Note: This is not a tutorial, how-to, or guide. Merely a journey trying to figure out how to easily and simply upgrade the Essential PH-1 from an existing /e/ Nougat ROM to Pi/e/ without losing data, going back to stock, or what have you.
Okay, for testing purposes I went all the way back down to stock Nougat firmware. Using last Nougat build from Essential (some of the Nougat back-to-stock builds are no longer available).
I edited the flashall.bat a bit. With ‘fastboot -w’ in the first line, to erase userdata beforehand.
The last two lines I used also:
‘fastboot reboot bootloader’
After that I did the following procedure to install TWRP using the official image and zip.
twrp-installer-mata-3.2.3-0.zip (renamed to twrp-mata.zip)
twrp-3.2.3-0-mata.img (renamed to twrp-mata.img)
fastboot getvar current-slot
It returned “_a”.
I install TWRP image to both slots.
fastboot flash boot_b twrp-mata.img
fastboot flash boot_a twrp-mata.img
Use volume buttons to choose RECOVERY in bootloader screen and press power button to reboot.
Back in recovery, touch is working fine on slot b.
Push TWRP zip to phone.
adb push twrp-mata.zip /sdcard/
Flash it normally. When complete go to Reboot menu. Select original slot A. Back to Reboot Menu and select Recovery. Of course there will be repeated prompts to keep system read-omly or whether to install the TWRP app. That’s because TWRP’s settings aren’t being retained on the storage yet.
Touch is also working just fine on both slots.
Tried to boot into the stock ROM. Got thrown into TWRP instead. That’s fine.
Formatted /data and rebooted back into TWRP so I coukd change and keep its settings. Rebooted to System, it failed again. Still not a problem.
Push /e/ Nougat and TWRP to phone.
adb push -p e-0.7-n-2020021140863-dev-mata.zip /sdcard/eosn.zip (should’ve renamed it earlier )
adb push twrp-mata.zip /sdcard/
Flashed ROM, flashed TWRP, wiped dalvik and /data. Just in case. Reboot.
ROM boots up normally. Currently setting up and testing.
Nougat build was running great. All parts and pieces were a-ok. Now I get to the upgrading part.
Push Pie build and TWRP. I won’t do any wipes as I am not sure if there is anything to wipe except dalvik. Pie will flash to the other slot that may house the stock ROM. I could switch over to that slot, wipe system, flip back, then flash ROM or… take my chances that flashing will automatically remove existing /system contents. I’ll take my chances.
Flash Pie and TWRP. Wiped only Dalvik.
Pie ROM booted. First thing I noticed at the lockscreen was the mobile data icon without LTE. Even worse, no touch in the ROM. Cannot swipe at the lockscreen, cannot reboot via power menu.
Even worse than that, used Power+VolumeDown to boot to boatloader menu and then to recovery. In TWRP, no touch whatsoever. Pie killed touch.
Hook up to PC.
adb reboot bootloader
fastboot getvar current-slot “_a”
Reboot back into recovery via volume and power buttons.
Touch is working on the Nougat side (b).
Not sure if things work this way but I switched to slot A in TWRP, wiped system, then switched back to B (not really knowing if I wiped the Nougat or Pie side. Will know soon enough).
Reflash Pie build. Well, the warning page showed I may have wiped out Nougat after all. LOL.
Now that the hopes of a simple upgrade have failed for me I decided to go off the rails. The Back-To-Stock people also have what are known as NOVENDOR packages. From what I gather these allow for custom ROM users to update the underlying firmware without data or ROM loss. So making sure that I’m on the slot with the unreponsive TWRP and ROM I flashed a Pie NOVENDOR package, [PQ1A.190105.112-NOVENDOR.zip](https://sourceforge.net/projects/mata-bts/files/Pie/August/PQ1A.190105.112-NOVENDOR.zip/download].
Once complete i reboot back into recovery usimg volume rockers. Lo and behold, touch is working. Interesting. Reboot to System. Pie ROM boots but seems stuck at the lockscreen (probably should’ve wiped dalvik first). Long-pressed the volume button to reboot. ROM boots. Data is working and so is touch. Bkuetooth keeps stopping so I go back to TWRP, wipe dalvik, and reboot.
Pie for the most part is workimg. Most of the system settings have been retained. However, BlueTooth is broken. Constantly stopping even after clearimg cache and data. Wi-Fi also won’t turn on.
Everything else seems to be working fine. Syncimg of ecloud files, contacts, calendar, mail, location & Maps, and SMS.
Reaet network settings and rebooted. No change on BT and WiFi.
It’s only midnight but I’m done for the day. Next test I’ll see what happens if I do Nougat, then NOVENDOR, then Pi/e/ in a bid to retain data.
Regarding TWRP. The Essential Rooting Guide (Method 1) that provides the TWRP-SEP.img implies that touch in TWRP is technically fine but Pie images after a certain date broke it. The fact that touch worked perfectly durimg the Nougat phase but not after Pie was flashed kind of affirms that. Not the same as confirms though.
Addendum: Before retiring I flashed Pie and TWRP again so now the ROM occupies both slots. Rebooted back into recovery. Touch is working on both slots. Otherwise, no change.