obmc-flash-bmc

#!/bin/bash
set -eo pipefail

# Get the root mtd device number (mtdX) from "/dev/ubiblockX_Y on /"
findrootmtd() {
  rootmatch=" on / "
  m="$(mount | grep "${rootmatch}" | grep "ubiblock")"
  m="${m##*ubiblock}"
  m="${m%_*}"
  if [ -z "${m}" ]; then
    # default to bmc mtd (0)
    m=0
  fi
  echo "mtd${m}"
}

findrootubi() {
  rootmatch=" on / "
  m="$(mount | grep "${rootmatch}")"
  m="${m##*ubiblock}"
  m="${m% on*}"
  echo "ubi${m}"
}

# Get the mtd device number (mtdX)
findmtd() {
  m="$(grep -xl "$1" /sys/class/mtd/*/name)"
  m="${m%/name}"
  m="${m##*/}"
  echo "${m}"
}

# Get the mtd device number only (return X of mtdX)
findmtdnum() {
  m="$(findmtd "$1")"
  m="${m##mtd}"
  echo "${m}"
}

# Get the ubi device number (ubiX_Y)
findubi() {
  u="$(grep -xl "$1" /sys/class/ubi/ubi?/subsystem/ubi*/name)"
  u="${u%/name}"
  u="${u##*/}"
  echo "${u}"
}

# Get the ubi device number (ubiX_Y) on a specific mtd
findubi_onmtd() {
  u="$(grep -xl "$1" /sys/class/ubi/ubi"$2"/subsystem/ubi"$2"*/name)"
  u="${u%/name}"
  u="${u##*/}"
  echo "${u}"
}

# Get all ubi device names on a specific mtd that match requested string
findubiname_onmtd() {
  u="$(grep -h "$1" /sys/class/ubi/ubi"$2"/subsystem/ubi"$2"*/name)"
  u="${u%/name}"
  u="${u##*/}"
  echo "${u}"
}

# Get the name from the requested ubiX_Y volume
findname() {
  n="$(cat /sys/class/ubi/"$1"/name)"
  echo "${n}"
}

# Set the version path property to the flash location where the image was
# successfully flashed
set_flashid() {
  busctl set-property xyz.openbmc_project.Software.BMC.Updater \
    "/xyz/openbmc_project/software/${version}" \
    xyz.openbmc_project.Common.FilePath \
    Path s "$1"
}

# Set the u-boot envs that perform a side switch on failure to boot
set_wdt2bite() {
  if ! fw_printenv wdt2bite 2>/dev/null; then
    fw_setenv wdt2bite "mw.l 0x1e785024 0xa 1; mw.b 0x1e78502c 0xb3 1"
    fw_setenv bootalt "run wdt2bite"
    fw_setenv obmc_bootcmd "ubi part obmc-ubi; run do_rwreset; ubi read \
\${loadaddr} \${kernelname}; bootm \${loadaddr} || run bootalt"
  fi
}

# Make space on flash before creating new volumes. This can be enhanced
# determine current flash usage. For now only keep a "keepmax" number of them
ubi_remove_volumes()
{
  rootubi="$(findrootubi)"
  rootname="$(findname "${rootubi}")"
  rootversion="${rootname##*-}"
  rootkernel="kernel-${rootversion}"

  # Just keep max number of volumes before updating, don't delete the version
  # the BMC is booted from, and when a version is identified to be deleted,
  # delete both the rofs and kernel volumes for that version.
  rmnames="$(findubiname_onmtd "${name%-*}-" "${ro}")"
  mapfile -t array <<< "${rmnames}"
  ubicount="${#array[@]}"
  while [ "${ubicount}" -ge "${keepmax}" ]; do
    # Loop through existing volumes and skip currently active ones
    for (( index=0; index<${#array[@]}; index++ )); do
      rmname="${array[${index}]}"
      rmversion="${rmname##*-}"
      [ "${rmversion}" == "${version}" ] && continue
      rmubi="$(findubi_onmtd "rofs-${rmversion}" "${ro}")"
      if [[ ( "${rmubi}" != "${rootubi}" ) &&
            ( "${rmname}" != "${rootkernel}" ) ]]; then
        ubi_remove "rofs-${rmversion}" "${ro}"
        ubi_remove "kernel-${rmversion}" "${ro}"
        # Remove priority value
        fw_setenv "${rmversion}"
        break
      fi
    done
    # Decrease count regardless to avoid an infinite loop
    (( ubicount-- ))
  done
}

ubi_rw() {
  rwmtd="$(findmtd "${reqmtd}")"
  rw="${rwmtd#mtd}"
  ubidev="/dev/ubi${rw}"

  # Update rwfs_size, check imgsize was specified, otherwise it'd clear the var
  if [ -n "$imgsize" ]; then
    rwsize="$(fw_printenv -n rwfs_size 2>/dev/null)" || true
    if [[ "${imgsize}" != "${rwsize}" ]]; then
      fw_setenv rwfs_size "${imgsize}"
    fi
  fi

  vol="$(findubi "${name}")"
  if [ -z "${vol}" ]; then
    ubimkvol "${ubidev}" -N "${name}" -s "${imgsize}"
  fi
}

ubi_ro() {
  keepmax=2 # Default 2 volumes per mtd
  romtd="$(findmtd "${reqmtd}")"
  romtd2="$(findmtd "${reqmtd2}")"

  if [ ! "${romtd}" == "${romtd2}" ]; then
    # Request to use alternate mtd device, choose the non-root one
    keepmax=1 # 1 volume on each of the requested mtds
    rootmtd="$(findrootmtd)"
    if [ "${rootmtd}" == "${romtd}" ]; then
      romtd="${romtd2}"
    fi
  fi
  ro="${romtd#mtd}"
  ubidev="/dev/ubi${ro}"

  ubi_remove_volumes

  if [ -z "${imgfile}" ]; then
    echo "Unable to create read-only volume. Image file not specified."
    return 1
  fi

  # Create a ubi volume, dynamically sized to fit BMC image if size unspecified
  img="/tmp/images/${version}/${imgfile}"
  imgsize="$(stat -c '%s' "${img}")"

  vol="$(findubi "${name}")"
  if [ -n "${vol}" ]; then
    # Allow a duplicate kernel volume on the alt mtd
    if [[ "${name}" =~ "kernel" ]]; then
      vol="$(findubi_onmtd "${name}" "${ro}")"
    fi
  fi
  if [ -z "${vol}" ]; then
    ubimkvol "${ubidev}" -N "${name}" -s "${imgsize}" --type=static
    vol="$(findubi "${name}")"
  fi

  set_flashid "${version}"
}

# Squashfs images need a ubi block
ubi_block() {
  vol="$(findubi "${name}")"
  ubidevid="${vol#ubi}"
  block="/dev/ubiblock${ubidevid}"
  if [ ! -e "$block" ]; then
    ubiblock --create "/dev/ubi${ubidevid}"
  fi
}

ubi_updatevol() {
  vol="$(findubi "${name}")"
  ubidevid="${vol#ubi}"
  img="/tmp/images/${version}/${imgfile}"
  ubiupdatevol "/dev/ubi${ubidevid}" "${img}"
}

ubi_remove() {
    rmname="$1"
    rmmtd="$2"
    if [ -n "${rmmtd}" ]; then
      vol="$(findubi_onmtd "${rmname}" "${rmmtd}")"
    else
      vol="$(findubi "${rmname}")"
    fi

    if [ -n "$vol" ]; then
        vol="${vol%_*}"

        if grep -q "$rmname" /proc/mounts; then
            mountdir=$(grep "$rmname" /proc/mounts | cut -d " " -f 2)
            umount "$mountdir"
            rm -r "$mountdir"
        fi

        ubirmvol "/dev/${vol}" -N "$rmname"
    fi
}

ubi_cleanup() {
    # When ubi_cleanup is run, it expects one or no active version.
    activeVersion=$(busctl --list --no-pager tree \
            xyz.openbmc_project.Software.BMC.Updater | \
            grep /xyz/openbmc_project/software/ | tail -c 9)

    if [[ -z "$activeVersion" ]]; then
        vols=$(ubinfo -a | grep "rofs-" | cut -c 14-)
    else
        flashid=$(busctl get-property xyz.openbmc_project.Software.BMC.Updater \
            "/xyz/openbmc_project/software/${activeVersion}" \
            xyz.openbmc_project.Common.FilePath Path |  awk '{print $NF;}' | tr -d '"')
        vols=$(ubinfo -a | grep "rofs-" | \
                grep -v "$flashid" | cut -c 14-) || true
    fi

    mapfile -t array <<< "${vols}"
    for (( index=0; index<${#array[@]}; index++ )); do
         ubi_remove "${array[index]}"
    done
}

mount_ubi_alt_rwfs() {
  altNum="$(findmtdnum "alt-bmc")"
  if [ -n "${altNum}" ]; then
    altRwfs=$(ubinfo -a -d "${altNum}" | grep -w "rwfs") || true
    if [ -n "${altRwfs}" ]; then
      altVarMount="/media/alt/var"
      mkdir -p "${altVarMount}"
      if mount ubi"${altNum}":rwfs "${altVarMount}" -t ubifs -o defaults; then
        mkdir -p "${altVarMount}"/persist/etc
      fi
    fi
  fi
}

remount_ubi() {
  bmcmtd="$(findmtd "bmc")"
  altbmcmtd="$(findmtd "alt-bmc")"
  mtds="${bmcmtd: -1}","${altbmcmtd: -1}"

  rootubi="$(findrootubi)"
  rootname="$(findname "${rootubi}")"

  IFS=',' read -r -a arrayMtds <<< "$mtds"
  for mtd in "${arrayMtds[@]}"; do
    # Get information on all ubi volumes
    ubinfo=$(ubinfo -d "${mtd}")
    presentVolumes=${ubinfo##*:}
    IFS=', ' read -r -a array <<< "$presentVolumes"
    for element in "${array[@]}"; do
      elementProperties=$(ubinfo -d "$mtd" -n "$element")
      # Get ubi volume name by getting rid of additional properties
      name=${elementProperties#*Name:}
      name="${name%Character*}"
      name="$(echo -e "${name}" | tr -d '[:space:]')"

      if [[ ${name} == rofs-* ]]; then
        if [[ "${name}" == "${rootname}" ]]; then
          mountdir="/media/${name}-functional"
        else
          mountdir="/media/${name}"
        fi

        if [ ! -d "${mountdir}" ]; then
          mkdir -p "${mountdir}"
          # U-Boot will create the ubiblock for the running version, but not
          # for the version on the other chip
          if [ ! -e "/dev/ubiblock${mtd}_${element}" ]; then
            ubiblock --create "/dev/ubi${mtd}_${element}"
          fi
          mount -t squashfs -o ro "/dev/ubiblock${mtd}_${element}" "${mountdir}"
        fi
      fi
    done
  done

  set_wdt2bite
}

mount_static_alt() {
  typ=$1
  altFs=$2
  mountName=$3
  altNum="$(findmtdnum "${altFs}")"
  if [ -n "${altNum}" ]; then
    altFsMount="/run/media/${mountName}"
    mkdir -p "${altFsMount}"
    altFsBlock="/dev/mtdblock${altNum}"
    mount -t "${typ}" "${altFsBlock}" "${altFsMount}"
  fi
}

umount_static_alt() {
  altFs=$1
  altFsMount="/run/media/${altFs}"
  umount "${altFsMount}"
}

# Read the current env variable and set it on the alternate boot env
copy_env_var_to_alt() {
  varName=$1
  value="$(fw_printenv -n "${varName}")"
  fw_setenv -c /etc/alt_fw_env.config "${varName}" "${value}"
}

# When the alternate bmc chip boots, u-boot thinks its the primary mtdX.
# Therefore need to swap the chip numbers when copying the ubiblock and root to
# alternate bmc u-boot environment.
copy_ubiblock_to_alt() {
  value="$(fw_printenv -n ubiblock)"
  bmcNum="$(findmtdnum "bmc")"
  altNum="$(findmtdnum "alt-bmc")"
  replaceAlt="${value/${altNum},/${bmcNum},}"

  if [[ "${value}" == "${replaceAlt}" ]]; then
    replaceBmc="${value/${bmcNum},/${altNum},}"
    value=${replaceBmc}
  else
    value=${replaceAlt}
  fi

  fw_setenv -c /etc/alt_fw_env.config ubiblock "${value}"
}

copy_root_to_alt() {
  value="$(fw_printenv -n root)"
  bmcNum="$(findmtdnum "bmc")"
  altNum="$(findmtdnum "alt-bmc")"
  replaceAlt="${value/${altNum}_/${bmcNum}_}"

  if [[ "${value}" == "${replaceAlt}" ]]; then
    replaceBmc="${value/${bmcNum}_/${altNum}_}"
    value=${replaceBmc}
  else
    value=${replaceAlt}
  fi

  fw_setenv -c /etc/alt_fw_env.config root "${value}"
}

ubi_setenv() {
    # The U-Boot environment maintains two banks of environment variables.
    # The banks need to be consistent with each other to ensure that these
    # variables can reliably be read from file. In order to guarantee that the
    # banks are both correct, we need to run fw_setenv twice.
    variable=$1
    if [[ "$variable" == *"="* ]]; then
        varName="${variable%=*}"
        value="${variable##*=}"
        # Write only if var is not set already to the requested value
        currentValue="$(fw_printenv -n "${varName}" 2>/dev/null)" || true
        if [[ "${currentValue}" != "${value}" ]]; then
          fw_setenv "$varName" "$value"
          fw_setenv "$varName" "$value"
        fi
    else
        fw_setenv "$variable"
        fw_setenv "$variable"
    fi
}

mtd_write() {
  flashmtd="$(findmtd "${reqmtd}")"
  img="/tmp/images/${version}/${imgfile}"
  flashcp -v "${img}" /dev/"${flashmtd}"
}

backup_env_vars() {
  copy_env_var_to_alt kernelname
  copy_ubiblock_to_alt
  copy_root_to_alt
}

update_env_vars() {
  vol="$(findubi rofs-"${flashid}")"
  if [ -z "${vol}" ]; then
    return 1
  fi
  ubidevid="${vol#ubi}"
  block="/dev/ubiblock${ubidevid}"
  if [ ! -e "${block}" ]; then
    return 1
  fi
  ubi_setenv "kernelname=kernel-${flashid}"
  ubi_setenv "ubiblock=${ubidevid//_/,}"
  ubi_setenv "root=${block}"
}

#TODO: Replace the implementation with systemd-inhibitors lock
#      once systemd/systemd#949 is resolved
rebootguardenable() {
  dir="/run/systemd/system/"
  file="reboot-guard.conf"
  units=("reboot" "poweroff" "halt")

  for unit in "${units[@]}"; do
    mkdir -p ${dir}"${unit}".target.d
    echo -e "[Unit]\nRefuseManualStart=yes" >> ${dir}"${unit}".target.d/${file}
  done
}

#TODO: Replace the implementation with systemd-inhibitors lock
#      once systemd/systemd#949 is resolved
rebootguarddisable() {
  dir="/run/systemd/system/"
  file="reboot-guard.conf"
  units=("reboot" "poweroff" "halt")

  for unit in "${units[@]}"; do
    rm -rf ${dir}"${unit}".target.d/${file}
  done
}

# Create a copy in the alt mtd
create_vol_in_alt() {
  alt="alt-bmc"
  altmtd="$(findmtd "${alt}")"
  if [ -n "${altmtd}" ]; then
    reqmtd="${alt}"
    reqmtd2="${alt}"
    ubi_ro
    ubi_updatevol
  fi
}

# Copy contents of one MTD device to another
mtd_copy() {
  in=$1
  out=$2

  # Must erase MTD first to prevent corruption
  flash_eraseall "${out}"
  dd if="${in}" of="${out}"
}

mirroruboot() {
  bmc="$(findmtd "u-boot")"
  bmcdev="/dev/${bmc}"
  alt="$(findmtd "alt-u-boot")"
  altdev="/dev/${alt}"

  checksum_bmc="$(md5sum "${bmcdev}")"
  checksum_bmc="${checksum_bmc% *}"
  checksum_alt="$(md5sum "${altdev}")"
  checksum_alt="${checksum_alt% *}"

  if [[ "${checksum_bmc}" != "${checksum_alt}" ]]; then
    bmcenv="$(findmtd "u-boot-env")"
    bmcenvdev="/dev/${bmcenv}"
    altenv="$(findmtd "alt-u-boot-env")"
    altenvdev="/dev/${altenv}"

    echo "Mirroring U-boot to alt chip"
    mtd_copy "${bmcdev}" "${altdev}"
    mtd_copy "${bmcenvdev}" "${altenvdev}"

    copy_ubiblock_to_alt
    copy_root_to_alt
  fi
}

# Compare the device where u-boot resides with an image file. Specify the full
# path to the device and image file to use for the compare. Print a value of
# "0" if identical, "1" otherwise.
cmp_uboot() {
  device="$1"
  image="$2"

  # Since the image file can be smaller than the device, copy the device to a
  # tmp file and write the image file on top, then compare the sum of each.
  # Use cat / redirection since busybox does not have the conv=notrunc option.
  tmpFile="$(mktemp /tmp/ubootdev.XXXXXX)"
  dd if="${device}" of="${tmpFile}"
  devSum="$(sha256sum "${tmpFile}")"
  cat < "${image}" 1<> "${tmpFile}"
  imgSum="$(sha256sum "${tmpFile}")"
  rm -f "${tmpFile}"

  if [ "${imgSum}" == "${devSum}" ]; then
    echo "0";
  else
    echo "1";
  fi
}

# The eMMC partition labels for the kernel and rootfs are boot-a/b and rofs-a/b.
# Return the label (a or b) for the running partition.
mmc_get_primary_label() {
  # Get root device /dev/mmcblkpX
  rootmatch=" on / "
  root="$(mount | grep "${rootmatch}")"
  # shellcheck disable=SC2295
  root="${root%${rootmatch}*}"

  # Find the device label
  if [[ $(readlink -f /dev/disk/by-partlabel/rofs-a) == "${root}" ]]; then
    echo "a"
  elif [[ $(readlink -f /dev/disk/by-partlabel/rofs-b) == "${root}" ]]; then
    echo "b"
  else
    echo ""
  fi
}

# The eMMC partition labels for the kernel and rootfs are boot-a/b and rofs-a/b.
# Return the label (a or b) for the non-running partition.
mmc_get_secondary_label() {
  root="$(mmc_get_primary_label)"
  if [[ "${root}" == "a" ]]; then
    echo "b"
  elif [[ "${root}" == "b" ]]; then
    echo "a"
  else
    echo ""
  fi
}

mmc_mount() {
  primaryId="$(mmc_get_primary_label)"
  secondaryId="$(mmc_get_secondary_label)"

  primaryDir="${mediaDir}/rofs-${primaryId}-functional"
  secondaryDir="${mediaDir}/rofs-${secondaryId}"

  mkdir -p "${primaryDir}"
  mkdir -p "${secondaryDir}"

  mount PARTLABEL=rofs-"${primaryId}" "${primaryDir}" -t ext4 -o ro || rmdir "${primaryDir}"
  mount PARTLABEL=rofs-"${secondaryId}" "${secondaryDir}" -t ext4 -o ro || rmdir "${secondaryDir}"
}

mmc_update() {
  # Update u-boot if needed
  bootPartition="mmcblk0boot0"
  devUBoot="/dev/${bootPartition}"
  imgUBoot="${imgpath}/${version}/image-u-boot"
  if [ "$(cmp_uboot "${devUBoot}" "${imgUBoot}")" != "0" ]; then
    echo 0 > "/sys/block/${bootPartition}/force_ro"
    dd if="${imgUBoot}" of="${devUBoot}"
    echo 1 > "/sys/block/${bootPartition}/force_ro"
  fi

  # Update the secondary (non-running) boot and rofs partitions.
  label="$(mmc_get_secondary_label)"

  # Update the boot and rootfs partitions, restore their labels after the update
  # by getting the partition number mmcblk0pX from their label.
  zstd -d -c "${imgpath}"/"${version}"/image-kernel | dd of="/dev/disk/by-partlabel/boot-${label}"
  number="$(readlink -f /dev/disk/by-partlabel/boot-"${label}")"
  number="${number##*mmcblk0p}"
  sgdisk --change-name="${number}":boot-"${label}" /dev/mmcblk0 1>/dev/null

  zstd -d -c "${imgpath}"/"${version}"/image-rofs | dd of="/dev/disk/by-partlabel/rofs-${label}"
  number="$(readlink -f /dev/disk/by-partlabel/rofs-"${label}")"
  number="${number##*mmcblk0p}"
  sgdisk --change-name="${number}":rofs-"${label}" /dev/mmcblk0 1>/dev/null

  # Run this after sgdisk for labels to take effect.
  partprobe

  # Update hostfw
  if [ -f "${imgpath}"/"${version}"/image-hostfw ]; then
    # Remove patches
    patchdir="/usr/local/share/hostfw/alternate"
    if [ -d "${patchdir}" ]; then
      rm -rf "${patchdir:?}"/*
    fi
    hostfwdir=$(grep "hostfw " /proc/mounts | cut -d " " -f 2)
    cp "${imgpath}"/"${version}"/image-hostfw "${hostfwdir}"/hostfw-"${label}"
    mkdir -p "${hostfwdir}"/alternate
    mount "${hostfwdir}"/hostfw-"${label}" "${hostfwdir}"/alternate -o ro
  fi

  set_flashid "${label}"
}

mmc_remove() {
  # Render the filesystem unbootable by wiping out the first 1MB, this
  # invalidates the filesystem header.
  # Check if the requested id is the one the BMC is running from since dd
  # can still write and corrupt the running partition.
  primaryid="$(mmc_get_primary_label)"
  if [[ "${flashid}" == "${primaryid}" ]]; then
    return 1
  fi
  dd if=/dev/zero of=/dev/disk/by-partlabel/boot-"${flashid}" count=2048
  dd if=/dev/zero of=/dev/disk/by-partlabel/rofs-"${flashid}" count=2048

  hostfw_alt="hostfw/alternate"
  if grep -q "${hostfw_alt}" /proc/mounts; then
    hostfw_alt=$(grep "${hostfw_alt}" /proc/mounts | cut -d " " -f 2)
    umount "${hostfw_alt}"
  fi
  hostfw_base="hostfw "
  if grep -q "${hostfw_base}" /proc/mounts; then
    hostfw_base=$(grep "${hostfw_base}" /proc/mounts | cut -d " " -f 2)
    rm -f "${hostfw_base}/hostfw-${flashid}"
  fi
}

# Set the requested version as primary for the BMC to boot from upon reboot.
mmc_setprimary() {
  # Point root to the flashid of the requested BMC rootfs.
  fw_setenv bootside "${flashid}"
}

case "$1" in
  mtduboot)
    reqmtd="$2"
    version="$3"
    imgfile="image-u-boot"
    mtd_write
    ;;
  ubirw)
    reqmtd="$2"
    name="$3"
    imgsize="$4"
    ubi_rw
    ;;
  ubiro)
    reqmtd="$(echo "$2" | cut -d "+" -f 1)"
    reqmtd2="$(echo "$2" | cut -d "+" -f 2)"
    name="$3"
    version="$4"
    imgfile="image-rofs"
    ubi_ro
    ubi_updatevol
    ubi_block
    ;;
  ubikernel)
    reqmtd="$(echo "$2" | cut -d "+" -f 1)"
    reqmtd2="$(echo "$2" | cut -d "+" -f 2)"
    name="$3"
    version="$4"
    imgfile="image-kernel"
    ubi_ro
    ubi_updatevol
    create_vol_in_alt
    ;;
  ubiremove)
    name="$2"
    ubi_remove "${name}"
    ;;
  ubicleanup)
    ubi_cleanup
    ;;
  ubisetenv)
    ubi_setenv "$2"
    ;;
  ubiremount)
    remount_ubi
    mount_ubi_alt_rwfs
    ;;
  createenvbackup)
    backup_env_vars
    ;;
  updateubootvars)
    flashid="$2"
    update_env_vars
    ;;
  rebootguardenable)
    rebootguardenable
    ;;
  rebootguarddisable)
    rebootguarddisable
    ;;
  mirroruboot)
    mirroruboot
    ;;
  mmc)
    version="$2"
    imgpath="$3"
    mmc_update
    ;;
  mmc-mount)
    mediaDir="$2"
    mmc_mount
    ;;
  mmc-remove)
    flashid="$2"
    mmc_remove
    ;;
  mmc-setprimary)
    flashid="$2"
    mmc_setprimary
    ;;
  static-altfs)
    mount_static_alt "$2" "$3" "$4"
    ;;
  umount-static-altfs)
    umount_static_alt "$2"
    ;;
  *)
    echo "Invalid argument"
    exit 1
    ;;
esac