key_file} *.sig"
fi

echo "Generating tarball to contain the SquashFS image and its MANIFEST"
tar -cvf $outfile $manifest_location pnor.xz.squashfs $additional_files

echo "SquashFSTarball at ${outfile}"
rm -r "${scratch_dir}"