Re: Would Linux still be Linux if it didn't have an MMU was Re: Linux Port to NS486? (without MMU)
Alan Cox (alan@lxorguk.ukuu.org.uk)
Thu, 17 Oct 1996 22:44:00 +0100 (BST)
> around way before MMUs), but you'd lose a lot of the nice functionality
> of 'modern' unices such as linux. (paging vs. process swapping, memory
> protection, memory mapping)
You don't lose the protection for the intel case. The intel chips are strange
as they have two levels of insanity not one. The segmentation maps blocks of
memory to segment:offset pairs and those have base,limit,protection tuples
attached. Thus we can give each process a code,data and stack segment, and
even share code segments