content: Usually an OS on the ROM is only there so it can be installed (factory reset) into the hard drive.  Modern operating systems want to be mutable because they need to be updated.  So a ROM would o  1449  nly explain it being in the OEM install. Ultimately there is going to have to be a table on the phone of installed apps that will be mutable.  It's not like every time you boot your phone it goes through all blocks of memory and tests if there is an app there.