Android Project Mainline "Google Play system updates" security patches
are built weekly & hotfix your Android 10+ device seamlessly every month,
forever (at least as far as anyone can tell anyway). <== pray tell.

These forever security updates are apparently applied when you reboot.
(Although I do not know if the A/B Pixel partitioning modifies that.)

To complicate things, the "Reboot Chronicles" talks about soft reboots.
"From Android 11 onwards, devices can employ soft reboots that refresh
system elements." <== if you know more about soft reboots - pray tell.

This forever monthly security update is almost completely hidden from
the view of the typical user - which is likely why most people do not
seem to know about it - even as we've been discussing it here for years.

Apparently in Android 12 Google introduced a progress bar during reboot.
<https://www.xda-developers.com/google-play-system-update-percent-progress/>
<https://9to5google.com/2021/07/01/google-play-system-update-install-progress-now-displayed-under-boot-animation/>
<https://www.androidpolice.com/2021/07/01/android-12-got-a-small-reboot-animation-tweak-for-the-impatient-among-us/>
etc.

But otherwise, it's hard to notice these seamless forever monthly updates.

However... "Advanced users can leverage command-line tools to manage
and inspect APEX module installations..." <== pray tell!

August 13, 2023
*Reboot Chronicles: An in-depth look at Android Mainline updates*
<https://www.intuneirl.com/why-your-android-device-reboots/>

At its core, Project Mainline breaks down the essential components
of the Android OS into distinct modules. Each module encapsulates a
specific fragment of the system, paving the way for them to be updated
individually without a full system overhaul.
<https://source.android.com/docs/core/ota/modular-system?ref=intuneirl.com#available-modules>

Introduced with Android 10, Project Mainline enables Google to update
specific internal components of the Android OS directly via the Play Store,
without needing full system updates.

It is designed to distribute new Android features to users of various
Android versions without requiring them to perform a complete OS update.

This approach offers several benefits:
1. Speed: Updates can be rolled out faster since they bypass the traditional
lengthy manufacturer and carrier validation processes.
2. Frequency: As updates can be smaller and more targeted,
users can receive them more frequently.
3. Security: Critical security patches can be delivered promptly,
ensuring devices remain secure.

For experts like Andy Burns, using adb, I looked at the "/proc/last_kmsg" file
on my unrooted Samsung and it was empty (although they said it was a folder).
--
Forever here means nobody knows of any EOL date for the 37 core Android
modules and even if there were, the source code is donated to the AOSP.