Re: Proposal to change partition table layouts for EFI bootable ISOs

["Thomas Schmitt" <scdbackup@gmx.net>]

Hi,

i wrote:
> >- Fully specs compliant GPT announced by Protective MBR.
> >  Produced by grub-mkrescue.
> > [...]
> > GPT partitioning of an image file has the disadvantage that the GPT backup
> > at the end of the image will not sit at the end of the physical storage

Steve McIntyre wrote:
> Right.

Just for completeness:

The proposed layout can be achieved by submitting to grub-mkrescue a
wrapper script as pseudo-xorriso:
  https://dev.lovelyhq.com/libburnia/libisoburn/raw/master/frontend/grub-mkrescue-sed.sh

To be used like:

  grub-mkrescue ...your.options... \
                -partition_offset 16 -iso_mbr_part_type 0x83 \
                --xorriso=...path.../grub-mkrescue-sed.sh

The script manipulates the options which grub-mkrescue submits to xorriso,
maybe moves the EFI image file out of the temporary directory with the
prepared files, and then runs real xorriso to produce the ISO image.
Further it can fix a pitfall for ~2010 MacBooks caused by the use of mformat
for creating the EFI partition image.
(See script comments up to "Do the work".)


Have a nice day :)

Thomas