On Fri, Jun 28, 2013 at 7:38 PM, <tlaronde@polynum.com> wrote:

On Fri, Jun 28, 2013 at 12:40:46PM -0400, erik quanstrom wrote:
>
> this iso uses the traditional el-torito method. unfortunately,
> the installer is size-constrained (1.44MB) and doesn't support usb.
>

FWIW (I implemented El-Torito support for GRUB years ago), the image has
to be some floppy size, and 2.88MB is perfectly supported.

There is also hd emulation, but this it seems not to be widely
supported by BIOSes.

There are various ways of booting with El-torito.

http://download.intel.com/support/motherboards/desktop/sb/specscdrom.pdf

One of the ways is non-emulation (I thought it had appeared in a later version of El-torito,

but checking the spec it was already in version 1, 1995), the byte 1 in page

19, description in page 16.

Mkisofs lets you create a non-emulation bootable image (see

/sys/src/cmd/disk/9660/boot.c:166, which is set with -B) or an emulation image.

Emulation goes hand in hand with pbsraw.s.

It used to be that many BIOSes did not support non-emu, but that has not been true

AFAIK for a long while (at least more than 10 years). As long as you have

the blocks 2M aligned you should be fine with most modern BIOSes.

I think the problem is that the Plan 9 iso is somewhat different than k3b expects

and it is "fixing" it, although as I said, the iso format is complex enough and has enough

variants that there may be some error somewhere or the BIOS may have a bug...