ZFSBootMenu from source, generate-zbm: 'Unable to determine stub alignment!'

[serge-vk]

Hi everyone,
I am trying to build and install ZBM on Ubuntu 25.10 by following the guide, and after a couple of snags (cpio and systemd-boot-efi packages needed, but not installed), I am stuck at this error from generate-zbm:

# generate-zbm
No initramfs generator specified; using dracut
Creating ZFSBootMenu 3.1.0 from kernel /boot/vmlinuz-6.17.0-8-generic
Unable to determine stub alignment!

This message probably comes from dracut because I did not find it in the ZBM sources. Can anyone point me to the right direction in trying to solve this?

[zdykstra]

I assume this was on an x86_64 host. Can you confirm the version of your EFI stub file, and if possible, share it some how?

[serge-vk]

Yes, you are right, x86_64. At first, generate-zbm failed to find the EFI stub file at /usr/lib/systemd/boot/efi/linuxx64.efi.stub. By trial and error, I discovered that the package systemd-boot-efi that installs the stub was missing. I have installed this package and then got the alignment error. I tried uploading the files installed by the package here. I am not sure how to find the version of those files.

[ahesford]

The error message you see comes directly from generate-zbm. We look for a SectionAlignment field in the output of

objdump -p /usr/lib/systemd/boot/efi/linuxx64.efi.stub

(or wherever your stub resides) to determine alignment for sections in the UEFI bundle. Please try to run this on your system, and report the output here.

[serge-vk]

Thank you for your instructions. I have uploaded the objdump output in this file. Let me know if this worked.

[zdykstra]

Did you have to install objdump to generate that output, or was it already installed?

[serge-vk]

I had to install binutils to do that just now. I largely followed the guide and only installed additional packages when I ran into problems.

[zdykstra]

generate-zbm should work now that objdump is available. We'll need to add additional documentation and a sanity check to the tool to make sure that it's available when EFI output is requested.

[serge-vk]

Yes, I was able to generate the boot image and start the system from it. In summary, the guide missed the following packages that I had to install manually:

• system-boot-efi
• cpio
• binutils

Unfortunately, it is not obvious to identify the problem of missing binutils.