flash-SDCard-from-eMMC.sh

#!/bin/bash -e
#
# Copyright (c) 2013-2014 Robert Nelson <robertcnelson@gmail.com>
# Portions copyright (c) 2014 Charles Steinkuehler <charles@steinkuehler.net>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.

#This script assumes, these packages are installed, as network may not be setup
#dosfstools initramfs-tools rsync u-boot-tools

if ! id | grep -q root; then
	echo "must be run as root"
	exit
fi

source="/dev/mmcblk0"
destination="/dev/mmcblk1"

flush_cache () {
	sync
	blockdev --flushbufs ${destination}
}

write_failure () {
	echo "writing to [${destination}] failed..."

	echo "-----------------------------"
	flush_cache
	umount ${destination}p1 > /dev/null 2>&1 || true
	umount ${destination}p2 > /dev/null 2>&1 || true
}

check_running_system () {
	echo "-----------------------------"
	echo "debug copying: [${source}] -> [${destination}]"
	lsblk
	echo "-----------------------------"

	if [ ! -b "${destination}" ] ; then
		echo "Error: [${destination}] does not exist"
		write_failure
	fi

	if [ ! -f /boot/config-$(uname -r) ] ; then
		zcat /proc/config.gz > /boot/config-$(uname -r)
	fi

	if [ -f /boot/initrd.img-$(uname -r) ] ; then
		update-initramfs -u -k $(uname -r)
	else
		update-initramfs -c -k $(uname -r)
	fi
	flush_cache
}

format_boot () {
	mkfs.vfat -F 16 ${destination}p1 -n BEAGLEBONE
	flush_cache
}

format_root () {
	mkfs.ext4 ${destination}p2 -L rootfs
	flush_cache
}

partition_drive () {
	echo "Erasing: ${destination}"
	flush_cache
	dd if=/dev/zero of=${destination} bs=1M count=20
	sync
	dd if=${destination} of=/dev/null bs=1M count=20
	sync
	flush_cache

	if [ -f /boot/SOC.sh ] ; then
		. /boot/SOC.sh
	fi
	conf_boot_startmb=${conf_boot_startmb:-"1"}
	conf_boot_endmb=${conf_boot_endmb:-"12"}
	sfdisk_fstype=${sfdisk_fstype:-"0xE"}

	echo "Formatting: ${destination}"
	#96Mb fat formatted boot partition
	LC_ALL=C sfdisk --force --in-order --Linux --unit M "${destination}" <<-__EOF__
		${conf_boot_startmb},${conf_boot_endmb},${sfdisk_fstype},*
		,,,-
	__EOF__

	flush_cache
	format_boot
	format_root
}

copy_boot () {
	mount ${source}p1 /boot/uboot -o ro

	echo "Copying: ${source}p1 -> ${destination}p1"
	mkdir -p /tmp/boot/ || true
	mount ${destination}p1 /tmp/boot/ -o sync
	#Make sure the BootLoader gets copied first:
	cp -v /boot/uboot/MLO /tmp/boot/MLO || write_failure
	flush_cache

	cp -v /boot/uboot/u-boot.img /tmp/boot/u-boot.img || write_failure
	flush_cache

	echo "rsync: /boot/uboot/ -> /tmp/boot/"
	rsync -aAX /boot/uboot/ /tmp/boot/ --exclude={MLO,u-boot.img} || write_failure
	flush_cache

	flush_cache
	umount /tmp/boot/ || umount -l /tmp/boot/ || write_failure
	flush_cache
	umount /boot/uboot || umount -l /boot/uboot
}

copy_rootfs () {
	echo "Copying: ${source}p2 -> ${destination}p2"
	mkdir -p /tmp/rootfs/ || true
	mount ${destination}p2 /tmp/rootfs/ -o async,noatime

	echo "rsync: / -> /tmp/rootfs/"
	rsync -aAX /* /tmp/rootfs/ --exclude={/dev/*,/proc/*,/sys/*,/tmp/*,/run/*,/mnt/*,/media/*,/lost+found,/lib/modules/*} || write_failure
	flush_cache

	#ssh keys will now get regenerated on the next bootup
	touch /tmp/rootfs/etc/ssh/ssh.regenerate
	flush_cache

	mkdir -p /tmp/rootfs/lib/modules/$(uname -r)/ || true

	echo "Copying: Kernel modules"
	echo "rsync: /lib/modules/$(uname -r)/ -> /tmp/rootfs/lib/modules/$(uname -r)/"
	rsync -aAX /lib/modules/$(uname -r)/* /tmp/rootfs/lib/modules/$(uname -r)/ || write_failure
	flush_cache

	unset root_uuid
	root_uuid=$(/sbin/blkid -c /dev/null -s UUID -o value ${destination}p2)
	if [ "${root_uuid}" ] ; then
		sed -i -e 's:uuid=:#uuid=:g' /tmp/rootfs/boot/uEnv.txt
		echo "uuid=${root_uuid}" >> /tmp/rootfs/boot/uEnv.txt

		root_uuid="UUID=${root_uuid}"
	else
		#really a failure...
		root_uuid="${source}p2"
	fi

	echo "/boot/uEnv.txt: disabling flasher script"
	script="cmdline=init=/opt/scripts/tools/eMMC/init-eMMC-flasher-v2.sh"
	sed -i -e 's:'$script':#'$script':g' /tmp/rootfs/boot/uEnv.txt
	cat /tmp/rootfs/boot/uEnv.txt

	echo "Generating: /etc/fstab"
	echo "# /etc/fstab: static file system information." > /tmp/rootfs/etc/fstab
	echo "#" >> /tmp/rootfs/etc/fstab
	echo "${root_uuid}  /  ext4  noatime,errors=remount-ro  0  1" >> /tmp/rootfs/etc/fstab
	echo "debugfs  /sys/kernel/debug  debugfs  defaults  0  0" >> /tmp/rootfs/etc/fstab
	cat /tmp/rootfs/etc/fstab
	flush_cache
	umount /tmp/rootfs/ || umount -l /tmp/rootfs/ || write_failure

	echo "Syncing: ${destination}"
	#https://github.com/beagleboard/meta-beagleboard/blob/master/contrib/bone-flash-tool/emmc.sh#L158-L159
	# force writeback of eMMC buffers
	sync
	dd if=${destination} of=/dev/null count=100000

	echo ""
	echo "This script has now completed its task"
	echo "-----------------------------"

	if [ -f /boot/debug.txt ] ; then
		echo "debug: enabled"
	else
		echo "Shutting Down"
		umount /tmp || umount -l /tmp
		mount

		echo ""
		echo "-----------------------------"
		echo ""
		echo "eMMC has been flashed, please remove power and microSD card"
		echo ""
		echo "-----------------------------"

		halt -f
	fi
}

check_running_system
partition_drive
copy_boot
copy_rootfs