From mboxrd@z Thu Jan 1 00:00:00 1970 From: Timur Tabi Date: Thu, 18 Jan 2007 13:07:16 -0600 Subject: [U-Boot-Users] DTB /OF_TREE Newbie and U-boot In-Reply-To: <000301c73b2f$635eb000$6405a8c0@absolut> References: <000301c73b2f$635eb000$6405a8c0@absolut> Message-ID: <45AFC564.6080609@freescale.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Russell McGuire wrote: > I realize now that for SOC chips such as a MPC8360E that passing a DTB > structure into the bootm command is probably a required step??? Is this > True? Yes. > If so I see in some cases that this structure might be partly > constructed within the U-boot code, at least I see code doing something > with OF_TREE?s. Yes, U-Boot updates the tree with its own values. > 1) Is the U-boot compilation process generating a .dtb structure > that we can burn into firmware, at least or certain CPU architectures? No. You need to use the DTC compiler, which is available here: http://www.jdl.com/git_repos/?p=dtc.git > 2) Is this a manual process that requires an outside dtb compiler, Yes. > and if so why is U-boot code dealing with this? Because the Linux kernel is currently coded such that the boot loader must pass the DTB to it. To reduce the amount of dual-maintenance, U-Boot can take some of the data that it knows about, and put that into the tree. > 3) Is this built into the bd_info structure? I'm not sure I understand. The DTB itself is not part of U-Boot, but U-Boot can parse the tree and modify it. -- Timur Tabi Linux Kernel Developer @ Freescale