TWRP Zip: Crossflash Sprint g8 to OPEN US 20C

antintin

Senior Member
Sep 11, 2019
595
118
43
Finally!

First of all, this is mostly only useful for those who bootloader unlocked the sprint g8 for other reasons and lost the ability to update because of a lack of kdz support. I would not recommend bootloader unlocking just to flash this at all, except for volte if it is an absolute must. It also only works if your active slot is A, and if the slot with the engineering abl is B.

As many of you likely already know, crossflashing on LG's sdm 855 models is a huge pain because of a hardware lock put in place, which crosschecks a hardware ID with a software ID and gives you an OPID mismatch error on boot if they aren't the same.

Some people, including myself, crossflashed system, vendor, and product a while ago, but the OP partition was the culprit in the OPID mismatch error mystery. In my sprint 20d OP partition, I decided I would try and edit every single file containing "sprint" "SPR" or "SPR_US," to try and see if editing them would cause an OPID mismatch. Turns out it did, and the exact file ended up simply being /OP/totc.cfg, which only contained "SPR_US"

So all I had to do was extract the OP partition from a OPEN US kdz, flash it in twrp, and then manually replace totc.cfg with one I had saved from my sprint OP. Extracting OP is a pain since kdztools doesn't do it correctly on its own, so unless you specifically need the OP from a different variant, I would stick with the zip provided here.

However, this might only work for the sprint model, as on the korean v50, the NT code must be edited after crossflashing OP to be able to use any networks, which can only be done when IMPL = 0.

This is just a compiled zip containing the system, product, vendor, and OP partitions from OPEN US 20c (August patch and volume bar but no full velvet UI). It also flashes the metaphysics kernel 1.7 with magisk 21.0 and TWRP pre-included, in addition to flashing vbmeta, p_persist_lg, and dtbo partitions from sprint 20d (which may or may not be identical to the OPEN US ones).

Looking for volte and vowifi? It works without any additional modifications on most if not all US carriers as far as I'm aware (personally on t-mobile)! You also get access to the full hidden menu with *#546368#*820#, so you can configure APNS or other things there

I also made some pretty significant changes in these partitions, (just for myself originally, don't want to take credit for being a dev or anything) listed below:
- Heavily Debloated
> if you want some of the LG apps back, like qmemo+, download them on apkmirror
> All the removed google apps can be downloaded on play store, which is good because they'll be user apps

- Replaced LG Home with lawnchair as default launcher and recents provider
> I was going to use oneplus launcher instead (which is what I use), but it has some trackers and is not open source, so I decided against it.
> If you do want to try it, just look up "xda oneplus launcher mod 4.6.5," and flash the magisk module provided in the thread. I would also install app manager from fdroid / aurora droid and use it to block its trackers

- LG RCT (root checking tool, known to impact performance) removed

- Replaced LG's file manager with Amaze (fdroid version) as default file manager

- Replaced google messages with Qksms (fdroid version)

- Replaced chrome with bromite

- Deleted LG and google keyboard and replaced with openboard (if you want to use gboard like me, use afwall+ on it)

- That's it... Was going to try some System UI edits, but I'll leave that for the future ;)

Here's the gdrive download for the TWRP flashable zip:
https://drive.google.com/file/d/1mTm3kCxkwUKTVBq4_NaJE-sw36_P_QGS/view?usp=sharing


Finally, if you want the stock feel back, here is a zip containing unmodified OPEN US 20c product and system partitions. Extract the zip and flash the partitions, DO NOT try and flash just the zip in TWRP:
https://drive.google.com/file/d/12eeNXR7gq4d-WdDVz6SXhn6PEt2MSIhP/view?usp=sharing
 
Last edited:
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Pino13

Member
Apr 30, 2011
41
11
0
Excellent ROM, I'm enjoying it, really clean and fast, battery life is better than the Sprint ROM.
My active slot was B, but I was able to flash it using Fastboot (thanks antintin for the support).
 

maksimbl4

Member
Apr 10, 2013
18
2
23
Excellent ROM, I'm enjoying it, really clean and fast, battery life is better than the Sprint ROM.
My active slot was B, but I was able to flash it using Fastboot (thanks antintin for the support).
Can you write instructions please)
I try write files from archive in B slot, but OP and another partition give error on console that. "Can not flash this partition in unlocked station"

Отправлено с моего LM-G820 через Tapatalk
 

hellokuan

Member
Dec 3, 2020
5
0
11
@antintin,how to active “screen sharing" fuction of your "Crossflash Sprint g8 zip" image, thanks you provide this good firmware,
please,please add this fuction!
@antintin
and “unmodified OPEN US 20c product and system partitions”,can you update file link?

thanks very much
 

hellokuan

Member
Dec 3, 2020
5
0
11
@antintin
We like your work very much and it will benefit us.
but for me, i need “share screen” function,
If you have time to do this feature well, we thank you very much, otherwise we feel helpless
 

Bronnel

Senior Member
Nov 14, 2015
262
101
73
Iraq
does this allow flashing modem partition so that you can get rid of sprint carrier restrictions completely?

Update
I believe the the OP partition is same as Modem, but I don't know if there is hardware limitations.
 
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brigantti

Senior Member
Jul 25, 2013
151
19
38
Calexico

brigantti

Senior Member
Jul 25, 2013
151
19
38
Calexico
Thanks

But after that i realise it has lost dual speaker and hand id. Do you have same thing ?
No on my side in fact i runs fine on mine.
The only thing different that i did was to change to stock boot img 20c modded with magisk,because the kernel that atintin use makes my phone to random reboot.now with stock everything is perfectly smooth.