From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Thu, 20 May 2010 11:18:21 +1000 From: David Gibson To: Timur Tabi Subject: Re: [PATCH] powerpc: make the padding for the device tree a configurable option Message-ID: <20100520011820.GT25892@yookeroo> References: <1274298809-12772-1-git-send-email-timur@freescale.com> <1274304013.1931.6.camel@pasglop> <4BF4593E.8030101@freescale.com> <1274309050.1931.21.camel@pasglop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Cc: devicetree-discuss@lists.ozlabs.org, linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, May 19, 2010 at 07:03:17PM -0500, Timur Tabi wrote: > On Wed, May 19, 2010 at 5:44 PM, Benjamin Herrenschmidt > wrote: > > > It's still not kernel business to have to deal with u-boot memory > > allocation constraints. > > I agree, but it still makes sense to me to allow the padding to be configurable. > > > The padding in the kernel built is intended to > > make space for DT changes done by the zImage wrapper. > > Well, okay. I think it would be nice if we expanded that to handle > general usage. > > > Maybe we could add to libfdt a way to provide a realloc() callback to it > > when it hits the max size, and uboot can then move things around (or > > fail). > > The problem is that the code which allocates a block for the fdt is > completely distinct from the code that manipulates the fdt. We'd need > to put in either some kind of funky callback mechanism, or insist that > every fdt exist in a block of memory allocated by some specific method > (e.g. lmb). > > I'm stuck between a rock and a hard place, it seems. No one is > willing to compromise on any of my ideas. It's hard to convince our > BSP developers that they should be pushing more code upstream when I > get so much resistance for a such a mundane change. Couldn't you use the configurable padding, but put the stuff to do it into u-boot. i.e. repad the dtb at u-boot build time, rather than u-boot runtime. -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson