From mboxrd@z Thu Jan 1 00:00:00 1970 From: Luca Ceresoli Date: Tue, 18 Jan 2011 23:32:01 +0100 Subject: [Buildroot] beagleboard support In-Reply-To: <20110118182007.GD9083@bulix.org> References: <895970.43224.qm@web161805.mail.bf1.yahoo.com> <20110118182007.GD9083@bulix.org> Message-ID: <4D3614E1.4080904@lucaceresoli.net> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net Maxime Petazzoni ha scritto: > Hi Steve, > > * Steve Calfee [2011-01-17 17:06:51]: > > >> I found a patch from last may proposing a beagleboard defconfig, but it is not >> in my 11/10 release of buildroot. Does anyone know the status of beagleboard >> support? >> > > AFAIK BeagleBoard support has not been merged in yet. The patch from > last May is being progressively reworked. I recently submitted a patch > for X-Loader support which is a pre-requesite to BeagleBoard support. We > then need to implement building a kernel from Git instead of from a > released tarball (kernel trees with BeagleBoard support are usually not > tarballed), and finally we can add the board support. > > I haven't heard anything back on my X-Loader support patch though, but I > guess everyone is pretty busy in the beginning of the new year. > Sorry for not having found the time to comment your patch timely. I'll do it now. Your contribution is naturally appreciated, but what I think is that X-loader should not be in buildroot at all. Although it has historical merits, I find X-loader totally useless nowadays. I develop the buildsystem for a custom OMAP3 board, and I completely eliminated X-loader with great relief. X-loader is made for two uses: 1. a serial loader for being able to burn a "main" bootloader (e.g. U-boot) onto an empty or corrupted flash (a "bricked" board); 2. a 2nd stage bootloader for normal boot, being run by the boot ROM (1st stage bootloader) and used to run the "main", or 3rd, bootloader (e.g. U-boot). For the first usage, I found that barebox is a great alternative. In its omap3530_beagle_per_uart_defconfig it has the same functionality as X-loader, but it is well-written, supported and actively developed (while X-loader is a fork from a very ancient version of U-boot). About the second usage, a 2nd stage bootloader is just not needed. The OMAP3 boot ROM can directly boot the "main" bootloader if the latter is prefixed by a suitable configuration header. You can read more about this at http://nishanthmenon.blogspot.com/2009/05/configuration-header-no-more-x-loader.html Finally, I don't know if X-loader can act as a "main" bootloader but I think it doesn't. Anyway, since barebox and U-boot are around, would you choose anything else? Instead of putting efforts on integrating X-loader, I would instead investigate how to integrate in buildroot the steps to generate a bootloader with a configuration header (as per Nishanth's blog entry). I hadn't time to do it so far, but I'd be glad to to so if time permits, as well as to review someone else's proposal. Luca