build_gpt.sh

#!/bin/bash
#
# Copyright (c) 2010 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.

# --- BEGIN COMMON.SH BOILERPLATE ---
# Load common CrOS utilities.  Inside the chroot this file is installed in
# /usr/lib/crosutils.  Outside the chroot we find it relative to the script's
# location.
find_common_sh() {
  local common_paths=(/usr/lib/crosutils $(dirname "$(readlink -f "$0")"))
  local path

  SCRIPT_ROOT=
  for path in "${common_paths[@]}"; do
    if [ -r "${path}/common.sh" ]; then
      SCRIPT_ROOT=${path}
      break
    fi
  done
}

find_common_sh
. "${SCRIPT_ROOT}/common.sh" || (echo "Unable to load common.sh" && exit 1)
# --- END COMMON.SH BOILERPLATE ---

# Load functions and constants for chromeos-install
[ -f /usr/lib/installer/chromeos-common.sh ] && \
  INSTALLER_ROOT=/usr/lib/installer || \
  INSTALLER_ROOT=$(dirname "$(readlink -f "$0")")

. "${INSTALLER_ROOT}/chromeos-common.sh" || \
  die "Unable to load chromeos-common.sh"

# Script must be run inside the chroot.
restart_in_chroot_if_needed "$@"

get_default_board

# Flags.
DEFINE_string arch "" \
  "The target architecture (\"arm\" or \"x86\")."
DEFINE_string board "$DEFAULT_BOARD" \
  "The board to build an image for."
DEFINE_integer rootfs_partition_size 1024 \
  "rootfs parition size in MBs."

# Usage.
FLAGS_HELP=$(cat <<EOF

Usage: $(basename $0) [flags] IMAGEDIR OUTDEV

This takes the image components in IMAGEDIR and creates a bootable,
GPT-formatted image in OUTDEV. OUTDEV can be a file or block device.

EOF
)

# Parse command line.
FLAGS "$@" || exit 1
eval set -- "${FLAGS_ARGV}"

if [[ -z "$FLAGS_board" ]] ; then
  error "--board is required."
  exit 1
fi

if [[ -z "$1" || -z "$2" ]] ; then
  flags_help
  exit 1
fi
IMAGEDIR="$1"
OUTDEV="$2"

if [[ -n "$FLAGS_arch" ]]; then
  ARCH=${FLAGS_arch}
else
  # Figure out ARCH from the given toolchain.
  # TODO: Move to common.sh as a function after scripts are switched over.
  TC_ARCH=$(echo "$CHOST" | awk -F'-' '{ print $1 }')
  case "$TC_ARCH" in
    arm*)
      ARCH="arm"
      ;;
    *86)
      ARCH="x86"
      ;;
    *)
      error "Unable to determine ARCH from toolchain: $CHOST"
      exit 1
  esac
fi

# Only now can we die on error.  shflags functions leak non-zero error codes,
# so will die prematurely if 'set -e' is specified before now.
set -e
# Die on uninitialized variables.
set -u

# Check for missing parts.
ROOTFS_IMG="${IMAGEDIR}/rootfs.image"
if [[ ! -s ${ROOTFS_IMG} ]]; then
  error "Can't find ${ROOTFS_IMG}"
  exit 1
fi

KERNEL_IMG="${IMAGEDIR}/vmlinuz.image"
if [[ ! -s ${KERNEL_IMG} ]]; then
  error "Can't find ${KERNEL_IMG}"
  exit 1
fi

STATEFUL_IMG="${IMAGEDIR}/stateful_partition.image"
if [ ! -s ${STATEFUL_IMG} ]; then
  error "Can't find ${STATEFUL_IMG}"
  exit 1
fi

ESP_IMG="${IMAGEDIR}/esp.image"
if [ ! -s ${ESP_IMG} ]; then
  error "Can't find ${ESP_IMG}"
  exit 1
fi

# We'll need some code to put in the PMBR, for booting on legacy BIOS.
if [[ "$ARCH" = "arm" ]]; then
  PMBRCODE=/dev/zero
else
  PMBRCODE=$(readlink -f /usr/share/syslinux/gptmbr.bin)
fi

# Create the GPT. This has the side-effect of setting some global vars
# describing the partition table entries (see the comments in the source).
install_gpt $OUTDEV $(numsectors $ROOTFS_IMG) $(numsectors $STATEFUL_IMG) \
    $PMBRCODE $(numsectors $ESP_IMG) false $FLAGS_rootfs_partition_size

# Emit helpful scripts for testers, etc.
${SCRIPTS_DIR}/emit_gpt_scripts.sh "${OUTDEV}" "${IMAGEDIR}"

sudo=
if [ ! -w "$OUTDEV" ] ; then
  # use sudo when writing to a block device.
  sudo=sudo
fi

# Now populate the partitions.
echo "Copying stateful partition..."
$sudo dd if=${STATEFUL_IMG} of=${OUTDEV} conv=notrunc bs=512 \
    seek=${START_STATEFUL}

echo "Copying kernel..."
$sudo dd if=${KERNEL_IMG} of=${OUTDEV} conv=notrunc bs=512 seek=${START_KERN_A}

echo "Copying rootfs..."
$sudo dd if=${ROOTFS_IMG} of=${OUTDEV} conv=notrunc bs=512 \
    seek=${START_ROOTFS_A}

echo "Copying EFI system partition..."
$sudo dd if=${ESP_IMG} of=${OUTDEV} conv=notrunc bs=512 seek=${START_ESP}

# Clean up temporary files.
if [[ -n "${MBR_IMG:-}" ]]; then
  rm "${MBR_IMG}"
fi