Date: Sat, 6 Nov 1999 19:42:56 +0100 From: Juergen Lock <nox@jelal.kn-bremen.de> To: Matt Behrens <matt@zigg.com> Cc: zzhang@cs.binghamton.edu, freebsd-stable@FreeBSD.ORG Subject: Re: easyboot far into disk Message-ID: <19991106194256.A45418@saturn.kn-bremen.de> In-Reply-To: <Pine.BSF.4.10.9911060829110.14199-100000@megaweapon.zigg.com> References: <199911061143.MAA35365@saturn.kn-bremen.de> <Pine.BSF.4.10.9911060829110.14199-100000@megaweapon.zigg.com>
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On Sat, Nov 06, 1999 at 08:34:07AM -0500, Matt Behrens wrote: > On Sat, 6 Nov 1999, Juergen Lock wrote: > > : In article <Pine.GSO.3.96.991105105730.28840B-100000@sol.cs.binghamton.edu> you write: > > : >Also, Linux can boot from a floppy. Can FreeBSD does similar things (boot > : >from a floppy and then use data on the hard drive)? > > : Seems so, use a modified kern.flp with your kernel and change its > : loader.rc: remove the loading of the mfsroot image and add a line > : that sets currdev to point to your root fs (you can use lsdev in > : the loader to find it), and you should be ready to go. (I first > : tried setting rootdev instead but that seems to be getting ignored > : completely at least when booting from a floppy.) > > I had a system with a 3.7GB drive and a BIOS that refused to boot > off it. Boy, it confused the hell out of Windows. :-) In any > event, I wanted to put my own kernels on there while tracking > -STABLE so I made a minimal disk with /boot stuff and threw a new > kernel.gz on there every time I rebuilt the kernel. It was > surprisingly easy once I sat down and read the manpages (up until > then I'd been sheltered from newfs and disklabel by the "friendlier" > tools in sysinstall) :-) An easier (for newbies) method would be to just dd the kern.flp image to another floppy, mount it, and change the kernel and loader.rc. And in case of the newbie who just installed and cannot boot and who hasn't got another BSD box around to do this on, he can even use the kern.flp as it is if he just leaves it in the drive at the `insert mfsroot' prompt (ignoring the error), stops the autoboot countdown, does a lsdev and sets currdev by hand, followed by `boot'. (And when the system is up, create his custom boot floppy.) Oh and the bootable CD might work for this too, if you first `unload' to get rid of the mfsroot image, `load /kernel' again and then set currdev... > > : (Maybe this should be added to the FAQ as a method of last resort when > : the BIOS boot code can't see above cyl 1024?) > > I definitely agree. Maybe there should even be a Makefile option > while building a kernel to put it on a mounted floppy instead of > always putting it in / when install is called. (``make KERNTARGET=/mnt > install''?) And if we add a loader command that sets currdev to the first non-floppy ufs root found (or could this be done in forth too? :) we could even distribute a general emergency-boot-floppy... Regards, -- Juergen Lock <nox.foo@jelal.kn-bremen.de> (remove dot foo from address to reply) To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
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