Subject: Re: Create bootable kernel-only ISOs in addition to *.fs floppy images
To: None <>
From: Frederick Bruckman <>
List: tech-install
Date: 05/12/2006 00:28:19
In article <>,
	Hubert Feyrer <> writes:
> On Fri, 12 May 2006, Havard Eidnes wrote:
>>> To solve that, I'd like to use the kernels from #3d) above, and use
>>> them to make bootable ISOs in addidion to the floppy images we have
>>> now. Those ISOs would be made using makefs(8)'s "-t cd9660
>>> -no-emul-boot" options, removing the 2.88MB limit. The ISO would use
>>> bootxx_cd9660 as bootloader to load the kernel with its embedded
>>> ramdisk.
>> So, this would use the "HD emulation" boot method?  There has
>> been reports of i386 systems which are unable to boot using that
>> method.  I am however unsure of how widespread that problem is;
>> it may be sufficiently small that telling people to revert to
>> using the 2+ floppy sets as an alternative boot method would be
>> reasonable.  I would think/hope that machines without floppies (a
>> relative new thing?) have sufficient BIOS support for the "HD
>> emulation" boot method?
> I have no idea, and I don't know how to find out.
> I'd say we offer the files with 'hd emulation' now (in addition to the 
> *.fs images), and then see if people can use them or not. If not, we know, 
> and can react.

It doesn't sound like you're doing "hard disk emulation".  "Hard
disk emulation" is to use an emulation image, like the floppy image,
but of arbitrary size. (The BIOS gets the size and geometry of the
image from the MBR in the first sector.)  The "no emulation option"
that you propose is likely to be much more widely supported, since
the BIOS has less to do than for the floppy emulation.