Date: Thu, 25 Mar 1999 19:49:50 -0600 (CST) From: Richard Wackerbarth <rkw@dataplex.net> To: Mike Smith <mike@smith.net.au> Cc: hackers@freebsd.org Subject: Re: Booting from non-standard floppy Message-ID: <Pine.BSF.4.05.9903251901470.932-100000@nomad.dataplex.net> In-Reply-To: <199903260033.QAA01323@dingo.cdrom.com>
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On Thu, 25 Mar 1999, Mike Smith wrote: > > I needed to cram "a few more bytes" on a floppy. > > recall, the "bios" read the 0th sector (boot1) and jumped to it. > > That short piece of code got the disk format from the label and > > read in the next piece of the loader. After that, address->c.t.s > > was under the software control. > > > > Is there some reason we no longer do this? > > Several; > > - Disklabels on floppies can't be trusted. > - All disks are treated as equal, and geometries in disklabels on many > disks can't be trusted. Often you can't get to the disklabel until > after you've made assumptions about geometry anyway. > > You can save space a couple of ways; if you haven't already, gzip > everything except the loader. Been there. My stuff is based on the PicoBSD kernel. Almost all the extras are already purged. > If you don't need the loader for anything other than loading a kernel, > throw the loader away; the bootblocks themselves know how to load ELF > kernels. Thanks, that will save a little. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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