Nanobsd on a CD-ROM

Vince Hoffman jhary at
Fri Jun 13 13:51:22 UTC 2008

to make a freebsd CDROM bootable you need to use the /boot/cdboot as the
loader and make an ISO image. the nanobsd procedure creates a ufs disk
image from what I understand.
Try mounting the disk image
mdconfig -a -t vnode -u 11 -f /path/to/image/_.disk.full
mkdir /mnt/image
mount /dev/md11 /mnt/image
(might be /dev/md11s1a or similar, see whats created and find what works.)

Then make an ISO of the mounted nanobsd image

mkisofs -J -R -no-emul-boot -b /boot/cdboot \
-iso-level 3 -o nanobsd.iso /mnt/image

Then either burn it to CD or install qemu to see if it boots before
making another coaster.

I havent tried this exactly but this should work, may need polishing though.


J. Porter Clark wrote:
> On Thu, Jun 12, 2008 at 06:54:45PM +0200, Pietro Cerutti wrote:
>> J. Porter Clark wrote:
>> | On Thu, Jun 12, 2008 at 04:40:25PM +0200, Pietro Cerutti wrote:
>> |> J. Porter Clark wrote:
>> |> | Is it possible to build a CD-ROM with a bootable NanoBSD on it?
>> |> | If so, how?
>> |>
>> |> Yes, Section 2.2 of
>> |>
>> |>
>> |
>> | Well, no, because I can't do this:
>> |
>> |   # dd if=_.disk.full of=/dev/acd0 bs=64k
>> |
>> | If I do this:
>> |
>> |   % cdrecord -v -immed driveropts=burnfree dev=1,0,0 -data _.disk.full
>> Try with burncd
>> | burncd -f /dev/acd0 data _.disk.full fixate
> No joy.  Produces the same disk that cdrecord does, and boots
> from hard disk instead.
> I think that this is the problem: The BIOS knows how to boot
> from a CD if and only if that CD is an "El Torito" bootable
> image.  That is, the first sector of the CD is NOT a Master Boot
> Record.  That's just a hypothesis based on the observation that
> all of the successfully bootable CDs I have appear to be in "El
> Torito" format.
> I don't have a way to make such an image without using mkisofs.
> Figuring out how to pack the nanobsd image in such a way that
> mkisofs can make an "El Torito" bootable CD from it sounds
> difficult, offhand.  Anybody know how to do this sort of thing?
> Is it even possible?

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