From owner-freebsd-questions@freebsd.org Fri Apr 7 21:44:31 2017 Return-Path: Delivered-To: freebsd-questions@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id BAD14D3329B for ; Fri, 7 Apr 2017 21:44:31 +0000 (UTC) (envelope-from 2018@casidy.com) Received: from smtp3.galacsys.net (smtp3.galacsys.net [IPv6:2001:1b78:0:9:d918:5905:0:1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 8979E9D0 for ; Fri, 7 Apr 2017 21:44:31 +0000 (UTC) (envelope-from 2018@casidy.com) Received: from smtp3.galacsys.net (unknown [127.0.1.2]) by smtp3.galacsys.net (Postfix) with ESMTP id A367BD2D5CA for ; Fri, 7 Apr 2017 23:44:29 +0200 (CEST) Received: from [192.168.0.23] (sds31-1-88-124-146-144.fbx.proxad.net [88.124.146.144]) (Authenticated user) by smtp3.galacsys.net (Postfix) with ESMTPSA for ; Fri, 7 Apr 2017 23:44:29 +0200 (CEST) Subject: Uboot won't boot when a device is connected on serial port To: freebsd-questions@freebsd.org References: From: freebsd@casidy.com Message-ID: Date: Fri, 7 Apr 2017 23:44:48 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 07 Apr 2017 21:44:31 -0000 Hi, I exposed my problem of getting back the serial port on a Raspberry 2 in "Liberate the serial port". My problem is in fact getting worse. I realised that I cannot boot my Pi2 when I have a device connected on a serial port. The boot process breaks: it looks like Uboot is considering that someone typed in some characters... How can I have uboot ignoring the serial port? I have installed 11.0-RELEASE-p1. Thanks Philippe. On 07/04/2017 17:31, freebsd@casidy.com wrote: > Hi, > > > I have a Raspberry Pi2 and I am struggling at using the serial port > uart0 for my own purpose. > > I have install 11.0-RELEASE-p1 a few months ago and now I have > attached a device that send characters on the Raspberry uart0 and I > try to read them by a > > setting the tty > > stty -f /dev/ttyu0 1200 sane evenp parenb cs7 -crtscts > > > trying to read > > cat /dev/ttyu0 > > or cat < /dev/ttyu0 > > > But my understanding is that the kernel at some point grabbed uart0 to > provide a serial console. > > > I tried to change /etc/ttys > > ttyu0 "/usr/libexec/getty 3wire.115200" vt100 off secure > > but no avail, I have nothing while trying to cat /dev/ttyu0. > > > I tried with Raspbian, and after disabling the use of the uart as a > console on boot, I have been able to get my characters... so the > hardware works fine. > > > How can I use my serial port for another purpose than a serial console? > > What am I missing? > > > Thanks in advance, > > Philippe >