From mboxrd@z Thu Jan 1 00:00:00 1970 To: 9fans@cse.psu.edu Subject: Re: [9fans] new bootstrap structure In-reply-to: Your message of "Tue, 13 Nov 2001 18:40:08 -0500." <20011113234030.E5B8319A4A@mail.cse.psu.edu> Message-ID: <25787.1005695324@apnic.net> From: George Michaelson Date: Wed, 14 Nov 2001 09:48:44 +1000 Topicbox-Message-UUID: 21dc6d26-eaca-11e9-9e20-41e7f4b1d025 As I understand it, the El-Torrito method used by BSD releases depends on a facet of the CD standard which lets the CD act as a 2.88Mb floppy via a CD-FS pointer to a specific file in the real IS09660 CD dataset. This file is usually exposed in the FS as a .flp file so you can in BSD terms mount it as a virtual device and look in it. More to the point, you can write it (or more plausibly the 1.44mb variants) to a floppy via rawrite command, from a mounted CD in any operating system which reads ISO9660 format CDs. So the kit doesn't need to ship a floppy, it just needs to expose the file which is the boot image, or a variant of it, and tell the user to mount the CD in Windows, and use a rawriter method to copy the boot image to a floppy, and then reboot off that floppy. in the FreeBSD releases, this is the dataset /floppies in the root of the CD. I used this to cut my own FreeBSD install image, which required making floppy images, copying to /tmp, vnconfig mounting as virtual devices, copying the kernel, then writing into the kernel image the memory-mapped FS image of the root with the modified sysinstall script, then writing the modified kernel back to the vnconfig mount of the floppy image, then re-making the .ISO image with that floppy .flp file as the boot disk pointer, and burning to CD. I know it sounds tortuous but each stage was rational, and simple. I am sure a Plan9 install modification process would be simpler btw. cheers -George