[syslinux] xorriso issue? - Failed to load COM32 file ldlinux.c32

[Thomas Schmitt]

Hi,

> Guess I better contact Thomas Schmitt

Here i am. :))

> When I build the ISO with different parameters for xorriso it works (omit
> EFI boot image and isohybrid boot sector). 

So it does not work from CD or DVD if you let xorriso give it
MBR and GPT ?

If so, then try what happens with such an MBR+GPT-enhanced image
after you zeroized its first 32 KiB. E.g. by

  ( dd bs=1024 if=/dev/zero count=32 ; \
    dd bs=1024 skip=32 if=image_with_mbr_gpt.iso ) \
    >zeroized_mbr_gpt.iso

This zeroizing will remove MBR and GPT but keep any damage that
might have been done to El Torito.

If this partly zeroized image boots properly from CD or DVD,
then your BIOS/EFI/whatever is confused by the presence of
the hard disk partition tables. Maybe because they are wrong.
Question then: Does the not-zeroized image boot from USB stick ?

If the zeroized image does not boot (and if your zeroizing really
only hit the first 32 KiB), then xorriso spoiled El Torito somehow,
or your EFI El Torito "boot image" partition is bad in some way.
Next tests would be to produce
- El Torito for BIOS and EFI by options -b and -e but no isohybrid
  options.
- El Torito for BIOS only but with -b and -isohybrid-mbr but without
  -e and -isohybrid-gpt-basdat or -isohybrid-gpt-hfsplus.


I could need a link to an un-zeroized image in any case.
Best would be if the image is small but demonstrates the problem.
Regrettably i have no system that boots via EFI. But i can do some
theoretical examinations.


Have a nice day :)

Thomas