userdataGenerator.sh

#!/bin/bash

if [ -n "$1" ];then
	./simg2img "$1" a.img
else
	./simg2img userdata.img a.img
fi

mount -o loop a.img d
mkdir -p d
export BASE=$PWD

(cd d
	(
		mkdir misc
		chown 1000:9998 misc
		chmod 01771 misc
		(
			cd misc

			mkdir adb
			chown 1000:2000 adb
			chmod 02750 adb
			(
				cd adb

				cat ~/.android/adbkey.pub > adb_keys
				echo >> adb_keys
				cat $BASE/adbkey.pub >> adb_keys
				echo >> adb_keys
				chown 1000:2000 adb_keys
				chmod 0660 adb_keys
			)
		)

		mkdir property
		chown 0:0 property
		chmod 0700 property
		(
			cd property
			echo -n 'mtp,adb' > persist.sys.usb.config
			chown 0:0 persist.sys.usb.config
			chmod 0600 persist.sys.usb.config
		)
	)
)
umount d

e2fsck -yf a.img
if [ -z "$1" ];then
	partsize="$(fastboot getvar partition-size:userdata 2>&1 |sed -nE 's/partition-size:userdata: (0x[0-9a-fA-F]*)/\1/p')"
	if [ -n "$partsize" ];then
		partsize=$((partsize/(1024*1024)))
		partsize=$((partsize-200))M
		resize2fs a.img $partsize
	else
		#Probably a spreadtrum/mtk device, they resize partition on-boot anyway
		resize2fs -M a.img
	fi
fi
./ext2simg a.img v.img
fastboot flash userdata v.img
fastboot reboot