Subject: Re: Create bootable kernel-only ISOs in addition to *.fs floppy
To: None <hubert@feyrer.de>
From: Havard Eidnes <he@NetBSD.org>
List: tech-install
Date: 05/12/2006 00:22:18
Hi,

a few comments/questions:

> 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?

> 2.3) After moving things, code for building ISOs can be added as
> described in "2) Add CD-ROM creation code" of [1]:
>
>  	src/distrib/{i386,amd64}/cdroms/bootcd
>  	src/distrib/{i386,amd64}/cdroms/bootcd-com
>  	src/distrib/{i386,amd64}/cdroms/bootcd-laptop
>  	src/distrib/{i386,amd64}/cdroms/bootcd-ps2
>  	src/distrib/{i386,amd64}/cdroms/bootcd-tiny

Hm, I'm wondering whether we need the bootcd-ps2 (can PS/2
systems boot from CD-ROM?) and bootcd-tiny (I would have thought
that machines which are memory-constrained are typically from the
age when CD-ROM booting was not supported by the BIOS).  I'm sure
some can find some exception -- therefore I'm saying "typically"
here.

>   * Add something to build.sh that builds *all* architectures
>     ("full-release"?), so the CDs in src/distrib/cdrom can be built
>     after/by that.

Sounds like a lot of work, as it's currently geared towards
building a single architecture.

> Any objections?

I'm not, although there are some concerns above which needs to be
answered.

Regards,

- H=E5vard