How much of an endeavour is it to compile a custom Android ROM from source for a specific device?

pythonmegapixel · September 12, 2020

I have a Lenovo A1010a20 (A Plus). It shipped with Lollipop but I'd really like to install a custom ROM. I have the bootloader unlocked and a TWRP image for it but I can't find it supported by any of the major custom ROMs.

I'm just wondering - how difficult would it be to compile the ROM (I was particularly looking at ResurrectionRemix but I could use another if it makes a massive difference) from source, to work on my device? I'm not too bothered about this phone, it wasn't very good even when it came out so I'm willing to use it as an experiment.

I have some experience with this stuff, but not a massive amount. Any help would be much appreciated.

Eigenvektor · September 12, 2020

Unless you have the particular drivers needed for the device's hardware, it's most likely a hopeless endeavor. Which is probably why you can't find any custom ROMs supporting it.

Nayr438 · September 12, 2020

For that device, more effort than its worth.

This will give a basic idea, this guide is however outdated. It also isn't very specific about things like vendor blobs and additional configuration. I really don't know any good guides to reference however.

https://fat-tire.github.io/porting-intro.html

You should also reference the AOSP documentation for general building.

https://source.android.com/setup

You would typically want to start with building the same AOSP version as what shipped with your device, then port it to a newer version of AOSP. Once that is done and working, you can target porting to various custom roms.

The process will mostly involve dumping blobs and configs, then adding them to the AOSP build system. It may be necessary as well when moving up versions to find other devices with similar hardware to pull various blobs from.

You may also need to upgrade your kernel along the way, which is a whole different discussion that comes with its own problems.

You should however be familiar with building AOSP and making modifications already for a device that is already apart of AOSP or another rom source before taking on a port.