Date: Sat, 30 Nov 1996 09:57:18 -0500 (EST) From: "John S. Dyson" <toor@dyson.iquest.net> To: msmith@atrad.adelaide.edu.au (Michael Smith) Cc: toor@dyson.iquest.net, msmith@atrad.adelaide.edu.au, imp@village.org, platforms@FreeBSD.org, dyson@FreeBSD.org Subject: Re: FreeBSD/MIPS anybody Message-ID: <199611301457.JAA10579@dyson.iquest.net> In-Reply-To: <199611300916.TAA25734@genesis.atrad.adelaide.edu.au> from "Michael Smith" at Nov 30, 96 07:46:38 pm
next in thread | previous in thread | raw e-mail | index | archive | help
> > This is an understatement of the first order 8) and the problem that I > was trying to get at; there's a significant body of > processor-dependant code tied to the VM required for any port, and for > FreeBSD, this code is sufficiently different I couldn't, for example, > take a pmap/locore from an old BSD port to the Sony NEWS and use it > (even modulo hardware changes) on my Mipsco boxes for FreeBSD. > > Of course, if I'm wrong and it's actually totally trivial, then I'll > just go sit in the corner and cry 8) Any chance of a pmap(9) manpage > detailing its features and requirements? 8) > I have problems even making trivial mods to the pmap code, and being successful. One problem is that wrong-ness in the code doesn't always break things immediately. I suspect that given a new architecture just to get it barely running, the pmap mod would be approx as complex as two or three typical drivers (just a wild estimate.) In the pmap code, one needs to understand precisely what it needs to do (both the machine and the VM code.) For example, Bill Jolitz, writing the pmap code for the 386, apparently copied the hp code. I started a VM doc, but lost it in a disk crash. I might be able to start one again, but it would be a week or so at least to write (to complete.) Can't promise anything in the next week or so though, as bugs like the MSDOS problem appear regularly. John
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199611301457.JAA10579>