Arch Linux

Lessclue

Member

Registered: 2025-05-30

Posts: 2

mkinitcpio failure to build uki

Hi all

when running

mkinitcpio -P

i get this error:

==> ERROR: Invalid option -U -- '/efi/EFI/Linux/arch-linux-hardened.efi' must be writable

directory:

/mnt/boot

contains:

EFI initramfs-linux-hardened.img initramfs-linux-hardened-fallback.img loader vmlinuz-linux-hardened

loader & EFI were created by

bootctl install

.
required directory "exists":

EFI/EFI/Linux

using sudo does not change a thing

Is the issue with the naming of efi vs EFI?
Where is the option -U passed?
I got 845.5M available, is 1 gig not enough for the uki? If so what size would you recommend?

Thank you

Last edited by Lessclue (2025-05-30 13:29:19)

Snowflake2

Member

Registered: 2025-05-27

Posts: 2

Re: mkinitcpio failure to build uki

Unless you have a really big image 1GB should be enough.
Similarly, FAT (the filesystem which I'm assuming is at /mnt/boot ) doesn't care about the case of case-sensitivity, everything will appear uppercase to it.

Short file names passed to the file system are always converted to upper case and their original case value is lost.

from the Microsoft FAT Specification section 6.1

Now for your problem could you run the mkinitcpio with the --verbose flag? That will give us more information

P.S. you can have a look at this post: https://bbs.archlinux.org/viewtopic.php?id=299115 that might give you some leads on diagnosing your problem

Lessclue

Member

Registered: 2025-05-30

Posts: 2

Re: mkinitcpio failure to build uki

Thank you, the error was due to a typo, leading to a non existing directory, however now I am stuck again at this output:

==> Building image from preset: /etc/mkinitcpio.d/linux-hardened.preset: 'default'
==> Using default configuration file: '/etc/mkinitcpio.conf'
  -> -v -k /mnt/boot/vmlinuz-linux-hardened -U /mnt/boot/EFI/Linux/arch-linux-hardened.efi -g /mnt/boot/initramfs-linux-hardened.img --splash /usr/share/systemd/bootctl/splash-arch.bmp
==> ERROR: '/lib/modules/6.14.8-hardened' is not a valid kernel directory

This error is due to the fact I am trying to build the uki from a liveboot lacking the kernel in question, chrooting (arch-chroot) into /mnt, after copying all configuration files to /mnt will solve the issue.

Last edited by Lessclue (2025-05-30 16:12:04)

cloverskull

Member

Registered: 2018-09-30

Posts: 236

Re: mkinitcpio failure to build uki

Yeah look like you know the solve - arch-chroot is the key here if booting from a live environment.