Per one tech forum this week: “Google has quietly installed an app on all Android devices called ‘Android System SafetyCore’. It claims to be a ‘security’ application, but whilst running in the background, it collects call logs, contacts, location, your microphone, and much more making this application ‘spyware’ and a HUGE privacy concern. It is strongly advised to uninstall this program if you can. To do this, navigate to 'Settings’ > 'Apps’, then delete the application.”
Halium is basically what you’re talking about. It uses the Android HAL to run Linux.
The thing is, that also uses the Android kernel, meaning that there will essentially never be a kernel update since the kernel patches by Qualcomm have a ton of technical debt. The people working on porting mainline Linux to SoCs are essentially rewriting everything from scratch.