From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Vasut Date: Thu, 28 Feb 2013 19:50:03 +0100 Subject: [U-Boot] [PATCH 1/4] common: imx: Implement generic u-boot.nand target In-Reply-To: <20130227173311.GC30746@bill-the-cat> References: <1361823013.27903.8@snotra> <1636401851.120330.1361878432310.JavaMail.root@advansee.com> <20130227173311.GC30746@bill-the-cat> Message-ID: <201302281950.03523.marex@denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Dear Tom Rini, > On Tue, Feb 26, 2013 at 12:33:52PM +0100, Beno??t Th??baudeau wrote: > > On Tuesday, February 26, 2013 8:19:42 AM, Marek Vasut wrote: > > > Dear Beno??t Th??baudeau, > > > > > > > Dear Scott Wood, > > > > > > > > On Tuesday, February 26, 2013 12:07:25 AM, Scott Wood wrote: > > > > > On 02/25/2013 05:03:30 PM, Marek Vasut wrote: > > > > > > Dear Scott Wood, > > > > > > > > > > > > > So maybe we need a more general (but optional) > > > > > > > CONFIG_BUILD_TARGET. > > > > > > > > > > > > Can you elaborate? > > > > > > > > > > Same as CONFIG_SPL_TARGET, but not SPL-specific. Basically a way > > > > > for a board config file to add to $(ALL-y). > > > > > > > > > > > > So each one would set the appropriate CONFIG_BUILD_TARGET for > > > > > > > > > > > > whatever > > > > > > > > > > > > > needs to get built, and then something like CONFIG_NAND_IMAGE > > > > > > > could hold the image name that should be linked to produce a > > > > > > > standard u-boot-nand.bin output. > > > > > > > > > > > > Yea, sounds reasonable. But why call it CONFIG_ , it can't be > > > > > > stored in the > > > > > > board.h files, it has to be somewhere in the Makefile hierarchy. > > > > > > > > > > Why can't it go in the board.h files? > > > > > > > > We could do all that, but should we? As I said to Marek, I think that > > > > it's a big mistake to omit the SPL here. The only other solution to > > > > get a reliable boot would be the DBBT, but it's very hard to use in > > > > real life, away from a production line. The SPL is really easy to > > > > enable here, and it's only a matter of time before someone gets > > > > bitten by this lack of reliability, so why not just do things right? > > > > The boot time and footprint of an SPL would really be negligible, > > > > and it's not because other implementations omit both SPL and a valid > > > > DBBT that U-Boot should do the same. > > > > > > I'm not against SPL, but then we're starting to drift away from the > > > whole idea > > > of generating u-boot-nand.bin or similar image. Being able to generate > > > u-boot- > > > nand.bin or u-boot-sd.bin etc ... on a per-CPU basis (since this is CPU > > > specific) is the ultimate goal here, whatever is embedded in the image. > > > > OK, I didn't know that this was your goal here. If the contents of the > > image do not matter, then my u-boot-with-nand-spl.imx could be renamed > > into your u-boot-nand.bin with the appropriate FCB header, and > > CONFIG_SPL_TARGET could be changed to something more generic as Scott > > explained. > > I wonder how the rules start looking. In the end, some way to say "Here > is the image to write to NAND, called u-boot-nand.bin" which will have > whatever board needs (say spl/u-boot-spl.bin + some header attached > followed by pad, followed by u-boot.img). And also allow for > u-boot-nand.bin to be what someone else needs (say a different header on > u-boot-spl.bin), etc. They'd be CPU specific rules, so that depends on the CPU really. Best regards, Marek Vasut