init

minimal init for x86_64 unix-like systems

compile

$ clang init.c -o init -Os -s -static

rootfs, qemu etc..

$ mkdir -p rootfs/{bin,proc}

$ cp init rootfs/

$ doas cp /bin/busybox rootfs/bin/sh

$ cd rootfs/

$ find . -print0 | cpio --null -v -o --format=newc | gzip > ../initramfs.cpio.gz

$ cd ../

$ qemu-system-x86_64 -kernel /boot/vmlinuz-linux -initrd initramfs.cpio.gz -nographic -append "console=ttyS0 init=/init"

stat for usage