Re: [Buildroot] Hybrid UEFI-Only CD-ROM image with systemd-boot

[Thomas Kindler]

On Thu, November 7, 2024 08:09, Thomas Schmitt via buildroot wrote:

Thanks for your great answer!

>
> consider to Cc: bug-xorriso@gnu.org when asking xorriso questions.
>

Can do - I'll CC this mail, so other people know that there's a xorriso
thread on the buildroot mailing list.

>> [..]
>> 1) How can I get xorriso to generate an image with only the EFI
>> partition?
>
> If all is in the EFI partition, you want GPT, and want to avoid nested
> partitions, try with an appended partition attached to a minimal ISO with a
> dummy file (here: README).
>
> # There is no need to have $BINARIES_DIR/cdrom
>
>
> echo "No payload data in this ISO 9660 filesystem" >README
>
> xorriso -as mkisofs \ -o "$BINARIES_DIR"/cdrom.iso \
> -eltorito-catalog boot.cat \
> -appended_part_as_gpt \
> -partition_offset 16 \
> -append_partition 2 0xef "$BINARIES_DIR"/efi-part.vfat \
> -e --interval:appended_partition_2:all:: \
> -no-emul-boot \
> -no-pad \
> README
>
>
> The resulting .iso then yields with fdisk -l something like:
>
>
> Disklabel type: gpt
> Disk identifier: 402F6C62-D96C-4257-B9A8-A4E20CD84888
>
>
> Device     Start   End Sectors Size Type
> cdrom.iso1    64   203     140  70K Microsoft basic data
> cdrom.iso2   204 20555   20352  10M EFI System
>
>

Is there a way to generate only one partition?
That way it would look like a normal USB stick.

As a workaround I use sgdisk:

# Remove partition 1, swap 1 and 2, rename to "esp", print
#
sgdisk -d1 -r1:2 -c1:esp -p $BINARIES_DIR/cdrom.iso


But a xorriso-only solution would be best.


best regards,
-- 
Thomas Kindler <mail_buildroot@t-kindler.de>