factory_reset.sh

#!/bin/sh -x

# 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 runs from the factory install/reset shim. This MUST be run
# from USB, in developer mode. This script will wipe OQC activity and
# put the system back into factory fresh/shippable state.

# Preserve files in the CRX cache.  Largely copied from clobber-state.
# TODO(dgarrett,jsalz): Consolidate.
#
# Note that some variables are shared with restore_crx_cache.
preserve_crx_cache() {
  PRESERVED_TAR="/tmp/preserve.tar"
  PRESERVED_FILES=""
  STATE_PATH="/mnt/stateful_partition"
  mkdir -p $STATE_PATH
  mount $STATE_DEV $STATE_PATH
  IMPORT_FILES="$(cd ${STATE_PATH};
                  echo unencrypted/import_extensions/extensions/*.crx)"
  if [ "$IMPORT_FILES" != \
       "unencrypted/import_extensions/extensions/*.crx" ]; then
    PRESERVED_FILES="${PRESERVED_FILES} ${IMPORT_FILES}"
  fi
  PRESERVED_LIST=""
  if [ -n "$PRESERVED_FILES" ]; then
    # We want to preserve permissions and recreate the directory structure
    # for all of the files in the PRESERVED_FILES variable. In order to do
    # so we run tar --no-recurison and specify the names of each of the
    # parent directories. For example for home/.shadow/install_attributes.pb
    # we pass to tar home home/.shadow home/.shadow/install_attributes.pb
    for file in $PRESERVED_FILES; do
      if [ ! -e "$STATE_PATH/$file" ]; then
        continue
      fi
      path=$file
      while [ "$path" != '.' ]; do
        PRESERVED_LIST="$path $PRESERVED_LIST"
        path=$(dirname $path)
      done
    done
    tar cf $PRESERVED_TAR -C $STATE_PATH --no-recursion -- $PRESERVED_LIST
  fi
  # Try a few times to unmount the stateful partition.
  local unmounted=false
  for i in $(seq 5); do
    if umount $STATE_DEV; then
      unmounted=true
      break
    fi
    sleep 1
  done
  if ! $unmounted; then
    # Bail out: we may not be able to successfully mkfs.
    echo "Unable to unmount stateful partition. Aborting."
    exit 1
  fi
}

# Restores files previously preserved by preserve_crx_cache.
restore_crx_cache() {
  if [ -n "$PRESERVED_LIST" ]; then
    # Copy files back to stateful partition
    mount $STATE_DEV $STATE_PATH
    tar xfp $PRESERVED_TAR -C $STATE_PATH
    sync  # Try as best we can, in case umount fails
    umount $STATE_PATH
    # Sleep for a bit, since we will shut down soon and want to give
    # the drive a chance to flush everything
    sleep 3
  fi
}

echo "Factory reset"

# TODO(crosbug:10680): replace arch detection with crossystem?
if uname -m | grep -q "^i.86\$"; then
  ARCH="INTEL"
elif [ $(uname -m ) = "x86_64" ]; then
  ARCH="INTEL"
elif [ $(uname -m ) = "armv7l" ]; then
  ARCH="ARM"
else
  echo "Failed to auto detect architecture"
  exit 1
fi

if [ "$ARCH" = "INTEL" ]; then
  DEV="/dev/sda"
  STATE_DEV="/dev/sda1"
elif [ "$ARCH" = "ARM" ]; then
  DEV="/dev/mmcblk0"
  STATE_DEV="/dev/mmcblk0p1"
else
  DEV=""
  STATE_DEV=""
fi

# Tcsd will bring up the tpm and de-own it,
# as we are in developer/recovery mode.
start tcsd

if [ "$#" = "1" -a "$1" = "wipe" ]; then
  if [ ! -b "$DEV" ]; then
    echo "Failed to find root disk."
    exit 1
  fi
  # Nuke the disk
  DEV_SIZE=$(blockdev --getsize64 ${DEV})
  pv -etpr -s ${DEV_SIZE} -B 8M /dev/zero 2>/dev/tty1 | \
      dd bs=8M of=${DEV} oflag=dsync iflag=fullblock
else
  if [ ! -b "$STATE_DEV" ]; then
    echo "Failed to find stateful partition."
    exit 1
  fi

  preserve_crx_cache

  # Just wipe the start of the partition and remake the fs on
  # the stateful partition.
  dd bs=4M count=1 if=/dev/zero of=${STATE_DEV}
  /sbin/mkfs.ext4 "$STATE_DEV"

  restore_crx_cache
fi

# Do any board specific resetting here.
# board_factory_reset.sh will be installed by the board overlay if necessary.
BOARD_RESET=/usr/sbin/board_factory_reset.sh
if [ -x "${BOARD_RESET}" ]; then
  echo "Running board specific factory reset: ${BOARD_RESET}"
  ${BOARD_RESET} || exit 1
fi

echo "Done"