From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755205Ab3GWFk5 (ORCPT ); Tue, 23 Jul 2013 01:40:57 -0400 Received: from b.ns.miles-group.at ([95.130.255.144]:1660 "EHLO radon.swed.at" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751459Ab3GWFk4 (ORCPT ); Tue, 23 Jul 2013 01:40:56 -0400 Message-ID: <51EE1765.2000402@nod.at> Date: Tue, 23 Jul 2013 07:40:53 +0200 From: Richard Weinberger User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130620 Thunderbird/17.0.7 MIME-Version: 1.0 To: Lennart Poettering CC: Ramkumar Ramachandra , LKML Subject: Re: [PATCH] um: change defconfig to stop spawning xterm References: <1374258017-19606-1-git-send-email-artagnon@gmail.com> <51E988FF.9010201@nod.at> <51ED0BBF.7060502@nod.at> <20130722223238.GC13191@tango.0pointer.de> In-Reply-To: <20130722223238.GC13191@tango.0pointer.de> X-Enigmail-Version: 1.5.1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Lennart, Am 23.07.2013 00:32, schrieb Lennart Poettering: > On Mon, 22.07.13 16:13, Ramkumar Ramachandra (artagnon@gmail.com) wrote: > >> >> [Corrected Lennart's email ID] >> >> Richard Weinberger wrote: >>> CC'ing Lennart. >>> >>> Am 22.07.2013 11:45, schrieb Ramkumar Ramachandra: >>>> Ramkumar Ramachandra wrote: >>>>> [1]: http://lists.freedesktop.org/archives/systemd-devel/2013-July/012152.html >>>> >>>> ... and the patches were rejected. Lennart says that UML providing >>>> /dev/tty* is wrong, and that UML should call them /dev/hvc* (or >>>> something). Can we do something about the situation? Can we remove >>>> /dev/tty*, and provide /dev/hvc*? Will we be breaking existing users? >>>> >>>> Thanks. >>>> >>>> Lennart Poettering wrote: >>>>> UML shouldn't be penalized for not implementing some terminal emulation, >>>>> but it should be penalized for doing so under the label of "VT support", >>>>> which it simply is not providing. >>>>> >>>>> They can call their ttys any way they want. If the call them >>>>> /dev/tty[1..64] however, then they need to implement the VC >>>>> interfaces. All of them. >>> >>> Lennart, can you please explain us why /dev/tty[1..64] is forced to >>> have virtual console support? > > /dev/tty[1..64] is the userspace API to the kernel VT subsystem. If you > support it you need to match up all /dev/tty[1..64] with a > /dev/vcs[1..64] + /dev/vcsa[1..64]. You need to expose a tty that > understands TERM=linux and the ioctls listed on console_ioctl(4). You > need /dev/tty0 as something that behaves like a symlink to the fg > VT. You should also support files like /sys/class/tty/tty0/active with > its POLLHUP iface. I sightly disagree with you. /dev/tty[1..64] is not directly bound to VT. You can have systems with CONFIG_VT=n and still have /dev/tty[1..64]. Linux supports this perfectly. UML does not have VT because having virtual consoles makes no sense. (Same like on s390) Thanks, //richard