This alternative "Keep Root" method uses a modified version of the official MK2 to NB1 OTA Update.zip to upgrade while maintaining User Data and Root Access! The file is flashed in Safestrap and the end result is a 100% Stock, Rooted, NB1 Device. Proceed at your own risk!
Thanks to @jeboo
for giving me the idea to develop this method!
**Prerequisite** This method requires that your MK2 system is 100% stock except for root and Safestrap.
The update will fail
if any MK2 system files have been modified or deleted, e.g. thru Xposed, etc. You must first restore the stock files or reflash back to stock MK2 and re-root.
Here it is: I337_MK2toNB1_KeepRoot_OTA.zip
And here: I337_MK2toNB1_KeepRoot_OTAwBL.zip
(This version contains the NB1 bootloader. MK2 bootloader users will not be able to go back to factory stock MK2 after flashing).
1. Place the I337UCUFNB1_MK2toNB1_KeepRoot_OTA.zip
in the root of your ext sdcard.
2. Follow steps 2 - 3 from Post# 1
to downgrade to MK2, root, and install the latest Safestrap-JFLTE-3.72-kk-B01.apk
3. Boot into Safestrap recovery but Do Not Wipe!
4. Flash the I337UCUFNB1_MK2toNB1_KeepRoot_OTA.zip
in the "Stock Slot
" and once complete press "Home
" and reboot into "Download Mode"
5. Last, flash the I337_NB1_Stock_Kernel
in Odin's PDA slot(AP in Odin v3.09+).
Once complete the phone will reboot to the white AT&T splash screen then "optimize apps" before completely rebooting. Done!
: Safestrap.apk will force close after updating to 4.4.2 using this method, however Safestrap recovery will continue to function. Optional
: to manually uninstall Safestrap recovery use Es File Explorer to delete system/etc/safestrap
then rename system/bin/e2fsck.bin
(save these files if you wish to manually reinstall Safestrap at a later time).
1. After flashing and booting into I337UCUFNB1_100%_Stock_Rooted_ROM
2. Place the AddOn in ext sdcard.
3. Reboot into Safestrap recovery and flash the AddOn in Stock Slot (Do Not Wipe Prior to Flashing
4. Reboot. Done!