Re: [Bug-xorriso] About run xorriso under Win32

[Thomas Schmitt]

Hi,

i will need some hours to digest your mails.

>    ..\xorriso -as mkisofs -U -A centos65 -V centos65 -volset centos65 
> -J -joliet-long -r -v -T -o ../centos65.iso -b isolinux/isolinux.bin -c
> isolinux/boot.cat -no-emul-boot .
> But the generated iso can't boot bios machine too.

This is lacking the -boot-info-table option which is
needed to patch the block address of isolinux/isolinux.bin into
its code.
Regrettably it is exactly that option which sabotages
the ISO image creation run by xorriso.


The result from the mkisofs run looks nearly ok for EFI:

> EI Torito images   : N Pltf B Emul Ld_seg Hdpt Ldsiz      LBA
> EI Torito boot img : 2 UEFI y none 0x0000 0x00  4672       49
> EI Torito img path : 2 /boot/grub/efi.img
> EI Torito img opts : 2 boot-info-table

But mkisofs patched a boot info table into the FAT filesystem
image /boot/grub/efi.img . This has overwritten bytes 8 to 67
of the file.
Not knowing anything about the FAT format, i glimpse into an
example (/mnt/iso/EFI/archiso/efiboot.img) and see a Master
Boot Record. It seems unused except of its partition table,
which would not get overwritten by -boot-info-table.

So it seems not very likely that patching is to blame for
the failure to boot. (Nevertheless it is not appropriate.)

Can you mount the ISO image and then mount the FAT image
inside the ISO ? Are all files inside the FAT readable ?
On Linux that would be
  mount -o loop a.iso /mnt/iso
  mount -o loop /mnt/iso/boot/grub/efi.img /mnt/fat
  tar cvf /dev/null /mnt/fat
Watch out for error messages.


I will next look into the compile time problems and try to
invent some test code by which we can analyze the reason for
the short read(2) results.


Have a nice day :)

Thomas