I just got back a Oneplus 9 which is in OxygenOS with Android 13.
I’d like to install e/OS/ on it.
As it says in the documentation page [https://doc.e.foundation/devices/lemonade/install] “Before following these instructions please ensure that the device is on the latest Android 12 firmware.”, I guess you can’t install without switching back to stock Android 12 rom.
I can’t find where to download the Oneplus firmware archives with the Android 12 version and the software to install. (sorry i’m more used to xiaomi…)
If anyone knows, I’m interested.
Thank you for your help.
I’m sorry I can’t help you on the process but just wanted to say hi to a fellow OP9 user. Should you plan to root your device: I made an interesting topic about that. Good luck!
I’ve been out of the loop with oneplus devices for a long time so can’t be much help.
That XDA link is the place to go for starters. Checkout post#300 which broadly confirms my thoughts, i.e: you need specific firmware package for downgrading from major android version to another.
I remember doing this from 12 to 11 on device, and I think a wipe of data is involved. In your case you would probably try the C.62 downgrade zip for whichever variant of phone you have, global, eu or india.
The basic steps to do this are described in my old post that @piero has linked.
Is the local updater available in the settings under oos13 by the way? If not you may need to install something.
MSM download tool is another option but you need windows pc/laptop for that. and some good instructions from somewhere on the forum. I’ll have a look to see if I can find my old links.
I’ve already tried Local updater.
Unfortunately, it’s no longer available in OOS 13. In fact it appears but it’s grayed out.
So I had to install the system updater from apk file and I got the message “downgrading is not allowed”.
MSM isn’t my first choice as I’m on linux…
I’ll take my time.
And yes, waiting for e/OS/ android 13 is a solution I’m considering too.
Well, when I saw that Android version 13 of e/OS/ had been pushed back to version 1.15, I resumed my research.
In case this happens to anyone else, I don’t know why the local updates option was grayed out on the phone, but by doing a factory reset and not connecting the phone to the wifi and without a sim card (in short, without a network), this option became usable.
So I was able to downgrade to version 12 using the “Downgrade zip” LE2113_11_C.62: LE2113_11.C.62_1620_202206251351
After connecting to wifi, I got the C66 version proposed as an update, which I installed.