Originally Posted by Cozume
From all I am reading, Android disables write protection when you boot into recovery and any changes that you make in recovery stick when you boot into system. And if you have root access, you can make changes to system in recovery.
So what advantages are there to having write protection disabled when you boot into system? Why can't you make any changes you want while in recovery? Isn't that safer anyhow? Do some apps need write protection disabled to run?
I don't have a technical response or even very good response, but I do have an example of why you need access to the write protection.
I use AdAway to block advertising on my phone. (The ethics of doing this are up for debate, but lets leave that to another venue)
AdAway needs root access and the ability to modify the hosts
file on the phone, which is a system protected file (for good reason). If write protection is on, then AdAway fails to modify the phone's hosts file and the ad blocking does not take place. With write protection off, AdAway is successful an my browser screen is far less cluttered when surfing.
I set the app to notify me when updates are available, but not to automatically apply the updates. Then I manually reboot to recovery and update my hosts file via AdAway. After I get the successful update I reboot normally and use my phone in the regular non-recovery mode.