在调试RK3288的OV2718的驱动时，需要remount  /system目录为rw以push文件到/system/lib/hw目录下，常规的是用adb登录上去后以root权限执行mount -o remount,rw /system即可，然而在拿的新板子后这么做失效了，于是百度找到方法如下：

adb shell  
 su  
 mount -o rw,remount -t ext4 /system

Edit: Found a better solution

From host machine(Linux or windows PC), execute the following commands.

>> adb root  
>> adb remount

remount will by default remount the /system partition with rw, if you have the permissions.

Note 1: To do su or adb root, your device must be rooted and have su executable on it. When you do an su, if it is executed properly, your terminal prompt will change from $ to #. Thanks..

Note 2: In recent mobiles, few of acer and samsung that i know, Security has been tightened, and even after rooting the phone, adb remount wouldn't work. As of i know, there is no solution available for it so far.