General Starting kernel from source

[thomas1991_12]

Hello everyone,

I recently got this phone and of course noticed xiaomi didn't release the kernel source.
So I'm planning on trying to build a kernel from source that would work with stock miui (I'm aiming for 13.0.13.0 EU android 11 version at first).
My starting point is the source from CAF: LA.UM.9.15.1.r1-07200-KAMORTA.0. If you think a different source would be better please let me know, but I thought this one came closest).
Now I am looking at the Mi github for devices comparable so I can get some specific xiaomi/component source stuff. Currently looking at Redmi POCO M3 its A10 but should be okay.
I will post a link to github soon.

Just letting you know.

SOURCE: https://github.com/daeiron/spes_kernel

 

[thomas1991_12]

So I now have a compilable source here: https://github.com/daeiron/spes_kernel
I used proton clang to compile.

 

[thomas1991_12]

Okay so here is the first result, this is untested. But if someone wants to test it go ahead. My phone isn't unlocked yet
You could first try flashing test_boot.img to boot partition and see what it does (you should be on 13.0.13.0 stock), if that doesn't work you could try flashing dtbo.img to the dtbo partition.
Please make a backup first! This probably won't work.

 

[Vagelis1608]

This is very interesting.
It's great to see that there is another way to have a kernel source, even if Xiaomi doesn't want to release the official.
I'm in the middle of a move, so I can't test it because I need my phone fully functional, but I should be able to help out in time, especially once the kernel is more stable.

 

[thomas1991_12]

Can someone provide me a full dmesg log and maybe a logcat from just after boot. I could take a look at that while I am waiting for the unlock time of a stupid 7 days.

 

[thomas1991_12]

Does anyone have a schematic diagram for our phone? Im trying to find the UART pins

 

[hadrbass89]

How the project is doing?

 

[thomas1991_12]

I have some of the drivers, extra functions, device specific stuff ready in the source with some cherry picking and reverse engineering the stock kernel with ghidra, but not (nearly) everything. I was planning to find if there are uart pins on the main board with a logic analyzer as it wouldnt make sense to go forth without testing and getting it booting. Because it isn't booting yet. But Im going on a vacation to mid February so there won't be much progress until then unfortunately. If i remember correctly I still need to do the touchscreen/lcd driver (nt36...& focaltech, bq25.. charge driver, all camera's, all connectivity (this shouldn't be hard) and probably some more stuff. There is some source code out there for some of the things but they are not identical to the reversed source so that will be more tricky.

 

[Vagelis1608]

Something to keep in mind, there is most likely a bug in the wifi or the Bluetooth driver ( perhaps both? ) that causes the device to freeze a bit when both are on and the wifi signal is bad.
My guess is that the wifi driver tries to reconnect way too often and something freezes

 

[yorux2016t]

this is for redmi note 11?
and what's android version 11,12 or 13? pls

 

[Alex Zander-kun]

this is for redmi note 11?
and what's android version 11,12 or 13? pls

Presumably based on Android 12 kernels. But I believe it works regardless on the version. OP of this post literally is doing God's work

 

[Renate]

Does anyone have a schematic diagram for our phone? Im trying to find the UART pins.

I've never seen any schematics for anything and I can't believe they would be helpful.
A PCB layout would be helpful, but I haven't seen that either.

In ye old day a UART might have some level shifters.
Nowadays things are more minimal.
You'll get the raw pins out of the SoC.
You'll probably need a USB UART adapter that can work with 1.8V logic levels.

It would be nice to find the reset line, that's very helpful for hacking.
That way you don't have to wait for 10 second power button pushes.

An oscilloscope on likely test points on the board while booting is the easiest way to find a UART.

My specialty is Android ereaders and I've got a half dozen with permanently installed UART connectors.

 

[sonic011gamer]

I think UART should be your last resort, pretty sure the kernel should be writing to RAM and you can read that.

 

[Samuel Ladziansky]

Okay so here is the first result, this is untested. But if someone wants to test it go ahead. My phone isn't unlocked yet
You could first try flashing test_boot.img to boot partition and see what it does (you should be on 13.0.13.0 stock), if that doesn't work you could try flashing dtbo.img to the dtbo partition.
Please make a backup first! This probably won't work.

well Im going right now try it on pixelexperience 12.1. after that I give some feedback

well, phone instantly boot in to fastboot so nothing there, I was thinking if the source code is not out yet, then what source is used to create kernel for PE roms?

 

[luistro]

bueno, voy ahora mismo, pruébalo en pixelexperience 12.1. después de eso doy algunos comentarios

bueno, el teléfono se inicia instantáneamente en fastboot, así que no hay nada, estaba pensando que si el código fuente aún no está disponible, ¿qué fuente se usa para crear kernel para roms PE?

Stock kernel

 

[Samuel Ladziansky]

hmmm, so they edit only ramdisk to get it work with PE, interesting

 

[Samuel Ladziansky]

I do little searching and found this...

GitHub - javashin/android_kernel_xiaomi_bengal at 11.0-gcc

MoonBase™ CAF MSM-4.19 kernel source for POCO M3 / Redmi 9T [Fury-Bengal] [Force-Fast-Foward] /.PUSH./ - GitHub - javashin/android_kernel_xiaomi_bengal at 11.0-gcc

github.com

EDIT: here is original source from is forked https://github.com/MiCode/Xiaomi_Kernel_OpenSource/tree/lime-q-oss

is for "bengal" board but not SM6225 (sdm665) but SM6222 (sdm662)

but I think when we use kernel configuration from stock kernel (like in /proc/config.gz) we maybe get working kernel?

I am going to try it, I downloaded it and we will see

 

[7uta]

This seems interesting. Does it work as nicely as the kernel extracted from MIUI that all these custom ROMs are using?

 

[TheusKhan]

The time is over, guys.
Behold the source!!!

GitHub - MiCode/Xiaomi_Kernel_OpenSource at spes-r-oss

Xiaomi Mobile Phone Kernel OpenSource. Contribute to MiCode/Xiaomi_Kernel_OpenSource development by creating an account on GitHub.

github.com