From owner-freebsd-questions Sun Jan 2 11:27: 8 2000 Delivered-To: freebsd-questions@freebsd.org Received: from mass.cdrom.com (castles551.castles.com [208.214.165.115]) by hub.freebsd.org (Postfix) with ESMTP id C5B8C14EAA for ; Sun, 2 Jan 2000 11:27:06 -0800 (PST) (envelope-from msmith@mass.cdrom.com) Received: from mass.cdrom.com (localhost [127.0.0.1]) by mass.cdrom.com (8.9.3/8.9.3) with ESMTP id LAA12062; Sun, 2 Jan 2000 11:32:24 -0800 (PST) (envelope-from msmith@mass.cdrom.com) Message-Id: <200001021932.LAA12062@mass.cdrom.com> X-Mailer: exmh version 2.1.1 10/15/1999 To: Adam Mackler Cc: freebsd-questions@freebsd.org Subject: Re: creating bootable CD-ROM In-reply-to: Your message of "Sun, 02 Jan 2000 09:49:38 EST." <200001021449.JAA10783@barter.dewline.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Sun, 02 Jan 2000 11:32:24 -0800 From: Mike Smith Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG One list only, please. Especially, don't crosspost between -questions and -hackers. > First, is "El Torito" the only way to boot from a CD-ROM? On the PC, the "El Torito" standard is the only CD-ROM boot method with any sort of wide support. > Is there some way to use disklabel to make the ISO9660 > filesystem bootable, so that /boot and /kernel can just > go in the CD-ROM filesystem, rather than being embedded in > the image of a floppy disk? No. disklabel is strictly for UFS filesystems, and knows nothing about CDROMs. You should read the El Torito standard (it's quite brief) and learn about "no emulation" mode. (That's what mkisofs calls it, I don't have the document handy to give you the real name.) In this mode, your bootstrap code (which must live in a file in the iso filesystem) is loaded as a primary bootstrap, and the CD-ROM is exposed directly as a BIOS device. This is how the NT bootstrap works; we will probably be adopting it now that the latest release of mkisofs claims to support it. > Second, what is the purpose of the -C boot flag? On the boot(8) > man page is says "boot from CDROM," but I can boot from > a CD (El Torito style) without it. Does it have any use, > possibly in the context of my first question? It's an obsolete flag passed to the kernel telling it to search for a CDROM that it can mount as the root filesystem. -- \\ Give a man a fish, and you feed him for a day. \\ Mike Smith \\ Tell him he should learn how to fish himself, \\ msmith@freebsd.org \\ and he'll hate you for a lifetime. \\ msmith@cdrom.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message