Bug#740504: Any update on having an upgraded xorriso so we don't have GPT failures ?

["Thomas Schmitt" <scdbackup@gmx.net>]

Hi,

because debian-cd also records the arguments of its xorriso run,
it should be not too hard to repack it with a newer xorriso,
which produces better GPT. E.g. xorriso-1.3.2 from Debian Sid.

You will need to copy the MBR from the original ISO

  dd if=debian-7.3.0-amd64-netinst.iso bs=512 count=1 \
     of=my_old_debian.mbr

and to mount it

  mount debian-7.3.0-amd64-netinst.iso /mnt

The originally used arguments are stored in the ISO filesystem
as file

  /.disk/mkisofs

Omitting the Jigdo options, this would be for Debian 7.3 amd64:

  xorriso -as mkisofs \
     -r -V 'Debian 7.3.0 amd64 1' \
     -o my_new_debian.iso \
     -J \
     -isohybrid-mbr my_old_debian.mbr \
     -joliet-long -cache-inodes \
     -b isolinux/isolinux.bin \
     -c isolinux/boot.cat \
     -no-emul-boot -boot-load-size 4 -boot-info-table \
     -eltorito-alt-boot \
     -e boot/grub/efi.img -no-emul-boot -isohybrid-gpt-basdat \
     -isohybrid-apm-hfsplus \
     --sort-weight 2 isolinux/isolinux.bin \
     --sort-weight 2 boot/grub/efi.img \
     /mnt

It is important to keep the original Volume Id, as told by
xorriso -pvd_info, by mediainfo, or alike.
This id is used to mount the ISO at boot time, afaik.

I attributed --sort-weight to both boot images, in order
to push them to low block addresses. Beginning with xorriso-1.3.4
this is done by default.

(I am tempted to omit option -isohybrid-apm-hfsplus which
 is intended for marking HFS+ enhanced ISOs. But on the other
 hand: Who knows what an Apple Mac wants to see ?)


Have a nice day :)

Thomas