From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.ebshome.net (gate.ebshome.net [64.81.67.12]) (using TLSv1 with cipher EDH-RSA-DES-CBC3-SHA (168/168 bits)) (Client CN "gate.ebshome.net", Issuer "gate.ebshome.net" (not verified)) by ozlabs.org (Postfix) with ESMTP id 3447D680DF for ; Fri, 12 Aug 2005 09:14:57 +1000 (EST) Date: Thu, 11 Aug 2005 16:14:54 -0700 From: Eugene Surovegin To: Shawn Jin Message-ID: <20050811231454.GA5796@gate.ebshome.net> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Cc: ppcembed Subject: Re: What's wrong with the serial port? List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, Aug 11, 2005 at 03:41:21PM -0700, Shawn Jin wrote: > Hi, > > I'm porting linux 2.6.11.4 to a custom SoC with ppc440 core. The UART > is 16550 compatible. U-Boot is already running fine. > > When the kernel is booting, it gets to the point where console_init() > is called, which calls individual early console initialization > functions. In my case it's serial8250_console_init(). Before > register_console() is called in serial8250_console_init(), everything > seems fine because the debugging logs are printed on the serial port. > But once register_console() is called, the serial port continues > spitting out ?. See the following message. What's wrong? > > Any hints are appreciated! > > Boot reached stage 4 > Boot reached stage 5 > Boot reached stage 6 > OK > Boot reached stage 7 > Boot reached stage 8 > ## Current stack ends at 0x01FC6B80 => set upper limit to 0x00800000 > ## cmdline at 0x007FFF00 ... 0x007FFF10 > bd address = 0x01FC6F90 > memstart = 0x00000000 > memsize = 0x02000000 > flashstart = 0x00000000 > flashsize = 0x00000000 > flashoffset = 0x00000000 > sramstart = 0x00000000 > sramsize = 0x00000000 > bootflags = 0x00000000 > intfreq = 400 MHz > busfreq = 266 MHz > ethaddr = 00:00:00:00:00:00 > IP addr = 0.0.0.0 > baudrate = 115200 bps > Boot reached stage 14 > No initrd > ## Transferring control to Linux (at address 00000000) ... > Boot reached stage 15 > id mach(): done > MMU:enter > MMU:hw init > MMU:mapin > MMU:setio > MMU:exit > setup_arch: enter > setup_arch: bootmem > arch: exit > ?????? Try disabling early text debugging (all that "MMU:..." stuff). -- Eugene