From owner-freebsd-stable@FreeBSD.ORG Thu Mar 26 14:22:43 2009 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 3160D1065752 for ; Thu, 26 Mar 2009 14:22:43 +0000 (UTC) (envelope-from avg@icyb.net.ua) Received: from citadel.icyb.net.ua (citadel.icyb.net.ua [212.40.38.140]) by mx1.freebsd.org (Postfix) with ESMTP id 60BD88FC1B for ; Thu, 26 Mar 2009 14:22:41 +0000 (UTC) (envelope-from avg@icyb.net.ua) Received: from odyssey.starpoint.kiev.ua (alpha-e.starpoint.kiev.ua [212.40.38.101]) by citadel.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id QAA27562; Thu, 26 Mar 2009 16:22:36 +0200 (EET) (envelope-from avg@icyb.net.ua) Message-ID: <49CB8FAC.4080505@icyb.net.ua> Date: Thu, 26 Mar 2009 16:22:36 +0200 From: Andriy Gapon User-Agent: Thunderbird 2.0.0.21 (X11/20090323) MIME-Version: 1.0 To: Erik Trulsson References: <20090326130634.GA36270@owl.midgard.homeip.net> In-Reply-To: <20090326130634.GA36270@owl.midgard.homeip.net> X-Enigmail-Version: 0.95.7 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Ronald Klop , freebsd-stable@freebsd.org Subject: Re: remote debug over usb vs. old serial cable? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 26 Mar 2009 14:22:46 -0000 on 26/03/2009 15:06 Erik Trulsson said the following: > On Thu, Mar 26, 2009 at 01:56:13PM +0100, Ronald Klop wrote: >> Hello, >> >> In the past I could catch a panic during boot via a serial cable connected >> to another computer. >> My new computer only has USB-ports and ethernet. What kind of cable do I >> need now to do remote debugging? >> The old computer also has usb, so I think the connection should be in that >> corner. >> They all run 7-STABLE. > > USB won't work for that purpose. It requires far too much kernel support to > be useful after a panic. Erik, in fact, there is a special USB (EHCI) mode for such purposes: http://www.coreboot.org/EHCI_Debug_Port But that requires some special HW in addition to SW support which our doesn't have. BTW, Ronald, it is possible that you might have a serial header on motherboard which is not connected to any traditional port. -- Andriy Gapon