RE: [gentoo-soc] Weekly Report: Portage Powered Android

[Pengcheng Xu]

Sorry for not getting back for some time; I had some other affairs that kept my hands busy.  I have some comments for this week's report.

> -----Original Message-----
> From: Gunwant Jain <therealgunwant@×××××.com>
> Sent: Tuesday, June 23, 2020 3:16 AM
> To: gentoo-soc@l.g.o
> Cc: heroxbd@g.o
> Subject: [gentoo-soc] Weekly Report: Portage Powered Android
>
> Hello Everyone,
>
> I was supposed to integrate `bootstrap-init` and `sar-preinit` into SharkBait
> this week. I couldn't quite do that.
> `bootstrap-init` was initially cross-compiled for aarch64 using NDK. So the
> first job was to get rid of NDK and use a different "build-system".
> I opted for CMake and ported the project to use it [1]. But the binary compiled
> by CMake on my phone (arm64 Gentoo), would not boot Android.
> The build rules can be inspected on [1].

Have you figured out _why_ Android is not booting?  I can think of a bunch of reasons, such as missing dependencies for a dynamically-linked executable, crashing on execution, etc.  Simply saying "would not boot Android" does not convey any information.

Besides, I don't think you need NDK for something as low-level as an init; you shouldn’t need one as long as the code does not use Android-specific functions or call into Android service (e.g. vold).  You should be able to get away with something standard, i.e. newlib/musl/glibc.  I haven't read the source code though, and I might be wrong here; do your survey.

>
> I believe this is because of the fact that I am not using a Bionic based toolchain.
> So, I started working on building such a toolchain mid-week.
> And this is where my current task starts coinciding with my next scheduled task
> of providing a aarch64-linux-android toolchain where we build Bionic as well.
> The crux of this task was already performed by KireinaHoro in his GSoC [2].
> Since my next scheduled task is required to be finished for my current task,
> I propose to merge `bootstrap-init` along with `sar-preinit` together later
> in the SharkBait workflow.

You may try with bionic toolchain, but just as I said, so long as no Android-specific APIs are involved, libc should not be the problem.

>
> And to cover the installing process for users right now, I will write a blog
> and post it on [3] within 24 hours of writing this mail. The blog will provide
> a guide on assembling the components required for System-As-Root based Android
> devices and installing SharkBaitOS. Keep in mind that this process will indeed
> be simplified for the user later.
> And I propose to edit SharkBait's official wiki later in my GSoC tenure explaining
> the simplified procedure to end-users and porters.
>
> Thanks,
> Gunwant
>
> [1] https://gitlab.com/WantGuns/bootstrap-init/-/tree/cmake
> [2]
> https://wiki.gentoo.org/wiki/Android/SharkBait/Building_a_toolchain_for_aa
> rch64-linux-android
> [3] https://wantguns.gitlab.io/

Regards,
-- 
Pengcheng Xu
https://jsteward.moe