Date: Tue, 20 Aug 1996 22:11:21 +0200 (MET DST) From: J Wunsch <j@uriah.heep.sax.de> To: freebsd-hackers@freebsd.org (FreeBSD hackers) Subject: Re: Making Bootable Disks Message-ID: <199608202011.WAA17519@uriah.heep.sax.de> In-Reply-To: <199608201429.JAA20513@brasil.moneng.mei.com> from Joe Greco at "Aug 20, 96 09:29:21 am"
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As Joe Greco wrote: > > > Is it outlined/described anywhere how to make a bootable system floppy? > > > > disklabel -Brw fd0 > > newfs ... /dev/rfd0a (look into /etc/disktab for the options) > > mount /dev/fd0a /mnt > > cp /kernel /mnt > > umount /mnt > > With all due respect Joerg, that's nice but not very useful :-) The kernel > alone will take 2/3 the floppy. The question was about a ``bootable floppy'', not about a useful one. ;-) Actually, that's the ``classical'' boot/root floppy pair approach. You load the kernel off the boot floppy, and then provide a root floppy as the root f/s. The minimal contents of a (marginally) useful root floppy is /sbin/init, /bin/sh, and /dev/console. Everything else is optional. crunchgen is a nice tool to create the contents of the root floppy. The installation floppy, while still using the name ``boot.flp'' (for hysterical reasons -- root.flp has just been eliminated recently, but didn't server for exactly this purpose for more than a year now), is another matter: it uses a builtin MFS acting as the root file system. I think you can also create something like the MFSROOT floppy now with Julian's new floppy creation tools (/usr/src/release/floppies/). Both approaches have its pros and cons. The boot/root pair has the disadvantage of a more complicated handling (you gotta swap floppies after loading the kernel), and of blocking the floppy drive while running. The MFS root system has the disadvantage of a more complicated system to manipulate the kernel or the contents of the root file system. It also requires a much bigger memory footprint (unless you're going to back the MFS on floppy swap space ;-). Dennis wasn't exactly specific about the purpose of his question, thus i couldn't answer it much better. -- cheers, J"org joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE Never trust an operating system you don't have sources for. ;-)
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