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mokkurkalve

Member

From: Bergen, Norway

Registered: 2009-08-29

Posts: 80

[SOLVED] Fail to get input promt for LUKS2 passphrase

I basically followed the receipt  https://wiki.archlinux.org/title/Dm-cry … ecure_Boot
I have not started fiddeling with TPM2 or Secure Boot yet, I want to be able to boot into this system first. I just used efibootmgr to boot the UKI, it works fine.
But the root cannot be mounted in boot as the LUKS2 partition are not opened; I don't get any passphrase promt at all, just a message "Failed to start Dispatch Password Requests to Console Directory Watch", process times out and I'm dropped to the emergency shell.
I can post more info if needed, now I just wondered if this is something well known that someone can tell me about from the top of their head.

Last edited by mokkurkalve (2025-12-12 19:09:41)

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"ONLY THOSE WHO ATTEMPT THE IMPOSSIBLE WILL ACHIEVE THE ABSURD"
- Oceania Association of Autonomous Astronauts

Scimmia

Fellow

Registered: 2012-09-01

Posts: 13,342

Re: [SOLVED] Fail to get input promt for LUKS2 passphrase

How are you generating the initramfs and UKI?

mokkurkalve

Member

From: Bergen, Norway

Registered: 2009-08-29

Posts: 80

Re: [SOLVED] Fail to get input promt for LUKS2 passphrase

How are you generating the initramfs and UKI?

mkinitcpio -P

I basically used what I found here https://wiki.archlinux.org/title/Unifie … mkinitcpio
First the line in mkinitcpio.conf
HOOKS=(base systemd autodetect microcode modconf kms keyboard sd-vconsole block sd-encrypt filesystems fsck)
Then edit /etc/mkinitcpio.d/linux-zen.preset to comment default_image and uncomment default_uki (and pointed it to /boot/EFI/Linux as /boot is the esp here).
I wonder if there is something with /etc/cmdline.d/root.conf, should "root=" point to the root partition or to the cryptdevice?
Yes, and I marked the partiton holding the luks root 8304 ("Linux root (x86-64)").
UKI got installed in /boot/EFI/Linux and I used efibootmgr to make it boot.

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"ONLY THOSE WHO ATTEMPT THE IMPOSSIBLE WILL ACHIEVE THE ABSURD"
- Oceania Association of Autonomous Astronauts

Scimmia

Fellow

Registered: 2012-09-01

Posts: 13,342

Re: [SOLVED] Fail to get input promt for LUKS2 passphrase

That should be fine, what about your kernel command line?

mokkurkalve

Member

From: Bergen, Norway

Registered: 2009-08-29

Posts: 80

Re: [SOLVED] Fail to get input promt for LUKS2 passphrase

I tried several (in /etc/cmdline.d/root.conf) because I figured boot might not find the right device. Finally I went all the way and tried this:

root=UUID=f1162d8d-d94d-4dcc-8127-023e5f8121b1 cryptdevice=UUID=83dfee1d-4a6a-4987-a8c7-76cc7176d818:root resume=UUID=7e3bf4e8-5c5e-48b5-a949-5eae548eecc3 mt7925e.disable_aspm=1 udev.log_priority=3 rw

This is probably all wrong...

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"ONLY THOSE WHO ATTEMPT THE IMPOSSIBLE WILL ACHIEVE THE ABSURD"
- Oceania Association of Autonomous Astronauts

Scimmia

Fellow

Registered: 2012-09-01

Posts: 13,342

Re: [SOLVED] Fail to get input promt for LUKS2 passphrase

cryptdevice is for a busybox based initramfs, not a systemd based one.
https://wiki.archlinux.org/title/Dm-cry … -generator

mokkurkalve

Member

From: Bergen, Norway

Registered: 2009-08-29

Posts: 80

Re: [SOLVED] Fail to get input promt for LUKS2 passphrase

OK. What should I put in /etc/cmdline.d/root.conf ? Should I just leave it empty?
Usually I think that "root=" should point to the root filesystem, but that is not visible until the LUKS2 is opened. Should therefore "root=" point to the UUID of the cryptdevice in this setup?

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"ONLY THOSE WHO ATTEMPT THE IMPOSSIBLE WILL ACHIEVE THE ABSURD"
- Oceania Association of Autonomous Astronauts

Scimmia

Fellow

Registered: 2012-09-01

Posts: 13,342

Re: [SOLVED] Fail to get input promt for LUKS2 passphrase

You read the link

mokkurkalve

Member

From: Bergen, Norway

Registered: 2009-08-29

Posts: 80

Re: [SOLVED] Fail to get input promt for LUKS2 passphrase

Yes, sorry. I will attempt to create a /etc/crypttab.initramfs now.

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"ONLY THOSE WHO ATTEMPT THE IMPOSSIBLE WILL ACHIEVE THE ABSURD"
- Oceania Association of Autonomous Astronauts

mokkurkalve

Member

From: Bergen, Norway

Registered: 2009-08-29

Posts: 80

Re: [SOLVED] Fail to get input promt for LUKS2 passphrase

I made a /etc/crypttab.initramfs with following content:

root	UUID=83dfee1d-4a6a-4987-a8c7-76cc7176d818
swap	UUID=7ef8a607-549b-4c5c-a30b-3e0126d11ed8
home	UUID=2c672fff-48fe-4004-b819-814bb2a4227b

That is what it took.
Now I can input passphrase on console once and all three cryptdevices gets unlocked (they have same passphrase, obviously).
I have a /etc/fstab with the normal content too, I don't know if it is necessary in this setup, but I reckon it can't hurt.
Anyways, Thanks a bunch! I will mark this solved.

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"ONLY THOSE WHO ATTEMPT THE IMPOSSIBLE WILL ACHIEVE THE ABSURD"
- Oceania Association of Autonomous Astronauts