From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Roese Date: Wed, 26 Mar 2008 10:01:46 +0100 Subject: [U-Boot-Users] [PATCH v3] ppc: Add CFG_MEM_TOP_HIDE option to hide memory area that doesn't get "touched" In-Reply-To: <20080326083542.4ACF2241A2@gemini.denx.de> References: <20080326083542.4ACF2241A2@gemini.denx.de> Message-ID: <200803261001.46585.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 Wednesday 26 March 2008, Wolfgang Denk wrote: > In message <1206518897-15473-1-git-send-email-sr@denx.de> you wrote: > > If CFG_MEM_TOP_HIDE is defined in the board config header, this specified > > memory area will get subtracted from the top (end) of ram and won't get > > "touched" at all by U-Boot. By fixing up gd->ram_size the Linux kernel > > should gets passed the now "corrected" memory size and won't touch it > > either. This should work for arch/ppc and arch/powerpc. Only Linux board > > ports in arch/powerpc with bootwrapper support, that recalculate the > > memory size from the SDRAM controller setup will have to get fixed. > > I'm afraid we still have a problem here... > > > - Changed value of CFG_MEM_TOP_HIDE from 256 to 4k so that memory > > end location is on a page boundary > > This assumes a page size of 4 KiB, which is not necessarily true. As > you know, we also support page sizes of 16, 64 and 256 KiB on 44x > systems (even though so far this is only avaiable in arch/ppc). Right. Unfortunately I can't take care of this in an other way as to set this define to the max possible page size value. And I don't think this is acceptable, since removing 256k (or even more) from all Sequoia's and other 440EPx boards isn't a good idea. > I don't know of a good way to fix this, but I ask that you at least > document the new variable in the README and probably add a big fat > warning for page sizes other than 4 KiB. OK, will do. 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 =====================================================================