Re: [Bug-xorriso] Test Proposal for [bug #46716] Protective MBR partition is not marked as bootable

[Thomas Schmitt]

Hi,

i wrote:
> > And the other non-working "EFI Boot" offer is gone ?
> > (That would mean it was the APM/HFS+ boot path.)

Alexander E. Patrakov wrote:
> Yes.

So APM with block size 2048 seems not to work on HDD with size 512.
(The bytes 2 and 3 of the GRUB2 MBR in its role as fake APM Block0
 tell 2048.)


> > [2007 Mac]
> > Are there any bootable media for it, which are not from Apple ?

> Yes: http://porteus-kiosk.org/public/3.6/Porteus-Kiosk-3.6.0-i486.iso

The partitioning was most probably made by mjg's augmentations
to the program isohybrid.c. It shows the traces of some known
and meanwhile fixed bugs. E.g. the GPT partition names:
ASCII plus a few buffer overflow bytes where UTF-16LE is expected
yields chinese letters.

BIOS equipment is obviously ISOLINUX.

The file /EFI/BOOT/bootx64.efi in the EFI partition contains:
  GNU GRUB  version %s
  2.00
So it is from here. :))

The following xorriso -as mkisofs options would reproduce its
bootability:

  -V 'Porteus-Kiosk'
  --modification-date='2015122119452136'
  -isohybrid-mbr $MBR_TEMPLATE
  -partition_cyl_align on
  -partition_hd_cyl 64
  -partition_sec_hd 32
  -c '/boot/isolinux/isolinux.boot'
  -b '/boot/isolinux/isolinux.bin'
  -no-emul-boot
  -boot-load-size 4
  -boot-info-table
  -eltorito-alt-boot
  -e '/boot/isolinux/efi/efiboot.img'
  -no-emul-boot
  -isohybrid-gpt-basdat

The argument $MBR_TEMPLATE is the path to ISOLINUX file isohdpfx.bin
on the local disk. The first 446 bytes of the ISO image would serve
the same purpose.


Have a nice day :)

Thomas