From owner-freebsd-alpha Mon Nov 11 6:44:49 2002 Delivered-To: freebsd-alpha@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id F180437B401 for ; Mon, 11 Nov 2002 06:44:47 -0800 (PST) Received: from critter.freebsd.dk (critter.freebsd.dk [212.242.86.163]) by mx1.FreeBSD.org (Postfix) with ESMTP id 2095543E77 for ; Mon, 11 Nov 2002 06:44:46 -0800 (PST) (envelope-from phk@critter.freebsd.dk) Received: from critter.freebsd.dk (localhost [127.0.0.1]) by critter.freebsd.dk (8.12.6/8.12.6) with ESMTP id gABEiVOr055060; Mon, 11 Nov 2002 15:44:31 +0100 (CET) (envelope-from phk@critter.freebsd.dk) To: Andrew Gallatin Cc: alpha@FreeBSD.ORG Subject: Re: ev4/5/6 issue ? In-Reply-To: Your message of "Mon, 11 Nov 2002 08:56:57 EST." <15823.46889.535089.487743@grasshopper.cs.duke.edu> Date: Mon, 11 Nov 2002 15:44:31 +0100 Message-ID: <55059.1037025871@critter.freebsd.dk> From: Poul-Henning Kamp Sender: owner-freebsd-alpha@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org In message <15823.46889.535089.487743@grasshopper.cs.duke.edu>, Andrew Gallatin writes: > >Poul-Henning Kamp writes: > > (gdb) where > > #0 0x12001f4e8 in ?? () > >Try 'disassemble' here, please. (gdb) disassemble 0x12001f4e8 No function contains specified address. (gdb) disassemble No function contains program counter for selected frame. > > 1. Why doesn't file(1) tell me if a binary is ev45 or ev6 ? > > > > 2. Couldn't the elf activator not find out and say "Sorry, > > cannot execute ev6 on this machine" ? > >Because there is no way of knowing, and in general, you don't need to >know. Well, the compiler could put it somewhere in the elf and it seems like I do :-) >As I said previously, the kernel is supposed to fixup newer >instruction executed on older machines. However, this is expensive, >and the toolchain should not be emitting code with those instructions >in the first place, unless it is told to. Right, so much for theory :-) -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message