From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeroen Hofstee Date: Tue, 12 Aug 2014 19:29:02 +0200 Subject: [U-Boot] [PATCH 1/3] config: introduce a generic $bootcmd In-Reply-To: <53E911AF.4080908@wwwdotorg.org> References: <1406759836-556-1-git-send-email-swarren@wwwdotorg.org> <53E25145.2090706@wwwdotorg.org> <53E4F400.6060508@wwwdotorg.org> <53E63816.60703@redhat.com> <53E6A3FE.6080807@myspectrum.nl> <53E6E2D0.7090303@wwwdotorg.org> <53E7A3A2.80707@myspectrum.nl> <53E8F50A.1060606@wwwdotorg.org> <53E90294.7060604@myspectrum.nl> <53E905AC.9050903@wwwdotorg.org> <53E90E90.4020204@myspectrum.nl> <53E911AF.4080908@wwwdotorg.org> Message-ID: <53EA4EDE.7030904@myspectrum.nl> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hello Stephan, On 11-08-14 20:55, Stephen Warren wrote: >>> No, Linux distros need to be able to install a single bootloader >>> configuration file to tell the bootloader how to boot. >> >> Don't understand this, I though extlinux is yet another >> chainloaded bootloader? I doubt there is "the bootloader". >> I don't understand why it needs a single bootloader. It gets >> in handy if the last bootloader is known, but I don't even see >> why that is required. > > This is obviously where the disconnect is... > > extlinux is (IIRC) a bootloader yes. However, this patch isn't about > extlinux, but extlinux.conf. > haha, right that is a funny misunderstanding. Yes, extlinux is indeed a bootloader and I was in the impression you actively searched for it to chainload it. And to make extlinux a requirement for distro support... And as I tried to explain I am not that fond of such an approach in general, and that had nothing to do, as Tom suggested, with booting FreeBSD, it is just the image I encountered searching for it in various places. It remains a badly named file though (for U-boot), but well so be it, I guess. > extlinux.conf is a text file format the defines a menu of bootable > OSs. It's a (de-facto I suppose) standard that's implemented by > extlinux (if indeed that is a piece of SW:-) and also U-Boot and > barebox and likely other bootloaders too. > > So, when U-Boot locates extlinux.conf on disk and processes it, it's > parsing a configuration file/menu, not chain-loading/executing another > bootloader. > I see, so shouldn't we document then who is in charge of its format at least, before we start making a U-boot/distro specific version of it? > > That would require all Linux distros to have specific support to > install boot.scr, which is a bootloader-specific format script file. > Systems that boot using e.g. Barebox or other bootloaders presumably > can't process boot.scr. However, if all bootloaders end up supporting > extlinux.conf, the distro won't care what bootloader is on the HW. We will see if this works, I am bit skeptical, but it is at least a whole lot better then polling all possible options, where I took the patch for. (Well not all yet, but the start to do so). Regards, Jeroen