Reminds me of ZeroPhone project from 2017: https://www.xda-developers.com/project-zerophone-news/ https://www.xda-developers.com/project-zerophone-news/, but no

Reminds me of ZeroPhone project from 2017: https://www.xda-developers.com/project-zerophone-news/ https://www.xda-developers.com/project-zerophone-news/, but now using a full-size Pi and a touchscreen. With the current availability and prices of Raspberry Pis, you might be better off getting a PinePhone as a Linux phone.