Would Linux still be Linux if it didn't have an MMU was Re: Linux Port to NS486? (without MMU)

Steve VanDevender (stevev@efn.org)
Thu, 17 Oct 1996 09:12:24 -0700


mmap() just maps files into regions of memory. If an OS does not have
mmap() it may still require an MMU to run. Generally if an OS provides
reliable process memory protection (that is, there is NO WAY for a
process to ever write outside the memory region allocated to it) or
demand-paged virtual memory, then it almost certainly requires a
hardware MMU. Linux as we know it must run on a processor with a
hardware MMU (that's why the 680x0 port requires an '020 with MMU or an
'030 or later). Linux-8086 is a proposed stripped-down version that
could run on 80x86 processors without the MMU hardware, at the cost of
losing demand-paged virtual memory and process memory protection.