From owner-freebsd-hackers Thu Apr 17 20:37:47 1997 Return-Path: Received: (from root@localhost) by freefall.freebsd.org (8.8.5/8.8.5) id UAA29077 for hackers-outgoing; Thu, 17 Apr 1997 20:37:47 -0700 (PDT) Received: from kithrup.com (kithrup.com [205.179.156.40]) by freefall.freebsd.org (8.8.5/8.8.5) with SMTP id UAA29068 for ; Thu, 17 Apr 1997 20:37:45 -0700 (PDT) Received: (from sef@localhost) by kithrup.com (8.6.8/8.6.6) id UAA18664; Thu, 17 Apr 1997 20:37:24 -0700 Date: Thu, 17 Apr 1997 20:37:24 -0700 From: Sean Eric Fagan Message-Id: <199704180337.UAA18664@kithrup.com> To: chadf@bookcase.com Subject: Re: FS & GS registers not in sigcontext? Newsgroups: kithrup.freebsd.hackers In-Reply-To: References: Organization: Kithrup Enterprises, Ltd. Cc: hackers@freebsd.org Sender: owner-hackers@freebsd.org X-Loop: FreeBSD.org Precedence: bulk >#ifdef linux >/* fs and gs are not supported on *BSD. Hopefully we won't need them. */ >#define FS_sig(context) ((context)->sc_fs) >#define GS_sig(context) ((context)->sc_gs) >#endif > > And I was just kinda curious why they weren't in there? I mean is >there a reason behind it, or is it just one of those "nobody's bothered >yet" kinda things? The fs and gs registers are not saves on the stack by the processor except in VM86 mode. We have some support for that, as announced on -emulation several times, but it's not perfect, and, frankly, the interest level has not seemed worth the effort we've put into it. (The learning we all got from it has probably been worth it :).) (Before I get a dozen people saying, "Hey, I'm interested" -- it won't run 32-bit programs, which means it won't run most Windows binaries. Most of the OpenDOS programs I've tried seem to work, but not all, and we have very mixed success with "real programs." of course, part of that is because it's *hard* to find DOS-only "real programs" these days! But if you do think you're interested, some 2.2-relative patches are on freefall.cdrom.com:~ftp/pub/sef.) Sean.