I'm 99% sure the original kernel and thus the boot&root disk Linux (the original "distribution" I guess) only ran on the 386 & up as it required & used the memory management capabilities.
There were some forks that could run without the mmu (micro-Linux I think?) but as I recall it they came quite a bit later.
There were some forks that could run without the mmu (micro-Linux I think?) but as I recall it they came quite a bit later.
Edit: Ah, close, this: https://en.m.wikipedia.org/wiki/%CE%9CClinux