From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-out.m-online.net ([212.18.0.9]:53382 "EHLO mail-out.m-online.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752020Ab3BVGzw (ORCPT ); Fri, 22 Feb 2013 01:55:52 -0500 From: Wolfgang Denk Subject: Re: [U-Boot] [RFC] Kbuild support for ARM FIT images MIME-Version: 1.0 Content-type: text/plain; charset=UTF-8 Content-transfer-encoding: 8bit In-reply-to: <20130221232821.GA2823@obsidianresearch.com> References: <20130221103705.GB17852@n2100.arm.linux.org.uk> <51261F38.2030902@ti.com> <20130221134656.GC17852@n2100.arm.linux.org.uk> <51262A7A.8040103@ti.com> <20130221182724.GA14329@obsidianresearch.com> <20130221211444.GB20114@obsidianresearch.com> <20130221231848.880DE200552@gemini.denx.de> <20130221232821.GA2823@obsidianresearch.com> Date: Fri, 22 Feb 2013 07:55:46 +0100 Message-Id: <20130222065546.F1609200550@gemini.denx.de> Sender: linux-kbuild-owner@vger.kernel.org List-ID: To: Jason Gunthorpe Cc: Nicolas Pitre , "Fernandes, Joel A" , Russell King - ARM Linux , linux-kbuild@vger.kernel.org, tony@atomide.com, Grant Likely , u-boot@lists.denx.de, Tom Rini , Grant Likely , OMAP List , ARM Kernel List Dear Jason, In message <20130221232821.GA2823@obsidianresearch.com> you wrote: > > > > own seems to be rather static and stable, and unlike software there is > > > no way I can change it (soldering irons don't count). > > > > There is other hardware available (for example FPGA based) where this > > does not apply. > > Agreed.. We do that here as well, the DT is also used to describe the > functionality inside FPGA(s). We do things like declare a GPIO > controller inside the FPGA, then stack the bitbang MDIO/I2C on top of > that, then declare a bunch of devices on those busses. DT makes this > extremely straightforward. > > However, it is critical that the DT, kernel and FPGA are matched > together - we always arrange things so that the DTB, kernel and FPGA > config are bundled together and update atomically during firmware > upgrade. Agreed. > Xilinx's Zynq is a great example of this kind of stuff, FWIW. IIRC Indeed - Xilinx's Zynq, Altera's SoC FPGA, and others. Such highly flexible hardware configurations require a new level of software support that by far exceeds the classic static setups of more "PC-like" systems where the only change you would expect is adding or removing some PCI cards or the like. Best regards, Wolfgang Denk -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de Don't tell me how hard you work. Tell me how much you get done. -- James J. Ling