[Debburn-devel] Mysterious multisession failure

[Thomas Schmitt]

Hi,

> http://www.puppylinux.com/news/news2005a.htm

Oops. -D is _disable_ relocation.
I should read man pages more often.


> -iso-level 4

According to the man page this is the 1999 version
of ISO 9660. The question is which operating
systems are willing to mount this.
1999 is an attempt to make ISO 9660 a bit less
restricted. Nevertheless it falls short in
comparison to the capabilities of the Rock Ridge
extensions.


Well, since you already had disabled relocation,
and since it did not work with relocation in 2005,
i think it is time to try xorriso.

It can emulate most of your mkisofs and cdrecord
options:

  xorriso -as mkisofs \
     -R -o cd-puppy.iso -b isolinux.bin -c boot.cat \
     -no-emul-boot -boot-load-size 4 -boot-info-table ./build/

  xorriso -as cdrecord \
     -multi -tao -pad -data -eject -v speed=10 dev=/dev/sr0 \
     cd-puppy.iso

  SECT=`xorriso -as cdrecord -msinfo dev=/dev/sr0 | grep '^[0-9]*.[0-9]'`
  export SECT
  xorriso -as mkisofs \
     -print-size -R -C $SECT -M /dev/sr0 -quiet \
     -graft-points 2009-07-15=/root/nothing

I would propose padsize=300k rather than -pad
because the Linux TAO read bug meanwhile easily
hops over 30 kB of padding.

xorriso can do the jobs by its own options
and without the need for intermediate .iso
files on hard disk:

  xorriso -dev /dev/sr0 -blank as_needed \
          -map ./build / \
          -boot_image isolinux bin_path=/isolinux.bin \
          -boot_image isolinux cat_path=/boot.cat \
          -boot_image isolinux load_size=2048 \
          -commit_eject all

  xorriso -dev /dev/sr0 \
          -map /root/nothing /2009-07-15 \
          -chmod 0755 /2009-07-15 \
          -print_size

  (resp.  -commit_eject all
   to actually burn and eject)

Depending on the media type one should give the
-boot_image options with each session. With
multi-session media (e.g. CD-R[W] or DVD-R[W]) the
BIOSes normally do not obey El Torito specs and
boot via the first session. (The specs say it
shall be the last one.) The booted OS then normally
mounts the last session.

On overwriteable media (DVD+RW, DVD-RAM, BD-RE)
the BIOS and the OS see only one session. This
session has to be made bootable with every
new session added by xorriso.


Have a nice day :)

Thomas