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From: terry@cs.weber.edu (A Wizard of Earth C)
Subject: Re: 386BSD - what a pain to install!
Message-ID: <1992Sep27.091749.2076@fcom.cc.utah.edu>
Sender: news@fcom.cc.utah.edu
Organization: Weber State University (Ogden, UT)
References: <19pph4INNp6j@disaster.Germany.EU.net> <19r472INNnot@corax.udac.uu.se> <1992Sep27.020909.2692@cs.unca.edu>
Date: Sun, 27 Sep 92 09:17:49 GMT
Lines: 36
In article <1992Sep27.020909.2692@cs.unca.edu> snodgras@cs.unca.edu (Ryan Snodgrass) writes:
>Also is it possible to have both DOS and BSD on the system? Thanks. Oh and
>one other quick question. I know it is 386BSD, but is it possible to put it
>on a 286?
You can store it on any computer! 8-).
Seriously: No. A 286 is not capable of a lot of the modern memory management
required byt a BSD UNIX. The last version of a UNIX that would run on a 286
with little effort is SVR3.2. You had to rewrite the code dealing with the
two memory operations which could fail abnormally (ie: requiring a hardware
trap mechanism or MMU); these were a segementation violation (which you treat
as a segmentation violation, and a stack grow, which you anticipated using
"stack probes".
The memory protection on a 286 is rather primitive as well, and it's difficult
to limit address spaces. This is generally accomplished (by Xenix, as an
example) by only running code in medium model, where you have unlimited text
(read only) pages per program, but only 64K (1 segment) of data (read/write)
pages.
Of course, anyone who wants to is welcome to retrofit the kernel and the
compiler to make this work for 386BSD.
Terry Lambert
terry_lambert@npd.novell.com
terry@icarus.weber.edu
---
Any opinions in this posting are my own and not those of my present
or previous employers.
--
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"I have an 8 user poetic license" - me
Get the 386bsd FAQ from agate.berkeley.edu:/pub/386BSD/386bsd-0.1/unofficial
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