From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from de01egw01.freescale.net (de01egw01.freescale.net [192.88.165.102]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "de01egw01.freescale.net", Issuer "Thawte Premium Server CA" (verified OK)) by ozlabs.org (Postfix) with ESMTP id C135BDDE22 for ; Tue, 14 Aug 2007 01:53:45 +1000 (EST) Date: Mon, 13 Aug 2007 10:53:26 -0500 From: Scott Wood To: "Morrison, Tom" Subject: Re: Early UART setup on 2.6 kernel for mpc85xx Message-ID: <20070813155326.GA17535@ld0162-tx32.am.freescale.net> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Cc: linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, Aug 13, 2007 at 07:09:40AM -0400, Morrison, Tom wrote: > >> In order to debug the kernel 2.6, I want setup serial port with > >> UART on mpc85xx as early as possible. I add the register access > >> code at the beginning of platform_init(). For example, I try > >> to write THR register(0xe0004500). However the system just > >> hanging there with this line. Make sure there's a mapping in the TLB for that address. > FWIW, you really can't debug the earliest init code > because most of that is in assembly. Get a JTAG emulator > (BDI or Lauterbach) and start stepping through. It's quite possible to debug assembly code without JTAG. :-) -Scott