So, I've been looking around the Web, but haven't found anything conclusive. The closest things I could find were either options after rooting or an XDA post regarding near-full backups via ADB, but nothing regarding ROM/Firmware backup only without root. My question is: "How to back up ROM/Firmware onto a PC from a non-rooted Android device (Galaxy S4 to be exact)?".
Thank you kindly in advance!