From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 5 Nov 2015 16:15:44 +0100 From: Gilles Chanteperdrix Message-ID: <20151105151544.GD16314@hermes.click-hack.org> References: <20151105015114.GJ21923@csclub.uwaterloo.ca> <20151105110141.GC16314@hermes.click-hack.org> <20151105145159.GK21923@csclub.uwaterloo.ca> <20151105145725.GL21923@csclub.uwaterloo.ca> <20151105150226.GM21923@csclub.uwaterloo.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151105150226.GM21923@csclub.uwaterloo.ca> Subject: Re: [Xenomai] ARM bus error due to alignment List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Lennart Sorensen Cc: xenomai@xenomai.org On Thu, Nov 05, 2015 at 10:02:26AM -0500, Lennart Sorensen wrote: > On Thu, Nov 05, 2015 at 09:57:25AM -0500, Lennart Sorensen wrote: > > On Thu, Nov 05, 2015 at 09:51:59AM -0500, Lennart Sorensen wrote: > > > Hmm, I thought I had read that as of 2.6.38 and higher arm systems were > > > supposed to not generate the fault anymore, but maybe I misunderstood > > > it and they meant it sets fixup to enabled by default. > > > > > > I should check the SCTLR.A flag. > > > > Of course the arm docs say it is off by default at reset, so something > > in either u-boot or the kernel seems like it must have to enable it > > explicitly. Well once I figure out how to read it I guess I will know. > > > > Of course if the memory happens to be flagged as something other than > > normal memory, then it should also fault. I wonder if a page used to dma > > data to/from a network driver would be flagged as normal memory or not. > > Would using this cause such a problem: > > /usr/include/xenomai/native/heap.h:#define H_DMA 0x100 /* Use memory suitable for DMA. */ Do you have alignment issues with the same version of Linux with exactly the same configuration, but without Xenomai? -- Gilles. https://click-hack.org