From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Roese Date: Mon, 28 Apr 2008 17:29:34 +0200 Subject: [U-Boot-Users] [PATCH] PPC405EX(r) ECC and SDRAM Initialization Clean-ups In-Reply-To: References: Message-ID: <200804281729.34880.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 On Monday 28 April 2008, Grant Erickson wrote: > The primary goal of this patch is to unify some of the low-level SDRAM and > ECC initialization code for the PPC4xx processors that use a common DDR2 > SDRAM controller. > > In particular, in the case of the 405EX[r], it must initialize SDRAM before > a primordial stack is available since OCM doesn't exist and the data cache > doesn't work for such a purpose. As a consequence, the ECC (and SDRAM) > initialization code must be stack-free. We need to investigate here, why exactly the init-RAM in d-cache is currently not working on 405EX. Any ideas on this are very welcome. I'll try to dig into this in the a few days too. > This patch creates such a stack-free ecc_init() routine that should, > nonetheless, still be compatible from a C runtime environment. > > In addition, the patch cleans-up the Kilauea and Makalu SDRAM > initialization code by polling SDRAM0_MCSTAT[MIC] as recommended by AMCC > AN2131 rather than just waiting some arbitrary period of time. Also, the > final controller initialization is generalized by ORing in > SDRAM_MCOPT2_DCEN_ENABLE rather than just slamming 0x28000000 into the > register. This is to make way for a future patch that uses CFG_SDRAM0_* > values for boards that use such low-level initialization so they might > share this SDRAM init code. Finally, while neither Kilauea nor Makalu have > ECC memory, code is added to init.S for each to demonstrate how ecc_init() > would be called if it were available as a reference. > > Signed-off-by: Grant Erickson > > --- > board/amcc/kilauea/init.S | 53 > +++++++++++++++++++++++++++++++++++++++------ The patch is line-wrapped. Please use git-send-email is possible. > board/amcc/makalu/init.S | 53 > +++++++++++++++++++++++++++++++++++++++------ > cpu/ppc4xx/Makefile | 1 + > cpu/ppc4xx/sdram.c | 47 +++------------------------------------ > 4 files changed, 97 insertions(+), 57 deletions(-) The ECC code seems to be missing. I'll wait with further review until the missing ECC code is included. :) Thanks. 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 =====================================================================