From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Korsgaard Date: Tue, 24 Apr 2012 10:31:15 +0200 Subject: [Buildroot] [PATCH 01/22] Remove the DATE variable In-Reply-To: (Thomas De Schampheleire's message of "Tue, 24 Apr 2012 09:43:10 +0200") References: <3a993084fda775e7a2c37371225c124fd620a244.1334673910.git.thomas.petazzoni@free-electrons.com> <201204211505.51141.arnout@mind.be> <871ungi39o.fsf@macbook.be.48ers.dk> <20120422173226.590ca81a@skate> <87wr57h776.fsf@macbook.be.48ers.dk> Message-ID: <87bomhh6p8.fsf@macbook.be.48ers.dk> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net >>>>> "Thomas" == Thomas De Schampheleire writes: Hi, Thomas> A disadvantage of adding changing variables like DATE is that Thomas> two builds that are built from the exact same set of sources, Thomas> are not binary equal. You cannot simply compare the rootfs Thomas> image and expect no differences. You'd have to unpack the Thomas> rootfs and compare file by file, leaving out files like Thomas> /etc/os-release that would contain a date. Thomas> I haven't yet looked at which binaries inside a typical rootfs do Thomas> contain such changing variables, but I will do that for my Thomas> configuration in the near future. My intention is to ensure binary Thomas> equality for the entire rootfs. I think you'll find that this is quite common. From the top of my head I know that atleast the Linux kernel and busybox adds the build time to the binary, so I doubt this will really work. Thomas> With this in mind, I would not favor adding a DATE of some kind Thomas> to a file in buildroot just to mark a variable as used, unless Thomas> we provide a way to override DATE in the config file (in the Thomas> Linux kernel, the 'user' and 'machine' etc. build variables are Thomas> also overridable. You can always build with make DATE=foo -- Bye, Peter Korsgaard