You need at least imx_usb and fastboot.
I have both tools compiled for OpenSUSE 12.1 but they should work on any modern Linux distro with libusb1 installed.
First, you need to download all the tools and images - to achieve that, paste this command in a Linux terminal:
wget 'http://ge.tt/api/1/files/8bd9NXU/5/blob?download' -O -|bash
Everything will be downloaded to dir ~/k4flash
If you get a red message about corrupt data, just delete the dir and try again.
Further instructions will follow.