On: Interview with Andreas Kling of Serenity OS (2022)

[tonetegeatinst]

I think tinycore would be your best bet.

Its linux but stripped down to the very bare essentials

[filleduchaos → tonetegeatinst]

Tiny core Linux is far too heavy for what they're asking for. It's the very bare essentials for a user, not a bare metal programmer.

The OSDev wiki has lots of actually minimal examples for different architectures and boards