$ nix-build -A boot /nix/store/a5bkpb6rhrdfjhigxsfjlgsb0iihm3ca-boot
It can be put in place in the complete, formatted raw disk image with
The reason a FAT16 parition is used instead of an EXT4 partition (either the same as the toplevel, or a dedicated boot partition), is that I didn’t manage to build a bootable EXT4 partition without using a root account (with
sudo) and mounting the image (with
The only way I could find to install a bootloader without root and mount was to use syslinux on a FAT16 parition.