Xiaomi Mi 9 (cepheus) for /e/OS-T 3.1
e-3.1-t-20250811-UNOFFICIAL-cepheus.zip
https://sourceforge.net/projects/eosbuildsronnz98/files/XiaomiSmartphones/e-3.1-t-20250811-UNOFFICIAL-cepheus.zip/download
Please see sources and install instructions including recovery here:
https://xdaforums.com/t/rom-13-cepheus-official-sparkos-23-09-23.4588447/
Use it at your own risk!
Please support the developer(s)
oh @ronnz98 has created a new system for the cepheus. 
it is a true joy.
I’ll test it and give a feedback.
Many thanks to @ronnz for the creation and your time and effort. 
hey @ronnz98
I have tested
clean installation.
Installation without error.
recovery only works to install but cannot start the system.
alternative recovery of lineagos or twrp works.
first test.
Fingerprint Scanner 
NFC
Bluetooth
WiFi
all standard apps work.
I will continue to test it as a daily companion and give feedback when I notice a mistake.
many many thanks for the creation and your time when creating the system.
.
hi @ronnz98
second test
from the best EOS creator of unsupported devices.
that is the first and only EOS for cepheus which runs smoothly and works. for me the best.
no freeze no forced restarts no automatic restarts until now.
tested for several days.
over 103 hours of current duration.
GPS
fake gps
hide IP address
applounge
Call/Internet/SMS
find my device
…
have not found anything yet, which does not work.
I find the option for slow charging of the battery really good.
it would be great who it would be available for all EOS systems for these devices.
Big thanks to the only @ronnz98 for its perfect creation of the EOS system.
it is a true pleasure and joy to see how perfect it works.
.
Hi, do you know where were the source of the kernel and how i would compile it? I wanted to enable some kernel features
You can fork it and add you commits:
I can then do a new build if you want
Thanks, i think i can compile the kernel myself. It is more of a project i want to do.
One last thing, you used the GitHub - Spark-Devices/android_kernel_xiaomi_cepheus at spark branch right?
no, I used pyro branch
Update for /e/OS-T 3.3 (beta):
Hey @ronnz98
What a joy 
@ronnz98 has created a new update for the mi9.
I will test it if it works and share experiences.
a big thanks for his hard work and time to the best creator for me for EOS. 
You can even try A15 based version:
e-3.2-a15-20251122-UNOFFICIAL-cepheus.zip
Sources:
Install instructions for A15, to be found here;
https://xdaforums.com/f/xiaomi-mi-9-roms-kernels-recoveries-other-dev.8592/
Hey @ronnz98
oh what happens today there is an a15 to test.
of course I will test it after 3.3 beta.
many many thanks for your hard work and time With the creation of the EOS system.
as soon as I have tested it I will of course give a feedback.
hey @ronnz98
First impression and installation
e-3.3-t-20251121-UNOFFICIAL-cepheus.zip
ota update without any problems 
tested for clean installation afterwards:
EOS Recovery only works when installing but system cannot start. 
alternative recovery works and let the system start.
What I have tested:
Bluetooth
all standard apps
Fingerprint Scanner
magicearth is not included, but you can install what you want in the F-Droid store.
system runs nice and smooth. 
Once again an excellent work from the best creator of eos. many many thanks for it.
Hey @ronnz98
First impression and installation:
e-3.2-a15-20251122-UNOFFICIAL-cepheus.zip
Clean installation tested:
EOS Recovery now works when installing and can also start the system.
There are errors when installing in the sideload, but in the end as a success. (status 0)
This is the first EOS recovery that works.
What I have tested:
Bluetooth
Standard apps
Fingerprint Scanner
What doesn’t work:
NFC no activation possible
sounds don’t work
But vibration goes.
SMS Messages APP crashes when opened
Note
Screen:
The colors look somehow pale compared to the 3.3beta and previous versions. Man can imagine it that way OLED to LCD.
Changing the modes in the settings did not lead to success.
But otherwise it works smoth.
Thank you so much for the a15 version with the first working recovery and your time the hard work you put in to make EOS work on so many devices.
Hi what does that mean sound does not work?
There is no sound. From either jack, hear and speaker ?
Is it a lake of dtb?
Is mic works?
Hey @rosbeef
As far as I remember, there was no sound from the speakers.
I didn’t test the microphone, if the sound doesn’t work, the microphone won’t help me.
You can test it yourself how it works for you.
Hi, sorry to bother you once again, do you mind if i ask how you are building it (docker or on bare linux)
and also, which blobs you are using (im assuming lineage os)
Thank you once again, (I am currently using your a15 build 
)
I’m using the traditional repo way and I’m using the sources that I refer to
