Issue with boot partition sizing for UEFI installs
setup-disk sets the bootpartition to be 34MB in size when installing on a UEFI system with a 512byte sector size drive (HDD or SSD): https://gitlab.alpinelinux.org/alpine/alpine-conf/-/blob/master/setup-disk.in#L1602-1608
This appear to be ok for a basic UEFI Sys-mode disk installation as the 34MB boot partition is actually the UEFI ESP partition, is mounted as /boot/efi and only holds the EFI related files (and so only uses approx 1MB of the 34MB).
However there is a problem with UEFI LUKS Sys-mode disk installations as the 34MB boot partition is used as both the ESP partition and also for holding the /boot files (kernel, initramfs, microcode, etc). Whilst such an installation may complete without filling the boot partition and then machine run fine whenever mkinitfs is triggered to build an updated initramfs file the boot partition runs out of space.
The same disk space issue may apply if UEFI is used via EFISTUB (rather than Grub) where a larger EFI file will be created (illustrated by !106 (merged)), and may also apply if many of the linux-firmware-* packages are installed (and so initramfs grows in size accordingly)
I see the issue as being due to a 'confusion' between the purpose of a ESP partition, the purpose of a boot partition, and the use of a single partition for both purposes. The contents of a "pure" ESP partition are somewhat static (just Grub EFI in most cases, though a custom EFISTUB file in other, currently not supported by setup-disk, cases).
There are 2 solutions, either (a) have separate ESP and boot partitions and size them accordingly, or (b) have a single "boot" partition which is sufficiently larger than 34MB to ensure that there is adequate excessive space unused for kernel upgrades/firmware-in-initramfs/mkinitfs temporary usage/EFISTUB files).
Which ever solution is decided upon should be backported to Alpine 3.16.