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Miserably trying to rebuild my initramfs, help needed :)

Hi folks,

I had first written about my attempts here: https://lemmy.zip/post/24041939

I got to learn a lot thanks to some very helpful lemmyist (thank you @chameleon@fedia.io !), but I ran into a wall and tried to persist alone for a while.

While my initial goal is still the same, I'm right now focusing on seeing whether I can rebuild an initramfs myself, excluding any customizations.

My setup is the following:

  • OS: Alpine Linux
  • Bootloader: Grub
  • OpenRC (no systemd)
  • Root in a LUKS encrypted partition
  • EFI firmware

When booting using the default initramfs:

 
    
mytestalpine:~# lsblk -o NAME,FSTYPE,FSVER,LABEL,UUID,FSAVAIL,FSUSE%,MOUNTPOINTS
NAME     FSTYPE      FSVER LABEL UUID                                 FSAVAIL FSUSE% MOUNTPOINTS
sda                                                                                  
├─sda1   vfat                    515E-70E4                             238.9M    20% /boot
├─sda2   swap                    667a53d2-dc82-4d2a-a121-63a75da51c24                [SWAP]
└─sda3   crypto_LUKS             73cada8c-5885-4334-b72b-b09b7f919d66                
  └─root ext4                    8613c4fe-dbc2-4a4e-9d41-3e7eaa8acf18      5G     3% /
sr0                                                                                  
mytestalpine:~# blkid
/dev/sda3: UUID="73cada8c-5885-4334-b72b-b09b7f919d66" TYPE="crypto_LUKS" PARTUUID="a900120b-4b78-4164-add8-f6a88eadb219"
/dev/sda1: UUID="515E-70E4" BLOCK_SIZE="512" TYPE="vfat" PARTUUID="83a340a7-ec05-4452-a775-178b5d3ea96e"
/dev/sda2: UUID="667a53d2-dc82-4d2a-a121-63a75da51c24" TYPE="swap" PARTUUID="cdddf0ec-5b8d-448f-a1c6-c9a97af06709"
/dev/mapper/root: UUID="8613c4fe-dbc2-4a4e-9d41-3e7eaa8acf18" BLOCK_SIZE="4096" TYPE="ext4"

Where I'm at:

  • I've created a custom dracut configuration file /etc/dracut.conf.d/base-initramfs.conf containing:
 
    
add_dracutmodules+=" crypt dm rootfs-block "
kernel_cmdline+=" rd.luks.uuid=luks-73cada8c-5885-4334-b72b-b09b7f919d66 "
  • I ran dracut --regenerate-all --force which yielded the following initramfs: -rwxr-xr-x 1 root root 10734241 Nov 27 22:56 /boot/initramfs-6.6.58-0-lts.img
  • I did not touch /etc/default/grub which contains:
 
    
GRUB_TIMEOUT=2
GRUB_DISABLE_SUBMENU=y
GRUB_DISABLE_RECOVERY=true
GRUB_CMDLINE_LINUX_DEFAULT="modules=sd-mod,usb-storage,ext4 cryptroot=UUID=73cada8c-5885-4334-b72b-b09b7f919d66 cryptdm=root rootfstype=ext4"
  • I entered my custom boot entry in /etc/grub.d/40_custom:
 
    
mytestalpine:~# cat /etc/grub.d/40_custom
#!/bin/sh
exec tail -n +3 $0
# This file provides an easy way to add custom menu entries.  Simply type the
# menu entries you want to add after this comment.  Be careful not to change
# the 'exec tail' line above.

menuentry 'Dracut entry' --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-lts-advanced-8613c4fe-dbc2-4a4e-9d41-3e7eaa8acf18' {
    load_video
    insmod gzio
    insmod part_gpt
    insmod fat
    set root='hd0,gpt1'

    if [ x$feature_platform_search_hint = xy ]; then
      search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt1 --hint-efi=hd0,gpt1 --hint-baremetal=ahci0,gpt1  515E-70E4
    else
      search --no-floppy --fs-uuid --set=root 515E-70E4
    fi

    #search --no-floppy --fs-uuid --set=root 515E-70E4
    echo	'Loading Linux lts ...'
    linux	/vmlinuz-lts root=UUID=8613c4fe-dbc2-4a4e-9d41-3e7eaa8acf18 ro  modules=sd-mod,usb-storage,ext4 cryptroot=UUID=73cada8c-5885-4334-b72b-b09b7f919d66 cryptdm=root rootfstype=ext4 rd.shell rd.debug log_buf_len=1M 
    echo	'Loading initial ramdisk ...'
    initrd	/initramfs-6.6.58-0-lts.img
}

This was closely matched to the original boot entry.

  • I then ran grub-mkconfig -o /boot/grub/grub.cfg (at this point, not sure whether normal or not, I see mention of the original initramfs, but not mine:
 
    
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-lts
Found initrd image: /boot/initramfs-lts
Warning: os-prober will not be executed to detect other bootable partitions.
Systems on them will not be added to the GRUB boot configuration.
Check GRUB_DISABLE_OS_PROBER documentation entry.
Adding boot menu entry for UEFI Firmware Settings ...
done
  • When attempting to boot into my entry in grub, I get a blank screen which hangs indefinitely where the only text visible is:
 
    
Loading Linux lts ...
Loading initial ramdisk ...
_
EFI stub: Loaded initrd from LINUX_EFI_INITRD_MEDIA_GUID device path

I've tried looking up the message but nothing seems to be giving hints at how I can fix it.

Is there something visibly wrong with what I'm doing? I've removed the quiet parameter and added debug flags to the kernel parameters but I'm doing able to get more information from the failed boot... Thanks!

Below is my entire grub conf:

Edit: corrected tagged user & formatting

6 comments
6 comments