Is Unified kernel image suppported for arm64?

[gp-sbg]

I booted up an ubuntu arm machine in OCI and made unified kernel image using the following sbctl command,

sudo ./sbctl bundle -e /usr/lib/systemd/boot/efi/linuxaa64.efi.stub -f /boot/initrd.img-6.5.0-1020-oracle -k /boot/vmlinuz-6.5.0-1020-oracle linux_arm.efi

I copied the unified kernel image so created into /boot and in the grub, i did

chainloader (hd0,gpt1)/boot/linux_arm.efi boot

But it fails in grub telling

kern/verifiers.c:214: string: boot, type: 2
Execution of embedded linux image failed: Load Error
error: unknown error.

I tried the exact same thing from an ubuntu x86 machine and the unified kernel image created in x86 is working correctly.

So, is unified kernel image not supported in arm64??

I also ensured that my kernel has the CONFIG_EFI_ZBOOT=y as mentioned in https://wiki.gentoo.org/wiki/Unified_kernel_image#Supported_architectures

[Foxboron]

Please don't use sbctl to make UKIs as it will do a worse job than using ukify or any of the proper initramfs generators.

[gp-sbg]

i am using systemd version 233, whereas systemd-unkify is only present in systemd version 255. I am also unable to download and build ukify manually, that's why i had gone down the sbctl route, since i can just download the sbctl repo and then run a make command, and the sbctl tool is ready to use.
Can u kindly tell me how to install ukify without upgrading systemd version?

[DaanDeMeyer]

@gp-sbg You need a very recent systemd version and kernel to use UKIs on arm64. Please switch to a modern system with systemd 254 or newer. ukify will also be available then.

[poettering]

v233 is more than 7 years old. That's pre-historic