This uses Busybox static binary from Fedora's RPM to create a simple initramfs.
$ ./create_initramfs.sh --help Usage: ./create_initramfs.sh --arch <string> [options] Required options: --arch <string> architecture, e.g. aarch64, arm, ppc64, ppc64le, i386, x86_64 Options: --dir <dir> directory to use for building and output of initramfs --debug enable set -x --noclean don't clean the build directory (we clean by default) --noinit don't use busybox init system, boot to /bin/sh instead --overlay <dir> files to copy over top of initramfs filesystem --overlay-dst <dir> dir to copy overlay files into on initramfs, defaults to / --printk enable printk on console --tty <string> the tty(s) to run getting on, defaults to "tty0 hvc0" --help show this help message Short Options: -a <string> Same as --arch -d <dir> Same as --dir -o <dir> Same as --overlay -O <dir> Same as --overlay-dst -t <string> Same as --tty -h Same as --help