From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1c4Dt3-0006ZV-0K for barebox@lists.infradead.org; Tue, 08 Nov 2016 21:24:58 +0000 Date: Tue, 8 Nov 2016 22:24:34 +0100 From: Sascha Hauer Message-ID: <20161108212434.gvlq5fy6vrbn2en5@pengutronix.de> References: <20161104071821.jqrhtfmgz3432527@pengutronix.de> <20161107074346.pb4uivigwa5gbj6z@pengutronix.de> <20161108075317.j4xkf7zpkdfyt5y3@pengutronix.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: Configure RAM size on iMX53 board To: Jose Luis Zabalza Cc: barebox@lists.infradead.org On Tue, Nov 08, 2016 at 09:51:36PM +0100, Jose Luis Zabalza wrote: > > So you have 512MiB on each chip select, so I assume that on the 512MiB > > board variants CS1 is not equipped. > > Yes, it is. > > >In that case you can in lowlevel.c > > test if you find SDRAM on CS1 and if not, disable the chip select > > completely in the SDRAM controller. > > OK. But how ? I enable CS0 and CS1 on DCD table. Is there any way to > tell barebox not to use CS1 ? > > > I am not sure how you can detect if there's SDRAM on CS1. I've seen > > situations in which the board just hangs if you access non existent RAM > > areas. > > I have tried it, but I have not be able to implement a code for > autodetect. If the code write or read a value on a position without > physical chip, the microcontroller hangs. ???? > > But it's not a problem. A solution is configure both CS and MMU. If > bootloader don't access to high positions, there is not problem. After > I set a environment variable with memory size and the mem kernel > parameter (or ATAG) does the rest. You said that both board variants work with the same U-Boot binary, how does it work there? Is there some detection mechanism or is it only some environment variable that you have to set manually? Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox