Re: [PATCH 2/3] grub-mkrescue: Preserve a copy of the EFI bootloaders on the ISO9660 file system

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

Hi,

On Mon,  6 Jun 2022 17:50:32 +0100, Pete Batard <pete@akeo.ie> wrote:
> To enable file system transposition support for UEFI, we also must ensure that
> there exists a copy of the EFI bootloaders, that are currently embedded in the
> efi.img for xorriso, at their expected UEFI location on the ISO9660 file system.
>
> This is accomplished by removing the use of a temporary directory to create the
> efi/ content, to instead place it at the root of the ISO9660 content.
>
> Signed-off-by: Pete Batard <pete@akeo.ie>

Reviewed-by: Thomas Schmitt <scdbackup@gmx.net>
Tested-by: Thomas Schmitt <scdbackup@gmx.net>


I reviewed (modulo style aspects) and applied the patch [2/3] to a freshly
pulled grub-mkrescue.c . It compiles and produces (on Debian) an ISO with:

  grub/grub-mkrescue -d /usr/lib/grub/x86_64-efi \
                     --locale-directory=/usr/share -o test.iso minimal

(It would be more realistic if i knew how the Debian binary of grub-mkrescue
 knows that there is also /usr/lib/grub/i386-pc and combines it with
 x86_64-efi. If i use two -d options, then the latter overrides the former.)

Whatever, the resulting test.iso has EFI boot equipment of the same size as
the ISO from Debian's grub-mkrescue with the same arguments as above.
Different than with Debian's binary, there is now a directory tree /efi in
the ISO with 146 KiB of storage space (measured by xorriso -dus).


Have a nice day :)

Thomas