Shipping this requires a long term commitment to porting all the relevant Pixel and Motorola/Snapdragon kernel drivers to the latest upstream LTS code. We've determined that's much easier than expected. The hard part is making the device independent LTS with all the backports.
@GrapheneOS one curiosity question, how much differt Android Kernel from a normal linux one, if we magically can be sure the device drivers work on linux's and exclude minimal bug, will it work ?
@maya Android itself essentially works with mainline kernels but it expects a lot of fixes and features to be backported to the LTS branches from mainline. It's nearly entirely the device drivers which are actually out-of-tree and need a lot of out-of-tree changes to support them. The device drivers are not hard to port forward to newer kernel branches but depend on having a lot of added infrastructure for writing drivers against a stable ABI. We're going to port that to the latest LTS revision.
@maya We've made a port already which can boot with basic functionality working using the latest LTS revision but we're still far away from being able to ship it in production. We're making a lot of progress towards using 6.18 for all devices in the near future and then porting to the latest upstream 6.18 LTS from the GKI LTS branch. That means having to port all the useful backported fixes and features to the upstream 6.18 LTS branch combined with adding the GKI hooks, etc. the drivers call.
@maya The purpose of porting this to the upstream LTS instead of following Google's approach of merging the upstream LTS into the GKI branch is to abandon ABI stability. We don't want ABI stability requiring reverting tons of changes deemed not required and also adding more GKI indirection when it is deemed required. It used to be going relatively smoothly but we believed it was a huge mistake and kept saying. We've been proven right now that the system has collapsed. GKI was a clear mistake.
@GrapheneOS i guess that the actual need of somewhat fresh kernel, due to the massive amount of AI found vulnerability in those kernel had some weight in your idea to drop GKI ?
@maya Yes, we need to be on the most recent or 2nd most recent LTS branch. A new LTS branch is going to be released soon. We can wait around 6-10 months for it to be stable and have enough of the newly introduced vulnerabilities eliminated prior to moving to it. We can't be on older LTS branches than that anymore.
The mainline releases and very short lived stable branches are not a reasonable choice for production and have a lot of new security vulnerabilities. LTS is good but only recent LTS.
@GrapheneOS You are awesome. Thanks for taking on this greater effort.