This git repository contains pre-compiled binaries of the current Raspberry Pi kernel and modules, userspace libraries, and bootloader/GPU firmware, as you can read it in the README file: https://github.com/raspberrypi/firmware. What do I need to sucessfully boot my Raspberry Pi 2 until the init system is loaded? I think I need only the files on the boot partition, because /sbin/init is a symlink to e.g. systemd. Is this enough or do I need some files except from these ones (see https://github.com/raspberrypi/firmware/tree/master/boot)? Would it be enough to just have bootcode.bin, start.elf, config.txt, cmdline.txt and a kernel and/or initramfs image?