From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.free-electrons.com ([94.23.35.102]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UbwLD-00021I-Ny for barebox@lists.infradead.org; Mon, 13 May 2013 17:15:16 +0000 Date: Mon, 13 May 2013 19:14:47 +0200 From: Thomas Petazzoni Message-ID: <20130513191447.21181904@skate> In-Reply-To: <51911971.2040303@gmail.com> References: <1368364146-6024-1-git-send-email-sebastian.hesselbarth@gmail.com> <1368364146-6024-4-git-send-email-sebastian.hesselbarth@gmail.com> <20130513075852.GG32299@pengutronix.de> <5190AFA1.1080503@gmail.com> <20130513105722.GP32299@pengutronix.de> <5190E56F.9080903@gmail.com> <20130513162313.4f5849a9@skate> <519110D0.5040801@gmail.com> <20130513182141.12af9b31@skate> <51911510.8050207@gmail.com> <20130513183418.4f9ce9e2@skate> <51911971.2040303@gmail.com> Mime-Version: 1.0 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: [PATCH 3/5] arm: initial support for Marvell Dove SoCs To: Sebastian Hesselbarth Cc: barebox@lists.infradead.org, Ezequiel Garcia Dear Sebastian Hesselbarth, On Mon, 13 May 2013 18:48:49 +0200, Sebastian Hesselbarth wrote: > Turned out to be easier than I thought! > > You can always read from 0xd0020080 (REG_BASE_REMAP) without lockup. > > So if that what you read equals 0xd0000000, you are still on boot-up > reg bases. If not, and as long as we only remap to 0xf1000000 you are > remapped to 0xf1000000. Are you sure this is safe? Imagine you have 4 GB of RAM. Once registers are remapped to 0xf1000000, what you read at 0xd0020080 is RAM. And, what happens if by chance (or lack therefore), what the RAM contains at 0xd0020080 is 0xd0000000 ? You'll believe you're still mapped at the old location. Now that I think of it, not sure of what will happen though, you will write 0xf1000000 at this address, and then continue with the rest of boot. Would that be a problem? Thanks, Thomas -- Thomas Petazzoni, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox