[syslinux] can't boot isohybrid-ized image on CG2100

Thomas Schmitt scdbackup at gmx.net
Mon Mar 21 14:38:33 PDT 2011


Hi,

> Am I correct that the -isohybrid-mbr option is only available with -as
> mkisofs in effect? 

It is the mkisofs emulation way to express xorriso option
  -boot_image isolinux system_area=/usr/lib/syslinux/isohdpfx.bin

The example from my previous mail would be:

  xorriso -outdev output.iso \
          -blank as_needed \
          -map ./CD_root / \
          -boot_image isolinux dir=/isolinux \
          -boot_image isolinux \
                      system_area=/usr/lib/syslinux/isohdpfx.bin \
          -boot_image isolinux partition_offset=16

Note that sequence matters with generic xorriso options.
You first have to add the boot image file as /isolinux/isolinux.bin,
which happens by the -map command, before you can perform
  -boot_image isolinux dir=/isolinux
which is equivalent to
  -as mkisofs \
  -b isolinux/isolinux.bin -c isolinux/boot.cat \
  -no-emul-boot -boot-load-size 4 -boot-info-table \
  --

-as is actually a generic xorriso command.
Its first argument chooses emulation of mkisofs or cdrecord.
Its arguments end at the first "--" or at the end of program
arguments.
All arguments of an -as mkisofs command get processed in the peculiar
sequence of mkisofs. But two different -as commands get executed
separately. This might cause user confusion. So one will normally
use only one -as mkisofs command per xorriso run.


> anyway, I was using mkisofs previously, so I just threw all the
> same options

That's why i usually show mkisofs emulation examples for bootable
images. Experienced system producers shall be able to re-use their
knowledge and scripts.
See man xorrisofs for a description of emulation options.

There are usage scenarios where xorriso's generic commands are much
stronger than mkisofs emulation. Especially with multi-session
and in dialog mode.
Nearly all features of the emulation are available as generic
commands. Only truncation of existing -o files is not a feature
of xorriso.


Have a nice day :)

Thomas




More information about the Syslinux mailing list