Skip to content

Latest commit

 

History

History
106 lines (77 loc) · 3.01 KB

systemdboot.md

File metadata and controls

106 lines (77 loc) · 3.01 KB
Raw

systemdboot

Multiple kernels can be managed with this plugin and systemd-boot, but it will require changing the mountpoint of the esp (EFI System Partition).

Requirements

  • Create configuration for currently active boot environment
  • Copy kernels to new directory
  • Create fstab entries

Problem With Regular Mountpoint

Usually the $esp would get mounted at /boot, /boot/efi, or /efi. The kernels would sit in the root of the $esp, and the configs for systemdboot in $esp/loader/.

$esp 
. 
├── initramfs-linux-fallback.img 
├── initramfs-linux.img 
├── intel-ucode.img 
├── vmlinuz-linux 
│ 
└── loader/ 
    ├── entries/ 
    │   └── arch.conf 
    └── loader.conf

The configs would then reference kernels in the root directory.

title           Arch Linux 
linux           vmlinuz-linux 
initrd          intel-ucode.img 
initrd          initramfs-linux.img 
options         zfs=bootfs rw

The problem with this method, is multiple kernels cannot be kept at the same time. Therefore this hierarchy is not conducive to boot environments.

Alternate Mountpoint

First, remount the $esp to a new location, the default is /efi.

If you would like to explicitly specify the mountpoint used, you can set the systemdboot:efi property on your current boot environment, and the plugin will use the specified location:

$ zectl set systemdboot:efi=<esp>

Don't forget to change the mount point in /etc/fstab.

UUID=9F8A-F566    /efi    vfat    rw,defaults,errors=remount-ro  0 2

Now, make a subdirectory $esp/env, kernels will be kept in a subdirectory of this location.

Copy your current kernels to $esp/env/org.zectl-<boot environment>/

The bootloader configuration can now use a different path for each boot environment.

So the 'default' boot environment config, located at $esp/loader/entries/org.zectl-default.conf, would look something like:

title           Arch Linux
linux           /env/org.zectl-default/vmlinuz-linux
initrd          /env/org.zectl-default/intel-ucode.img
initrd          /env/org.zectl-default/initramfs-linux.img
options         zfs=zpool/ROOT/default rw

Create this configuration file.

To make the system happy when it looks for kernels at /boot, this directory should be bindmounted to /boot.

If your system uses a different directory for kernels it can be set with:

$ zectl set systemdboot:boot=<kernel directory>

Bindmount $esp/env/org.zectl-default to /boot in /etc/fstab.

/efi/env/org.zectl-default   /boot     none    rw,defaults,errors=remount-ro,bind    0 0

If this directory is not here, the kernels will not be updated when the system rebuilds the kernel.

Once a system is set up in the proper configuration, zectl will update the bootloader, and fstab when a new boot environment is created.

It will also copy the configuration described above, replacing the currently activated boot environment's configuration with the new boot environments name.