Re: Developing Linux boot from CDROM

Michael Fulbright (msf@redhat.com)
Wed, 16 Oct 1996 18:28:19 -0400

I have just finished a set of patches to mkisofs which allow you to do
just what you are asking for. The standard which I followed is called
the "El Torito" standard. You can find documentation (pdf only) on the
Phoenix web page (//http://www.ptltd.com/techs/specs.html).

The idea is to at boot time have BIOS fake the CDROM drive as an A:
drive to a boot loader such as LILO. You just have to put a 1.44 meg
image of a boot floppy in your iso9660 filesystem, adjust some headers
in the non-user part of the iso9660 fs, and BOOM, bootable CD.

One catch is if you use a initrd you have to have LILO load it, not the
kernel ramdisk driver. This is because LILO will load it via BIOS calls
and the faking of the CDROM drive as a floppy drive will be in effect,
as desired.

Anyone with further questions are welcome to send me email...

Michael Fulbright
msf@redhat.com