Subject: Re: boot blocks - all platforms / kernel ramdisk load from file system
To: Christopher Tribo <>
From: David Laight <>
List: tech-kern
Date: 02/24/2003 16:12:34
> - El Torito CD-ROM in hard disk emulation mode loads kernel with MD 
> ramdisk stuffed into kernel.
> - /etc/rc mounts floppy drive to /etc && invokes the actual rc system 
> contained on it
> - /etc/fstab mounts cdrom file system
> - /usr file system mounted ro as vnd0 from iso9660 fs via fstab. (requires 
> hacking rc.d and/or extending mount?)

Given the cost of CDR mediam why have config files on floppy?

> 	This hits several big hurdles:
> -i386, El Torito hard disk emulation mode has near-zero documentation.

That is because it is so stupid^H^H^H^H^H^Htrivial.  You put a floppy
image in a file on the CD, the BIOS does translations to make that
data look EXACTLY like the floppy drive.

You can't load access the CD itself until the kernel is loaded because
everything before that is accessing the disks using bios calls.
Nothing in netbsd knows how to issue bios reads of the cdrom (I suspect
it may be drive E0 on some systems).

The install CD uses this...


David Laight: