From owner-svn-src-all@FreeBSD.ORG Wed Apr 30 17:34:29 2014 Return-Path: Delivered-To: svn-src-all@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 87CD1A4C; Wed, 30 Apr 2014 17:34:29 +0000 (UTC) Received: from smtp1.multiplay.co.uk (smtp1.multiplay.co.uk [85.236.96.35]) by mx1.freebsd.org (Postfix) with ESMTP id 9C0EE1D5E; Wed, 30 Apr 2014 17:34:28 +0000 (UTC) Received: by smtp1.multiplay.co.uk (Postfix, from userid 65534) id 14C9520E7088D; Wed, 30 Apr 2014 17:34:26 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.multiplay.co.uk X-Spam-Level: ** X-Spam-Status: No, score=2.2 required=8.0 tests=AWL,BAYES_00,DOS_OE_TO_MX, FSL_HELO_NON_FQDN_1,HELO_NO_DOMAIN,RDNS_DYNAMIC,STOX_REPLY_TYPE autolearn=no version=3.3.1 Received: from r2d2 (82-69-141-170.dsl.in-addr.zen.co.uk [82.69.141.170]) by smtp1.multiplay.co.uk (Postfix) with ESMTPS id 73F5D20E7088A; Wed, 30 Apr 2014 17:34:21 +0000 (UTC) Message-ID: <906E4322F37E42CABB19AE687605243C@multiplay.co.uk> From: "Steven Hartland" To: "Ian Lepore" References: <201404300620.s3U6Kmn6074492@svn.freebsd.org> <1398869319.22079.54.camel@revolution.hippie.lan> <1398878008.22079.67.camel@revolution.hippie.lan> Subject: Re: svn commit: r265132 - in head: share/man/man4 sys/dev/null Date: Wed, 30 Apr 2014 18:34:22 +0100 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5931 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6157 Cc: svn-src-head@FreeBSD.org, svn-src-all@FreeBSD.org, src-committers@FreeBSD.org, Eitan Adler X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 30 Apr 2014 17:34:29 -0000 ----- Original Message ----- From: "Ian Lepore" To: "Steven Hartland" Cc: "Eitan Adler" ; ; ; Sent: Wednesday, April 30, 2014 6:13 PM Subject: Re: svn commit: r265132 - in head: share/man/man4 sys/dev/null > On Wed, 2014-04-30 at 17:22 +0100, Steven Hartland wrote: >> ----- Original Message ----- >> From: "Ian Lepore" >> To: "Eitan Adler" >> Cc: ; ; >> Sent: Wednesday, April 30, 2014 3:48 PM >> Subject: Re: svn commit: r265132 - in head: share/man/man4 sys/dev/null >> >> >> > On Wed, 2014-04-30 at 06:20 +0000, Eitan Adler wrote: >> >> Author: eadler >> >> Date: Wed Apr 30 06:20:48 2014 >> >> New Revision: 265132 >> >> URL: http://svnweb.freebsd.org/changeset/base/265132 >> >> >> >> Log: >> >> Add a /dev/full device. >> >> >> >> /dev/full is similar to /dev/zero except it always returns >> >> ENOSPC when you attempt to write to it. >> >> >> > >> > For some reason this reminded me of something I've been wanting for a >> > while but never get around to writing... /dev/ones, it's just >> > like /dev/zero except it returns 0xff bytes. Useful for dd'ing to wipe >> > out flash-based media. >> >> Surely for that you want camcontrol security ...? >> >> Regards >> Steve > > I have no idea what that is, but given that it has "security" in the > name, it's almost certainly NOT what I want in any way shape or form. > Shocking as it may be, some people are just not obsessed with security, > for good reason. It just isn't a consideration in any way in my day to > day activities. Its a standard option which allows you to erase the contents of a device its named security as thats the class of the ATA commands which provides this functionality. > When I want to make an sdcard, or some portion thereof, look > empty/virgin/new-from-factory for testing on an embedded system, that > has nothing to do with security, and everything to do with just exactly > what I asked for: something that writes all-ones-bits. That does kind of describe the functionality thats provided by camcontrol security appart from it explicity asks for the cells to be erased, so results in the device being as close to from factory as possible but, not set to a specific value. Maybe thats the difference between ATA based flash media e.g. SSD and sdcard's? Regards Steve