Hi, 
  
I am currently working on a OLinuxIno A20 limeX system which works in read only mode. 
  
I use the code I developped here: https://github.com/lauhub/debian-to-readonly 
  
I have small problems with armbian evolutions, since it uses, creates and modifies some files in some directories that should not be modified according to this page. 
  
Example of files : 
  
/etc/init.d/armhwinfo (modifies permissions of /etc/logrotate.d/armhwinfo) 
/sbin/fake-hwclock (creates /etc/fake-hwclock.data