[syslinux] isohybrid --mac doesn't find the mac efi image

[Thomas Schmitt]

Hi,

email at missionaccomplish.com wrote:
> We been trying to boot the image in vbox using efi emulation but it
> complains about kernel not supporting handover.

If it complains about a kernel then it should be past El Torito
or GPT. The job of xorriso is to point BIOS and EFI to their
boot images. Everything else is in the scope of the boot images
resp. the operating system that shall finally come up.


> P.S the latest fedora ISO seems to boot fine in vbox perhaps you
> might want to look at their image. Enjoy the rest of your weekend.

You could try to re-pack it by a xorriso command like yours.
Use

  xorriso -indev ...imagefile...iso -toc

to learn about the "Boot image" files and the "Volume id",
which you will have to use in the xorriso run.
E.g. with an old Fedora-LiveCD.iso this would be

  Drive current: -indev 'Fedora-LiveCD.iso'
  ...
  Volume id    : 'Fedora-LiveCD'
  ...
  Boot record  : El Torito , ISOLINUX isohybrid MBR pointing to boot image
  ...
  Boot image   : '/isolinux/isolinux.bin' , boot_info_table=on
  Boot image   : '/isolinux/efiboot.img' , platform_id=0xEF 
  Boot image   : '/isolinux/macboot.img' , platform_id=0xEF 

Extract the MBR file for -isohybrid-mbr by

  dd if=Fedora-LiveCD.iso bs=512 count=1 of=/tmp/extracted.mbr

and use a path to it as parameter of -isohybrid-mbr.
Use the mounted original ISO as input directory.
E.g.:

  mount -o loop Fedora-LiveCD.iso /mnt/fedora_iso

  xorriso -as mkisofs -J -R -l -V 'Fedora-LiveCD' \
  -o ../image.iso \
  -isohybrid-mbr /tmp/extracted.mbr \
  -c isolinux/boot.cat \
  -b isolinux/isolinux.bin \
     -no-emul-boot -boot-load-size 4 -boot-info-table \
  -eltorito-alt-boot \
  -e isolinux/efiboot.img \
     -no-emul-boot -isohybrid-gpt-basdat -isohybrid-apm-hfsplus \
  -eltorito-alt-boot \
  -e isolinux/macboot.img \
     -no-emul-boot -isohybrid-gpt-basdat -isohybrid-apm-hfsplus \
  /mnt/fedora_iso

If this works as good or bad as the original, then xorriso does
its job as expectable. If the repacked image fails, tell me the
URL of the original which you used.


Have a nice day :)

Thomas