From owner-freebsd-arm@freebsd.org Sat Mar 11 17:54:06 2017 Return-Path: Delivered-To: freebsd-arm@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 866CCD0830D for ; Sat, 11 Mar 2017 17:54:06 +0000 (UTC) (envelope-from ian@freebsd.org) Received: from pmta2.delivery6.ore.mailhop.org (pmta2.delivery6.ore.mailhop.org [54.200.129.228]) (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 6B4BDE67 for ; Sat, 11 Mar 2017 17:54:06 +0000 (UTC) (envelope-from ian@freebsd.org) X-MHO-User: 9c4e6b69-0683-11e7-b3c2-c9f38144898e X-Report-Abuse-To: https://support.duocircle.com/support/solutions/articles/5000540958-duocircle-standard-smtp-abuse-information X-Originating-IP: 73.78.92.27 X-Mail-Handler: DuoCircle Outbound SMTP Received: from ilsoft.org (unknown [73.78.92.27]) by outbound2.ore.mailhop.org (Halon) with ESMTPSA id 9c4e6b69-0683-11e7-b3c2-c9f38144898e; Sat, 11 Mar 2017 17:53:19 +0000 (UTC) Received: from rev (rev [172.22.42.240]) by ilsoft.org (8.15.2/8.15.2) with ESMTP id v2BHrsue001663; Sat, 11 Mar 2017 10:53:58 -0700 (MST) (envelope-from ian@freebsd.org) Message-ID: <1489254834.40576.55.camel@freebsd.org> Subject: Re: Booting Raspberry Pi with input on serial console From: Ian Lepore To: Peter =?ISO-8859-1?Q?Ankerst=E5l?= , FreeBSD Stable , "freebsd-arm@FreeBSD.org" Date: Sat, 11 Mar 2017 10:53:54 -0700 In-Reply-To: <30CFED65-9A38-4332-B935-095B26A6FFFD@pean.org> References: <30CFED65-9A38-4332-B935-095B26A6FFFD@pean.org> Content-Type: text/plain; charset="ISO-8859-1" X-Mailer: Evolution 3.18.5.1 FreeBSD GNOME Team Port Mime-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Porting FreeBSD to ARM processors." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 11 Mar 2017 17:54:06 -0000 On Fri, 2017-03-10 at 11:40 +0100, Peter Ankerstål wrote: > Hi! > > I have a problem that should (?) have a simple solution but I havent > found one.  > > I have a raspberry pi with a NMEA-GPS constantly hooked up to the > serial console of the Pi.  > > My problem is that when booting the Pi it will interpet the output > from the GPS as input to the boot process and the boot will fail. How > can I have the serial interface of the GPS permanently hooked up to > the pi without preventing the system to boot? > > Thanks! > > /Peter. Ideally, the fix for this would be to "setenv stdin nulldev; saveenv", but unfortunately our copy of uboot is missing the option to include nulldev in uboot. I think a viable workaround for your case is probably to create a uEnv.txt file on the fat partition of the sdcard and put in it:  bootdelay=0  stderr=lcd  stdout=lcd That will prevent uboot from stopping if the gps receiver sends some text, and prevent uboot from sending most of its text output to the serial port, which may confuse the gps receiver (the uboot startup banner text still appears on the serial port tho). -- Ian