Written: 16-01-2024
I had an issue with my Surface Laptop not booting as it couldn’t find the encrypted root filesystem after an update (waiting on /dev/mapper/root). I use Arch Linux (btw) and I use systemd-boot and my initramfs used the udev hook to decrypt the drive.
My mkinitcpio.conf HOOKS:
HOOKS=(base udev autodetect modconf kms keyboard keymap consolefont block filesystems fsck)
And my boot loader entry:
title EndeavourOS surface
linux /vmlinuz-linux-surface
initrd /intel-ucode.img
initrd /initramfs-linux-surface.img
options cryptdevice=UUID=****-****-****-****-****:root root=/dev/mapper/root rootflags=subvol=@ rd.luks.options=discard,no-read-workqueue,no-write-workqueue rw
To fix it, the first thing I tried was to use the systemd and sd-encrypt HOOKS as per the Arch Wiki.[1] So I edited my mkinitcpio.conf to:
HOOKS=(base systemd autodetect modconf kms keyboard keymap consolefont block sd-encrypt filesystems fsck)
I updated my boot loader entry accordingly:
title EndeavourOS surface
linux /vmlinuz-linux-surface
initrd /intel-ucode.img
initrd /initramfs-linux-surface.img
options rd.luks.name=****-****-****-****-****=root root=/dev/mapper/root rootflags=subvol=@ rd.luks.options=discard,no-read-workqueue,no-write-workqueue rw
And now the partition was being detected on boot and it prompted me to unlock it. The problem was that the keyboard was not working anymore (this is a problem with the surface devices,[2] the modules needed for the keyboard weren’t loaded) and I needed to use a wired keyboard to unlock the root. To fix this, I added these modules to the mkinitcpio.conf:
MODULES=(surface_aggregator surface_aggregator_registry surface_hid_core intel_lpss intel_lpss_pci 8250_dw surface_kbd)
HOOKS=(base systemd autodetect modconf kms keyboard keymap consolefont block sd-encrypt filesystems fsck)
and now it just works.
My drive topology for reference. I have an encrypted btrfs root partition, a non-encrypted /boot and /boot/efi partitions.
> lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS zram0 253:0 0 5.1G 0 disk [SWAP] nvme0n1 259:0 0 238.5G 0 disk ├─nvme0n1p1 259:1 0 128M 0 part /boot/efi ├─nvme0n1p2 259:2 0 238G 0 part │ └─root 254:0 0 238G 0 crypt /var/log │ /var/cache │ /home │ / └─nvme0n1p6 259:3 0 384M 0 part /boot