From owner-freebsd-hackers Sat Mar 21 13:53:28 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id NAA08232 for freebsd-hackers-outgoing; Sat, 21 Mar 1998 13:53:28 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from smtp01.primenet.com (smtp01.primenet.com [206.165.6.131]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id NAA08225 for ; Sat, 21 Mar 1998 13:53:21 -0800 (PST) (envelope-from tlambert@usr09.primenet.com) Received: (from daemon@localhost) by smtp01.primenet.com (8.8.8/8.8.8) id OAA20314; Sat, 21 Mar 1998 14:53:12 -0700 (MST) Received: from usr09.primenet.com(206.165.6.209) via SMTP by smtp01.primenet.com, id smtpd020295; Sat Mar 21 14:53:08 1998 Received: (from tlambert@localhost) by usr09.primenet.com (8.8.5/8.8.5) id OAA06633; Sat, 21 Mar 1998 14:52:58 -0700 (MST) From: Terry Lambert Message-Id: <199803212152.OAA06633@usr09.primenet.com> Subject: Re: mremap? To: toor@dyson.iquest.net (John S. Dyson) Date: Sat, 21 Mar 1998 21:52:58 +0000 (GMT) Cc: jlemon@americantv.com, toor@dyson.iquest.net, mike@smith.net.au, perlsta@cs.sunyit.edu, hackers@FreeBSD.ORG In-Reply-To: <199803202238.RAA18127@dyson.iquest.net> from "John S. Dyson" at Mar 20, 98 05:38:01 pm X-Mailer: ELM [version 2.4 PL25] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > > (Why? I wanted a "vm86" process, with 1MB mapped starting at address 0, > > and the same region mapped into the "control" process, at a different > > location.) > > > > EG: > > boolean_t > > vm_map_shared(smap, dmap, saddr, daddr, size) > > vm_map_t smap, dmap; > > vm_offset_t saddr, daddr; > > vm_size_t size; > > > > Would this type of routine be useful? > > I suspect that it would be useful, given a "use." I don't know enough > about exactly what the userland API would/should look like (re: security, > and features) to implement it "off the top of my head." > > If there is a reasonable justification for a new system call or equiv, > I am all for it!!! I would expect that it would be useful for thunking work to a VM86 process that would then make BIOS calls based on the "work" you gave it. IMO, this would be most useful is the VM86 process was, in fact, a kernel process, so that it could be crafted and executed in kernel space priori to the system coming available, and used for things like INT 13 reads, INT 10 mode settings for video cards, and so on. My preferred mechanism for doing this would be to use a call through procfs to establish the mapping. Of course, I preferred using procfs to set attributes on one's self instead of an rfork implementation (this is, in fact, how I implemented the interprocess sharng of the per process descriptor table in UnixWare). Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message