Expert advice on restoring someone's efs?

[taran181]

hi all, as people are posting tutorial to downgrade from pie to oreo with the help of restoring boot and efs folder uploaded by them,, is it safe to restore from someone's else twrp backup i mean efs folder??
as per my knowledge efs is backup of imei right?
so restoring from someone's else efs won't affect mine imei?

 

[taran181]

No help here?

 

[taran181]

??????????????????????????????/

 

[vasu1]

i don't think so people are helpful here or either not expert as nobody is replying lol

 

[GuestK00164]

No idea. Sorry

 

[.:Addicted:.]

hi all, as people are posting tutorial to downgrade from pie to oreo with the help of restoring boot and efs folder uploaded by them,, is it safe to restore from someone's else twrp backup i mean efs folder??
as per my knowledge efs is backup of imei right?
so restoring from someone's else efs won't affect mine imei?

4-6 months back there was thread why we should not restore efs of someone & proper tutorial for people who messed up their mac address with some kernel.
Now this tutorial on downgrading pie to oreo. I have no idea. Someone's efs would mess your IMEI, wifi mac, Bluetooth mac, thats what i think. But there are tutorial how to edit imei using some Qualcomm tool.
Ask @CosmicDan. He's the expert.

 

[CosmicDan]

Just flash Oreo on fastboot, with full wipe. Why doesn't that work?

 

[tanapak1]

I was having an issue since using custom rom with december fw btw.

and I was mistaken flashing november fw back to solve some calling issue, so I ended up with no signal which should be came from I didn't restore dev's efs backup.

So I start from flashing full clean stock november and ended with bootloop on it, which is something I still curious what cause it.

At that times, I'm on locked bootloader and can't even enter edl to reflash the rom and can't unlock bootloader since the rom still not booting to enable oem unlocking option.

I don't remember what I have done to it, but at times my phone can boot with no signal, 0 imei on sim1 and null on sim2.

So I start to rewrite the imei then everything is back to normal.

 

[fhsd22]

Downgraded using the method of restoring boot and efs... Nothing changed for me, imei is the same as in the box of my mi a1. ? Maybe people did something before doing the downgrade that messed up something.

 

[taran181]

Just flash Oreo on fastboot, with full wipe. Why doesn't that work?

@CosmicDan no flashing just oreo doesn't help, phone gets stuck in bootloop, so people has posted tutorial about flashing their efs and boot etc through twrp to get out of bootloop.

Eg: https://forum.xda-developers.com/mi-a1/how-to/tutorial-downgrade-9-0-to-8-1-edl-imei-t3879624

 

[taran181]

Downgraded using the method of restoring boot and efs... Nothing changed for me, imei is the same as in the box of my mi a1. ? Maybe people did something before doing the downgrade that messed up something.

but my question why use someone's else efs while downgrading, as efs contains imei and modem backup ..

 

[CosmicDan]

@CosmicDan no flashing just oreo doesn't help, phone gets stuck in bootloop, so people has posted tutorial about flashing their efs and boot etc through twrp to get out of bootloop.

Eg: https://forum.xda-developers.com/mi-a1/how-to/tutorial-downgrade-9-0-to-8-1-edl-imei-t3879624

Well you can try it I guess, just backup the EFS partition and other stuff with my backup tool and you can always go back if worse comes to worst.

 

[barrack1]

Just flash Oreo on fastboot, with full wipe. Why doesn't that work?

Xiaomi put out a message on their forum that after the Pie update, the phone should not be rolled back. Its for all Android one models. When users flash an older roms, bootloops occur.
https://www.fonearena.com/blog/271177/xiaomi-pie-oreo-downgrading-disabled-android-one-devices.html

 

[CosmicDan]

but my question why use someone's else efs while downgrading, as efs contains imei and modem backup ..

But what he is saying is that he did downgrade EFS, but IMEI didn't change. This suggests that EFS isn't the original source of IMEI after all. Or maybe the bootloader can re-write IMEI and stuff on boot, who knows... Surely others have actually confirmed that EFS cross-flash = IMEI change, right? Not just assumed?

...point is, you can backup your EFS via EDL mode so there should be no risk. If you made a full EDL backup of your own device when you were still on Oreo then you would be golden, as EDL has full access to all partitions.