From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnout Vandecappelle Date: Sat, 22 Jul 2017 23:13:26 +0200 Subject: [Buildroot] [PATCH 06/20] system: move setting getty to the corresponding init systems In-Reply-To: <20170722215730.782162ca@windsurf> References: <20170722215730.782162ca@windsurf> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net On 22-07-17 21:57, Thomas Petazzoni wrote: > Hello, > > On Sat, 22 Jul 2017 15:11:57 +0200, Arnout Vandecappelle wrote: [snip] >> The only difference between these two is that for sysvinit we have to make sure >> it's only 4 characters. But it actually doesn't hurt to do the same for busybox >> as well. So perhaps we can factor the two in a single SYSTEM_SET_GETTY ? > > I am not sure if that works, because the semantic of the first field is > not the same between sysvinit and Busybox init. Right! I thought busybox init just ignored it, I forgot about the controlling terminal. Regards, Arnout > > For sysvinit (http://www.manpages.info/linux/inittab.5.html) > > id is a unique sequence of 1-4 characters which identifies an entry > in inittab (for versions of sysvinit compiled with libraries < > 5.2.18 or a.out libraries the limit is 2 characters). > > Note: For gettys or other login processes, the id field should > be the tty suffix of the corresponding tty, e.g. 1 for tty1. > Otherwise, the login accounting might not work correctly. > > For Busybox init: > > # : WARNING: This field has a non-traditional meaning for BusyBox init! > # > # The id field is used by BusyBox init to specify the controlling tty for > # the specified process to run on. The contents of this field are > # appended to "/dev/" and used as-is. There is no need for this field to > # be unique, although if it isn't you may have strange results. If this > # field is left blank, then the init's stdin/out will be used. > > Hence, with Busybox init, if you pass a truncated "id", the command > might fail to run as it will try to open a /dev/ that > doesn't exist. So, if you truncate ttyAMA0, it will be just ttyA, > Busybox will try to open /dev/ttyA and it will fail. > > Best regards, > > Thomas > -- Arnout Vandecappelle arnout at mind be Senior Embedded Software Architect +32-16-286500 Essensium/Mind http://www.mind.be G.Geenslaan 9, 3001 Leuven, Belgium BE 872 984 063 RPR Leuven LinkedIn profile: http://www.linkedin.com/in/arnoutvandecappelle GPG fingerprint: 7493 020B C7E3 8618 8DEC 222C 82EB F404 F9AC 0DDF