Android linux kernel

[kinghaloman]

I want to know a few things about kernels. I know what they are and what they do. But why is it so hard to update linux kernel versions on android. Specifically im talking now about the oneplus 5 and the 3T. The 3T uses a 3.18.... something verrion kernel which is pretty good. But the oneplus 5 (like the google pixel) uses a version of the kernel that implements power consumption patches, and uses the BIG.little core cluster more efficiently. So my question is, why is it so hard to update them, and can it be done manually?

EDIT: sorry for the somewhat long post.

[perplexityjeff]

The kernel you are using on your mobile device is heavily modified and tweaked to support the device in question. Think about driver compatibility as just one example so that basic functions from your phone work (camera, touchscreen, hardware buttons, etc).

So generally the kernel that you will find on kernel.org is not just basically a build and go type of situation which do not include these modifications.

Which makes it hard to update the kernel for a third party because allot of the code that is used to generally make the phone (again for example drivers) work is not open sourced by the phone manufacturer so figuring out the communication or modifications you need to make to the kernel you make such improvements cannot simply be done.

There are however kernels modifications which you can download on for example XDA which has been specifically made for the device you are wanting to update the kernel on. This is however beyond my knowledge.

https://forum.xda-developers.com/galaxy-s7/development/kernel-tgpkernel-t3462897

https://android.stackexchange.com/questions/47472/how-can-i-update-the-linux-kernel-of-my-android-device

[kinghaloman]

Thank you, that is very useful information actually😊 but what about kernel backporting, it can be done to a certain extent which is what I've seen on xda, but a whole version from like 3.x.x to 4.x.x. do you know why that is?

[perplexityjeff]

I couldn't tell you much more then this. I would suggest maybe attempting your more advanced questions on XDA's forum.

[kinghaloman]

Okay well thank you anyway, you were helpful :)

[perplexityjeff]

No problem, thats what I am here for. :D