From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Roese Date: Fri, 9 Jan 2009 06:53:00 +0100 Subject: [U-Boot] ppc440 (440EPx sequoia) - inhibiting the cpu cache? In-Reply-To: <821d59060901081203u6ae94d45gf24a5b009cdf760f@mail.gmail.com> References: <821d59060901081203u6ae94d45gf24a5b009cdf760f@mail.gmail.com> Message-ID: <200901090653.00702.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 Jonathan, On Thursday 08 January 2009, Jonathan Barrow wrote: > I'm in the process of bringing up a custom board featuring AMCC's > 440EPx processor. I'm using the uboot-2008-10 source tree and > "sequoia" board for my starting configuration, also using ELDK v4.2. > for cross-compiler tools and such. > > Although my board initializes and completes its memory tests > "relocate_code" fails. I've noted in the FAQ and mailing lists the > sensitive nature of sdram timing and have spent considerable effort > making sure the ddr_xx settings are correct. I thought my latest > adjustment would save the day, I realized 'BSTLEN' should likely be > changed from 4 words to 8 words because my memory configuration is x32 > not x64. Unfortunately my latest u-boot.bin is still not happy. > > To be really really certain my problem lies elsewhere, for the > purposes of hardware bringup I was wondering if there was a > relatively easy way to inhibit memory bursts, by turning off the CPU > Cache. I searched many of the the .h files and didnt' notice > anything along the lines of EN or DISABLE the cache, only size > adjustments and associations to Chip Selects. Usually caches are disabled on 44x platforms in U-Boot. So you shouldn't see any burst access to SDRAM anyway. > If I overlooked > something I'd would really appreciate a tip on strategy getting past > relocate_code. This is what I have so far: Most likely still an SDRAM configuration problem. Did you check if SDRAM is working after initialization either using a debugger or by using some simple memory test (write value to SDRAM and read it back and print the result)? This is what I would recommend to do. Only if this works you can continue to run U-Boot from RAM. 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 =====================================================================