From owner-freebsd-arch Tue Jun 13 0:25:27 2000 Delivered-To: freebsd-arch@freebsd.org Received: from anchor-post-34.mail.demon.net (anchor-post-34.mail.demon.net [194.217.242.92]) by hub.freebsd.org (Postfix) with ESMTP id F1E7D37BAB7 for ; Tue, 13 Jun 2000 00:25:20 -0700 (PDT) (envelope-from dfr@nlsystems.com) Received: from nlsys.demon.co.uk ([158.152.125.33] helo=herring.nlsystems.com) by anchor-post-34.mail.demon.net with esmtp (Exim 2.12 #1) id 131l4X-000HhD-0Y; Tue, 13 Jun 2000 08:25:17 +0100 Received: from salmon.nlsystems.com (salmon.nlsystems.com [10.0.0.3]) by herring.nlsystems.com (8.9.3/8.8.8) with ESMTP id IAA14192; Tue, 13 Jun 2000 08:26:43 +0100 (BST) (envelope-from dfr@nlsystems.com) Date: Tue, 13 Jun 2000 08:29:51 +0100 (BST) From: Doug Rabson To: Daniel Eischen Cc: Bruce Evans , arch@FreeBSD.ORG Subject: Re: Syscalls and execve In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Sat, 10 Jun 2000, Daniel Eischen wrote: > On Sat, 10 Jun 2000, Doug Rabson wrote: > > The trapframe which is created for syscall is identical to the trapframe > > for exceptions and interrupts, its just not fully populated with register > > values. > > On a related subject, the alpha sigcontext is different than the > trapframe. This makes implementing {get,set}context slightly more > difficult because they have to know which frame is in the machine > context. For the new threads architecture (similar to scheduler > activations), the context of threads that become unblocked in > the kernel is passed out to the user threads library. I want to > add {get,set}context as library routines and use them to handle > both signal contexts and trapframes as passed out of the kernel. > > This isn't a big deal, we can just have a different set of routines > to handle trapframes for the alpha, but if there is an opportunity > to make trapframes and signal frames consistent (as they are on > i386)... It would be difficult to make trapframe match sigcontext without changing sigcontext to look more like the current trapframe (which is partly dictated by PALcode). I don't think the associated cost of changing the kernel ABI is worth the gain. Also, the fpregs state is totally unneeded for trapframe since the kernel doesn't disturb the fp state during traps. -- Doug Rabson Mail: dfr@nlsystems.com Nonlinear Systems Ltd. Phone: +44 20 8442 9037 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message