xiaomi mi2s system2 partition ubuntu touch initrd modify

#transfusian@gmail.com
# Local filesystem mounting			-*- shell-script -*-

pre_mountroot()
{
	[ "$quiet" != "y" ] && log_begin_msg "Running /scripts/local-top"
	run_scripts /scripts/local-top
	[ "$quiet" != "y" ] && log_end_msg
}

mount_ubuntu_overlay() {
	source=$1
	target=$2

	if [ -d ${source} ]; then
		OLD_PWD=$PWD
		cd ${source}

		for overlay in `find . -type f`; do
			[ -f ${target}/${overlay} ] && mount --bind ${source}/${overlay} ${target}/${overlay}
		done

		cd $OLD_PWD
	fi
}

sync_dirs() {
	base=$1
	source=$2
	target=$3

	OLD_PWD=$PWD
	cd $base

	for file in $source/*
	do
		# Skip empty directories
		[ ! -e "$base/$file" ] && continue

		# If the target already exists as a file or link, there's nothing we can do
		[ -e "$target/$file" -o -L "$target/$file" ] && [ ! -d "$target/$file" ] && continue

		# If the target doesn't exist, just copy it over
		if [ ! -e "$target/$file" -a ! -L "$target/$file" ]; then
			cp -Ra "$base/$file" "$target/$file"
			continue
		fi

		# That leaves us with directories and a recursive call
		[ -d $file ] && sync_dirs $base $file $target
	done

	cd $OLD_PWD
}

mountroot()
{
	# list of possible userdata partition names
	partlist="userdata UDA DATAFS USERDATA"

	pre_mountroot

	[ "$quiet" != "y" ] && log_begin_msg "Running /scripts/local-premount"
	run_scripts /scripts/local-premount
	[ "$quiet" != "y" ] && log_end_msg

	# Mount root
	#
	# Create a temporary mountpoint for the bindmount
        # Create a temporary mountpoint for the data partition which includes
        # data and data1
        mkdir -p /data_root
	mkdir -p /tmpmnt

	# Make sure the device has been created by udev before we try to mount
	udevadm settle

	# find the right partition
	for partname in $partlist; do
		part=$(find /dev -name $partname|tail -1)
		[ -z "$part" ] && continue
		path=$(readlink -f $part)
		[ -n "$path" ] && break
	done

	# override with a possible cmdline parameter
	if grep -q datapart= /proc/cmdline; then
		for x in $(cat /proc/cmdline); do
			case ${x} in
			datapart=*)
				path=${x#*=}
				;;
			esac
		done
	fi

	if [ -z "$path" ]; then
		echo "initrd: Couldn't find data partition. Spawning adbd ..." >/dev/kmsg || true
		panic "Couldn't find data partition. Spawning adbd ..."
	fi
	echo "initrd: mounting $path" >/dev/kmsg || true

	# Mount the data partition to a temporary mount point
	mount -o discard $path /data_root
        mount -o bind /data_root/system1 /tmpmnt

	# Loop-mounted flipped model
	if [ -e /tmpmnt/system.img ]; then
		# Transition .developer_mode to .writable_image
		[ -e /tmpmnt/.developer_mode ] && mv /tmpmnt/.developer_mode /tmpmnt/.writable_image

		# Prepare the root filesystem
		# NOTE: We mount it read-write in all cases, then remount read-only.
		#       This is to workaround a behaviour change in busybox which now
		#       uses read-only loops if the fs is initially mounted read-only.
		#       An alternative implementation would be to add losetup support
		#       to busybox and do the mount in two steps (rw loop, ro fs).
		mount -o loop,rw /tmpmnt/system.img ${rootmnt}
		if [ -e /tmpmnt/.writable_image ]; then
			echo "initrd: mounting system.img (image developer mode)" >/dev/kmsg || true
			mountroot_status="$?"
		else
			echo "initrd: mounting system.img (user mode)" >/dev/kmsg || true
			mount -o remount,ro ${rootmnt}
			mountroot_status="$?"
		fi
		mount --move /tmpmnt ${rootmnt}/userdata

		# Mount the android system partition to a temporary location
		mkdir -p /android-system
		mount -o loop,ro ${rootmnt}/var/lib/lxc/android/system.img /android-system

		# Get device information
		device=$(grep ^ro.product.device= /android-system/build.prop |sed -e 's/.*=//')
		[ -z "$device" ] && device="unknown"
		echo "initrd: device is $device" >/dev/kmsg || true

		# Mount some tmpfs
		mkdir -p ${rootmnt}/android
		mount -o rw,size=4096 -t tmpfs none ${rootmnt}/android
		mount -o rw,nosuid,noexec,relatime,mode=755 -t tmpfs tmpfs ${rootmnt}/run

		# Create some needed paths on tmpfs
		mkdir -p ${rootmnt}/android/data ${rootmnt}/android/system

		# Prepare the fstab
		FSTAB=${rootmnt}/etc/fstab
		touch ${rootmnt}/run/image.fstab
		mount -o bind ${rootmnt}/run/image.fstab $FSTAB || panic "drop to adb"
		echo "/dev/root / rootfs defaults,ro 0 0" >> $FSTAB

		# Process the list of bind-mounts
		# (but don't mount them, mountall will do it)
		cat ${rootmnt}/etc/system-image/writable-paths | while read line; do
			set -- $line
			# Skip invalid/commented entries
			([ -z "$1" ] || [ -z "$2" ] || [ -z "$3" ] || [ -z "$4" ] || [ -z "$5" ]) && continue
			[ "$1" = "#" ] && continue

			# Skip invalid mount points
			dstpath="${rootmnt}/$1"
			[ ! -e "$dstpath" ] && continue

			if [ "$3" = "temporary" ]; then
				# Temporary entries are simple, just mount a tmpfs
				echo "tmpfs $1 tmpfs $5 0 0" >> $FSTAB
			elif [ "$3" = "persistent" ] || [ "$3" = "synced" ]; then
				# Figure out the source path
				if [ "$2" = "auto" ]; then
					srcpath="${rootmnt}/userdata/system-data/$1"
					path="/userdata/system-data/$1"
				else
					srcpath="${rootmnt}/userdata/$2"
					path="/userdata/$2"
				fi

				if [ ! -e "$srcpath" ]; then
					# Process new persistent or synced paths
					dstown=$(stat -c "%u:%g" $dstpath)
					dstmode=$(stat -c "%a" $dstpath)
					mkdir -p ${srcpath%/*}
					if [ ! -d "$dstpath" ]; then
						# Deal with redirected files
						if [ "$4" = "transition" ]; then
							cp -a $dstpath $srcpath
						else
							touch $srcpath
							chown $dstown $srcpath
							chmod $dstmode $srcpath
						fi
					else
						# Deal with redirected directories
						if [ "$4" = "transition" ] || [ "$3" = "synced" ]; then
							cp -aR $dstpath $srcpath
						else
							mkdir $srcpath
							chown $dstown $srcpath
							chmod $dstmode $srcpath
						fi
					fi
				elif [ "$3" = "synced" ]; then
					# Process existing synced paths
					sync_dirs $dstpath . $srcpath
				fi

				# Write the fstab entry
				if [ "$5" = "none" ]; then
					echo "$path $1 none bind 0 0" >> $FSTAB
				else
					echo "$path $1 none bind,$5 0 0" >> $FSTAB
				fi
			else
				continue
			fi
		done

		# Extract the fstab from the android initrd
		# NOTE: we should find a faster way of doing that or cache it
		OLD_CWD=$(pwd)
		mount -n -t tmpfs tmpfs ${rootmnt}/var/lib/lxc/android/rootfs
		cd ${rootmnt}/var/lib/lxc/android/rootfs
		cat /android-system/boot/android-ramdisk.img | gzip -d | cpio -i
		cd $OLD_CWD

		# Mount all the Android partitions
		cat ${rootmnt}/var/lib/lxc/android/rootfs/fstab* | while read line; do
			set -- $line

			# Skip any unwanted entry
			echo $1 | egrep -q "^#" && continue
			([ -z "$1" ] || [ -z "$2" ] || [ -z "$3" ] || [ -z "$4" ]) && continue
			([ "$2" = "/system" ] || [ "$2" = "/data" ]) && continue

			label=$(echo $1 | awk -F/ '{print $NF}')
			[ -z "$label" ] && continue

			echo "initrd: checking mount label $label" >/dev/kmsg || true

			for dir in by-partlabel by-name by-label by-path by-uuid by-partuuid by-id; do
				path="/dev/disk/$dir/$label"
				[ -e "$path" ] && break
			done

			# MTD based devices, such as the emulator
			if [ ! -e "$path" ] && echo $label | egrep -q "^mtdblock"; then
				path="/dev/$label"
			fi

			[ ! -e "$path" ] && continue

			mkdir -p ${rootmnt}/android/$2
			echo "initrd: mounting $path as ${rootmnt}/android/$2" >/dev/kmsg || true
			mount $path ${rootmnt}/android/$2 -t $3 -o $4
		done

		# system is a special case
		echo "initrd: mounting ${rootmnt}/var/lib/lxc/android/system.img as ${rootmnt}/android/system" >/dev/kmsg || true
		mount --move /android-system ${rootmnt}/android/system

		# Ubuntu overlay available in the Android system image (hardware specific configs)
		mount_ubuntu_overlay ${rootmnt}/android/system/ubuntu ${rootmnt}

		# Apply device-specific udev rules
		if [ ! -f ${rootmnt}/android/system/ubuntu/lib/udev/rules.d/70-android.rules ] && [ "$device" != "unknown" ]; then
			mount --bind ${rootmnt}/usr/lib/lxc-android-config/70-$device.rules ${rootmnt}/lib/udev/rules.d/70-android.rules
		fi

		# Bind-mount /lib/modules from Android
		[ -e ${rootmnt}/android/system/lib/modules ] && mount --bind ${rootmnt}/android/system/lib/modules ${rootmnt}/lib/modules

		# Bind-mount /var/lib/ureadahead if available on persistent storage
		# this is required because ureadahead runs before mountall
		if [ -e ${rootmnt}/userdata/system-data/var/lib/ureadahead ] && \
				[ -e ${rootmnt}/var/lib/ureadahead ]; then
			mount --bind ${rootmnt}/userdata/system-data/var/lib/ureadahead ${rootmnt}/var/lib/ureadahead
		fi

		# Setup the swap device
		[ -e ${rootmnt}/userdata/SWAP.img ] && swapon ${rootmnt}/userdata/SWAP.img

		# Apply customized content
		for user in ${rootmnt}/userdata/user-data/*
		do
			if [ -d ${rootmnt}/custom/home ] && [ ! -e "$user/.customized" ]; then
				echo "initrd: copying custom content tp " >/dev/kmsg || true
				cp -Rap ${rootmnt}/custom/home/* "$user/"
				cp -Rap ${rootmnt}/custom/home/.[a-zA-Z0-9]* "$user/"
				touch "$user/.customized"
				dstown=$(stat -c "%u:%g" "$user")
				chown -R $dstown "$user/"
			fi
		done


	# Old flipped model
	elif [ -d /tmpmnt/ubuntu ]; then
		mount --bind /tmpmnt/ubuntu ${rootmnt}
		mountroot_status="$?"

	# Possibly a re-partitioned device
	else
		echo "initrd: Couldn't find a system partition." >/dev/kmsg || true
		panic "Couldn't find a system partition. Spawning adbd ..."
	fi

	[ "$quiet" != "y" ] && log_begin_msg "Running /scripts/local-bottom"
	run_scripts /scripts/local-bottom
	[ "$quiet" != "y" ] && log_end_msg
}