Consider a Single Program and Operating System
In the embedded world where a small computer is used for a specific function, such as the one in your keyboard or mouse, there is typically no general purpose operating system involved. The computer does one thing and typically does it well.
A cellphone that is not a smartphone is almost the same. There is no need to be able to run other programs, especially user downloaded programs.
Often a non-general purpose device can be a significant help in reducing the possibility of a virus being loaded by a user or due to an operating system flaw.
ShofarNexus is designed for that purpose. It can be used in it’s basic form for things like phones, web servers, or media servers. ShofarNexus can be customized and renamed to be something completely different, such as running gas pumps, which has been done. Perhaps you have a need?