From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from az33egw01.freescale.net (az33egw01.freescale.net [192.88.158.102]) by ozlabs.org (Postfix) with ESMTP id 266AC67B99 for ; Sat, 18 Nov 2006 21:04:03 +1100 (EST) Received: from az33smr01 (az33smr01.freescale.net [10.64.34.199]) by az33egw01.freescale.net (8.12.11/az33egw01) with ESMTP id kAIA3ti3019526 for ; Sat, 18 Nov 2006 03:03:55 -0700 (MST) Received: from zch01exm21.fsl.freescale.net (zch01exm21.ap.freescale.net [10.192.129.205]) by az33smr01 (8.13.1/8.13.0) with ESMTP id kAIA3rGt001287 for ; Sat, 18 Nov 2006 04:03:54 -0600 (CST) Subject: Re: memory corruption after MMU turned on From: Dave Liu To: Lei Sun In-Reply-To: References: <1163753324.3655.18.camel@localhost.localdomain> Content-Type: text/plain Date: Sat, 18 Nov 2006 18:03:52 +0800 Message-Id: <1163844232.3659.15.camel@localhost.localdomain> Mime-Version: 1.0 Cc: linuxppc-embedded@ozlabs.org List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Did you enable the i-cache or d-cache in u-boot? if you enable i-cache, I think the core are burst reading from memory. On Fri, 2006-11-17 at 11:47 -0500, Lei Sun wrote: > No, i didn't do the burst memory test, how do i do it then ? > > On 11/17/06, Dave Liu wrote: > > On Thu, 2006-11-16 at 10:44 -0500, Lei Sun wrote: > > > Hi all: > > > I am trying to bring up customized board based on MPC8270, the > > > kernel version is 2.4.30, it works fine on one of the Eval board > > > (PQ2FADS-VR, which use MPC8275). > > > The kernel hangs after uncompressing is done, further debug shows > > > that it hangs right after "rfi " instruction of the turn_on_mmu: > > > function in head.S > > > > > > turn_on_mmu: > > > 240 mfmsr r0 > > > 241 ori r0,r0,MSR_DR|MSR_IR > > > 242 mtspr SRR1,r0 > > > 243 lis r0,start_here@h > > > 244 ori r0,r0,start_here@l > > > 245 mtspr SRR0,r0 > > > 246 SYNC > > > 247 RFI /* enables MMU */ > > > > > > After i step over the RFI instruction, the PC points to C000XXX , but > > > all memory content is 0 by then. > > > my BATU0 is 0xC000FFE0 BATL0 is 0x00000002, I have 128MB RAM. The > > > u-boot works fine, without MMU turned on. We do have some hardware > > > problem, such that i have to lower the bus frequency to make the SDRAM > > > stable. What physical parameter could cause the board not working with > > > MMU on? > > > > When MMU turn on, the kernel memory should be cacheable, so the > > processor will burst read instructions from memory to i-cache. Did you > > do the burst read/write memory test in u-boot? As you said, you did not > > do the test. > > > > -Dave > > > > > >