Re: Writing a bootable image on-the-fly

[Thomas Schmitt]

Hi,

by mistake, i replied to Tom Lisjac's mail in private.
So here is the public answer with an additional proposal.


Tom Lisjac wrote:
> Replacing -o /tmp/output.iso with -outdev /dev/sr0 produces a genisoimage
> related error

It says "-as genisofs", not "-as genisoimage". :))
That's because originally there was planned to be another ISO program
named "genisofs" which was quickly obsoleted by the progress of xorriso.

But yes, -outdev is not a recognized -as mkisofs option.

Try:

  xorriso -outdev /dev/sr0 -blank as_needed \
          -as mkisofs ... your options, but not -o /dev/sr0 ...


Additional proposal which was not in the private mail:

The classical way to let mkisofs burn on the fly is to pipe its output
into cdrecord. xorriso can serve in that cdrecord role, too.
Just omit option -o with xorrisofs, so that it directs the emerging ISO
image to standard output:

  xorrisofs ... your options, but not -o /tmp/output.iso ... \
  | xorrecord -v dev=/dev/sr0 -waiti -eject -

(End of additional proposal)


> -o /dev/sr0 writes the data to the console

This surprises me. It should try to use /dev/sr0 via the usual Linux
block device driver. This would work with DVD-RAM, DVD+RW, and BD-RE media.

Output to the console would happen if there is no -o option at all.

The interpretation by the mkisofs emulation avoids to use /dev/sr0 as a
libburn drive but rather insists on using it as Linux block device.
In xorriso's native mode that would be done by -outdev stdio:/dev/sr0 .

My above proposal lets xorriso in its native mode acquire the drive,
blank it if appropriate and needed, and only then enter mkisofs emulation.
The acquired drive will stay in effect for the emulation run. But of course
you must not override it by an -o option of the emulation.


Have a nice day :)

Thomas