From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Roese Date: Fri, 24 Jul 2009 08:52:46 +0200 Subject: [U-Boot] PPC440GX TLB setting problem. In-Reply-To: <4CD35CD1F8085945B597F80EEC8942130348D991@exc01.bk.prodrive.nl> References: <4CD35CD1F8085945B597F80EEC8942130348D991@exc01.bk.prodrive.nl> Message-ID: <200907240852.46998.sr@denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi Wouter, On Thursday 23 July 2009 20:39:44 Wouter Eckhardt wrote: > I'm working on trying to get VxWorks to boot on a PPC440GX processor > using U-Boot, using an ALPR board. In order to boot VxWorks properly (it > expects caching on the SDRAM to be disabled), I created a new board > directory and such (based on the ALPR board), and then changed the TLB > settings in init.S. Are you sure that the cache needs to be disabled? Perhaps it just needs to get properly flushed before booting VxWorks? Just checking. > My problem is that when my new U-Boot has booted, the TLBs are not > configured as I have programmed them. I verified this using a BDI > debugger. The TLB settings are still the same as the settings the > original ALPR U-Boot used. I'm really at a loss here. It seems that no > matter what I try (I tried quite a few variantions of the TLB settings), > the TLB settings won't change. > > So now I several, related, questions: > - What could be the cause of this? Have I done something wrong? This could have multiple reasons. Are you sure that you are running the freshly compiled image on the board? Did you check the build time? > - Is U-Boot reconfiguring the TLBs after init.S has executed? Yes. But only one (IIRC). The first TLB for bootrom access. Caching will be disabled before relocating to SDRAM. > - If so, how can I control those TLBs? All other TLB's should be the same. Not sure what's going wrong here. Best regards, Stefan ===================================================================== DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: +49-8142-66989-0 Fax: +49-8142-66989-80 Email: office at denx.de =====================================================================