I was wondering why the root filesystem in Udoo and Raspberry is mounted with the rw option instead of ro (read only).
Mounting it in read/write mode prevents the system from checking the filesystem at boot, when the maximum mount count, or time is reached (I usually set them to 30 mounts, and 30 days).
I tested my Udoo quad with the latest kernel (4.1.1-1) mounting the root filesystem read only and the check happens when needed, and then the filesystem is re-mounted writable, so all works fine.