From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from wx-out-0506.google.com (wx-out-0506.google.com [66.249.82.233]) by ozlabs.org (Postfix) with ESMTP id BD38F67BCF for ; Fri, 24 Nov 2006 15:13:37 +1100 (EST) Received: by wx-out-0506.google.com with SMTP id i31so748585wxd for ; Thu, 23 Nov 2006 20:13:36 -0800 (PST) Message-ID: Date: Thu, 23 Nov 2006 23:13:36 -0500 From: "Lei Sun" To: linuxppc-embedded@ozlabs.org Subject: MMU issue on mpc8270 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi all: While trying to bring up the kernel-2.4.30, my debugger failed to show memory content after MMU is turned on. So I added some debug serial_putc() function copied from u-boot. (since u-boot has intialized the UART). The code did printed out the debug message untill it reached "mapin_ram()" function. To be precise, in map_page() funcion, after pte_alloc() , serial_putc() doesn't work anymore. My questions are : 1. in mapin_ram() function, since it uses "bat_mapin_ram()" , why does it still map in page? 2. why would pte_alloc() affect my serial debug output ? Rigth now, my kernel does seems to be running, but i just couldn't see anything on the serial console, I have examined the serial console portion of the code for many times, couldn't seems any thing wrong. The worst is that i can't set break point with MMU turned on. Any suggestion? Thanks lei