systemd-boot (sd-boot / gummiboot)

Install sd-boot:

$ bootctl install
Created "/efi/EFI/systemd".
Created "/efi/loader".
Created "/efi/loader/entries".
Created "/efi/EFI/Linux".
Copied "/usr/lib/systemd/boot/efi/systemd-bootx64.efi" to "/efi/EFI/systemd/systemd-bootx64.efi".
Copied "/usr/lib/systemd/boot/efi/systemd-bootx64.efi" to "/efi/EFI/BOOT/BOOTX64.EFI".
Random seed file /efi/loader/random-seed successfully written (32 bytes).
Created EFI boot entry "Linux Boot Manager".

Change default boot entry

Edit /efi/loader/loader.conf

Automated kernel image management and boot loader entries

kernel-install-for-dracut

Kernelstub

Kernelstub is a utility to automatically manage your OS's EFI System Partition (ESP). It makes it simple to copy the current kernel and initramfs image onto the ESP so that they are automatically probable by most EFI boot loaders as well as the EFI firmware itself.

Github
What is Kernelstub
Developed by System76, packaged in Pop-Os deb repo
Not packaged in Arch, neither in AUR
Sample template: /etc/default/kernelstub.SAMPLE

Copy current kernel and inintd to EFI partition:

kernelstub -v

Install older kernel as default

kernelstub -v -k /boot/vmlinuz-5.19.16-76051916-generic -i /boot/initrd.img-5.19.16-76051916-generic

Then copy the older kernel to i.e. *-previous:

cp vmlinuz.efi vmlinuz-previous.efi
cp initrd.img initrd.img-previous

Then override the default kernel + initrd entries:

kernelstub -v

Dracut

From Arch wiki: Dracut;

dracut creates an initial image used by the kernel for preloading the block device modules (such as IDE, SCSI or RAID) which are needed to access the root filesystem. Upon installing linux, you can choose between mkinitcpio and dracut. dracut is used by Fedora, RHEL, Gentoo, and Debian, among others. Arch uses mkinitcpio by default.

Manually create intiramfs images (not needed when using kernel-install-for-dracut):

dracut --hostonly --no-hostonly-cmdline /efi/initramfs-6.1-x86_64-dracut.img
dracut /efi/initramfs-6.1-x86_64-dracut-fallback.img

Migrate from grub/mkinitcpio to sd-boot/dracut

see ./systemd-boot-migration.md