I have a rooted Samsung Galaxy S4 (SGH-I337M) and I want to backup my stock ROM before installing a custom ROM. When I open the Android System recovery, I do not have backup and recovery option. The options that I have are :
1. reboot system now,
2. apply update from ADB
3. apply update from external storage
4. wipe data/factory reset
5. wipe cache partition
6. apply update from cache.
Can anyone please share some more information regarding backing up stock ROM ? Thanks in advance.