[arch-general] initramfs: execute own script

Hi there. I'm newbie in Archlinux's boot process. I need to run my own script in early userspace (initramfs). It must be after mounting root file system, but before switch root. I've opened default initramfs (kernel26.img) and reviewed it's content. So, Archlinux uses some kind of tool called 'kinit'. And it seems, that this tool mounts root and then switch. How to run my own script in kinit? Where can be found documentation of kinit? Thanks for patience. -- )\._.,--....,'``. /, _.. \ _\ (`._ ,. `._.-(,_..'--(,_..'`-.;.'